Transcript

May 1982 a Volume 5 Issue 5

Fall of the giantsrise of the Cowboys?Reviews:PBM-1000Genie IMBasicSuperCalc

Whitehall gameAtom assemblerPet machine -codesubroutines

Cromemco System OneMicroCentre introduce Cromemco's new System One computer,available with an integral 5 megabyte Winchester hard disk, at anew low price.

The System One supports the full range of Cromemco interface cards,including high resolution colour graphics, and software packages.The choice of operating systems includes CDOS, CP/M andCROMIX Cromemco's answer to Unix.

Call MicroCentre for Q CromemcoMicroCentre Ltd(Complete Micro Systems)

Britain's independentCromemco importer

30 Dundas StreetEdinburgh EH3 6JN

Fall of the giants - page 84

EditorPeter Laurie 01-661 3500Associate EditorDuncan ScotDeputy EditorToby WolpeAssistant EditorBill BennettSub -editorsMeirion JonesJohn LiebmannPrestel EditorMartin HaymanEditorial SecretaryJulie MilliganConsultants Nick Hampshire,Chris Bidmead, Peter WoodAdvertisement ManagerIan Carter 01-661 3021Assistant AdvertisementManagerKenneth Watford 01-661 3139Advertisement ExecutiveFiona Howell 01-661 3500Midlands office:David Harvett 021-356 4838Northern office:Geoff Aikin 061-872 8861Advertisement SecretaryMandy MorleyPublishing DirectorChris Hipwell

Published by IPC Electrical ElectronicPress Ltd, Quadrant House, The Quad-rant, Sutton, Surrey SM2 5AS. Tel:01-661 3500. Telex/grams 892084 BIP-RESG.Typeset and printed by Eden Fisher(Southend) Ltd. Southend-on-Sea.Distributed by IPC Business Press(Sales and Distribution) Ltd, QuadrantHouse, The Quadrant, Sutton, SurreySM2 5AS.Subscriptions: U.K. £10 per annum;Overseas £16 per annum; selling price inEire subject to currency exchange fluc-tuations and VAT; airmail rates availableon application to Subscription Manager,IPC Business Press (S & D) Ltd, OakfieldHouse, Perrymount Road, HaywardsHeath, Sussex RH16 3DH. Tel: 044459188.© IPC Business Press Ltd 1982ISSN 0141-5433

Would-be authors are welcome tosend articles to the Editor but PCcannot undertake to return them.Payment is at £30 per published page.Submissions should be typed orcomputer -printed. Handwritten mater-ial is liable to delay and error.Every effort is made to check articlesand listings but PC cannot guaranteethat programs will run and can acceptno responsibility for any errors.

CONTENTS4143465354616971

77

849398

101104109117125127130133136

161163164167171187

Editorial / Hit any key to continue?

Feedback / Pet networks; the future for Prestel; structured languages

Printout / Bleasdale's Unix -style micro; Pet character generator; softwareby radioPrintout extra / What is the Government doing to encourage the use ofcomputers in British manufacturing industry?PBM-1000 / Chris Bidmead reviews the new small business system with acombination of hard and floppy discsGenie / Martin Eccles reviews the Genie I home computer and comparesit to the Video Genie and the Genie II business computerArfon light -pen / Nick Laurie tests the new light pen from Arfon: thehardware works, but is your software good enough?MBasic / MBasic has become the de facto standard for many personal -computer users. Chris Bidmead reveals the features which have kept it sopopular with amateurs and professionals alikeSuperCiao / VisiCalc proved such a success for 6502 -based systems that anumber of CP/M look -alike versions have been spawned. Kevin Caleyassesses one of themCover story / Will the new personal -computer companies oust theestablished giants in computing such as IBM?Whitehall / A game of skill, intrigue and a little chance, written for thePet by Simon GoodwinFair repair / Fiction by Brian Williams

Applications / Martin Hayman visits Dr Ranjit Gill at BrightonPolytechnic, who is developing computer systems to aid the handicappedAnimation / The latest developments in computerised film animation.

Education / John Craig presents some programs to help teach multi-plication tables in school.Pet subroutines / Make the most of the powerful machine -code routineshidden in the PetSampling / Malcolm Mountford gives the correct procedure andalgorithms for Fisher's randomisation test for statistical significanceArt / Brian Reffin Smith continues his series on design, graphics and sound

Telesoftware / Progress towards programmable "data grabbers"

Reader survey / Tell us about yourself and you could win £50 in ourlucky drawOpen File / A 16 -page section of your programs, including ZX-80/81Line-up, Z-80 Zodiac, 6502 Special, Pet Corner, Apple Pie, Disc Dialogueand Tandy ForumMicromouse / Bill Bennett anticipates this year's final of the Micromousecontest at the Computer Fair, Earls CourtBook Reviews

Puzzle

Atom assembler / Norman Kirkby illuminates some of the mysteries ofop codes and assemblerSoftware buyers' guide

The War Machine / Starfighter - an advanced arcade -style game forthe TRS-80

Prestel page number 357

PRACTICAL COMPUTING May 1982 3

WATFORD ELECTRONICS

17021802CP2101-22112-22114-1_300n2114L -200n2147-32532-450n256427082716-5V2732-450n276440274116-150n4116-200n4118-2504164-2004315-4K4334-3(CM05211414816A -120n51014864-36116-150nS6502 -CPU65036504-250650565216522 VIA6530 RR 1076532 RIOT6545 CRTC6551 ACIA6592 -PC68006802680368046805680868096810682168406843684568476850685268758080A8085A81L59581LS96811_59781238155820282128214821682248226822882518253825582578T26A87278T28A87318195N8197N9364APAM26L531CAM26L532AAY -3-1015AY -3-8910AY -3-8912AY -5-1013AY -5-2376FD1771FD1791FD1793FD1795FD1797I M6402MC1488MC1489MC14411MC14412MM5280DR0-3-25131R0.3-25131R0.3 -2513USFF96364ETMS2716-3VTMS6011ULN 2003ULN2004280CPU25Z130ACPU4MZ 80P 10

33/35, CARDIFF ROAD, WATFORD, HERTS, ENGLANDTel Watford (0923) 40586. Telex: 8956095

COMPUTER zan AP 10 320300325

10£15£23726775190138130345300600478210200675110180210158320350390850300210325620

1150825620

8125959999

1505555

1408052

IC's Z8OCTCZ8OACTCZ8ODMAZ80510-1Z80A510280DART280ADARTZN419CEZN423EZN424EZN425EZN426EZN427EZN428EZN429EZN10346ZN1040674513274513874518874518974519474520174524174526274528774528874547074547174547274547574S57175107751087518275183751547518875189753227545075451,275454754912

2997001102507

4;4360£20200210400E172409580

400620795

325250270785450399600550600150350

12625

10650E20300400850160670520999120125412

12750850140255500350550909090

125475E25170425

70200250250320799295800

99150115350

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28303035

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695795695700700600800875365100

90350385290

8565

TTL74007400 117401 117402 117403 147404 1474104 857405 187406 287407 287408 167409 167410 147411 207412 207413 247414 327416 257417 257420 167421 207422 207423 227425 287426 307427 277428 287430 167432 267433 277437 277438 277440 177441 387442 387443 907444 907445 657446 557447 507448 507450 167451 167453 167454 167460 167470 357472 307473 307474 257475 407476 307480 487481 1207482 707483 507484 807485 957486 267489 2057490 287493 457492 30

749374947495749674977410074104741057410774109741107411174112

711;3741197412074121741227412374125741267412874132741367414174142741437414474145741477414874150741517415374154741567415774159741607416174162741637416474165741667416774170741727417374174741757417674177741787417974180741817418274184741857418874190741917419274193741947419574196741977419874199

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70997580454575754599606062

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120

74LS

L500LS01LSO2L503LSO4LSO5LSO6L508

1213141415151515

L509 15LS10 15LS11 15LS12 15LS13 30LS14 481515 15LS20 15LS21 15LS22 15LS26 18LS27 15LS28 20L530 18LS32 15LS33 16LS37 16LS38 16LS40 16LS42 35LS47 40LS48 80LS49 601551 15LS54 15LS55 30LS63 150LS73 25LS74 25LS75 20LS76 20LS78 24LS83 50LS85 701586 38LS90 35LS91 801592 36LS93 36LS95 45LS96 12015107 43LS109 30LS112 30LS113 4015114 40'LS122 44LS123 55LS124 105LS125 30LS126 30LS132 45LS133 35LS136 28LS138 35LS139 38LS145 75LS147 199LS148 99LS151 39LS153 39LS155 90LS155 39LS156 39LS157 35LS158 36LS160 41LS161 41LS162 41LS163 41LS164 48LS165 145

LS170 170LS173 72LS174 72LS175 58LS181 130LS183 275L5190 58L5191 58LS192 5815193 6515194 40LS195 40LS196 58LS197 85LS200 345LS202 3451.6221 60LS240 60LS241 96LS242 85LS243 8515244 80LS245 70LS247 40LS248 65LS249 68LS251 40L5253 40L5257 48LS258 40LS259 85LS261 195LS266 25L5273 290LS279 88LS280 2250LS283 45LS290 57LS293 595LS295 215LS298 130

IS299LS300LS302LS320LS32315423LS323LS324LS325L5326L5327LS347LS348LS352L5353L53365LS366LS367LS368LS373L5374LS375LS377LS378LS379LS384LS3385LS3901$393LS395LS4451547115490L5541LS640LS641LS64515668LS66915670L5674

420157175270270200270200320330315150190185186

37373790757548906965

3953786260

199140620245135226225210175160550750

CMOS

4000 144001 144002 144006 66407 184008 624008 624009 354010 404011 154012 184013 344014 754015 664017 484018 684019 424020 614021 704022 664023 204024 464025 194026 13040274029 774030 504031 1704032 1254033 1654034 1954035 954036 2754037 1154038 1104039 2904040 594041 784042 804043 704044 654045 1704046 754047 754048 564049 304050 304051 784052 784053 784054 1254055 1254056 1204057 19154059 4804060 904061 12254062 9954063 994066 364067 3994067 3994068 224069 204070 264071 20

4072 204073 204075 204076 604077 264078 264081 264082 2'14085 654086 704089 1404093 434094 684095 904096 904097 3204098 884099 954160 954161 994162 994163 994174 994175 1054194 1054408 7904409 7904410 7254411 695412 8004415 48044419 2804422 7704433 7704435 8504440 9994450 8504451 3504490 3504500 6754501 284502 904503 504504 1054506 654507 404508 2654510 684511 684512 754513 1994514 1954515 1984516 754517 4154518 424519 294520 784521 2004522 1254526 954527 1154528 804529 1504530 904531 1304532 1104534 5004536 2954538 1154539 1154541 1404543 1354544 1504549 3954553 2994554 1904555 504556 554557 3204558 1204559 3954560 1804561 1044562 4954566 1754568 2604569 1754572 364580 4804581 2504582 994583 994584 484585 994597 3304598 2904599 59540097 8840100 21540101 13040102 18040103 17540104 9540105 11540106 7540107 6040108 45040109 10040110 30040114 24040163 10840193 10845106 595

ALL DEVICES FULL SPEC. AND FULLY GUARANTEED. TERMS OF BUSINESS:CASHICHEQUEP.O.S. (OR ACCESS) WITH ORDER. GOVERNMENT AND EDUCA-TIONAL INSTITUTIONS OFFICIAL ORDERS ACCEPTED. TRADE AND EXPORTINQUIRIES WELCOME. (P&P add 50p on all orders).

VAT ALLCOST I

PRICES ARE EXCLUSIVE OF VAT. PLEASE ADD 15% TO THE TOTALNG P&P.

SHOP HOURS. 9.00am-6.00pm MONDAY TO SATURDAY.AMPLE FREE CAR PARKING SPACE AVAILABLE.

WATFORD'S UNIVERSALMICRO EXPANSION

SYSTEM

Designed by Walford Electronics, thisextremely versatile and economicalExpansion System as published in E.T.I.,starting from Dec. 1981 issue, offers alow cost flexible expansion system forZX81, UK101, SUPERBOARD, ACORNATOM, PET, TANGERINE, etc.

The Motherboard (interfaces with thecomputer) has capacity to accept up tofive daughter cards and can be paral-leled for even more daughter cards.All PCBoards are of computer grade fin-ish and are supplied in kit form.Just look at the Expansion possibilities.

MOTHERBOARD - Accepts up to fivedaughter cards. Full kit: £36.50

SOUND CARD - Utilising up to threeAY -3-8910 sound chips (one suppliedwith the kit). Full kit: 1824.95

PIO CARD - Using two 6520 PIA chips,this Board offers Centronics parallelprinter driver, digital to analogue con-verter and a host of other outputfacilities. Full Kit: £19.95

PROM PROGRAMMER - This simplebut extremely useful card can blow2716r single rail EPROMS. (2732) FullKit: £25.95

PROM CARD - PCB cards for housingfour 2716 or two 2732 EPROMS.(4 x 2716) Full Kit: £11.95(2 x 2732) Full Kit: £11.75

RAM CARD - 8K RAM card. Accepts 16x 2114 RAMs. Board is supplied fullypopulated. Full Kit: £28.50Soon available: SPEECH CARD; HIGHRESOLUTION GRAPHICS CARD; DISCINTERFACE CARD; 32K DRAM CARD(NB PCBs may be bought separately).

SPECIALOFFER

2114L -300n2114L -200n25322716273241164334-36116-150nS652265206820

1

87p87p360p200p400p75p

325p450p350p150p150p

2580p80p

345p195p375p

68p290p420p320p125p125p

Bus it ssith 1cci".

Just phone yourorder through,we do the rest

We stock thou-sands moreitems. It pays tovisit us. We aresituated behindthe Watford Foot-ball Ground.

ILIA WATFORD'SUltimate

MON Monitor IC.A 41( Monitor Chip specially designed toproduce the best from your your Super -board Series I & II, Enhanced Superboard& UK 101. As reviewed by Dr. A.A.Berk in Practical Electronics, June 1981.

Price only £15

EPSONMX SeriesPRINTERS

Now availablefrom stock at very

competitive prices. MX8OT 10" Tractor Feed, 9x9

matrix, 80 column Speed 80 CPSbi-directional Centronics Inter-face, Baud rate 110-9600(RS232) £315

MX8OFT Has Fricton & Tractorfeed plus all the MX80T'sfacilities. £345

MX8OFT2 Has high resolutionGraphics option plus all theMX8OFT's facilities. £390

MX100 132 Column plus all thefacilities of MX8OFT2. Value formoney. £495

NEW

SO° SEIKOSHAGP100

Unihammer Printer,gives normal and double

width characters as well as dotresolution graphics 10" Tractor feed.Parallel Interface standard. £195

SOFTY -2As reviewed in PE September 1981. Thecomplete microprocessor developmentsystem for Engineers & Beginners. Newpowerful instruction. Accepts any 24 pin5V single rail EPROM. Supplied fullybuilt, tested & enclosed in a black ABScase. Price incl. encapsulated plug-inpower supply. £169

ACCESSORIES TEX EPROM ERASER. Erases up to 32

ICs in 15-30 min. TEX EPROM ERASER with incor-

porated Safety Switch £39 Spare UV lamp bulbs £9 5V/5A PSU Ready built and tested £25 Attractive Beige/Brown ABS CASE for

Superboard/UK101 or Home Brew £26 Full ASCII coded keyboard type '756'

£39 NUMERIC Keypad (Ready built) £9 4 x 4 matrix keypad (reed switch

assembly) £4 C12 Cassettes in Library Cases 40p8r Fan fold paper (500 sheets) (no

VAT) £6 9k" Fan fold paper (500 sheets) (no

VAT) £5 Teleprinter Roll ( no VAT) 250p UHF Modulator 6MH2 280p UHF Modulator 8MH2 450p Stack Pack 5 Drawers (10

Cassette racking Unit £2Stack Pack Unit incl. 10 C12 Cassettes

550p

CRYSTALS

32.768KH100KHz200KHz455K Hz1MHz1.008M1.6MHz1.8MHz1.843M2.0MHz2.4576M3.2768M3.57594M3.6864M4.0MHz4.032M4.80MHz4.1943M4.4336195.0MHz5.185M5.242886.0MHz6.144MHz6.5536M7.0MHz

100270295375295290392395220240220150

98300150290200200120160300390140225200150

7.168MHz7.68MHz8.0MHz8.083338.8672379.0MHz9.375M10.0MHz10.7MHz10.24MHz12.0MHz12.528M14.3181816.0MHz18.0MHz18.432M19.968M20.0MHz24.0MHz24.930M26.69M26.67M27.125M27.145M38.666748.0M100.0M116.0M

160200150395175200350175150200290300170250180150150325170325150325295190175175375300

IDC CONNECTORS(Speed PCB PlugBlock with latchtype) Pins

Strt Angle2x5 way 90p 99p2x8 way 130p 150p200 way 145p 166p2x13 way 175p 200p2017 way 205p 236p2x20 way 220p 250p2x25 way 235p 270p

Hdr PCB PinsFree Strt Angle

85p110p125p150p160p190p200p

60p 65p70p 78p80p 92p95p 110p

110p 135p125p 150p150p 175p

RIBBON CABLEWays Grey Colour

Pricefoot10 12p 22p20 25p 40p26 35p 52p40 55p 70p

JUMPER LEADS: Ribbon Cable AssemblyDIL Plug (Headers)Single Ended Lead, 24" LongLength 14pin 16pin 24pin 40pin24" 145p 165p 240p 380pDouble Ended Leads6" 185p 205p 300p 465p

12" 198p 215p 315p 490p24" 210p 235p 345p 540p36" 230p 250p 375p 595p

DIL PLUGS(Headers)

Sldr14pin 44p16pin 49p24pin 88p40pin 250p

IDC100p120p170p265p

VIC 20Micro ComputerReady built, tested and eleg-antly cased. Connects directlyto a colour TV. Has 5K RAMexpandable to 32K Availableex -stock £165

CASSETTE Deck for above in-cluding a free 6 program Cas-sette £39

AMPHENOL PLUGS24way IEEE 5/5p34 way CentronicsParallel 550p

ID Header Socket Jumper Leads 24"20pin 26pin 34pin 40pin

1 end 160p 200p 260p 300p2 ends 290p 370p 480p 525p

ZIF DIL SOCKETS24way 575p28way 850p40way 975p

DIL SOCKETS

Spin14pin16pin18pin20pin22pin24pin28pin40pin

Low WireProf Wrap

8p 25p10p 35p10p 42p16p 52p22p 60p25p 70p25p 70p28p 80p30p 99p

EDGE CONNECTORS(Double type/2x1Oway -2x1 Sway -2x18way 180p2x22way 199p2x23way 210p2x25way 225p2x30way 245p2x36way 295p2x4Oway 315p2x43way 395p2x75way 550p

.156"135p140p145p200p

'D' CONNECTORS Mini(Solder Bucket)Ways Plug Socket

9 55p 110p15 130p 160p25 160p 210p37 250p 350p

Cover100p98p95p

135p

Right Angle PCB Pins25 2105 275p 955

4 Circle No. 102

PRitsrrERSSEIKOSHA GP100

New Design unbelievably lowprice printer80 columns. 30 cps 5 x 7 dot matrix.Adjustable tractor up to 10 ins.Graphics. double & standard widthprinting. Parallel interface asstandard. RS232, Apple, IEEE &TRS-80 interface options.

£215

OKI MICROLINE 80, 82A & 83A.Compact Printers.80: Unidirectional 80 cps Parallelinterface, pin & friction feed.82A: Bidirectional 80 cps Parallel &serial interface83A: Bidirectional 120 cps 15 ins132 cpl at 10 cpi. Parallel & serialinterfaces. Graphics & fast serialinterface options.

ML -80 £325 82A £465 83A £880

TEC STARWRITERBest -Buy Daisy Wheel Printer.Bi-direction. 25 cps. Low costsupplies. Standard Daisy Wheel.Carbon and fabric ribbons. Parallelor RS232 interface Sheet feederoptions.

£799

ANADEX DP -9000 RANGEHigh Quality Fast, VersatilePrinter.Six models. Up to 15 inch paperwidth. Lower case descenders.160-220 cps bi-directional printingRS232 current loop & parallelinterface. X on X off. Optional 2Kbuffer. Multiple print densities.

:14 LH. VI Fast print of, high -density bitimage graphics.

DP -9000L £747 DP -9001 £888 DP -9500 £935DP -9000 £841 DP -9500L £841 DP -9501 £982

RIVA TERMINALS LTD.Head Office: 9, Woking Business ParkAlbert Drive, Woking, Surrey GU21 5JYTel: Woking (04862) 71001 Telex: 859502

EPSON MX -80 F/T SERIESProbably the most popularprinter in the world.Type I: 80 cps bidirectional printinglogic seeking. 9 x 9 matrix with truedescenders. 3 way paper handling.80 columns with condensedemphasised & enlarged characters.FF, VT & HT. Parallel interface.

MilliMiliMIMMMMEN" Type II: has programmable formfeed & line spacing. Bit imageprinting.

MX80 FT £399 MX8 FT TYPE II £445

EPSON MX -80T SERIESLow Cost, High Quality.Adopted by PET, HP, IBM, Sharp.MX -80T: Bidirection, logic seeking.180 cps. 9 x 9 matrix with truedescenders. 80 cols. Adjustable pinfeed. Normal condensed &enlarged characters. FF, VT, HTParallel interface.Type II: has programmable formfeed & line spacing. Bit imageprinting.

MX80-T £360 MX80-T TYPE II £399

EPSON MX -82 & 100High Resolution Low cost.MX -82: As MX -80 spec. plusprogrammable line spacing & formfeed. Bit image printing.MX -82 F/T.: Adds friction feed.MX -100: As MX -82 FT with 151/2ins. carriage.

MX -82 £415 MX -82 F/T £455 MX 100 £575

FROM

Northern Office: Tel Harrogate (0423) 503867Scottish Office: Tel Strathaven (0357) 22678

Prices exclude VAT

PRACTICAL COMPUTING May 1982 Circle No. 103

5

p,ok aGemini daj

MultiBoard4014,411116

CHEAPSKATEROUTE

ESOTERICROUTE

Utilising the powerful 4MHz Z80AMicroprocessor the GM811 CPUcard can be used as either astand alone controller or as theheart of a complexmicrocomputer system. Four'Bytewide' sockets allow greatflexibility in the type and size ofmemory devices chosen. Inputand output facilities includeboth programmable serial andparallel interfaces- RS232, 1200baud CUTS cassette interface.Z80A PIO, and an eight bit inputport. In an expanded systemthe unique on -board RPIMmonitor allows the creation ofcassette or Eprom basedprograms or files which areupwards compatible with adisk based CP/M system.

3 amp PSU for thesmalle system

Similar to the popularGM811 CPU card, the newGM813 CPU/RAM card has64K of dynamic RAMreplacing the 'bytewidesockets. An extendedaddressing modefacilitates future memoryexpansion up to 2megabytes! The RPIM 2monitor retains full RPIM- CP/M compatability.

80 BUS STATION

5 amp PSU with an8 -slot Motherboard

notcomOWNERS

START HERE

GM813CPU/RAM

STOP &PICK UP ANY

MULTIBOARDSON YOUR WAY

With a 59 key fullQWERTY layout, thisASCII encodedkeyboard includescursor control keys,caps. lock, two keyrollover andauto -repeat.

KEYBOARD

ROUTEThe Gemini MultiBoard concept is thelogical route to virtually anymicrocomputer system you care toname. Whether you require a businesssystem, an educational system, aprocess control system or any othersystem, there is a combination ofMultiBoards to fulfil that function.

This concept ensures maximumflexibility and minimal obsolescence.Maintenance and expansion is greatlyenhanced by the modular boarddesign. MultiBoard is based on the80 -BUS structure, which is findingincreasing acceptance among otherBritish manufacturers, thus broadeningthe product base.

FARESHardware (Built& tested)GM802 64K RAM cardGM803 EPROM/ROM cardGM807 3A PSUGM808K EPROM programmerGM809 FDC cardGM810K 5A PSU/E1

slot motherboardZ80CPU cardZ80IVC card

GM811GM812

Kit)

SoftwareGM512 CP1v12.2 for MultiboardGM517 Gem-Zapedit/asrn tapeGM518 Gem-Zapeditlasm diskGM519 Gem Pen editor/

text formatter tapeGM520 Gem Pen editor/

text formatter EPROM.GM521 Gem Pen editor/

text formatter disk

£140£65£40£29.50£125

£69.50£125£140

£90£45£45

£45

£45

£45

GM813 Z80 CPU/64K RAM cardEV814 IEEE 488 cardGM815-1 Single drive disk unit

with PSU (350K)GM815-2 Double drive disk unit

with PSU (700K)GM816 Multill0 boardAM819 Speech boardAM820 Light PenGM821 ASCII keyboard

GM524

GM525

GM526GM527GM528

£225£140

£325

£550£125£85£35£57.50

Gem Dis disassembleddebugger tape £30Gem Dis disassembleddebugger disk £30Comal-80 tape £100Comal-80 disk £100APL disk £200

PRACTICAL COMPUTING May 1982 6

GM812- IVC

GICAThe GM812 Intelligent Video Controller card features anon board Z80A processor to provide independence ofthe host processor and the ability to redefine thefunctions and parameters of the display.

Normally used in an 80 x 25 mode the card containsa programmable character generator allowingthree additional modes of operation - inversecharacters, 160 x 75 block graphics, or userdefined characters.

A keyboard socket allows buttered characterinput, and a light pen socket is provided forspecialist applications. Being I/O mapped thecard does not occupy any system memory space.

The GM802 RAM board provides a full64K of dynamic memory. The 80 BUSRAMDIS signal is fully supported sothat any EPROM in the system is givenpriority over the RAM, preventing anypossibility of bus contention. PageMode is also supported by the cardwhich, with the appropriate software,allows up to four memory boards tobe used in a system.

GM8209.

The GM803 Eprom Board will accept up to 162708 or 2716 Eprom devices. This allows theaddition of up to 32K of firmware to thesystem. The board supports the Page Modesystem and consequently need not occupyany memory space when not in use.

A number of manufacturers are busyworking on additional 80 -BUS boardswhich will progressively increase thepotential of your MultiBoard system.

ONEWAY

RPIM software is available on tape andincludes EditorlAssembler; Text Editor/Formatter; Disassembler/Debugger;Pascal and Comal -80. These packagescan also be run under CP/M.

A MEN ATWORK

AM819SPEECHBOARD

- III CIMID

AM820

LIGHT PEN

The Arfon Microelectronicsspeech board utilises theNational SemiconductorDigitalker chip set. This givesa vocabulary of over 140words and sub sounds.Output is from an on -boardspeaker.

80 BUS compatibleprototyping boards areavailable from both Veroand WinchesterTechnology. These allowthe user to easily add acard of their own designto the system.

GM815

DRIVE UNIT

1III MED =

ERGM 809 FDCThe GM809 floppy disk controller card cansupport up to four disk drives in either single ordouble density modes. The card uses the WesternDigital 1797 controller and has variable writeprecompensation and phase locked loop datarecovery circuitry.GM 815 Drive unitThe GM815 floppy disk housing contains one ortwo 51/4" double density, double sided Pertec FD250 drives. This gives a storage capacity of 350Kper drive. Power for the drives is provided by anintegral supply unit.

AUTO -EXCHANGEAll your RPIM software automatically

transferred to CPIM

0=0

FILL -UP WITH SOFTWARE

RP/M

GM803EPROMBOARD

000 MEI

PROTO-TYPING

BOARDS

M:.

This low cost light pencan be used with theGM812 IVC for manyapplications,including answerselection, editing,menu selection andmovement ofdisplayed datablocks.

EV814IEEE 488

00

GM816

I 0 BOARD

GM808

EPROMPROGRAMMER

I I EMI -

Ow&

A UM 2.2 packageis available with theGM 809 card andPertec drives.On -screen editingauto single/doubledensity selection andparallel or serialprinters aresupported. Runningunder CP/M is a widerange of utilities,application softwareand languages.

The Gemini I/O boardprovides a uniquesolution for interfacing to"the real world". Theboard contains 3 PIO's,

a CTC and a realtime clock withbattery back up."Daughter"boards may alsobe added andthese include A -D,D -A, opto-couplingand serialinterface boards.

The GM808 Epromprogrammer connects tothe PIO on the CPU cardand allows the user toprogram 2708 or 2716type Eproms.

The EVC IEEE 488 Controller card hasbeen designed to fully implementall IEEE 488 interface functions. Thiscard gives the user a very versatilemethod of controlling anyequipment fitted with a standardIEEE 488 or GPIB interface at minimalcost.

GEMINI MULTIBOARDS-BUY THEM AT YOURLOCAL MICROVALUEDEALERAU the products on these two pagesare [wadable while stocks last fromthe MicroValue dealers listed on right(Mail order enquines shouldtelephone for delivery dates and postand packing costs )Access andBarclaycard welcome MalINTERFACE COMPONENTS LTD.Oakfield Comer,Sycamore Road,Arnersham,Bucks.Tel:(02403)22307.Tlx:837788.

COMPUTER INTERFACING& EQUIPMENT LTD.,The MICRO -SPARES Shop,19 Roseburn Terrace,Edinburgh EH12 5NGTel: (031)337 5611E. V. COMPUTING700 Bumage Lane,Burnage,Manchester M19 1NA.Tel:(061) 431 4866.ELECTROVALUE LTD.28 St Judes, Englefleld Green,Egham,Surrey TW20 OHB.Tel:(0784) 33603. TIx:264475.SKYTRONICS,2 North Road, The Park,Nottingham.Tel: (0602)45053/45215

TARGET ELECTRONICS16 Cherry Lane,Bdstol BS1 3NG.Tel:(0272) 421196.BITS & PC'S4 Westgate,Wetherby,W.Yorks.Tel:(0937) 63774.HENRY'S RADIO404 Ed are Road, London W2.Tel:(01gw) 402 6822.Tlx:262284 (quote ref:1400).LEEDS COMPUTER CENTRE,62 The Balcony,Merrion Centre, Leeds.Tel: (0532) 458877

Circle No. 104

PRACTICAL COMPUTING May 1982 7

Retailer

and OEM

terms

available

Full

descriptive

Catalogue:available

£1

deductablefrom

first

purchase

mcRo compuTER PRODUCTSSOFTWARE FOR CP/M COMPUTERS

BYROM SOFTWARE asliAtawnaurael mcrn

BSTAM-Utility to link one micro-computer to another also using BSTAM £95BSTMS-Utility to link a micro to a minior mainframe £95

CP/M USER LIBRARY51 Volumes -Price per volume8" disc (one volume per disc)5" disc (one volume per 2 discs)Index

£5£10£2

CREATIVE COMPUTINGBASIC Games Volume 1 £14BASIC Games Volume 2 £14More BASIC Games Volume 1 £14More BASIC Games Volume 2 £14

DIGITAL RESEARCHCBASIC v 2.08MPM 1.1MPM 2.0CP/M86CP/M 2.2CP/NETSIDZSIDMACTEXDESPOOLPL/1BT -80

£65£195£250£160£95£120£50£55£60£50£33£300£140

£6

£11

£15£20£30£27£20£14£14£14£14£14£6£27£20

FOX & GELLERQUICKSCREEN £87 £12

INFORMATION UNLIMITEDWHATSIT (Database ManagementSystem) £80

KLH SYSTEMSSpooler for CPM systems v3.0 £70 £6

MPI LTD.FORTHPAYROLLSALES LEDGERPURCHASE LEDGERNOMINAL LEDGERINCOMPLETE RECORDS

MICRO -APSELECTOR V

MICROFOCUSCIS COBOL version 4.4FORMS 2 v11

£72£500 £15£200 £15£200 £15£200 £15£1200 £20

£275 £25

£425 £25£100 £10

MICROLOGYFTNUMB (FORTRAN -80 RENUMBER £50 £5

& REFORMATTER)

MICROPRO INC.WORD -MASTER 1.7A £75 £22TEX-WRITER 2.6 £37 £17WORDSTAR 3.0 £250 £38MAIL MERGE 3.0 (requires Wordstar) £75 £10SPELLSTAR 1.0 (requires Wordstar) £125 £10WORDSTAR TRAINING MANUAL £18WORDSTAR CUSTOMIZATION NOTES £50SUPER -SORT 1.6: Version 1 £125 £22

Version 2 £110 £22DATASTAR 1.101 £175 £25DATASTAR CUSTOMIZATION NOTES £50CALCSTAR £150 £25

MICROSOFT INC.BASIC -80 5.21BASIC Compiler 5.3FORTRAN -80 3.43COBOL -80 4.01M/SORT 1.01EDIT -80 2.02MACRO -80 3.43MULISP 2.10MUMATH 2.10

Software Manual& Manual Only

£185£205£260£380£75£65£105£105£130

MICROTECH EXPORTSREFOR MATTERCPM IBMCPM DEC

MT MICROSYSTEMSPASCAL MT 5.5PASCAL MT , 5.5 with SPPLibrary SourcesSpeed Programming Pkge. (Softbus)

£98 £17£98 £17

£150 £25£265 £50£110£125 £25

OSBORNE & ASSOCIATESACCOUNTS PAYABLE &ACCOUNTS RECEIVABLEGENERAL LEDGER

£50 £15£50 £15

PHOENIX SOFTWAREASSOCIATES (For Z80 only)PLINK -Disc to disc link loaderPASM-Macro AssemblerPEDIT-Line editor with MacrosBUG -Very powerful debugPDEVELOP Package with all the abovePLINK -2 Overlay Link Loader

£72£72£72£72£193£185

£15£15£15£15£33£15

STRUCTURED SYSTEMS(All converted to UK Standard)SALES LEDGERPURCHASE LEDGERNOMINAL LEDGERSTOCK CONTROLLETTERIGHTANALYST(File management Reporting System)NAD (Name and Address selectionsystem)OSORT

£350 £20£350 £20£350 £20£350 £20£95 £11

£125 £11

£55 £11£55 £11

Software ManualSUPERSOFT INC. &Manual OnlyDIAGNOSTICS 1 £45 £9DIAGNOSTICS 2 £55 £9TERM £72 £7

TDL SOFTWARE(Technical Design Labs)BUSINESS BASIC £80ZTEL (Text Editing Lang.) £35LINKER £35

TINY -C ASSOCIATESTiny -C language for 8080. 8085, Z80systems £55 £39

flEltPiEEIL315

DIGITAL RESEARCHCB -80XLT-86CBASIC-86MAGIC CIRCLE SOFTWARE CPMSIM

MICROPROINFOSTARDATASTAR CUSTOMIZATION NOTES

TBATBATBA£120

TBA£50

ORDER INFORMATIONWhen ordering CP/M software please specify the format you require.

All software items are subject to VAT. Manuals, when purchased separately,are not subject to VAT.

Please add £4.00 for postage, packing and insurance on each itempurchased. For overseas please add £6.50 per item.

Most software in this advertisement is available from stock and a 72 hourreturn service is thereby offered on most prepaid orders.

These details and prices are all current as of March 1982. Our prices reflectan exchange rate of U.S. $2.00 to £1.00. Should the exchange rate vary bymore than 5 cents, a surcharge may be added or a discount given.

MAIL ORDER TELEPHONE ORDER VISITSend Cash, Cheque, Postal Order, IMO, Access or Barclaycard/Visanumber to Microcomputer Products International Ltd., Room PC. 11Cambridge House, Cambridge Road, Barking, Essex IG11 8NT.All payments must be in Sterling and drawn against a U.K. bank.

MEDIA ANDFORMATS

AltosAPPLE CP/M-80 13 SectorAPPLE CP/M-80 16 SectorBlackhawk Micropolis Mod IICalifornia Computer Sys 6 inCDS Versatile 4Columbia Data Products 8 inCOMART COMMUNICATOR

CP50

AlRGRR02Al02Al

P2

COMART COMMUNICATORCP100

COMART COMMUNICATORCP200

COMART COMMUNICATORCP500

COMPAL-80CPT 8000Cromemco System 3Cromemco System 2 SD/SSCromemco System 2 DD/SSCSSN BackupDatapoint 1550/2150Delta SystemsDynabyte DB8/4Exidy Sorcerer CP/M-80

Exidy Sorcerer Exidy CP/M-80 8 AlP2 EXO Al

Heath H8 H47 AlP2 Hewlett-Packard 125.8in Al

ICOM 3712 AlP2 IMSAI VDP-80 Al02 Industrial Microsystems 5000 RAAl Industrial Microsystems 8000 AlAl Intel MDS SD AlR6 Intertec Superbrain SSDD RKRX Intertec Superbrain OD RST1 ISC Intercolor 8063/8360/8963 AlAl Micromation AlAl Micropolis Mod II 02Al Morrow Discus Al02 Mostek Al

MULTI -TECH 1MULTI -TECH 2Nascom (Gemini Drives SSDD)Nascom (Gemini Drives DSSD)Nascom/LucasNCR 8140/9010NNC-80NNC-80WNorth Star SDNorth Star DDNorth Star ODNylac Micropolis Mod IIPertec PCC 2000RAIR BLACK BOXResearch Machines 5.25inResearch Machines 8in

02 SD Systems 5.25in02 SD Systems sinR3 SpacebyteR7 Tarbell SinN1 TEI sinAl Televideo DD/DSAl Toshiba T200Al TRS-80 Modell Shuffle -P1 board SinP2 TRS-80 Modell IIP3 Vector MZ02 Vector Systems 2800Al Vector System BRE Vector VIPAl XEROX 820 5.25inAl XEROX 820 Sin

R3AlAlAlAlS5SF

AlAl02Al0202S6Al

QUALITY PRODUCTS FROM THE HOME OF MICROCOMPUTER SOFTWARE

stip-

/4L

Its I

-7-f"r 1

All our Software isnow available inApple 13 and 16

40. Sector formats

AAAO

GOOD REASOMSTO RIMG 01 "'591 6511

,,vp!°Ptoilycpmsim\soi\1141 FAMINE/ 'I41'

At last the software famine isover. CPMSIM is a powerfulsimulator program for CDOS andCROMIX users. You can nowsavour the vast range of CP/Msoftware that is available. Thismeans you will no longer bestarved of off -the -shelf softwarepackages, you can indulge in thegourmet delight of your choicefrom our large range of CP/Mprograms.

PAYROLLComprehensive Master FileAll Employees details stored on disc --Six Pay Rates. standard LAY

Spayments; deductions it , the ,

and pension scalesEmployee Details screened Pail/so //for easy updatingLeavers stored until Year End 410/11.57..Ek

Manual Data Input for PayrollApplicable for hourly paidemployees working overtime etcScreen displaysstandard payments anddeductions peremployeeCursor addressing used toInput hours workedVariable payment input with rdescription e.g. Sick 20.00Manual overide for allstandards screenedAutomatic calculation of Tax and N.I. for allrates and levelsCompleted Payslip to NETT PAY screened forcheckingTax Refunds flagged for operators acceptanceor overideTotals Updated only on acceptance ofscreened details

Exceptions PayrollOperated when paying weekly/salaried staffInput only for employees with variances to standardsExceptions List printed for checking prior to payrollAutomatic or Manual acceptance of payslips

Print Routines Employees Master File DetailsComprehensive PayslipsCoinage Analysis by Department. Credit Transfers and ChequesSummary of Totals and Cost Centre AnalysisN.I. and Tax Payment DetailsP35 for Weekly ReconciliationYear End P60's prepared automaticallyPro -Forma for all current employees

MAILORDER

TELE-PHONE

CREDITCARD

ORDER

* VISIT *

Trade

EnquiriesWelcome

ROOM PC, 11 CAMBRIDGE HOUSE, CAMBRIDGE ROAD, BARKING, ESSEX, IG11 8NT, ENGLANDTelephone: 01-591 6511 Telex: 892395 Circle No. 105 9

But the real beauty of the CompuStar isits "shared logic" design concept. Eachuser station contains its own distinctmicroprocessor and RAM. The result islightning fast program execution. Evenwhen all 16 users are on-line. Even whenall are performing different tasks! A spe-cial multiplexor circuit in the CompuStarties all external users together to "share"the system's disk resources so that nosingle user ever need wait on another. Anincredibly exciting concept!A remarkable breakthrough in price/performance, the CompuStar boasts nearly 1megabyte of on -fine mini -disk storage (almost 2 megabytes on CompuStar II) andcan be easily expanded to 20, 36 or 96 megabytes of hard -disk in just seconds. Andsince each user station can accommodate up to 64K or RAM, a total of over onemillion bytes can be incorporated into the system to tackle even your most difficultprogramming tasks.CompuStar user stations can be configured in a countless number of ways. A seriesof three intelligent -type terminals are offered. Each is a perfect cosmetic andelectrical match to the system. The CompuStar 10 - a 32K programmable RAM -based terminal (expandable to 64K) is just right if your requirement is a data entry orinquiry/response application. And, if your terminal needs are more sophisticated,select either our CompuStar 20 or CompuStar 40 as user stations. Both units offerdual disk storage in addition to the disk system in the CompuStar. The Model 20features 32K of RAM (expandable to 64K) and 350K of disk storage. The Model 40comes equipped with 64K of RAM and over 700K of disk storage. But, mostimportantly, no matter what your investment in hardware, the possibility ofobsolence or incompatibility is completely eliminated since user stations can beconfigured in any fashion you like - whenever you want.

Our New CompuStarTM 10 Megabyte Disk Storage System (called a DSS)features an 8 inch Winchester drive packaged in an attractive, compact desktopenclosure. Complete with disk, controller and power supply. Just plug it into the Z80adaptor of your SuperBrain and turn it on. It's so quiet, you'll hardly know it's there.But, you'll quickly be astounded with its awesome power and amazing speed. Thesecret behind our CompuStar DSS is its unique controller/multiplexor. It allowsmany terminals to "share" the resources of a single disk. So, not only can you usethe DSS with your SuperBrain, you can configure multiple user stations using ournew series of CompuStarTM terminals, called Video Processing Units of VPU'sTM.

G.W. COMPUTERS LTD, 01-636 8210 01-631 4818

' THE NEW DBMS (DATABASE)DBMS2 is a record relational as well as a file relational database management tool that is capable of being at different times, many different things.The one core program can beset up to perform tasks normally associated with the following list.

Accounting Budgeting CashflowStock control Address mailing Letter writingSimulations Time recording FilingCalc-type predictions Hospital indexing Profit analysisBureaux services General analysis MathematicsAnswer what -ifs Employees records Tabulate valuesPrint reports Sort files Edit recordsWithin hours perform all the above in French or German.The list is as endless as that which meets the requirements of your own imagination.Within the appropriate frames of reference you could ask questions like the following:Find someone whose name begins with W, who is either in London or Birmingham, and available for work at a salary of less than 10,000.00; and is under 40 years of age, notmarried, of credit worthiness grade 1, with a car, prepared to travel, and who likes horses, does not mind the hours he works, is congenial and has good references. When youfind such persons produce a printed list of them showing their names, telephone numbers, and what their salaries are as well as their salary If Increased by 10% and showtheir availability for work. At the end of the list enumerate the total of such persons.

items that are codes micro -computers that are either in warehouse 1 or warehouse 2, where the quantity on hand is more than 50 units, the cost is less than1000.00, the selling price higher than 2000.00; that are not in cartons, bought from supplier 52, allocated more than 20, rated for tax at .15%and weigh less than 50 lbs. Whenyou find such categories then print a report showing the description, cost price, quantity on hand, lead time for refills, what the selling price should be if raised by 12.3% as wellas the profit in either percent or round figures of that projected selling price.Find all patients who suffered from cold, that are either girls or women younger than 23 years old, and who live in London at asocio-economic grade higher than 3; do not smoke;have more than 3 children, are currently at work and where treatment failed to effect a cure in under 6 days. When you find such persons then print a list showing their age,marital status, income, and frequency of illness in the past 2 years.Currently you can ask 5 types of questions 20 times for a single selection criterion, and then you can compute 10 mathematical relationships between the questions for theindividual as well as for the total number of matches. In all some 60 bits of information relating to one record or a group or records on simply one permutation of the selectioncriterion, with a cross referencing facility as well.Every word in the system, as well as the file architectures, print masks, and field attributes, is capable of alteration by you without programming expertise (but with someL thought).ALL IN ONE PROGRAM FROM G.W. COMPUTERS. THE DBMS2 !!.

G.W. COMPUTERS LTD, 01-636 8210 01-631 4818

*** ALL YOU NEED FROM A COMPUTER SYSTEM ***DATABASE MANAGEMENT + WORD-PROCESSING - MODELLING + DIY INTERPRETER + SERVICE

TWO TYPICAL PACKAGE DEALS NORMALLY NORMALLY01 - SUPERBRAIN 64K RAM 320 K 1950.00 01 - SUPERBRAIN OR N/STAR OD

239 50002 - EPSON MX80 FT (OR SIMILAR) 475.00 02 - NEC 5510 (OR SIMILAR) 1695.0003 - CABLE04 - 12 MONTH WARRANTY

25.00235.00

03 - CABLE ADAPTER04 - 12 MONTH WARRANTY 42105.'0°0°

05 - DELIVERY IN U.K. 40.00 05 - DELIVERY IN U.K. 50.0006 - TRAINING SESSION 50.00 06 - TRAINING SESSION 50.0007 - CPM HANDBOOK 8.75 07 - CPM HANDBOOK 8.7508 - 50 BASIC EXERCISES 8.75 08 - 50 BASIS EXERCISES 8.7509 - BOX PAPER (2000 SHEETS) 20.00 09 - BOX PAPER (2000 SHEETS) 20.0010 - DBMS2 (DATABASE) 575.00 10 - DBMS2 (DATABASE) 575.0011 - MAGIC WAND 190.00 11 - MAGIC WAND 190.0012 - MBASIC-80 150.00 12 - MBASIC-80 150.0013 - SUPER CALC 150.00 13 - SUPER CALC 150.0014 - 40 MEMOREX DISKETTES 114.00 14 - 25 DYSAN D/SIDE DISKETTES 150.0015 - DOS+ AND DIAGNOSTICS 125.00 15 - DOS+ AND DIAGNOSTICS 125.0016 - MSORT & DSORT 75.00 16 - MSORT & DSORT 75.0017 - RECOVER + AUTOLOAD 25.00 17 - RECOVER + AUTOLOAD 25.0018 - INSTANT BASIC 9.00 18 - INSTANT BASIC 9.0019 - 50 GAMES ON DISK 100.00 19- 50'GAMES ON DISK 100.00

(NOT INC VAT) 4325.50 (NOT INC VAT) 6320.50OUR PRICE 2995.00 OUR PRICE 4950.00

(NOTE: ITEMS 1 AND 2 ARE MORE FLEXIBLE)

EXTRA SPECIAL SUPERBRAIN PROGRAM MAIL ORDER OFFER OF THE 5 MAIN PROGRAMSDBMS2 + SORTS + MAGIC WAND + MBASIC 80 SUPER-CALC NORMALLY 1140 POUNDS

OUR PRICE eeeeee 595.00 eeeeee+ VAT

WARRANTY NOTE: WE HANDLE ALL REPAIRS OURSELVES.WARRANTY COVERS FREE REPLACEMENT EQUIPMENT IF DEFECTIVE IN FIRST THREE WEEKS.THEREAFTER UP TO 12 MONTHS THE COVER PROVIDES INSURANCE ON ALL SPARE PARTS AND LABOUR COSTS (EXCLUDING CARRIAGE).CALL OUT MAINTENANCE IS ALSO AVAILABLE AT 25.00 MINIMUM (LONDON) 50.00 MINIMUM ELSEWHERE IN U.K. PLUS MILEAGE.

CALL ONLY BY APPOINTMENT AT 55 BEDFORD COURT MANSION,BEDFORD AVENUE, LONDON W.C.1. TELEX 892031 TWC G

10 PRACTICAL COMPUTING May 1982

r

SuperBrain users get exceptional performance for just a fraction of what they'dexpect to pay. Standard SuperBrain features include: two double density mini -floppies with 350K bytes of disk storage, 32K of ram mergory (expandable to 64K)to handle even the most sophisticated programs, a CP/MQ9 Disk Operating Systemwith a high powered text editor, assembler, debugger and a disk formator. And, withSuperBrain's S-100 bus adaptor, you can add all the programming power you willever need .. . almost any type of S-100 compatible bus accessory.SuperBrain's CP/M operating system boasts an overwhelming amount of availablesoftware in BASIC, FORTRAN, COBOL, and APL. Whatever your application . .

General Ledger, Accounts Receivable, Payroll, Inventory or Word Processing,SuperBrain is tops in its class. And the SuperBrain QD boasts the same powerfulperformance but also features a double -sided drive system to render more than700K bytes of disk storage and a full 64K of RAM. All standard!Whatever model you choose, you'll appreciate the careful attention given to everyengineering detail. A full ACSII keyboard with numeric pad and user -programmablefunction keys. A non -glare, specially focused, 12 -inch CRT for sharp imageseverywhere on the screen. Twin Z-80 microprocessors to ensure efficient datatransfer to auxiliary peripheral devices. Dual universal RS -232 communicationsports for serial data transmission. And, a single board design to make servicing asnap!

Integrated Desk Top Computer with 12 inch Bit -Mapped Graphics or CharacterDisplay. 64Kb RAM, 4 MHz Z80A,8 Two Quad Capacity Floppy Disk Drives,Selectric® Style 87 Key Keyboard, Business Graphics Software.The North Star ADVANTAGE TM is an interactive integrated graphics computersupplying the single user with a balanced set of Business -Data, Word, or Scientific -Data processing capabilities along with both character and graphics output.ADVANTAGE is fully supported by North Star's wide range of System andApplication Software.The ADVANTAGE contains a 4 MHz Z80AUa CPU with 64Kb of 200 nsec DynamicRAM (with parity) for program storage, a separate 20Kb 200 nsec RAM to drive thebit -mapped display, a 2Kb bootstrap PROM and an auxiliary Intel 8035 micro-processor to control the keyboard and floppy disks. The display can be operated asa 1920 (24 lines by 80 characters) character display or as a bit -mapped display (240x 640 pixels), where each pixel is controlled by one bit in the 20Kb display RAM. Thetwo integrated 51/4 inch floppy disks are double -sided, double -density providingstorage of 360Kb per drive for a total of 720Kb. The n -key rollover Selectric stylekeyboard contains 49 standard typewriter keys, 9 symbol or control keys, a 14 keynumeric/cursor control pad and 15 user programmable function keys.

G.W. COMPUTERS LTD, 01-636 8210 01-631 4818BUS

(BUSINESS EFFICIENCY)WIDELY USED IN U.K./FRANCE/U.S.A. AND ENGLISH SPEAKING COUNTRIES FOR ITS OVERALL FLEXIBILITY AS A COMPLETE BUSINESS PACKAGE

INCLUDES INVENTORY, DATABASE MANAGEMENT, INVOICING, MAILING ADDRESSES, STATEMENTS, SALES/PURCHASE LEDGER WITH OR WITHOUT AUTOSTOCK UPDATE AND DOUBLE ENTRY JOURNALS INCLUDING NOMINAL LEDGER; PLUS A'C RECEIVABLE AND PAYABLE MAKING AUTO BANK ENTRIES.

01 = ADDRESS SECTION 10 = ORDER FILES 19 = NOMINAL ANALYSIS02 = STOCK CONTROL 11 = 30/60/90 DAY AGE ANALYSIS 20 = AGED DEBTOR ANALYSIS03 = A/C RECEIVABLES 12 = ARITHMETIC SECTION 21 = DISK DIRECTORIES04 = SALES LEDGER 13 = PRINT CUSTOMER STATEMENTS 22 = FILE MANAGEMENT05 = A/C PAYABLES 14 = PRINT SUPPLIER STATEMENTS 23 = SORTS06 = PURCHASE LEDGERS 15 = PRINT AGENT STATEMENTS 24 = DISK SWAP/EXIT SYSTEM07 = BANK UPDATE08 = USER DATABASE AREA

1617

= PRINT TAX STATEMENTS= RUN SEPARATE PROGRAMS WHICH OPTION . .

09 = INVOICE CREATION 18 = CHANGE VOCABULARY (LEVEL 8.004875.00)

++++++++ SUPER - BUS + +++++++ A NEW HIGHER LEVEL OF THE ABOVE PACKAGE . .

IN SIZE BY 50 PER CENT TO A SINGLE 15K BASIC PROGRAM, MAKING ALL FILE RETRIEVALS A MATTER OF NANOSECONDS. WORKSUNDER M/PM AND COMPUSTAR FOR COMMON DATA RETRIEVAL LEVEL 10.00 1475.00 DBMS (DATABASE) HAS 01=; 02=; 04 = ; 06=; 07=; 08=; 17=; 18=; 21=; 24=. PRICE 475.00

DATABASE FEATURES ARE FOR ANY SIZE RECORD UP TO TWENTY FOUR FIELDS FILE ARCHITECTURES CAN BE DESIGNED WITH COMPLETE FREEDOMOVER THE LINGUISTIC CONVENTIONS ASSIGNED TO EACH FIELD. THE FILE THEN CAN STORE 32000 RECORDS WHICH CAN BE SEARCHED BY THE RANDOMACCESS NUMBER (RETRIEVED IN LESS THAN ONE SECOND) OR 'KEY' RANDOM ACCESS ON SPECIFIED FIELD OR SEQUENTIALLY COMPARING FOR LEFTFIELD PARTS, FIELD-INKEYS, OR PARTS OF RECORD, AND THEN CHANGED, PRINTED, DELETED, SKIPPED.

GRAMA (WINTER) LTD/G.W. COMPUTERS LTD. ARE THE PRODUCERS OF THIS PACKAGE WHICH IS UNEQUALLED FOR ITS LEVEL OF TOTAL INTEGRATION,LINGUISTIC FLEXIBILITY AND MAXIMISED DISK/MEMORY CONSERVATION.

L AUTHOR TONY WINTER (M.D.; B.A.LIT; B.A.HON.PHIL; AND LECTURER)

G.W. COMPUTERS LTD, 01-636 8210 01-631 4818IMPORTANTIII. NO HARDWARE IS ANY VALUE WITHOUT THE SOFTWARE, AND OUR SOFTWARE IS UNEQUALLED. WE GIVE YOU AGOING. JUST DECIDE ON THE SYSTEM YOU INTEND PURCHASING, AND TAKE 10% OF ITS VALUE OFF THE PRICE YOU WOULDSOFTWARE. YOU COULD GET THE SOFTWARE FREE WITH THE HARDWARE IF YOU CHOOSE THE BEST SYSTEM WE SELL.

DISCOUNT TO SET YOUHAVE TO PAY FOR THE

SUPERBRAIN CORVUS DSK NORTH STAR COMPUSTAR PRINTER PRINTER64K * 320 K DISK 1995.00 64K MDL 10 VPU 1695.00 OKI MICRO -82A 575.0064K + 700 K DISK 2495.00 64K MDL 15 PRNT 1595.00 OKI MICRO -83 795.0064K + 1.5 M DISK 2995.00 64K MDL 20 VPU 2495.00 OKI MICRO -83A 850.0064K + 6.3 M DISK 4595.00 64K MDL 30 VPU 2795.00 EPSON MX8OFT 475.00N'STAR & GRAPHICS 2395.00 64K MDL 40 VPU 2995.00 EPSON MX100 575.005.7 MG CORVUS DSK 2250.00 10 MEG INTERTEC 3250.00 TEXAS 810 1395.0010 MEG CORVUS DSK 3250.00 BUS VER 8.00 875.00 NEC 5510 1695.0020 MEG CORVUS DSK 4250.00 BUS MANUAL 25.00 NEC 5525 1895.00CORVUS MULTIPLEX 695.00 DBMS2 575.00 QUME 9/45 1695.00CORVUS MIRROR 695.00 N'STAR OD & CPM 2395.00 QUME 5/55 1950.00ADVANTAGE N/STAR 2395.00 OKI MICRO BO 295.00 DRE 8830 1675.00

SYSTEM 1 2395.00 SYSTEM 2 4595.00 FORTRAN -80 200.0064K +750 K DISK 64K + 5.6 MEGABYTE CORVUS PASCAL UCSD 475.00CRT AND GRAPHICS CP/M MICRO -WINCHESTER & CRT SUPER SORT 120.00IN 1 'N/STAR' UNIT IN 1 'SUPERBRAIN' UNIT BASCOMPILER 190.00

SYSTEM 3 2950.00 MAGIC CALC (CPM) 155.00IF YOU WISH TO MAKE THE WARRANTY TO 1 YEAR 64K + 1.5 MEG BUS VER 8.00 975.00THEN ADD 5% OF HARDWARE COST. OTHERWISE CRT AND TWIN 5" LETTERIGHT 100.00NO MAINTENANCE SCHEDULE, SIMPLY ADD -HOC IN COMPUSTAR UNIT COBOL -80 320.00CHARGES AFTER WARRANTY EXPIRATION, SAME MBASIC 80 150.00 WORD -STAR 250.00QUALITY SERVICE. (SITE MAINTENANCE ON CIS COBOL 420.00 CBASIC 75.00APPLICATION). MAIL MERGE 55.00 MAGIC WAND 190.00MAIL ADDRESS: G. W. COMPUTERS LTD, 55 DATASTAR 190.00 T/MAKER 150.00BEDFORD COURT MANSIONS, BEDFORD DBMS (DATABASE) 475.00 BUS VER 9.00 975.00AVENUE, LONDON WC1. TELEX 892031 TWC G DBMS (EXTENDED) 575.00 UTILITIES 75.00

BOSTON OFFICE TELEX 94-0890. MSORT & DSORT 75.00

DUE TO LONG TERM CONTRACTUAL COMMITMENTS, WE ARE ONLY GIVING RESTRICTED DEMONSTRATIONS BY APPOINTMENT AT ONE OF OUR LONDONOFFICES. WE EXPORT TO ALL COUNTRIES.CONTACT TONY WINTER ON 01-636 8210 OR 01-631 4818 AND IF UNAVAILABLE THEN LEAVE A CALL-BACK MESSAGE (CLEARLY STATING YOUR TELEPHONENUMBER AND NAME) ON THE 24 HOUR ANSWER -PHONE, WE CALL BACK ANYWHERE IN THE WORLD.OR SIMPLY LEAVE YOUR ADDRESS AND WE'LL MAIL YOU A STANDARD INFORMATION PACK. MAIL ADDRESS: 55 BEDFORD COURT MANSIONS, BEDFORDAVENUE, LONDON WC1.

CALL ONLY BY APPOINTMENT AT 55 BEDFORD COURT MANSIONS,BEDFORD AVENUE, LONDON W.C.1. TELEX 892031 TWC G

PRACTICAL COMPUTING May 1982

Circle No. 10611

ND Interlink

The INTERLINK by Karadawn64KRAM2.2 MEGABYTE DISK STORAGESERIAL AND PARALLEL PORTSADDS VIEWPOINT V.D.U. STANDARDEXPANDABLE TO 4 DRIVES (5.25"/8")HIGHLY RELIABLE

Z80 -A PROCESSOR. 4MHzTWIN 8" DRIVESACCEPTS MOST TERMINALSCP/M 2.2 INCLUDEDHARD DISK OPTIONEASY SERVICING

For the first time a computer that can be supplied in any configuration you require. Standard systemin two 8" slimline drives. Mixed 5.25" and 8" available. Add on further drives when you need them.Ideal for business systems, massive amount of CP/M software available. Telecommunicationssoftware for mainframe link -ups. Excellent for word processing, just add a daisy wheel printer.Great for software houses as development systems. Only three main component parts for ease ofservicing and high reliability. Outperforms the competition. Supports MBASIC, COBOL, PASCAL,C, FORTRAN, WORDSTAR, SUPERCLAC, DBASE II, many more.

Price including CP/M 2.2 £3,500* plus VAT

For demonstrationtelephone Warrington 572668/573212

or write

KARADAWN LTD., UNIT 2, FORREST WAY, GATEWARTH INDUSTRIAL ESTATE,GREAT SANKEY, WARRINGTON, CHESHIRE

'Printer not included in priceCP i M is a trademark of Digital Research Corp

12 PRACTICAL COMPUTING May 1982

le

The INTER BUS by Karadawn64K RAM EXPANDABLE UP TO 256K2 MEGABYTE DISK STORAGESERIAL AND PARALLEL PORTSADDS VIEWPOINT V.D.U. AS STANDARDEXPANDABLE TO 4 DRIVES

Z80 -A PROCESSORTWIN 8" DRIVESACCEPTS MOST TERMINALSCP/M 2.2 INC. IN PRICEHARD DISK OPTION

HIGHLY RELIABLE S-1000 SYSTEM DESIGN FOR EASY SERVICING

All the above plus MULTI TASKING, MULTI USER OPTIONUp to 16 users can be accommodated via the addition of a single board for each user incorporating a standard64K RAM expandable up to 128K per user. Each user has a terminal and printer if required. Software is aCP/ M 2.2+ MP/ M + CP/NET with file record lockout. In short, just what you have been waiting for.All too often, a small business will make a major investment in a computer system only to find out, a year orso later, that they have outgrown it. The computer can't keep up with the need for more workstations,additional printers, job functions, and your investment is jeopardised. Now the INTER BUS can solve thisproblem. By the addition of an extra board into the computer and a plug in matching terminal your computercan grow with you. The cost of all this excellence? A mere £2,000 per additional 64K unit, and up to128K can be configured. All the usual CP/M software is available or KARADAWN will provide you with acustom -written software package that will meet all your needs.

IF YOUR COMPANY IS GROWING THEN GROW WITH INTERBUSThe price of a 64K system with one terminal is £3,750 plus VAT

For further details or a demonstration, your place or ours, telephone WARRINGTON 572668

KARADAWN LTD., UNIT 2, FORREST WAY, GATEWARTH INDUSTRIAL ESTATE,WARRINGTON, CHESHIRE

PRACTICAL COMPUTING May 1982

`Printer not included in priceCP/M is a trademark of Digital Research Corp.

Circle No. 10713

COMPUTECH for IkapplaAuthorised dealer, service centre and

system consultancyrSUCCESS BREEDS SUCCESS!

As authorised dealer and service centre for Apple computers we have acquired extensive experienceof users' needs and the most cost effective means of satisfying them from the considerable resourcesof this popular and reliable machine. Over 1,000 of our financial accounting packages have beeninstalled. In the process we have have detected areas of special need and opportunities for enhancingthese resources. Our own manufactured hardware and system software have been produced to meetthese requirements. As a result we have compatible products for all configurations of Apple II andITT 2020 installations - and the new Apple /// !

Apple /// now on demonstration - systems from £1,645Pro -File 5 MB mass storage for Apple /// £2,256Computech mass storage for Apple II and Apple ///, up to 12 MB, from £1,950

COMPUTECH SOFTWARE AND HARDWARE INCLUDES:Payroll for 350 employees, 100 departments, all pay periods, printed payslips, approved year enddocuments, very quick and easy to use, £375. Sales, Purchases and General Ledgers £295 each,detailed statements. Job Costing and Group Consolidation are amongst many and various applicationsof the General Ledger package, which supports values to totals of one thousand million accurate to apenny! Our Utilities Disk available like other packages in 13 sector or 16 sector format, is widely used forreliable, error checking, copying, including single drive, and the renowned DPATCH program beloved ofprogrammers for £20. We have developed a Terminal Utilities package which enables Apple to Appleand Apple to mainframe communications with local processing and storage as well as Apple to hostcommunications from the amazingly low price of £130. Our Graphics Utilities program for use with theMicroline and Epson families of printers enable the plain paper production on low cost printers of highresolution screen pictures, graphs etc. - free with Microlines or £30 separately. Keyboard Driver enablesthe use of our Lower Case adaptor with BASIC programs and Applewriter Patches supplied ,FREEwith our character generator package (total cost £50) is separately available on disk with documents for£10. At the same price CAI (convert Apple pictures for ITT) makes binary high resolution picture filesdisplay properly on the ITT 2020. We sell the famous Visicalc for £111 and have delivered systems usingit to do amazing things like production control, shipping accounts and stocks and shares valuations! Theversatile Applewriter word-processing package at only £39, especially employed with our Lower CaseCharacter Generator is widely used by people who cannot type to produce word-perfect copy! Experiencewith Apple systems has led to the design and manufacture of compatible products with enhanced featuresat very favourable prices to satisfy users' needs. These include the Diplomat Serial Interface which I -ashandshaking capability and switchable options (BM, the Diplomat Parallel Interface which enables thedirect use of text and graphics with the Microline and Epson printers and is a complete 'plug in and go'item with gold-plated edge -connector at £80 and has optional direct connection for Centronics 730/737printers. Our new Diplomat Communications Card at £95 is a sophisticated peripheral especially suitablefor Apple to mainframe communications at high speeds in full duplex mode with switch selectable bitrates and other options. The Lower Case adaptor is available for Apples (revision 7 and earlier) as well asITT 2020, complete with diskette software for £50. It offers true descenders on screen and the £ sign. Wealso have an Optional Character Generator for the ever popular Microline M80 at £15. This provides£ sign and improved digits and lower case characters with USASCII special symbols. Our price for theMicroline M80, with graphics, 40, 80 and 132 characters per line, friction, sprocket and teleprinter feed,is only £295, amazing for this small, quiet reliable 'look alike' printer. Tractor option is £40 and SerialAdaptor £80. The Microline M82, bidirectional printer with both parallel and serial input is only £345, itcan have an optional 2K buffer, while the Microline M83 full width adjustable tractor 120 cps printer withsimilar specification is only £595. Then for all computer users there is the unique Micromux which from£800 provides up to 16 ports for simultaneous independent serial asynchronous communications! Telephonefor data sheets or to arrange a demonstration or for the address of our nearest dealer. Please hurry - thedemand for our products has been such that some have been temporarily out of stock. We offer theeffective low cost solutions you need. Prices exclude V.A.T., carriage and packing.

COMPUTECH SYSTEMS168, Finchley Road, London NVV3 6HP. Tel: 01-794 0202

At N VS THROUGFAC 1liT THE l JK AN( ) f )VF ;E

14

Circle No. 108PRACTICAL COMPUTING May 1982

We opened our doors with two basicgoals:

To distribute as many printers andVDU's to as many dealers as possibleand to make money doing so.

Our success on both counts is the resultof hard work, a positive business attitudeand a recognition that you, as a retailerhave a right to be treated fairly andhonestly by your distributor.

WE'RE 1 -UP FOR THREEGOOD REASONS:

1. We always offer a wideselection of the latest andbest peripheral hardwareavailable anywhere. (Whyshould you have to hunt forwhat you need?).

2. Our dealer discounts start ata quantity of 1. (Rememberall those times you justwanted one or two to seehow they'd sell?).

3. We don't play the back ordergame.(if we can't ship yourorder we'll let you know,instead of hanging you outto dry).

If there's anything else we cando for you, just let us know.Because we're 1 -up and weintend to stay that way.

3 & 4 DAWES COURT, ESHER, SURREY.Tel: ESHER (0372) 66397/8/9 or 62071

(from 01 nos. dial 78-66397/8/9 or 78-62071

IMPORTERS, DISTRIBUTORS & WHOLESALERS OF QUALITY COMPUTER PRODUCTSCircle No. 109

Remember Pearl?THE BEGINNING OF A NEW ERA IN MICROCOMPUTER

PROGRAMMINGPEARL ushered in the era where programmers could free themselves from boring,routine and repetitive tasks. Because PEARL handles 60-70% of programming details,which permits programmers to spend their time more creatively, and moreproductively.

But that was two years ago.Today, there's Personal PEARL - to be introduced at the Computer Fair. And it

goes a giant step further. Personal PEARL makes the capabilities of the computeravailable to virtually anyone.

For its £180 price, even people without technical backgrounds can use it to visuallycreate their own applications and reports on any computer.

So the ad you're reading now is announcing an even more important breakthroughin computer and personal productivity.

Just think about the possibilities. Then contact our Personal PEARL ProductManager. PEARL Software Tel: (0202) 741275.

CPU International is the former name of Relational Systems International. PEARL (Producing Error -Free Automatic Rapid Logic)

WITH INTERNATIONAL ACCLAIM

PEARLTM

Paved the way with Program GeneratorsNow once again Pearl Leads with

PERSONALPEARLTM

The Evolution in Software 1990's in 1982

It does what others are claimingTM. RELATIONAL SYSTEMS INTERNATIONAL SALEM, OREGON

To: PEARL INTERNATIONAL (UK) LTD, P.O. BOX 34, POOLE, DORSET BH14 8ARPlease send me details of PERSONAL PEARL.

Name Firm

Address Post Code

Tel.:

Type of Equipment

Disc Size and Format

16 PRACTICAL COMPUTING May 1982

Personal PEARLpurposeTo provide a natural, easy way for people to create custom application programs through an Englishlanguage interaction with a personal computer.

DescriptionPersonal PEARL is the natural, human way to create new computer solutions. Computers are designedto solve general problems at incredible speeds. Application programs are required to operate thecomputer in order to quickly solve specific human problems. Personal PEARL unlocks the power of thecomputer so you can resolve your unique business problems.Personal PEARL asks you for examples of the results you require from the computer. PersonalProgrammer then produces the application program. Personal PEARL is for the individual who requirescustom computer solutions without the cost and time delay of hiring a programmer.With Personal PEARL you can create a library of personal programs, each tailored to your individualrequirements. Accounting, mailing lists, data files, data management calculations and reporting.Personal PEARL builds the program library of your choice, for one price.Why buy several programs designed for the average computer use? Buy Personal PEARL to create anentire library of the highest quality programs designed by you, for your Personal PEARL leads youthrough the program design. Your answers are used by Personal PEARL to create the new program.

HighlightsInteractive English program development.Menu -oriented application description speedsdevelopment via formated screens, input errorchecking.

Built in HELP facility. Display handling is defined by using Personal

PEARL convenient full -screen facilities to simplytype in the display screens exactly the way they areto appear in the new program.

Report handling is defined in the same way; bysimply formatting the display screen to show thelayout of the reports required by the new program.

The application program display screens or reportsmay be modified at any time, or new displays orreports may be added.

Calculation edit: arithmetic operations, editing,translation, table look up, and data validation areincluded.

Data routine: display -to -display, display -to -printer,and display -to -file facilities are provided.

Files may be quickly and easily sorted, printed,searched for selected records, reorganised oranalysed.

Display screens, files or reports may be modifiedreflect changing program requirements.

Display screens may be custom designed in anyform.

Reports may be custom designed in any form.Several report formats may be stored for later use.

PEAQL60FTWAQE

Poole, Dorset, BH14 8AR, England.

Data may be sent to SuperCalc* or Multiplan* forforecasting.

No limitation on number of application programslone file per application).

Maximum file sizes determined only by themaximum capacity of the disk storage medium onthe computer.

Records may be up to several thousand characterslong, if needed.

The number of records that may be stored in a fileis determined by the total file size. Records arevariable length with record packing, eliminating thewasted space incurred by fixed length schemes.

Data base support is provided by an independentdata base manager.

File support is provided through indexing andsequential data access.

Security and Integrity of Data:- Data input can be validated against previously

defined edit criteria before changes are made todata files.

- Edit criteria can be modified dynamically. Automatic Screen Entry Message:

- Users of Personal PEARL can establish messagesto the program operator in order to direct correct

to data entry. Data File Independence:

- The descriptions of data files are maintained inan independent description file - the dictionary.

Multiple Program Integration- Several generic programs such as word

processing and spread sheet analysis may beintegrated through Personal PEARL.

Prerequisite Products

CP/M Operating System48K RAM Microcomputer

Circle No. 110

PRACTICAL COMPUTING May 1982 17

VITHeCOMCENComcen Microcomputers Ltd. are themanufacturing division of the first U.K.Computer Centre. Comcen are leaders inS100 Technology products.

0411

in 11111

Comcen OEM4 multi-userBoth the single user and multi-user versions of

these 20 megabyte winchester systems have been inproduction for more than a year and are now installedin some very prestigious applications. A highlydeveloped bank switching version with MP/M is usedfor the 4 user EDITH (Electronic Display ofInformation on Tourism and Holidays) system ofSwansea City Council.

CP/NET, MP/M 2.1, MP/NET extensions to thesystem are available. Mainframe asynchronous andsynchronous protocols (e.g. ICL CO2 and RJEemulators) are available.

5 MEGABYTE FIXED1 FLOPPY DISK

MP/M, FOUR USERSSERIAL OR PARALLEL

PRINTER OUTPUT

£5960

GROW WITH COMCEN

5 MEGABYTEWINCHESTER

1/2 MEGABYTE FLOPPYCP/86 OPERATING SYSTEM16 BIT MICROPROCESSOR

128K BYTES RAMSINGLE USER

£5960

GROW WITH COMCEN

10 MEGABYTES WINCHESTER3/4 MEGABYTE FLOPPY DISKMP/86 MULTI USER SYSTEM

512K RAM, 16 BIT MICROFOUR USERS

£7960

5 MEGABYTE FIXED1 FLOPPY DISK

CP/M, SERIAL, PARALLELSINGLE USER

£4500GROW WITH COMCEN

MINI BOX

COMCEN 5

TWIN 1 MEGFLOPPY DISK

CP/M, SERIAL, PARALLEL1 USER

£2950GROW WITH COMCEN

GROW FROM:8 TO 16 BIT MICROS1 TO 4 USERS1 TO 100 MEGABYTE DISKS64 TO 1024K RAM

DealerEnquiriesInvited

:EN GROW WITH18

PRACTICAL COMPUTING May 1982

GROW WITHVCS100HALF MEGABYTE RAM£850 assembled and tested.24 bit addressing: 250 n.s. access8 or 16 bit operation £3 A ffIEEE 696 spec. LIU (64K pop.)Tested with Z80, 8085 and 8088Dealer and OEM volume discounts available

COMCEN are EUROPEAN DISTRIBUTORS for:

COmpuProTM, Or visoon of @ODOR Ask for dealer price listELECTRONICS

DISK 1 - High Performance DMA Floppy Disk Controller.SYSTEM SUPPORT 1 - Battery clock/calendar; dual interrupt controllers; power fail interrupt;RS -232 port.CPU Z Z80 -4 or 6 MHz.CPU 8085/8088 - Dual Processor Executes 8 and 16 software 5 or 8 MHz.HIGH SPEED STATIC MEMORY -RAM 20 - Extended addressing or bank select. RAM 20-8K.RAM 17 - Ultra low power (1.6 Watts typical for 64K) RAM 17 (8 MHz operation).RAM 16 - 64K x 8 or 32K x 16 (8 MHz operation).RAM 21 - 128K x 8 or 64K x 16.INTERFACERS -Interfacer 1 - Two RS -232C ports. Full handshake and selectable Baud rates.Interfacer 2 - Three full duplex parallel ports plus one serial port.Interfacer 3-5 - 2 sync/async. 3 async. RS -232C ports.Interfacer 3-8 - 2 sync/async. 6 async. RS -232C ports with full handshake software programmableBaud rates.

COMCEN are EUROPEAN DISTRIBUTORS for:

kitsA SUA0104AA4 04

SBC 100/200 single board Z80, serial, parallel, 1K RAM, 4 EPROM.Expandoram I/11 64K dynamic RAM.Versafloppy 1/11 soft sectored 51/4" or 8" controllers.VDB 8024 : Prom 100 : MPC 4 : Starter kit.

COMCEN are EUROPEAN DISTRIBUTORS for:e-

(rgs

Tarbell Single density disk controller.roni Tarbell Double density DMA disk controller.

COMCEN also stock:SSM CB2 Z80 IEEE with EPROM. Check COMCEN pricing on: Boxed 51/4"

VB3 Memory mapped programmable video. drives from £199. Boxed 8" drives104 2 serial/2 parallel. from £499.PB1 2708/2716 programmer and Discounted 51/4" and 8" drives.

4 EPROM sockets. Apple at cash and carry prices.

We have moved to larger premises again. Note our new address and telephone numbers.45/46 WYCHTREE ST., Price list/catalogue: 0792 798337 (24 hours)MORRISTON, SWANSEA SA6 8EX Sales enquiries: 0792 796000 (day)

COMCEN GRPRACTICAL COMPUTING May 1982 Circle No. 111

19

Free PrinterSPECIAL MAIL ORDER OFFER

r EPSON MX 80T printer (RRP £360) or OKI Microline 80 included *FREE*when you buy the following Apple System:

APPLE II EUROPLUS 48K £812DISK DRIVE WITH CONTROLLER £397DISK DRIVE WITHOUT CONTROLLER £31112" GREEN MONITOR (HIGH QUALITY) & CABLE £174PRINTER INTERFACE CARD £85LIBRARY CASE OF (10) CDC s/s d/d DISKS £20EPSON MX 80T or OKI MICROLINE 80 FREE

TOTAL (excluding VAT): £1,799

NO HIDDEN EXTRAS - FREE DELIVERY mainland UK. INCLUDES 1 YEAR WARRANTY PARTS & LABOUR

If you prefer an alternative printer or any variation on above system,please contact us for an unbeatable offer.

BUSINESS APPLICATION SOFTWAREVISICALC 3.3 £99VISIDEX £99VISITREND/VISIPLOT £t39VISITERM £79VISIPLOT £75

VISIFILE NEW DATABASEFROM PERSONAL SOFTWAREFile Management on the Apple for only £150. Includes record filing,searching, sorting, prints reports and mailing labels. Fast, simple,automatic - numerous applications.

MAGIC WINDOW Word Processing Systemno extra requirements £75

MAGIC MAILER (combines with above) £45High Tech INFORMATION MASTER £79Stoneware DB MASTER £130BRAIN SURGEON fault diagnostic disk £30DISK RECOVERY PROGRAM £24PROGRAM LINE EDITOR programming aid £24

BUSINESS SYSTEMS AND SERVICES

FULLY INTEGRATED PASCAL ACCOUNTING PACKAGES BYSYSTEMATICSSales, Purchase and Nominal LedgersInvoicing. Stock Control & Payroll.TIME COST LEDGER SYSTEM - time recording system written byourselves for an accountancy practice in Manchester. (Dealer enquirieswelcome.)Systems installed by trained engineers. On -site training available for yourstaff. Maintenance contracts available on -site

7INTERFACE CARDS

VIDEX 80 COLUMN CARD £18516K RAM CARD £99APPLE LANGUAGE CARD £99MOUNTAIN CPS MULTIFUNCTION CARDAll -in -one bi-direction serial i/f ace parallel port, clock/calendar card £120Printer interface card & cable (Hi Res) £75

LPRINTERS

Epson MX80F/T New Type 2 (Hi Res Graphics)Epson MX100 (Hi Res Graphics) £525Epson MX82 (Hi Res Graphics) £399Other EPSON & OKI Printers write or call for best prices.ONE YEAR WARRANTY ON EPSON PRINTERS

Add 15% VAT - Post & packing FREE mainland UK. Overseasorders welcome. Write or phone for details

apple' computer-AB SALES AND SERVICE

Apple approved Level t Service Centre 1 year warranty on Apple productsand Epson printers.M

CC

MICRO COMPUTERCONSULTANTS LTD.ASCOTT HOUSE, 227 ELLIOTT ST.,TYLDESLEY, GREATER MANCHESTERTel Atherton (0942) 892818, (0942) 876141Evening, Weekend Tel: 061-707 2689

Circle No. 112

TEXAS INSTRUMENTSHOME COMPUTER STOCKISTS

ABERDEEN Dixons ALTRINCHAM Boots ASHFORDRumbelows BARNET Rumbelows BASILDON RumbelowsBASINGSTOKE Boots BATH Wildings, Boots BEDFORD CarlowRadio, Rumbelows, Boots, Comserve BILLERICAY RumbelowsBIRKENHEAD Dixons BIRMINGHAM Dixons, Hewards HomeStores, Boots BLACKPOOL Boots BLETCHLEY RumbelowsBOLTON Wildings BOREHAMWOOD Rumbelows BRADFORDAckroyd Typewriters BRAINTREE Rumbelows BRENTWOODRumbelows BRIGHTON Gamer, Boots BRISTOL Dixons, WildingsBROMLEY Rumbelows, Boots, Wildings BROMYARD AcoutapeSound CAMBRIDGE Rumbelows, Dixons, Wildings, HeffersCANTERBURY Rumbelows, Dixons CARDIFF Boots, Dixons,Computer Business Systems CARLISLE Dixons CHELMSFORDDixons, Rumbelows CHESTER Boots CHINGFORD RumbelowsCOLCHESTER Wildings, Rumbelows CORBY ComputerSupermarket CROYDON Wildings, Boots, Dixons, AlldersDARTFORD Rumbelows DERBY Datron Microcentre, BootsDORRIDGE Taylor Wilson DUNSTABLE RumbelowsEASTBOURNE Rumbelows EDINBURGH Robox, Esco, TexasInstruments, Dixons, B.E.M. ENFIELD Rumbelows EXETERPeter Scott, Boots, Dixons GLASGOW Boots, Esco, Robox,Dixons GLOUCESTER Wildings GRAVESEND WildingsGT. YARMOUTH Rumbelows HANLEY Boots HARLOWRumbelows HATFIELD Rumbelows HEMEL HEMPSTEADRumbelows, Dixons HIGH WYCOMBE Wildings HITCHINRumbelows HODDESDON Rumbelows HULL RadiusComputers, Boots, Dixons, Peter Tutty ILFORD Boots IPSWICHWildings, Rumbelows KINGSTON Wildings, Dixons LEEDSWildings, Dixons, Boots LEICESTER Dixons, Boots LEIGHTONBUZZARD Computopia LETCHWORTH Rumbelows LINCOLNDixons LIVERPOOL Dixons, B.E.C. ComputerworldLONDON: Balham Argos Bow Rumbelows Brent CrossDixons, Boots Camden Town Rumbelows City Road SumlockBondain Clerkenwell Star Business Machines Curtain RoadEurocalc Ealing Adda Computers EC1 Argos EdmontonRumbelows Finchley Road Star Business Machines GoodgeStreet Star Business Machines Hackney RumbelowsHammersmith Dixons Holborn Wildings, Dixons HornchurchWildings Hounslow Boots Knightsbridge Video Palace, HarrodsMarble Arch Star Business Machines Moorfield DixonsMoorgate Star Business Machines New Bond Street DixonsNW1 Mountaindene Oxford Street Selfridges, H.M.V. DixonsRegent Street Star Business Machines Tottenham CourtRoad Landau, Eurocalc Victoria Street Army & NavyWood Green Boots, Rumbelows Woolwich Wildings LoughtonRumbelows LUTON Dixons, Rumbelows, Wildings MAIDSTONEDixons, Boots, Rumbelows, Wildings MALDON RumbelowsMANCHESTER Orbit, Wildings, Boots, DixonsMIDDLESBROUGH Boots, Dixons MILTON KEYNESRumbelows, Dixons NEWBURY Dixons NEWCASTLE Boots,Dixons NORTHAMPTON Dixons NORWICH Dixons, RumbelowsNOTTINGHAM Bestmoor, Dixons, Boots ORPINGTONRumbelows OXFORD Science Studio PETERBOROUGH BootsPLYMOUTH J.A.D., Dixons PORTSMOUTH Boots, DixonsPOTTERS BAR Rumbelows PRESTON Dixons RAMSGATEDixons RAYLEIGH Rumblelows READING Dixons ROMFORDWildings, Rumbelows, Dixons RUSHDEN Computer ContactSANDY Electron Systems SHEFFIELD Datron Microcentre,Dixons SITTINGBOURNE Rumbelows SLOUGH Boots, Wildings,Texas Instruments SOUTHAMPTON Dixons, The Maths BoxSOUTHEND Rumbelows, Wildings, Dixons ST. ALBANSRumbelows STEVENAGE Dixons, Rumbelows STRATFORDRumbelows SUDBURY Rumbelows SUTTON WildingsSWANSEA Dixons SWINDON Wildings TONBRIDGERumbelows WALTHAM CROSS Rumbelows, WildingsWALTHAMSTOW Rumbelows, Wildings WARE RumbelowsWARRINGTON Boots WATFORD Computer Plus, Wildings,Computer Centre, WELWYN GARDEN CITY RumbelowsWETHERBY Bits & Pieces WIMBLEDON WildingsWOLVERHAMPTON Dixons WOODFORD RumbelowsWOOLWICH Rumbelows

20 PRACTICAL COMPUTING May 1982

TEXAS INSTRUMENTS

With the Home Computer from Texas Instruments,you can converse in the five major languages:BASIC, PASCAL, TI -LOGO, ASSEMBLERand it speaks English!

PRACTICAL COMPUTING May 1982

When you compare the TI -99/4A HomeComputer to its competition, you'll find it is atruly remarkable machine. For a start, it enablesyou to use the most important programminglanguages. Something that is difficult to find onother comparable computers. What's more, ithas a large 16 K Byte RAM memory capacity,expandable to 48 K Byte. With the additio,n ofcertain peripherals and a Solid State Software°Module a total combined RAM/ROM capacityof 110 K Bytes is available. The TI -99/4A HomeComputer plugs into an ordinary TV set andcan be expanded into a complete computingsystem with the addition of peripherals such astwo ordinary domestic cassette recorders, remotecontrol units, disk memory drives, speechsynthesiser, and thermal printer. Via'an RS 232interface option, other peripherals such ascommunication modems, impact printers and

plotters can be attached. With it's high resolu-tion graphics with 32 characters over 24 lines in16 colours (256 x192 dots), three tones in fiveoctaves plus noise, and BASIC as standardequipment and options such as other program-ming languages -UCSD-PASCAL, TI -LOGOand ASSEMBLER-and speech synthesis, you'llfind that the TI -99/4A Home Computer morethan compares with competition. Especiallywhen the starting price is £340 or less. Whenyou want to solve problems there are over 600software programs available worldwide -including more than 40 on easy -to -use SolidState Software° Modules.

After all, from the inventors of the micro-processor, integrated circuit and microcomputer,it's only natural to expect high technology at arealistic price.

The TI -99/4A HomeComputer: another way we'rehelping you do better.

Enjoy a new world of learning.

TEXAS INSTRUMENTSLIMITED

Circle No. 11321

Vic 20 Colour Computer £199.99*C2N Cassette Unit £44.95*4016 16K Computer £5504032 32K Computer £6952031 171K Single Drive Floppy Disk £3954040 343K Dual Drive Floppy Disk £6954022 Tractor Feed Printer £3958032 32K Computer £8958096 96K Computer £11958050 950K Dual Drive Floppy Disk £8958023 Tractor Feed Printer £8958422 22 Megabyte Winchester Disk £34959000 SuperPet 134K

Multilanguage Computer £1495*Price inclusive of VAT. All other prices VAT extra.

All prices are correct at time of going to press.

At Commodorewe leave you no choice

Send to: Commodore Information Centre, 675 Ajax Avenue, Slough, Berks., Tel. Slough 79292.I'd like to know more about how Commodore can help me make the right choice.

Name Position

Nature of Business Company

Address

Tel

LCr commodore

COMPJTERQuite simply, you benefit from our experience 10PR3

22 PRACTICAL COMPUTING May 1982

Commodore Official Dealer ListLondonAdda W1301-579 5845Capital Computer SystemsW101-636 3863Logic Computer SystemsSW101-222 1122/5492Merchant Systems LtdEC401-583 6774Micro Computation N1401-882 5104Microcomputer Centre SW1401-878 7044/7Sumlock Bondain Ltd EC I01-2500505Informer -London LtdSE1301-318 4213/7CSS (Systems) Ltd E801-254 9293Meares Consultants LtdNW301-431 3410Data Base NW201-4501388

Sunny & MiddlesexDouglas Moore Ltd Kingston -Upon -Thames01-5492121Micro Facilities LtdHampton Hill01-979 4546/941 1197PPM Ltd Waking04867-80111Datalect Computers LtdCroydon01-680 3581Datalect Corn puters Ltd Woking04862-25995Johnson MicrocomputersCamberley0276-20446We Computers LtdCaterham0883-49235Cream Computer Shop Harrow01-863 0833Da Vinci Computer Shop Edgware01-952 0526L & J Computers Stanrnore01-204 7525/206 0440

Kent, Sussex & HampshireAmplicon Micro Systems Brighton0273-562163/608331Business ElectronicsSouthampton0703-738248HSV (Microcomputers) Ltd Hants0256-62444/0703-331422Millhouse Designs LtdAlton042-084517The Computer Room Tonbridge0732-355%2Scan Computers Storrington09066-5432

EssexDataviewColchester0206-865835CSSC Ltd Ilford01-5543344DOM Brentwood0277-229379Stuart R Dean LtdSouthend-on-Sea0702-62707

Berkshire, Buckinghamshire, Oxfordshire & WiltshireCommonsense Business Systems Ltd High Wycombe0494-40116Orchard Computer ServicesWallingford0491-35529Wymark Micro -Computer Centre Salisbury04254-77012Alphascan Ltd Banbury029575-8202J R Ward Computers Ltd M ilton Keynes0908-562850The Computer ShopOxford0865-722872Kingsley Computers High Wycombe0494-449749

Hertfordshire & BedfordshireAlpha Business Systems Ware0920-68926Bromwall Data ServicesOld Hatfield07072-60980/63295Computer PlusWatford0923-33927HI3 Computers (Luton) Ltd Luton0582-454466Photo Acoustics Warlord0923-40698/32006MMS Ltd Bedford0234-40601Brent Computer Systems Rickmansworth87-71306/70329

East Midlands, South Humberside & DerbyshireDavidson Richards LtdDerby0332-366803/4Roger Clark (Business Systems) Ltd Leicester0533-20455Arden Data Processing Leicester0533-22255Betos Systems Ltd Nottingham0602-48108Caddis Computer Systems Ltd Hinckley0455-613544AJRLtdArnold Nottingham0602-206647

East Anglia, Lincolnshire & NorthamptonshireArden Data ProcessingPeterborough0733-47767HB Computers LtdKettering0536-520910Sumlock Bondain LtdNorwich0603-26259/614302Dataview Norwich0603-616221

West Midlands, Statfotdshire & WanvickshireJoseph Ware Associates Birmingham021-6438033Camden Electronics Ltd Birmingham021-7738240Micro Associates Birmingham021-3284574Taylor Wilson Systems Dorridge, Solihull05645-6192Walters Computer Systems LtdStourbridge03843-70811

CBS Consultants LtdBirmingham021-7728181Peach Data Services Burton -on -Trent0283-44968Computer Services Midlands Ltd Birmingham021.382 4171Business Equipment Rentals Ltd Rugby0788-65756Business Equipment Rentals LtdCoventry0203-20246

North Wales, Cheshire & MerseysideRockliff Micro Computers Mold0352-59629North Wales Computer Services Colwyn Bay0492-33151Office & Business Equipment (Chester)LtdQueensterry0244-816803Catlands Information Systems Wilmslow0625-527166Rockli If Micro Computers Liverpool051-5215830

ManchesterCytek (UK) LtdOld Trafford061-872 4682Executive Reprographic Manchester061-2281637Sumlock (Manchester) LtdManchester061-8344233D KippingSaltord061-834 6367/9Computastore Ltd Manchester061-832 4761

LancashirePreston Computer Centre Preston0772-57684Tharstern Ltd Burnley0282-813299

Yorkshire & HumbersideAckroyd Typewriter Co Ltd Bradford0274-31835Alcor Computer Systems Ltd Huddersfield0484-512352Deans Computer Services Leeds0532-452966Holbrook Business Systems Sheffield0742-484466Holdene Ltd Leeds0532-459459Microware Computers Hull0482-562107Mitre Finch Fishergate0904-52995Itukshire Electronics Morley0532-522181Computer Centre (Sheffield) LtdSheffield0742-53519/588731Microprocessor Services Hull0482-23146Ram Computer Services Ltd Bradford0274-391166

North EastCurrie & Maughan Gateshead0632-774540Dysons Instruments Houghton -Le -Spring0783-260452Intex Dablog Ltd Eaglescliffe0642-7811%Key Computer Services LtdJesmond0632-815157

Avon, Waits & Mesta:0rib),Calculator Services& Sales (BristoOLtdBristol0272-779452/3Computer Supplies (Swansea)Sketty0792-290047McDowell Knaggs & AssociatesWorcester0905-28466Somerset Business Computers Taunton0823-52149Milequip LtdGloucester0452-411010Reeves Computers LtdCarmarthen0267-32441/2Welsh Computer Centre Bridgend0656-2757Sigmaa.Satr5%litiit5C9ardiff

Reeves Computers Newport0633-212331/2Computer Shack LtdCheltenham0242-584343Midland Micro Stourport-on-Severn02993-77098/6706Sumlock Tabdown Ltd Bristol0272-276685/6Radan Computational Ltd Bath0225-318483

Devon & CornwallAC Systems Exeter0392-71718Devon Computers Paignton0803-526303Jeffrey Martin Computer Services LtdTruro0872-71626AC Systems Plymouth0752-260861JAD Integrated Services (Plymouth) Ltd Plymouth0752-662616/29038

ScotlandAyrshire Office Services LtdKilmarnock0563-24255/20551Holdene Microsystems LtdEdinburgh031-557 4060Robox Office Equipment Ltd Glasgow041-2218413/4Gate Microsystems Ltd Dundee0382-28194Gate Microsystems LtdGlasgow041-2219372Mac Micro Ltd Inverness0463-712774

Eire & Northern IrelandNorthern Ireland Computer Centre Co. Down02317-6548/9CrowleyComputers Ltd Dublin 20001-600681

Isle of ManResource Planning Ltd Douglas0624-4247/8

Circle No. 114PRACTICAL COMPUTING May 1982

a

UniversalData

BufferMicroprocessor based 6809

4K or 8K Static RAMFull RS232c

RTS and CTSCrystal controlled splitBaud rates50-9600 switch selectable

or

8 Bit Parallel InputCentronic standardSTROBE, ACK, BUSYCR/LF on CRor CR on CR2 Centronic 36 wayconnectors2 RS232c 25 wayconnectors

FullDocumentation

and support

Universal Printer &Ater30

f 5! ! 5!

Serial IN Serial OutIndependent IN/OUTBaud rateSerial IN - Parallel OUT

Parallel IN - Serial OUTData Format

switch selectable

All Operational Modesare switch selectable

on front panelLED's for System

Operation status

30Digital Design and Development18/19 Warren Street London W1P 5DB Tel 01 387 7388

Circle No. 11523

CCOLUIVIESA complete range ofmicrocomputers from320K -80MSingle and multi-user upgradeable/expandablemicrocomputer systems from Columbia DataSystems offer the disk storage capacity that'sexactly right for you. Single user machines totake 51/4" or 8" floppy disks giving 320K -2.4M capacity and multi-user machineswith up to 80M on hard disk.

Up to 5 users can worksimultaneously while sharing a singleprocessing system. Ideal for wordprocessing, general accounting orother special purpose businessapplications.

Icarus handle the whole range of microcomputer systems produced by ColumbiaData Systems of the U.S .A. This includes CPIM and MPIM single and multi -terminalunits with hard and floppy disk storage capacities. It is adaptable to suit each and every micro -basedapplication there is. So whenever you need a microcomputer, for whatever purpose, Columbia and Icarus have the answer.

The Icarus dealer network

or,

A

ABRAXAS COMPUTEREMPLOYMENT, 357 Euston Road,LONDON NW I 3AL.Tel: 01 388 2061

A.P. LTD, Maple House, MortlakeCrescent, CHESTER CH3 SUR.Tel: 0244 46024

AMCO LTD, Playfair Road, LEEDSLSIO 2GP. Tel: 0532 708321

BASIC BUSINESS SYSTEMS,61 Loughborough Road, WESTBRIDGEFORD, Nottingham.Tel: 0602 819713

BUSINESS INFORMATIONSYSTEMS, 602 Triumph House,189 Regent Street, LONDON.Tel: 01 437 1069

BORDER COMPUTING LTD,Dog Kennel Lane, BUCKNELL,Shropshire. Tel: 054 74 368

CAMBRIDGE MICROCOMPUTERS, Cambridge SciencePark, Milton Road, CAMBRIDGE.Tel: 0223 314666

COMMONSENSE COMPUTINGLTD, P.O. Box 7, BIDEFORD,Devon. Tel: 02372 4795

CONQUEST COMPUTER SALESLTD, 92 London Road, BENFLEET,Essex. Tel: 03745 59861

CULLOVILLE LTD, Thornfield,Woodhill Road, SANDON,Chelmsford, Essex. Tel: 024 541 3919

DATA PROFILE, Lawrence Road,Green Lane, HOUNSLOW,Middlesex. Tel: 01 446 1917

DATA WARE, 48 Eaton Drive,KINGSTON, Surrey KT2 7QX.Tel: 01 546 2984

DAYTA, 20b West Street, Wilton,SALISBURY, Wilts.Tel: 0722 74 3898

DRAGON SYSTEMS LTD,37 Walter Road, SWANSEA,W. Glam. Tel: 0792 474498

DUPLEX COMMUNICATIONS,2 Leire Lane, Dunton Bassett,Lutterworth, LEICESTERSHIRE.Tel: 0455 209131

EASIBEE COMPUTING LTD,133/135 High Street, LONDONE6 1HZ. Tel: 01 471 4884

ESCO COMPUTING LTD,154 Cannongate, EDINBURGH.Tel: 031 557 3937

ESCO COMPUTING LTD,40a Gower Street, GLASGOW G5I1PH. Tel: 041 427 5497

EFFICIENT BUSINESSSYSTEMS, 9 Clarence Street,BELFAST I, N. Ireland. Tel: 0232647 538

EMTEK, 40 oath Furzeharn Road,BRIXHAM, Devon. Tel: 08045 3566

FARMFAX LTD, 17 Hylton Road,PETERSFIELD, Hants.Tel: 0730 66123

B. FITTON, 97 Melbourne Road,ROYSTON, Herts.

FOREST ROW COMPUTERS, 53Feshfield Bank, FOREST ROW, EastSussex. Tel: 034282 4397

G.T. OFFICE SYSTEMS, 12Clovelly Road, LONDON W5 SHE.Tel: 01 567 9959

G.I.C.C., P.O. Box 519, Manama,Bahrain.

JAEMMA LTD, Unit 24, Lee BankHouse, Holloway Head, Lee Bank,BIRMINGHAM. Tel: 021 643 1609

JENNINGS COMPUTERSERVICES, 55/57 Fagley Road,BRADFORD, W. Yorks.Tel: 0274 637867

KENT BUSINESS SYSTEMSLTD, 85 High Street, Ramsgate,Kent. Tel: 0843 687816.

LONDON COMPUTER CENTRE,43 Grafton Way, LONDON WI.Tel: 01 388 5721

M.G. ENTERPRISES, 32 Rue VictorHugo, 92800 Puteaux, France.

MASS MICROS, Wellson House,Brownfields, WELWYN GARDENCITY, Herts. Tel: 96 31736

MICRO -K, Martin Way, MORDEN,Surrey. Tel: 01 543 1119

MICROAGE LTD, 53 Acton Road,LONG EATON, Nottingkarnshire.Tel: 06076 64264

MICROSERVE LTD, 811 KennedyWay, Pelham Road, IMMINGHAM.Tel: 0469 72346

MICRO SOLUTION LTD, ParkFarm House, Heythrop, CHIPPINGNORTON, Oxon. Tel: 0608 3256

NASTAR COMPUTER SERVICESLTD, Ashton Lodge, AbercrombieStreet, CHESTERFIELD. Tel: 0266207048

NORTHERN COMPUTERS LTD,128 Walton Road, Stockton Heath,WARRINGTON. Tel: 0925 601683

OMEGA ELECTRIC LTD,Finley Mill, Flaxley Road,MITCHELDEAN, Glos.Tel: 045 276 532

RANMOR COMPUTING LTD,Nelson House, 2 Nelson Mews,SOUTHEND-ON-SEA.Tel: 0702 339262

ROGIS SYSTEMS LTD, KeepersLodge, Frittenden,NR. CRANBROOK, Kent.Tel: 058 080 310

S.D.M. COMPUTER SERVICES,Broadway, BEBINGTON, MerseysideL63 5ND. Tel: 051 608 9365

S.M.G. MICROS, 39 WindmillStreet, GRAVESEND, Kent.Tel: 0474 55813

For further details, or i f you wantto become a dealer yourself, contact:

Computer Systems Ltd.

Icarus Computer Systems Ltd. Deane House 27 Greenwood Place London NW5 1NN Tel 01-485 5574 Telex: 264209

SAPPHIRE SYSTEMS, 19-27 KentsHill Road, BENFLEET, Essex.Tel: 03745 59756

SHEFFIELD COMPUTERCENTRE, 225 Abbeydale Road,SHEFFIELD S7 1FJ. Tel: 0742 53519

SORTFIELD LTD, E. Floor,Milburn House, Dean Street,NEWCASTLE-UPON-TYNE.Tel: 0632 329593

SPOT COMPUTER SYSTEMSLTD, New Street, Kelham StreetIndus. Estate, DONCASTER,S. Yorks. Tel: 0302 25159

STAG TERMINALS LTD, 30Church Road, Teddington, Middlesex.Tel: 01 943 0777

STUKELEY COMPUTERSERVICES, Barnhill, STAMFORD,Lincs. Tel: 0780 4947

TERMACRE LTD, 126 WoodwardeRoad, LONDON SE22 8TU.Tel: 01 693 3037

THAMES VALLEY COMPUTERS,10 Maple Close, MAIDENHEAD,Berks. Tel: 0628 23532

TURNKEY COMPUTERTECHNIQUE, 23 Caldcrglen Road,St. Leonards, EAST KILBRIDE.Tel: 03552 39466

THE COMPUTER ROOM, 87 HighStreet, TUNBRIDGE, Kent.Tcl: 0732 355962

WELSH BUSINESS SYSTEMSLTD, 1 Windsor Chambers, WindsorArcade, PENARTH. Tel: 0222 700059

WORD PERFECT, Old Town Hall,Box 148, READING, Berkshire.Tel: 0734 589068

24

Circle No. 116PRACTICAL COMPUTING May 1982

OURAPPLE PRICESTURN OTHERS

GREEN.C/WP Computer prices are so low,

we reckon they're the most competitiveyou will find for a standard factory -fresh Apple with a full 12 -monthwarranty.

And we're not just clever at keep-ing prices down: C/WP are experts inCP/M and its software. If you alreadyhave a 48K Apple II with two discdrives it could cost you only X0125 tomake it a CP/M APPLE.

If you are starting from scratch,you can buy a complete CP/M APPLEfor under £2,000.

Write or 'phone for our full CP/Mhardware and software list.

If you're hungry for an Apple atthese prices, contact C/WP Computerson 01-828 3127.

C/WPC/WP Computers

108 Rochester Row, London SW1P leJPTelephone: 01-828 3127

APPLE-CP/M OFFER

EX -VAT PRICES

C/WP PRICE A TYPICAL PRICE A

Apple 48K Europlus 579

2 Siemens disc driveswith controller 500

Microsoft CP/M systemwith Z80A processor 180

812

650

200

16 K RAM card 70

Green screenmonitor 24MHz 110

106

159

80 column card 170 200

Epson MX 80T printer 290 360

Printer interface 80 92

10 Floppy discs 20 31

1999 2580

Items available separately at same price.

SOFTWARE FOR CP/MC/WP PRICE A EX. VAT

Wordstar 3.0 200Wordstar training pack 40Calcstar 140dBase II 375M Fortran 110CIS COBOL + Forms -2 475M Basic Compiler 210

Circle No. 117PRACTICAL COMPUTING May 1982 25

EC

*Hardware or software, you don't haveto shop around. We continually check

all our prices and we're certainthey are as competitive as you willfind anywhere.

PACKAGE SYSTEMS NET VAT TOTALApple Executive System 1950.00 292.50 2242.50Apple Top Secretary System 2150.00 322.00 2472.50Apple Education System 1425.00 213.75 1638.75APPLE HARDWAREApple 48K Video Output only 625.00 93.75 718.7516K Add on 45.00 6.75 51.75Disk Drive with Controller (16 sec) 345.00 51.75 396.75Disk Drive without Controller 275.00 41.25 316.25ACCESSORIESProgrammers Aid 1 25.00 3.90 29.90Auto Start ROM Pack 33.00 4.95 37.95Graphics Tablet 399.00 59.85 458.85Appletel System 525.00 78.75 603.75TV Modulator 14.00 2.10 16.10

INTERFACE CARDSPrototype/Hobby Card 12.00 1.80 13.80Parallel Printer Card 79.00 11.85 90.85Communications Card 100.00 15.00 115.00High Speed Serial Card 90.00 13.50 103.50Centronics Card 100.00 15.00 115.00Integer Card 90.00 13.50 103.50Language Card 95.00 14.25 109.25Controller Card 95.00 14.25 109.25Eurocolour Card 65.00 9.75 74.75IEEE -48 Card 200.00 30.00 230.0016K RAM Card (48K to 64K( 60.00 9.00 69.00SOFTWAREDisk Utility Pack 12.00 1.80 13.80Apple Post Program 27.00 4.05 31.05The Shell Games 15.00 2.25 17.25Elementary My Dear Apple 16.00 2.40 18.40Apple Bowl Diskette 13.00 1.95 14.953.3 Operating System 34.00 5.10 39.10DOS 3.3 Tool Kit 41.00 6.15 47.15Apple Writer 1.1 34.00 5.10 39.10Stellar Invader 13.00 1.95 14.95Apple Plot 34.00 5.10 39.10Apple Adventure 19.00 2.85 21.85APPLE DISTRIBUTED SOFTWAREThe Go Beveen (Centronics) 26.50 3.98 30.48Micro Modeller 375.00 56.25 431.25Visicalc 3.3 105.00 15.75 120.75VisiFile 135.00 20.25 155.25VisiPilot 95.00 14.25 109.25VisiTrend/VisiPilot 135.00 20.25 155.25VisiTerm 80.00 12.00 92.00VisiDex 105.00 15.75 120.75Desktop Plan II 105.00 15.75 120.75

LANGUAGESPascal Language.System 225.00 33.75 258.75Apple Pilot 75.00 11.25 86.25Apple Fortran 95.00 14.25 109.25CIS Cobol with Forms -2 410.00 61.50 471.50

PRINTER & ACCESSORIES NET VAT TOTALSilentype Printer 170.00 25.50 195.5010 Rolls Thermal Paper 28.00 4.20 32.2010 Blank Disks SS/SD 17.00 2.55 19.55VIDEO MONITORSBMC 12" Green Screen 120.00 18.00 138.009" Black & White Monitor 100.00 15.00 115.00Cables 5.00 0.75 5.75OTHER ITEMSZ80 Softcard 170.00 25.50 195.50INTEGRATED ACCOUNTINGPACKAGES SYSTEMATICSSales Ledger 150.00 22.50 172.50General Ledger 150.00 22.50 172.50Purchase Ledger 150.00 22.50 172.50Stock Control 150.00 22.50 172.50Payroll 150.00 22.50 172.50Invoicing 150.00 22.50 172.50Financial Planning 150.00 22.50 172.50ATARI40016K Computer 250.00 37.50 287.5080016K Computer 450.00 67.50 517.50410 Tape Recorder 50.00 7.50 57.50810 Disk Drive 260.00 39.00 299.00822 Thermal Printer 200.00 30.00 230.00825 80 Column Printer 400,00 60.00 460.00850 RS232 Interface 110.00 16.50 126.5016K Ram Upgrade 50.00 7.50 57.50Conversational French 30.00 4.50 34.50Conversational German 30.00 4.50 34.50Conversational Spanish 30.00 4.50 34.50Conversational Italian 30.00 4.50 34.50Assembler Editor ROM 30.00 4.50 34.50Microsoft Basic 45.00 6.75 51.75Visicalc 105.00 15.75 120.75Word Processor 73.00 10.95 83.95Video Computer System 69.56 10.43 79.99

HARDWAREGUARANTEE

All advertised products areguaranteed one year from date ofpurchase against defects in materialsand workmanship.

During the guarantee period,Metrotech will repair or replace, at noextra charge, components that provedefective -providing that the product isreturned, shipping or postage prepaid,stating when bought and enclosingproof of purchase.

This guarantee does not apply if, inthe opinion of the Company, theproduct has been damaged byaccident, misuse or misapplication.

CONDITIONS OFBUSINESS.

We accept cheques or Access,Barclaycard, American Express andDiners Club Cards. All prices,specifications and terms are subjectto change without notice at thediscretion of the management. Alloffers subject to availability.

Prices correct at time of goingto press. E. & O.E.

Hardware Post and packagingsubject to confirmation.

(4-1

VII 'Leg Pi 'NV! L: .51.16111026 PRACTICAL COMPUTING May 1982

I

New CP/M softwareat hard to beat prices

CIO WORDSTAR 3WORDSTARtrm Version 3.xx has now

been released. New features include: columnmove capabilities, horizontal scrolling -up to240 columns and even clearer menus. Alsoreleased is MicroPro's own spelling checker-SPELLSTAR.

WORD -STAR 3.xx £195/£30MAILMERGE 3.xx (optional) £55/E10SPELLSTAR (optional) £105/£10IN ADDITION METROTECH SUPPLIES A TRUEENGLISH DICTIONARY, REPLACING U.S.WORDS WITH ENGLISH.

* RECORDSMANAGEMENT

Ideal for office records includingpersonnel, stock, clients and accounts.Features include:

Comprehensive calculation Record selection on updates and reports Full sorting facilities WORDSTAR INTERFACE -for selective

mailing.

COMPSOFT DMS £345/E25* MICROPLAN

If you have any problem that youwould normally solve with a pen, paper and acalculator, then MicroPlan will help you.MicroPlan will perform most types of calcu-lations working on rows and columns, as wellas advanced financial analysis.

MICROPLAN £245/E20CALCSTAR

CalcStar is MicroPro's new electonic Spreadsheet and financial modelling Program -asophisticated, yet easy to use calculating andplanning tool. CalcStar also links withWordStar, so you can easily include your finalcalculations within your report.

CALCSTAR E120/E30

POINTS TO REMEMBER All software is Ex -Stock except MDBS andavailable on standard 8" disks or 5" disks forVector MZ, Superbrain, Dynabyte andNEC PC 8000. Prices shown as Software with manual/Manual only. tml WORD -STAR is a trademark ofMicropro. METROTECH are sole U.K.distributors for DYNABYTEmicro -computer systems.

LANGUAGES/UTILITIESSUPERSORT I £105/£20WORD -MASTER SUPERIORTEXT EDITOR £601/E20

MET/IWAM INDEX SEQUENTIAL FILEACCESS IN CBASIC II £55/E20CBASIC II COMMERCIALDISK EXTENDED BASIC £75/E30

STRUCTURED BASIC £175/E30SBASIC COMPILER

MICROSOFT BASIC 80INTERPRETER £155/E25MICROSOFTBASIC COMPILER £195/£25MICROSOFT FORTRAN 80 £215/£25MICROSOFT COBOL 80 £315/E25

MICRO DATABASE SYSTEMS

MDBS is a database system offering fullnetwork CODASYL- orientated datastructures, variable length records, read writeprotection, one-to-one, one to many andmany to many set relationships. Add onfeatures are an intereactive report writer andquery system, a dynamic restructuring systemand a recovery transaction logging system.

MDBS prices start from £600/30Primer manual 5

BCPL*BCPL CINTCODE is a full and extended

implementation of the popular Systemsprogramming language BCPL CINTCODEgives a dramatic reduction in the spacerequired for programs, requiring about a thirdof the store of fully compiled Z80 code.

BCPL £250/£35HOW TO ORDER State disk type and size Add 15% VAT Include E2 per Software itemlor Postage

and Packing Enclose cheque/PO's payable to

METROTECH

DATAMANAGEMENTSELECTOR III -C2An easy to use Information ManagementSystem requires CBASIC II E185/E30SELECTOR IVAn advanced Information ManagementSystem, requires CBASIC II £275/E35DATASTARPowerful data entry, retrieval andupdate system £150/£30COMMUNICATIONS

BISYNC-80/3780 and BISYNC-80/3270are full function IBM 2780, 3780 and 3270emulators for micro computers. BISYNC-80/3780 gives you a Remote Job Entryterminal for the price of a micro!BISYNC-80/3270 combines the localprocessing power of a micro with asophisticated screen capability. Make yourdumb terminal smart!

MET/TTY will connect your micro to aTimesharing service in simple teletypeemulation.

BISYNC-80/3780BISYNC-80/3270MET/TTY

£445/£20£445/£20

£95/£20FINANCIAL REPORTINGREPORT WRITER You input the values. ReportWriter will perform your calculations andproduce a report with your headings, totalsand summaries. £70/00GLECTOR General ledger option in Selector III,requires Selector III and CBASIC II

£125/£30Newly released softwarePL/1 -80 from Digital Research TBAINFOSTAR from MICROPRO TBACB 80 £295/£35

Mail to METROTECH MAIL ORDER,WATERLOO ROAD, UXBRIDGE,MIDDLESEX UB8 2Y \X/CREDIT CARDS Telephone orders welcomeTel: 0895 58111 Ext 247 or 269.

Trade Enquiries Welcomed

!AFCA MEMBER OF THE GRAND METROPOLITAN GROUPVA:.' "10.9CI

PRACTICAL COMPUTING May 1982

ti

Circle No. 11927

THE NEW EtEXCITING

TRS80MOIIIDELall

48K599- VAT

ct(

The Radio Shack TRS-80TM Model III is a ROM -basedcomputer system consisting of: A 12 inch screen to display results and other information A 65- key console keyboard for inputting programs and datato the Computer A 7-80 Microprocessor, the "brains" ofthe system A Real -Time Clock Read Only Memory(ROM) containing the Model III BASIC Language (fullycompatible with most Model I BASIC programs) RandomAccess Memory IRAMI for storage of programs and datawhile the Computer is on (amount is expandable from "16K"to "48K", optional extra) A Cassette Interface for long-termstorage of programs and data (requires a separate cassetterecorder, optional 'extra) A Printer Interface for hard -copyoutput of programs and data (requires a separate line printer,optional Expansion area for upgrading to a diskbased system (optional extra) Expansion area for an RS232-C serial communications interface I optional extra)All these components are contained in a single moulded case,and all are powered via one power cord.

Disc Drives Kit with 2x40 Track Drives . £599 VATDisc Drives Kit with 2x80 Track Drives - £729 VAT

HITACHIPROFESSIONAL

MONITORS912"

-f-I-Bg £149"- .0-29 09.951

VAT

Reliability Solid state circuitry using an IC and s licontransistors ensures high reliability. 500 lines horizontalresolution Horizontal resolution in excess of 500 lines isachieved in picture center. Stable picture Even playedback pictures of VTR can be displayed without jittering, Looping video input Video input can be looped throughwith built-in termination switch. External sync opera-tion (available as option for U and C types) Compactconstruction Two monitors are mountable side by side in a

standard 19 -inch rack.

ACORN ATOMUNIQUE IN CONCEPTTHE HOME COMPUTERTHAT GROWS AS YOU DOfr Fully Assembled £157.50 vAT

inc. PSU

Special features include Full Sized KeyboardAssembler and Basic Top Quality Moulded Case Optional High Resolution Colour Graphics 6502Microprocessor

THE EPSON MX SERIES

801132 ColumnCentronics ParallelBi-directionalUpper & lower caseTrue Descenders9x9 Dot MatrixCondensed and

Enlarged Characters Interfaces andRibbons available

MX8OT £339 VAT

MX130F/T £389 VAT

Arkro

I4.0: 87Oct

filSp- /4/

MICROLINE 80 £289 . VAT 80 cps Uni-directional Small size: 342 1W) x 254 031 x108 (HI mm. 160 Characters, 96 ASCII and 64 graphics 3Character sizes: 40, 80 or 132 chars/line Frictionand Pin Feed Low noise: 65 dB Low weight: 6.5 kg

INTRODUCINGTHE NEW SHARP NIZ-80B

C41,?Ot.,1/V740tK.

£999 VAT. 4 Mhz Z-80CPU Dynamic RAM 2K ROM BASICis provided High Resolution Graphics 9" High FocusGreen Display Upper and Lower Case 80/40Characters x 25 line display Electro Magnetic CassetteDeck included ASCII Keyboard Numeric Keypad Sound Output Built-in Clock and Music.Available Soon -Discs, Printers and other Accessories

0,177:11pet 0.f..00

c,OTOS*6502 based system best value for money on the

market * Powerful 8K Basic Fastest around * FullOwerty Keyboard * 1K RAM Expandable to 8K on board.* Power supply and RF Modulator on board * No Extrasneeded Plug-in and go * Kansas City Tape Interface on

board. * Free Sampler Tape including powerfulDissassembler and Monitor with each Kit. * If you want tolearn about Micros, but didn't know which machineto buy then this is the machine for you.

CoMi5UkifIjiaii

KIT ONLY £99.95 VAT PLUS VISOPost Er

Fully Assembled £149 VAT } Parkinii

WE ARE NOW STOCKING THEAPPLE II AT REDUCED PRICES

AUTOSTARTEURO PLUS

48K£649

VAT

\,04040.

Getting Started APPLE II is faster, smaller, and morepowerful than its predecessors. And it's more fun to use toobecause of built-in features like: BASIC The Language that Makes Programming Fun High -Resolution Graphics lin a 54,000 -Point Array) forFinely -Detailed Displays. Sound Capability that BringsPrograms to Life. Hand Controls for Games and OtherHuman -Input Applications. Internal Memory Capacity of48K Bytes of RAM, 12K Bytes of ROM; for Big System Performance in a Small Package. Eight Accessory ExpansionSlots to let the System Grow With Your Needs.

You don't need to be an expert to enjoy APPLE IL It is acomplete, ready -to -run computer. Just connect it to a videodisplay and start using programs lor writing your own) thefirst day. You'll find that its tutorial manuals help you make ityour own personal problem solver

INTRODUCINGTHE NEW GENIEIdeal for small businesses, schools, colleges, homes, etcSuitable for the experienced, inexperienced, hobbyist.teacher, etc

,ubm 11111111 lllllllll 1011.1111 lllll

NOW INCLUDED: Sound, Upper and lower case, ExtendedBASIC and Machine Code enabling the Writing andExecution of Machine Codes Programming direct fromKeyboard.16K RAM. 12K Microsoft BASICExtensive Software Range.Self -Contained PSU UHF Modulator Cassette. ExternalCassette Interface. Simply plugs into TV or Monitor.Complete and Ready to Go. Display is 6 lines by 32 or 64Characters Switchable. 3 Mannuals included, Users Guide,Beginners Programming and BASIC Reference Mannual.BASIC Program Tape Supplied. Pixel Graphics.

M11111111111111IIIIIIIIMITIIMIT

£299 VATThe NEW GENIE II an ideal Business Machine. 13KMicrosoft BASIC in ROM. 71 Keyboard. Numeric Keypad,Upper Et Lower Case. Standard Flashing Cursor. CassetteInterface 16K RAM Expanded externally to 48K.

GENIE I Et I I EXPANSION UNITWITH 32K RAM £199

PARALLEL PRINTER INTERFACE CARDE35.00 A

- .. TEACDISK

11111111111111 DRIVES

I.:,

TEAC FD -50A has 40 tracks giving 125K Bytesunformatted single density capacity.mThoedeE13-50A can be used in double density recording

The FD -50A is Shugart SA400 interface compatible.Directly compatible with Tandy TRS80 expansioninterface.Also interfaces with Video Genie. SWTP, TRS80,North Star Horizon, Superbrain, Nascom, etc, etc.Address selection for Daisy chaining up to 4 Disks.Disks plus power supply housed in an attractive greycase.

40 TRACKSingleDisk Drive £225 -VAT vDouble VATDisk Drive a-40077 TRACKSingle £299 VATDisk Drive

Double cAnga VATDisk Drive .--*v

dM INk

ME 10111=1

MEMO liM1111111101"Europes Largest DiscountPersonal Computer Stores"

Delivery is added at cost. Please make cheques and postal orders payable to COMPSHOP LTD., or phone your orderquoting BARCLAYCARD, ACCESS, DINERS CLUB or AMERICAN EXPRESS number.

CREDIT FACILITIES ARRANGED - send S.A.E. for application form.MAIL ORDER AND SHOP:14 Station Road, New Barnet, Hertfordshire, EN5 1QW (Close to New Barnet BR Station - Moorgate Line).Telephone: 01-441 2922 (Sales) 01-449 6596 Telex: 298755 TELCOM GOPEN (BARNET) - 10am - 7pm - Monday to SaturdayNEW WEST END SHOWROOM:311 Edgware Road, London W2. Telephone: 01-262 0387OPEN (LONDON) - 10am - epm - Monday to Saturday* IRELAND: 19 Herbert Street, Dublin 2. Telephone Dublin 604165

TELEPHONE SALESOPEN 24 hrs. 7 days a week

01-449 6596wrtuuito

NSA4ip

28

Circle No. 120PRACTICAL COMPUTING May 1982

Cho 'Am makesApples moretemptingApple, the most popular micro -computer,

a now has a Software accessory whichI' enables the system to be

programmed by beginners!

the Softwarethat writes programsC.O.R.P. II is the most advanced and comprehensivecollection of program generators which writes Applesoftprograms. It enables a beginner to program quickly,simply, and error free by himself in everyday languagewith no programming knowledge. It's the first usable,

educational package!Handbooks and demodisk tutorial are

supplied with every system.C.O.R.P. II £249.

0s-ear- C.O.R.P. I: Database /PrintGenerator only: £149.Demodisk & Free BasicLanguage Tutorial £29.

Details of C.O.R.P. 'Turnkey' systems andTraining Courses from:

MICROSYSTEMSLIMITEDSUMMERF I ELD HOUSE, VALE, GUERNSEY, CHANNEL ISLANDS.Telephone: 0481 47377, Telex: 4191130 (DYN MIC GIC ORP de ...Wed trademark <0 Me MORON., & SCOTTO SOFTWARE CORP'APPLE reMetered trademark of APPLE COMPUTER INC

PRACTICAL COMPUTING May 1982

Circle No. 12129

The Seikosha GP100AManufactured by the Seiko Company, Japan.

The micropriced microprinter80 col dot graphics for around f215vAT

SeiKosha introduce the GP100A.A wider and updated version of thehighly successful GP80. Now able totake standard width paper, theamazingly compact GP100A offersbig printer performance at a fractionof the cost.

With a high quality output thatincludes full graphics capability, theSeikosha's proven reliability andvariety of interfaces make theGP100A the ideal choice forhobbyists, educationalists andbusinessmen. Full service support isprovided by DRG Business Machines'nationwide distributor network.

DRGBUSINESSMACHINES

FEATURES INCLUDE:

80 col. 30 cps.

Dot Matrix unihammer action.

ASCII standard.116 characters.

Full graphics.

Upper and lower case.

Double width printing.

Up to 10" paper width.

Original + 2 copies.

Tractor feed.

Self testing.

DEALERENQUIRIESWELCOME

INTERFACING for most systems:

Standard: Centronics.

Options: RS232C, Serial TTL,20mA current loop. IEEE -488.Apple II,Sharp (GP100D).

DIMENSIONS:

Depth - 91/4" (234mm)

Width -171/4" (420mm)

Height - 51/4" (136mm)

OPTIONS:

Pinch feed.Bath: Microstyle, (0225) 319705. Birmingham: Microcomputers at Laskeys, (021) 6326303.Bradford: Eltec Services Ltd., (0274) 491371. Bristol: Microcmputers at Laskeys, (0272) 20421.Cheltenham: Computershack, (0242) 584343. Chester:Microcomputers at Laskeys, (0244) 317667.Edinburgh: Microcomputers at Laskeys (031) 4452914. Exeter: A C Systems, (0392) 71184.Frodsham (nr Warrington): Northern Computers, (0928) 35110. Glasgow: Microcomputers atLaskeys, (041) 2263349. Leicester: Kram Electronics, (0533) 27556. Liverpool: Microcomputers atLaskeys, (051) 236 2828. London: Technomatic Ltd., London NW10, (01) 452 1500. London:Chromasonic Electronic (N19), (01) 263 9493. Manchester: Microcomputers at Laskeys, (061) 8326087. Newcastle upon Tyne: Newcastle Computer Services, (0632) 761168. Norwich: AngliaComputing, (0603) 29652. Preston: Microcomputers at Laskeys, (0772) 59264. Reading: PersonalComputer Palace, (0734) 589249. Sheffield: Microcomputers at Laskeys, (0742) 750 971. Watford:Watford Electronics, (0923) 40588. Circle No. 122DRG (UK) Ltd, Reg No. 22419 England. (Peripherals & Supplies Division)13/14 Lynx Crescent Winterstoke Road, Weston -super -Mare, BS24 9DN. Tel: (0934) 416392.

Superior %stems Ltd.Sheffield

APPLE II 48K

DISK DRIVE

WITH CONTROLLER £370.00

DISK DRIVE

WITHOUT CONTROLLER £290.00

BMC 12" GREEN MONITOR

12" GREEN MONITOR £145.00

178 West Street, Si 4ET. Tel. (0742) 755005.

£670.00

PC 1211 POCKET COMPUTER.69.50

MZ 80K (48K) COMPUTER. PHONE FOR

MZ 80B (64K) COMPUTER. PRICECHEAPEST

DUAL DISK DRIVE 550.00

P3 PRINTER 360.00

P4 PRINTER 745.00

P6 PRINTER 420.00

SPEED BASIC 10.00

MACHINE CODE 17.40 b

EDITOR/ASSEMBLER 35.00 b

PASCAL INTERPRETER 40.00 h

MZ 80K DUST COVER 5.00 a

APOLLO WORD PROCESSOR 24.95 b

CALC II 34.50 b

DATA BASE 29.50 b

ZEN EDITOR ASSEMBLER 19.50 a

MACHINE LANGUAGE 17.74 b

MZ 80K DUST COVER 5 00 a

POSIEDON 5 00 a

ADDRESS BOOK 5 00 a

MOONLANDER 5 00 a

COMBAT 5 00 a1

L

Mail OrderAccessoriesPostage Rates

a.75p b.1.00 c.1.50 d. 2.50 e.5.00BOOKS(SEND SAE FOR FULL LIST)

BASIC HANDBOOK 13.95 c

SOFTWARE SECRETS(MZ80K) 7.95 b

APPLE II USER GUIDE 11.10 c

BASIC BASIC 8 95 b

PROGRAMMING Z80 11.95 c

PROGRAMMING 6502 10.75 c

PROGRAMMING VIDEO GENIE 5.00 b

ZX 81 COMPANION 7 95 b

ZX 81 POCKET BOOK 5 95 b

GETTING AQUAINTED ZX81 4.95 b

GETTING AQUAINTED ACORN 7.95 b

HINTS & TIPS ZX81 4 25 b

CP/M HANDBOOK 11.50 c

6502 GAMES

MICROSOFT BASIC

ATOM BUSINESS

10.25 c

8 75 b

6 95 a

APPLE PASCAL GAMES 11.45 b

WORD STAR MADE EASY 7 60 b

APPLEVISICALC

VISIPLOT

VISITREND/VISIPLOT

97.50 b

95.00 b

135.00 b

VISIDEX 105.00 b

CIS COBOL 475.00 b

MICROMODELLER 420.00 b

APM 119.00 b

APPLEWRITER 39.00 b

MAGIC WINDOW 79.00 b

VIDEO GENIESOUND MOD 7 50 a

COLOUR MOD 39.46 b

SYNTHESISER 45.00 b

DUST COVER 5 00 a

ALL PRICES EXCLUDE VAT

VIC 20 COMPUTER 173.90 e

VIC CASSETTE DECK 39.09 d

VIC PRINTER 200.00

3K RAM CARTRIDGE 26.04 b

8K RAM CARTRIDGE 39.09

16K RAM CARTRIDGE 65.17 b

JOYSTICK 6 52 b

PADDLES 11.74 b

INTRODUCTION TO BASIC

PART I 13.00 b

VIC GAMES ROM CARTRIDGES

VARIOUS FROM 17.35 b

VIDEO GENIEMKI with sound &

lower case 309.00

MKII

BUSINESS COMPUTER 309.00

EXPANSION UNIT

WITH 16K ROM 199.00

ACORN ATOMACORN ATOM 8+5

with colour+PSU 199.00 d

ACORN DISK PACK 299.00 d

FLOATING POINT ROM 20.00 a

GAMES PACKS 1-10 10.00each

WORD PACK ROM 26.00 a

COLOUR ENCODER 39.00 b

B.B.C. ROM PACK PHONE b

MAGIC BOOK 5 50 c

MATHS PACK 10.00 a

ATOM CHESS 10.00 a

ATOM ADVENTURES 10.00 a

MAIL ORDER FORM

PLEASE SUPPLY

ACCESS/BARCLAYCARD/CHEQUEBARCLAYCARD

11111.1 CARD No

£

P&P+V.A.T. £

TOTAL ENCL.£

NAME

ADDRESS

POST CODE TEL

Circle No. 123

PRACTICAL COMPUTING May 1982 31

THE PRINTER YOUWANT HERE

PERTEC P80* Heavy duty matrix printer at asensible price. * 80cps.* 80/120 character lines.* Optional character sets, withtrue descenders. * Centronicsand RS232 serial interfaces.£439 + VAT

RICOH RP 1600* Advanced daisywheel printerfor word processing, mini andmicro applications. *60cps.* Intelli9ent option includesQume/Diablo compatiblecommands and autobidirectional operation.£1395 + VAT

4114

TRIUMPH-ADLER STYLIST* Low cost daisywheel printerfor most popular micros andminis. * 14.5cps. * Proportionalspacing. * Bidirectional / logicseeking. * Range of type stylesand languages.£695 + VAT

Trade and OEM discountsavailable.

Write or call for further information.Butel-Comco Limited

Garrick Industrial Centre,Garrick Road, London NW9 6AQ.

Telephone: 01-202 2277 Technology for businessCircle No. 124

CU -GRAPH ACORN COMPATIBLEGRAPHICS CARD

Send to:

8 colours in 512 x 256 pixels Uses EF9366 graphics processor chip. Each plane of colour (red, green, blue) displays 16kB of

memory, giving 512 x 256 resolution; each pixel can be red,blue, green, white, yellow, cyan, magenta or black.

Only 256 bytes of the host computer memory are used, all48k bytes of screen memory being on the memory map ofthe EF9366 only.

Text display can be superimposed on graphics, and can beup to 85 columns by 32 rows, using an on board charactergenerator. Each character can be scaled for height, width,slope and orientation, all independently.

Driver software for use on Acorn and Cubit systems isavailable now, and a high resolution graphics extension toAcorn BASIC will follow later.

£180 Single Eurocard monochrome 16k bytes RAM£360 Eurocard with Piggyback Extension; 48k bytes RAM 8colours centronics printer interface.

CONTROL UNIVERSAL LTDUnit 2, Andersons Ct, Newnham Rd, Cambridge, Tel 0223 358757.For free catalogue on Cubit, Acorn and Rockwell computers and Associated Peripherals

Circle No. 125

32 PRACTICAL COMPUTING May 1982

PET PRINTER GRAPHICSPLUS

by COMPUTACE LTD. North Star Horizon

1 I 1 1 I I 1 IN 1 1 I 1 1 1 I I rig 111 11111

fr

1'

1

Axis

I

4 II

1,

kII

k II 11

II

lit I

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1.11-ier-e A=1 -132/5eIrrP.=2 +A'T'Ci=63+A

1 +FI

I IIII iii.A I tii

COMPUTACE LTD., INFABCOGROUP, International Base,Greenwell Rd., East Tullos,ABERDEEN AB1 4AX

`TEL: (0224) 876622.

For fastest reply use:-COMPUTACE LTD.,PO BOX 50DNEW MALDEN, SURREY KT3 3BD

IThis graph is a typicalexample printed byAUTOGRAPH on aSTANDARD COMMODORE3022 or 4022 PRINTER.(Please specify when ordering)No disk drive or plotter requiredSimple to use. Hard copy.Fully flexible graphdimensions and position onpage. Automatic scaleoption. Variable backgroundformats. Plots any X,Yfunction. Multiple graphson same axes. FullAlphanumeric labelling forprofessional qualitypresentation:

AUTOGRAPH is supplied withextensive documentation.Send for Brochure.

AUTOGRAPH 1 (16K, 32K only)Plots any function as illus.or in spaced dots. £39.50 incl.

AUTOGRAPH 2 (16K, 32K only)

As Autograph 1 butincludes data point plotoption with joining linesand marking circles. Autographs1 and 2 combined pack. £49.50 incl.

CURVE FIT 1 (32 If only)

Powerful Linear and Non -Linear Regression of anyfunction to a least squaresdata fit. Complete with plotof regressed curve & data.

£55.50 incl.CURVE FIT 0As Curve Fit 1 plus CubicSpline Fit, Integrals andGradients throughout.

£65.50 incl.

Send for Brochure and details ofcombined packs at reduced prices.Including: Epson Printers and OxfordComputer Systems Compiler.

Circle No. 126

PRACTICAL COMPUTING May 1982 33

SATURN SYSTEMS128K and 32K doards and VC- ExpandThe 32K BOARDComes with utilities to allow the movementof DOS and the use of Integer togetherwith the ability to store subroutines on theboard to be called from a main program.The final utility allows the board ormultiple of boards to be used as a fast diskdrive£149.00

128K BOARDCan be used as above with the additionalfacility to use the card as a fast diskdrive in C/PM and PASCAL in addition toBASIC£359.00

VC EXPANDIs a utility that can be used with either theabove two boards to give additionalmemory for VISICALC models, up to 146Kwith the 128 board-and more withadditional boards£55.00

COMING SOONA version of VC EXPAND to allow use ofVISICALC with the VIDEX 80 column board(VIDEX 80 column board-£185.00)(VISICALC-£105.00)MICROSOFT PRODUCTSMICROSOFT have written most of theBASICS for the World's Micros. AsMICROSOFT'S biggest UK distributor wecarry a wide range of MICROSOFTproducts for APPLETASC the Applesoft computerTrue machine code programs for yourAPPLESOFT BASIC£109.00

Z-80 SOFTCARDTHE C/PM System for APPLE. Over 35,000sold to Apple users world-wide, makingAPPLE the most popular C/PM system£189.00

A.L.D.S.-Assembly LanguageDevelopmentSystem can handle 6502, Z-80 or 8080£79.00

FORTRAN 80 £109.00COBOL 80 £359.00THE ENHANCER IIThe dawn of a new era for the APPLE IIIntroducing the ENHANCER II-a newstandard which is improving therelationship between Humans and Apples.The Enhancer II can help your Apple II'skeyboard become more sociable byremembering words or phrases which canbe entered into the Apple by the meretouch of a key. Life can become even easierbecause the Enhancer II can rememberwhat you typed while your Apple was busytalking to your disk (or doing other things).Naturally, it knows the difference betweenupper and lower case letters and what shiftkeys are supposed to do. It even knows toauto repeat any key held down. TheEnhancer II replaces the encoder boardmaking installation simple.£99.00

The APPLE Computer SpecialistsEverything for the Apple Computers

including the AppleCOMING SOON-The 8088 Board lot Apple-run C/PM and MSDOS

Over 600 items forAPPLEFrom business to scientific,from education to pleasure. It'shere NOW, make sure you getYOUR Copy-write or telexeither of our offices now. Ifyou're interested in Applecomputers, you can't afford tobe without it.

THEPRICELIST

D BASE II-from Ashton TateFor Apple II with Z-80 softcardA true relational database able to work onmultiple files-gives you the power to useyour Apple for jobs that were previouslyreserved for main frames.£395.00

MICROSOFT Z-80 SOFTCARD £189.00WORD PROCESSINGThe Wordstar Family (requires Z-80)

WORDSTAR £145.00MAILMERGE £69.00SUPERSOFT £85.00DATASTAR £140.00SPELLSTAR £89.00WORDSTAR Training Manual £19.00

MACHINE COVERS-only the bestmaterial usedApple only £5.95Single Disk £2.952 stacked disks £4.45Apple, 2 disks and 9" monitor or Appleand 12" monitor £8.95Apple and 2 disk £7.95Epson MX 70/80 £5.45Paper Tiger 445-460 £5.45

computar

GAMESApple Galaxian-Galaxy Wars-HeadOn-Galactic Revolution-Galactic Trader-Galactic Empire-Mystery House-Bridge Partner-Checker King-GammonGambler-Roulette-Craps-Apple 21-Puckman-Global War-Space Warrior-Apple Typhoon-Sneekers-GalacticAttack-Olympic Decathlon-Cribbage-Star Dance-Asteroid Field-Anti BalisticMissileAll at £12.95

Microsoft Adventure-ABM-Dog Fight-Phantoms Five-Orbitron-Pulsar-Microchess 2-Odyessy-LA LandMonopoly-Morloc's Tower-Rescue atRigel-Space Eggs-Trilogy of Games-The Prisoner-Raster Blaster-Autobahn-Space Raiders-Tawala's Last Redoubt-Gamma Goblins-Apple Panic-Red Alert-Firebird-Genetic Drift-MadVenture-Space Quarks-CastleWolfenstein-Appleoids-Pegasus II-Softporn Adventure-Cross-Fire-Jaw-Breaker-Zork II-Crush-Crumble andChomp-Dragon's Eye-Dark Forest-Star Thief-Bug Attack-Outpost-Borg-Sneakers-Hi Res SoccerAll at £15.95

Cyborg-00-Topos-David's MidnightMagic-Akalabeth-Pool 1.5-Beer Run-Epoch-Hadron-Russki-Duck-Ulysses-Wizzard and the PrincessAll at £17.95

Computer Conflict-ComputerQuarterback-Cartels and Cutthroats-Space Album-Bill Budbge 3D GraphicsTutor-Cyber Strike -3 Mile Island-Adventure 789-Temples of Apshar-Hellfire Warrior-Zork-ComputerBaseball-President Elect-The Battle ofShiloh-Tigers in the Snow-Warp Factor-Computer Conflict-Gorgon-FlightSimulator-Ultima-Trick Shot-RobotWar-The Best of Muse-Cops andRobbers-Southern CommandAll at £20.95

Computer Air Combat-ComputerAmbush-Computer Bismark-OperationApocalypse-Torpedo Fire-Dragon Fire-Napoleons CampaignsAll at £29.95

Buy any 3 games-deduct 10%

Authorised Apple Sales andService

LONDON RETAIL98 Moyser Road, London SW16 6SHTelephone 01-677 2052/7341

MAIL ORDER AND DISTRIBUTIONWaingate Lodge, Waingate Close,Rossendale, Lanc. BB4 7SQTelephone (0706) 227011

Prices do not include VAT please add15% to your remmittancePostage and packing FREE

Telex No. 635740Orders welcome by phone or telexPETPAM G

M12=11VISA

34

I Circle No. 127

PRACTICAL COMPUTING May 1982

"Research Machines .S;ulnter acedf

,zteege.;eaielce

'ISAR/ ICA NTERRIACES1^'General 1

Data co mmun cat ton between compuhas been around s tnce the ear 1y days ofthe large range of low speed per sphere Isalmost unsoersal aCcePted ser sal dataThe tem most commonly used ser a I data cere the RS232 -1,24 standard and the 20 nettypes the RS232 V24 Is the most commonThere are s se r sal inter, aces ava I lab Ifor the Research Machines 380Z, these bethe S10-1. the S10-2, the SIO-3,S10-4 and the S10-5/6

7.a0-

TRED V 4 2 DCirrieht lc, 1980 by Research MaCh IMO

Swath Scrolling Smooth Scrolling Socotti Scrolling3885 3885

SEGO scrolling Smith scrolling .. Swath scrolling

Swath Scrolling . Sirooth Scrolling Smooth Scrolling3812 3812

Snciitti scrolling Smooth strolling Smith scrolling

IC JUROR Set

61

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77

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eses r. re, rs sbe ....I comet M IBA2 MI Sart 0 Mquells mem met I ikkitel or.td," M stems, orals rutsresrpratel

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sroles use a Ober triar Wad 0 'some, a sett..M hat al ede Yard /so spoons are Relate For ur we, nt 01. vIrvis ion sot thr eil.71Pulater bore .1 nue,

SOFor m enorst salite wart a, AA W.' steed Sr sue, servertee e. trier board PI.. [Olt. Sus Ohre tonet140119 stemmas II est raw a <mete area users Pr eatdsm V gm A. as ureters., Mani as Este we Mrmood mole or plugs ta tam M aeon ewes Ns me /de.

Rotation corrItre, te ,[ - 13015

Angle of rotas son -20 Degrees

Providing exactly the right facilities for differentapplications can be a real problem when a system is asversatile as the 380Z.

Take, for example, screen line length. Not only dodifferent users have different needs; so too do individual users.

They might welcome forty character clarity forpresentation, display, and control applications; but they alsowant eighty character capacity, because word processing,some programming languages, and many general-purposeapplications demand it.

So we've developed Varitext - to provide both, on thesame machine.

Varitext means that the 380Z user can always choosethe line length best suited to the application. It gives accessto a growing range of 80 character software without losingall those well -established and popular 40 characterapplications. It makes the 380Z equally effective as acomputer and a word processor. It lets programmers use thecharacter mode with which they arefamiliar -or which languages like ALGOL,FORTRAN, and PASCAL really need.

Research mach uses

And it improves the quality of our already exceptional graphics,by offering a smaller character size for neater annotation.

But the Varitext option goes a great deal further thanthat. We also saw it as the opportunity for a majorenhancement of the 380Z's screen handling capabilities.So we added:fl an 8 x 10 dot matrix, to further refine the character set;Li an additional set of 128 user -definable characters; reverse video, underlining, and selective character dimming;[I smooth scrolling and faster screen filling;[1 user defined windowing (and independent scrolling)

of screen areas;E audible tone generation (option)

And all that, we believe, makes the 380Z's screenhandling the best on the market.

The Varitext option is available with new systemsor as a user -installable enhancementto existing 380Z systems. Contactour Sales Office for details.

RESEARCH MACHINESMICROCOMPUTER SYSTEMS

RESEARCH MACHINES LTD Mill Street, Oxford OX2 OBW, Tel: (0865)49866

PRACTICAL COMPUTING May 1982

Circle No. 12835

I

ATLANTICCOMPUTER STORE

. RENT . . LEASE ...BUY...RE,. BUY . . . RENT . . . LEASE 7)SUPERBRAIN from £1750 Lease from £12 per week

WORD PROCESSING offer £2795 4.,N0Lease around £17 per week iii044.5 PO*Letter quality word processing cs4.includes 1 Days TrainingTAILORED BUSINESS SYSTEM from £30 per weekFully integrated accounts - Full training

plus maintenance 1 yearStock/Invoices/Sales Ledger/Purchase/Nominal/Payroll

1111111MilI

iTriliiTTERsd TELEVIDEO With full accounts

Softwarej Wide range of

application packagesavailable

CPM Compatible

Multi -User Multi -Tasking From £5130A MUST FORMULTI USERSwill run your

existing cp/m software.

la\ 2 3 9 5 } -2111111.111.v \"11111Buy a typewriter which you can (LOW COST £4 85use with your computer. DAISY WHEEL "i*Silver Reed/Olivetti RS232 -Centronics - IEEE interfaces now PRINTERavailable. SPECIAL OFFER

Olympia K S R£995.00 £485

+VAT

F

Smith -Corona TP-I

Serial/Parallel/Optional IEEE ExtraSimple Reliable Mechanism

/ATLANTIC SERVICE FACILITIESThe company provides full servicing cover throughout the entire country on a 24hour call -out basis. Additionally. the company has its own hardwareengineering team based at the main office in London.

ATLANTIC CONSULTANCYThe Company also retains the services of highly experienced computerconsultants who are readily available to design a system to meet your specialbusiness requirements.ATLANTIC TRAINING SERVICESAtlantic Micro Systems provide a modern. 3,000 sq. ft. professional trainingcentre capable of training up to 250 people a week using the latest teachingaids. DEALER ENQUIRIES WELCOMEyi

THIS MONTHSSPECIAL OFFER

PRINTERSOKI MICROLINE 80

£269RICOH 60 C.P.S.

£1295Free delivery for cash with ordeLl

COMMODORECommodore 8032CBM £755.00

£595.00Commodore 4032 PET n

Commodore Printer i®-4022£395.00 , swap aCommodore 8050

E795.00Bags of Software Special Offer

1APPLE II48K Apples E650.00

with ControllerDouble Disk Drives

[ i l I;

Card £550.00 -t"- rilt.i IMonitors from £99.00 '4N-i'280 Soft Card £195.00,/ -;::! /Serial/Parallel /7041;9/1",Cards £65.00Visicalc 3 3 £100.00

Full Range of software - too D.M.S. E200.00numerous to mention!

\,../ ss...,yisicalc £100.00

ATLAN IATLANTIC MICRO SYSTEMS

70-72 Honor Oak Park, London SE23 1DY.Telex: 896691 1RG ATLANTICOvernight deliveries. Telephone orderswelcome on all credit cards. All pricesme exclusive of VAT and delivery.ATLANTIC prices subject to dollarfluctuation.

ask for Trade Desk.

Tel: 01-699 2202

36

Circle No. 129PRACTICAL COMPUTING May 1982

AT OTHER MICRO FINANCIAL PLANNIPACKAGES LEAVE OUT.

At Comshare,while we're develop-ing our software, we're also developingour biceps.

(As we're No.1 suppliers of finan-cial packages in Europe, it's importantto have both.)

Fastplan is our powerful new menu driven micro based financial plan-ning system, at a cost effective £395.

However, add 24 offices through-out Europe, custom-built trainingschemes, a free enhancement service,as well as our Helpline and you'll

appreciate that brains aren't everything.Muscle counts as well.

James Lascelles, Comshare Ltd.32-34 Great Peter Street, London SW1.I want to know more now. Please send me yourFastplan Factsheet.Name.Company.Address:

PC 5/5/82

FASFPLANFROM CONISEVARE

Making the computer make sense.

PRACTICAL COMPUTING May 1982 Circle No. 130

37

TRADE AND EXPORTDefinitely the very best deal for

0.E511., DISTRIBUTORS 13110 OEfiLERSthroughout Europe

THE SIE1GLE SOURCE FOR iTlICROEOMPUTERPERIPHERRLS, SUPPLIES 13110 SOFTLUfiREEPSON - ANADEX - TEXAS INSTRUMENTS - QUME - DIABLO - NEC -

RICOH - OKI - CENTRONICS - TEC - OLYMPIA - ADLER - APPLE -COMMODORE - HITACHI - SHUGART - CONTROL DATA - BASF -

FACIT- FUJITSU- PRI NTRONIX - DATA PRODUCTS -OLIVETTI - ETC. ETC.

Obtain substantial savings by combining your purchases withhundreds of other trade buyers throughout Europe

No commitment to purchase minimum quantityParts and labour warranty

Fast deliveryTelephone or write for details of

INFORMEX CONSORTIUM PURCHASE SCHEMEINFORMEX-LONDON LTD8-12 Lee High Road, London SE13 5L0Tel: 01-318 4213 (10 lines) Telex: 892622

AGENTS REQUIRED WORLDWIDE Circle No. 131

MAXIMUM VALUE . . . MINIMAL COSTThe popular Houston Instrument HI -PLOT range of digital plotters: Well designed and ruggedly constructed Easy to interface via RS232C, IEEE or Centronics compatible

parallel interfaces Easy to use - software listings are available free of charge Wide choice of models Highly reliable Good quality 0.1mm step size Single or

multi pen

SINTROM GROUP

Sintrom ElectronicsComplete mini/microsystem capability

psa

DMP-2 The standard A4 sized£770 HI -PLOT

DMP-3 A4 sized but intelligent£985 with remote controls

DMP-4 Intelligent like the DMP-3£1055 with the same features but

with pushbutton controlsDMP-5 The A3 sized standard£1215 HI -PLOT with the same

features as the originalDMP-2, but with vacuumpaper holdA3 sized but intelligentwith remote controls

DMP-6£1430DMP-7£1570

Like the DMP-6 but withpushbutton controls

Add £340 for multipen operation

Sintrom Electronics LtdArkwright Road, Reading,Berks RG2 OLSTel: Reading (0734) 85464Telex: 847395

38

Circle No. 132PRACTICAL COMPUTING May 1982

WestrexLitton

The

Special Epson distributor

with

Special Epson prices

MX -80 FIT Type_TE

Dealerdiscountsavailable

Westrex Company Limited

Bilton Fairway Estate Long Drive Greenford Middlesex

Telephone: 01 5780950 Et 578 09571819

Circle No. 133

ONE STOP SHOP

Yes- one Calldoes it All!We're your One Stop Shop forApple, Superbrain and otherleading personal computers.We can offer the Tabs accountingand stock control packages,Wordstar for word processingand Visicalc for financialmodelling. We provide on -sitemaintenance and tailoredprogramming services secondto none. We pride ourselves ongiving first class customer supportand training.

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COMPUTER SALES AND SERVICESmake sure you get it right

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Circle No. 134PRACTICAL COMPUTING May 1982 39

THESE SHARP COMPUTERSCP/M, the world's most widely MZ8OB

used operating system is available as an option to run on theSharp MZ-80B, making it, arguably, the best scientific microon the market. With high resolution graphics as standard andhard disks, MP/M and CP/NET available, the MZ-80B is nowa superbly flexible machine, equally at home in commercialand technical environments.

I f a I a t-

PJ ;-,-J pn, p-1 )!J',1 )ji F±J.P-4)g-IP4.1.-u241PPPri

ftlt-,1t1-.tPArttnp.

PC3201CP/M is also available as an option on the SharpPC 3201. It is available in two forms. The first is a relocated CP/M giving you46.5K of user memory, all you need do is insert a disk and off you go. Thisversion will only run the products marked # in our price list. The secondprovides you with a second Z80A processor on a card which plugs in to theI/O interface card chassis and runs standard CP/M,64K memory, with accessto the whole library of products in our price list. This together with thePC 3201's large screen and keyboard makes the PC 3201 a superb businessmachine.

CP/M for both these machines is available from your local Sharp dealer:or in case of difficulty, please call us on (0892) 32116.

RUN ALLTHISCP/M BASED SOFTWARE

WORDSTAR # Powerful word-processingpackage, made easy to use by full functionkey support on the MZ -80B. £242MAILMERGE Add on to WORDSTAR,provides mail -shot and text inclusion. £73SPELLSTAR Add on to WORDSTAR, forspelling checking. £121DATASTAR Screen oriented form definitionand data entry tool. £171SUPERSORT I Powerful disk basedsort package. Stand alone program andMICROSOFT' compatible CALLINGSEQUENCE RELOCATABLEROUTINES. £122SUPERSORT II As SUPERSORT I, but onlythe stand alone program. £97WORDMASTER Superb screen based texteditor, all functions driven off MZ-8013function keys. £73CALCSTAR The new financial planningpackage from the MICROPRO stable. £144EASYFILER Flexible data definition, dataentry, data update and reportgenerator. £150GENISYS General insurance system foroffice admin and accounting of generalinsurance brokef. £1000EMIS Estate agent managementinformation system. Designed by estateagents for estate agents. £795COMAL-80 The revolutionary structuredprogramming languages, easy to use asBASIC. Recommended for education andteaching environment. £130BASIC -80 # Accepted standardMicroprocessor based BASICinterpreter. £209BASIC COMPILER # BASIC -80 compatiblecompiler, makes BASIC programs runmany times faster. £236FORTRAN -80 # ANSI standard FORTRAN,except for COMPLEX numbers. £298

40

COBOL -80 # 1974 ANSI standard COBOL.withlarge program chaining and screen:FUza:

M/SORT Powerful sorting facility for useprimarily with COBOL -80. £75Mu -MATH & MuSIMP Symbolic mathpackage, allows computation on to 611arithmetic digits. Superb for scientific andengineering applications. £149Mu -LISP & Mu -STAR Extended LISP 1.5.Includes screen based LISP environmenteditor. £119EDIT -80 & FILCOM Line oriented randomaccess text editor. Includes source andbinary file compare program. £71MACRO -80 # Assembler with Z80"mnemonics. Includes linking loader, librarymanager and cross referencer. £119CIS COBOL ANSI 74 standard COBOL tofull level 1 standard. £425FORMS -2 For use with CIS COBOL.provides superb screen handling capabilityfor CIS COBOL programs. £100PROSPERO PRO PASCAL Fastest Z80"PASCAL we know. £190PL/1 -80 ANSI standardsubset G basedPL/1 producing direct object code for fastexecution. £298BT -80 Record retrieval system or use withPL/1 -80, to give data base managementfacilities. £119MAC Upward compatible assembler fromASM, provides MACROs and Z80*assembly support. £53ZSID Super symbolic debugger, with fullZ80" mnemonic support. Works well withMACRO -80. £59TEX Text for matter ideal for producingmanuals and similar documents. Note thisIS not screen based. £59DESPOOL Allows listing of files al sametime as other processing. £29

CBASIC # Commercial BASIC, usedextensively for business packages. £65CB80 Full compiler for CBASIC. £298MINI MODEL # Very powerful professionalfinancial modelling package. £399MAGSAM # Indexed sequential accessroutines, for use with CBASIC. £110

BASKAM # Basic keyed access routines foruse with BASIC -80. £95DATAFLOW # Easy use data file entry tool.For reports, labels or MICROPRO"MAILMERGE compatible files. £99PADMEDE/MICRO TECHNOLOGY A fullrange of business software converted by usfrom the highly reliable PADMEDE originalsto run under CP/M.SALES LEDGER SYSTEM Fully integrated,secure, parameterisable with full reportfacilities. £249PURCHASE LEDGER SYSTEM All thesame flexibility as the sales ledgersystem. E249

SALES INVOICING SYSTEM Automaticproduct description access, audit trail,instantly updatable product file (even whilecreating an invoice). Integrates with salesledger system if required. £249NOMINAL LEDGER SYSTEM Integrates allthe sales and purchase side of yourbusiness. Trial balances can be producedfor incomplete records accounting. £249

STOCK CONTROL SYSTEM Full stockcontrol system with minimum stock leVelsand re -order levels. Integration to salesinvoicing system provided. £249MICRO TECHNOLOGY MICROTEXTEasy to learn and easy to use textprocessor with far more friendly userinterface than WORDSTAR. If you wish touse it, then far more power is available toyou, including calculator, column and rowtotalling and macro -text functions. £270MICROMERGE Integrate and merge facilityfor use with MICROTEXT. Use for mailshotsand simple database retrieval andreporting. £70EXPAND Library routines for use withMICROSOFT' calling sequence products.Gives MZ-80B graphics, cassette andmusic handling. £65Free with any MICROSOFT productpurchased at the same time from us.# All these products now available for thePC3201.

Please state for which. machine/version ofCP/M the product is intended.COMAL-80 The structured BASIC likelanguage that has been given so manyfavourable reviews in the computer press isnow available. £130

Dealer enquiries welcomed.

Kro TechnologyLIMITED

Royal Sussex Assembly Rooms, The Pantiles, Tunbridge Wells, KentTelephone: 108921 45344. Telex: 95441 MicroG.

16.10IF

Circle No. 135PRACTICAL COMPUTING May 1982

Editorial

Hit any key to continue?THE STORY GOES like this; there was a man selling micros and a

man who might buy one. The small-business customer thatevery micro dealer dreams about walked in and made veryhopeful noises, expressive of a desire to revolutionise hisbusiness by buying many small computers.

The man who might sell one was delighted. He produced hismost expensive program, with advanced, interactive, user-friendly features and proposed to blow the potential buyer'shead off with the wonderfulness of it all.

He sat there patiently while they wiggled plugs in the wall tosee why the disc drive would not boot, and he made not asign of annoyance, when young Donald, from the back roompointed out that someone had "borrowed" the computer'sfuse for the kettle.

Eventually the machine was persuaded to boot and load thewonder package. It first printed up a self-satisfied account ofitself and then : "Hit any key to continue?"

The customer was shown to the controls. He nodded, read themessage, pulled his chair up to the table and read it again.He leaned back, crossed his legs and looked at it once more.He looked at the back of the machine - no enlightenmentthere. A finger hovered over the keys, but then died and layon the desk. He rubbed his eyes, polished his glasses, shookhis head. He ran his finger along the line of text:

HITANYKEYTOCONTINUE?The more he looked, the less sense it made. Was it an order? -

No, it had a question mark. Was it a question? If so, whatwas the answer: Yes or No? Why was it asking him anyway?They said computing was not as easy as it seemed. Perhapsthe machine's problem was the word "any". Surely, the keywith "A" written on it produced a different effect to the keywith ")", yet the question seemed to imply either that theymight be the same, or that someone ill-informed might thinkso. Was the problem simply "hit"? Perhaps the computerhad suffered some bad experiences and like a stray cat wasrevealing its history by cringeing as it was approached.

Or was the problem "continue"? "Do you honestly think thatjust by delivering random blows you can make me carryon?" It had written some tendentious nonsense on its TVscreen. Did you have to believe what computers said? Werethey capable of lying? Without the "?" it would make sense.It had written something and was waiting for you to read itbefore it "continued" - whatever that might be. Butcomputers are infallible, so "?" must be there for a reason.Was it some sort of intelligence test? Is this the point wherethose who could hack the micro -revolution went on to fameand fortune and those who could not were relegated to thescrap -heap of history?

Computers are expensive and delicate. Surely you might wreckthe gear if you just pressed any old key. Perhaps that washow these people made their livings: they sat innocentvictims down in front of the machine, baffled them withunintelligible messages and then sent them a bill for thedamage. No - that was a bit extreme. But how was one tointerpret the voice of this text? Was it like a message writtenon a scrap of paper by someone sitting on the other side ofthis table? Or was it to be treated like an inscription onstone, intended for rhetorical effect only; or even likewriting in the clouds - a freak of nature interesting onlybecause it looks so much like writing?

The potential customer stood up, picked up his briefcase andwalked out without a word. Young Donald leaned over andhit any key. The machine wrote: "Disc Error".

We all know what happened. The programmer could not bebothered to write a proper input routine and just made dowith Input and a prompt string. Input helpfully puts up a"?", but we are all so used to it that we do not notice.

We are at a tricky stage, when the people who have to embracethe new era are completely baffled by computers. They cometo the machines with completely unrealistic expectations.They have no solid mental models of what a computer canand cannot do. They feel anxious and insecure about using amachine they do not understand.

Unfortunately, although this uncertainty is widespread, we arenow expecting people to gut their businesses and hurl theentrails into silicon. The problem cannot be concealed undera thin dressing of computer literacy in the population atlarge.

It goes much deeper than "Hit any key to continue?" Ifprograms work in a consistent, understandable way, it is easyto explain how to use them - for an example of how not todo it, read "The Unix Road to Power" in our March issue. Aprogrammed computer is an immensely complicatedmachine; and there are very few guidelines about how itshould work. After a century of trial and error, the manualsof most cars do not now explain how to drive them - theyare about the cigarette lighter and how to empty theashtrays.

The limitation on most general-purpose software is now notwhat can be done by the hardware, but what can beexplained so that the user can remember it without goingmad. The Americans often provide huge menus allowing forevery contingency. Their magazines assess rival products bycounting the number of "features" each offers and theweight of the manuals. In fact the best package is the onewith the fewest ineradicable bugs and the shortest manual.The perfect manual simply says: "Switch on". It can be thatconcise because the program is so lucid that it needs noexplanation.

There is no simple recipe for manual -less software but wecould build on those few conventions that already have afoothold. For instance CP/M users will be accustomed to theconvention that "*" will stand for an unknown word in afile -name, "?" will replace an unknown letter, so that "File?.*" will match to "File 1. BAS", "File Z. PRN" etc.Secondly, operators should have logical validity within theoperation of the program. You might be doing something onthe screen and use tB to jump back to the top, left-handcorner. If the cursor is already in the top, left-hand corner,'13 should jump back into the stage before the screenappeared - which might be a menu, and TB again should goto the menu before that.

There are plenty of chores that the computer could do. Forinstance if, at a certain stage, the user is only allowed to typein numbers the machine might just as well refuse to acceptanything that is not a number. Another convention might bethat from time to time the user has a default entry to use orreplace. The cursor might be positioned on the first charac-ter; hitting Return leaves the default in place and moves onto the next operation; hitting any other permitted key clearsthe field and starts a new entry.

Any conventions must be consistent within the program. Usersmust not find themselves in positions where the programappears to work differently and you also have to competewith conventions established by other software products.But once you have these conventions working you can cutdown the manual size - and the amount the user has toremember - simply by explaining briefly what is happeningand then moving on. If your software is well designed, a lotof interactions between different processes can be ignoredsince they will be understood, or at least accepted at theirface value, when the user comes to them.

Electronic engineering is no problem. Mental engineering is awhole, new untried field. Anyone got any ideas?

PRACTICAL COMPUTING May 1982 41

TRS 80GENIE SOFTWAREfrom the professionals

MEMDISKADDITIONAL DISK TYPE STORAGE FOR UNDER £25!!

One of the most fantastic utilities to hit the market in many a day! MEMDISK literallycreates a disk drive type storage in RAM. It uses many of the extensive sophisticated features ofLDOS in order to achieve this miraculous effect! When the "drive" has been created it may, ingeneral, be used as any other drive. Commands such as COPY, BACKUP, FREE, DIR, SAVE,LOAD and DUMP may all be utilised.

Memdisk is an absolute boon for the single drive user. Files may be copied from his singledrive to the drive in memory, disks changed and then copied back. To coin a phrase - theapplications are only limited by the imagination of the user whether you have one drive ormore - after all, you always need another!

There are, of course, some limitations. Chiefly, that the maximum size of storage is 27Kusable. The other side of the coin is that this space is user selectable from 1.5K to 27K. Tracksmay be set up in 1.5K or 3K blocks.

Memdisk may be used with Double Density drives without any problem, although thememory drive itself, of course, cannot be double density. To assure reliability, Memdisk teststhe RAM area which it is going to use before it installs itself.

Best of all, a Memdisk drive is faster than any floppy drive available and it is even fasterthan many hard disk drives. Memdisk involves no additional hardware of any sort. There isnothing to align, nothing to clean and nothing to break. It's all software.

Memdisk is available for all Genie machines and the Tandy Model 1 and Model 3. Itrequires a minimum of one drive 48K RAM and LDOS.

Memdisk E inclusive

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TEL: [0424] 220391/223636 TELEX 86736 SOTEX G

TRS-80 & VIDEO GENIE SOFTWARE CATALOGUE £1 .00 [refundable] plus £1 postage.

BANCINITAIII1

BipkwidAacan

42

Circle No. 136PRACTICAL COMPUTING May 1982

Feedback

Our Feedback columns offer readers the opportunity of bringing their computingexperience and problems to the attention of others, as well as to seek our advice orto make suggestions, which we are always happy to receive. Make sure you useFeedback-it is your chance to keep in touch.

Sorcerer graphicsFEBRUARY'S Z80 Zodiac contained ashort article of mine about Sorcerergraphics. Unfortunately, four lines wereincorrect.

In listing 1 line 1030 should read1030: AD= 1024 + (Y/8 - INT (Y/8)) *8 + 8* (CH - 1)

Line 1040 should read1040 : POKE AD. (2 ** (7 - 8*(X/8 - INT(X/8))) + PEEK(AD))

In listing 2, line 10010 should read10010 POKE 260,0: POKE 261,48: REM IFROUTINE STARTS AT 3000 H

In listing 3, line 40 should read40 : DX = X2 -X1 : DY =Y2 - Y1 : IF ABS(DX) <ABS(DY) THEN 80

Hans Middelbeek,Goirle,

Netherlands.

PetproA GREMLIN seems to have crept into myPetpro listing, Practical ComputingDecember 1981. In line 119, ORI = Cshould be deleted.

Ian Birnbaum,Needingworth,

Cambridgeshire.

Networked PetsTHE SIXTH FORM A -level group of ourschool is currently working on a networksystem for Pet 4032 micros. At presentwe have successfully programmed inBasic and implemented a system to allowkeyboard conversation between two Petsusing a connector constructed by our-selves for use with the parallel user port.

Anyone wanting further informationsuch as how to construct the connector,and a documentation of our two-wayPet -Talker should write to us. Also, itwould be appreciated if anyone who hasproduced a similar system would write tous with their ideas.

J Cantrill, N Dutton, S Hancock,N Hudson, A Lakin, N West,

The Pingle School,Burton -on -Trent,

Staffordshire.

Slide projectionTHE BCD-DECIMAI decoder described inPhilip Barker's February article onslide -projector control is the SN74145not 7145. It has open -collector outputs,capable of sinking 80mA, and dual -in -line relays are available such asRS -349-383 which require only 10mAcoil current. These may be driven directly

from the SN74145, without the 7404inverters and 2N3053 transistors shownin figure 4 of the article. Further, RSComponents does not stock a relay withthe code number given in the article, butthe pin -out diagram corresponds to thatof the RS -349-383.

A W Joines,Cambridge.

Arfon speech boardTHE REVIEW of the Arfon Microelec-tronics speech -synthesis board stated thata further £140 was needed to interface itto Pet, Tandy and RS -232. This is not so;a complete operational boxed system forthe Tandy, Video Genie and RS -232costs £138, for the Pet and Vic -20, £114,and the basic board for Nasbus 3/80 busand Apple costs £98. These prices are forcomplete operational systems.

P M English.Arfon Microelectronics,

Caernarfon.Gwynedd.

In praise of PrestelTHE FATE of Prestel in this country mustlie in the volume of sales during the nextcouple of years. Those of us who wish tosee Prestel as a success, and not leastBritish Telecom, must find a way toattract new subscribers. I have heardfrom many micro owners their envy at thegreat systems in the United States such asSource and MicroNet.

Such jealousy is misplaced - Prestel isjust as effective a system. If you have atelephone, it will cost £15 for installationof the necessary Prestel jack socket. Thequarterly rental is 50p. If your telephoneline is not a business one, then you haveno other rental cost for Prestel.

Duncan In Comal.

PRINT "Drunken Duncan"across:=40;down:=12;stop:=0REPEAT

CURSOR across, downPRINTdir:=RND(1,4)CASE dir OFWHEN 1

down:=down- 1WHEN 2

across:=across+1WHEN 3

down: =down +1WHEN 4

across: =across -1ENDCASE

step:=step+ 1UNTIL across <20 OR across>60 OR down <1 OR down> 23PRINT "Duncan took"; step: "steps"

When you go on-line on the U.S. sys-tems the cost for one hour during thecheap rate is about £2.50 plus the cost ofthe telephone call. The same time onPrestel at the cheap rate costs £1.20including the telephone call charge andVAT. The only other cost that you mayhave is the page charge. Some of theinformation providers charge a small sumfor the information they supply, but mostPrestel pages are free.

Another thing Prestel has is telesoft-ware. This is an expanding field and wemicrocomputer owners can make themost of it. Look at your computer andthink how Prestel will keep you in theforefront of viewdata.

John A Douglas.Dumbarton.

Duncan in ComalRAYMOND FOX'S challenge to produce afully working Drunken Duncan programis a strange way to conduct a seriouseducational debate, but here is the pro-gram which was a source of my originalarticle. There is no "rigmarole of sub-routines". The program runs on an SPC/1microcomputer and has been used fortwo years as a simple example of how amultiple decision may be handled.

Simple examples are used in articles toilluminate the essential ideas withoutbothering the reader with unimportantdetails, but if Mr Fox wants to see howmedium and substantial jobs are tackled,there are 114 examples in my book Struc-tured Programming with Comal.

Some versions of Comal use a three -line procedure for cursor control but theSPC/1 incorporates it in the system soft-ware. One can build up graphics packagesusing procedures, or these facilities canbe built into the system software. But thisis just the history of ideas moving fromapplications programs to systems soft-ware and finally into hardware. That ishow computers get better.

It is quite wrong to say that Comal isfull of complexities. Basic usually has aFor loop, a local If -Then -Else and aprimitive type of procedure, Gosub. Itachieves multiple decisions with On con-structions. Comal has the same For loopand tidies up the other three with a globalIf -Then -Else, named procedures and theCase statement. Additionally Repeat -Until, While-Endwhile cater for exit froma loop on a condition rather than a count.Why should Basic have For but notRepeat?

Advocates of Comal do understand the(continued on page 45)

PRACTICAL COMPUTING May 1982 43

THE PROFESSIONALS CHOICE

Act Sirius 116 Bit Stand Alone micro withsuperb features.128K,1.2MB Floppies.CPM86 as standard - £2395.

AltosUp to 4 terminals and 40MBof Winchester Disc.One of the biggest selling

MEIsmall business systemsstarting at £2350.16 Bit system with 8 terminals available soon.

OKI 1F800Quality graphics micro withfull colour screen and integralprinter. 64K and Basicare standard -L4750.Wide range ofperipherals available.

LSI M3High specificationStand Alone micro. CPM, 64Kand up to 10MB of Winchesterin one package. Very easy touse. Detachable keyboard.User programmablefunction keys. From £2250.

SuperbrainStill a leader in 8 bit priceperformance. KGB havingsold over 400 Superbrainshas unbeatable experienceon them. From £1875.

Word Processing - Wordstar £250, Mailmerge £75.Full on -screen facilities enabling the printing ofstandard letters and preparation of mail shots.

Accounting - From £300 per module.Integrated accounting systems with Invoicing,Sales. Purchase and Nominal Ledgers.

Financial Modelling - Micromodeller £645.Budgets, forecasts and accounting data becomeeasy to prepare. Allows "what if" projections.

Calculation - Supercalc L175.Electronic worksheet for preparation of budgetsand tables of data.

Record Keeping - DMS £400.Personnel, stock or any other recordswith quick retrieval, sorting and reporting.

Sales Office Management - Sales Desk £300.For the busy sales office to managesales leads and marketing lists.

Accounts - IRIS £750.Incomplete records and time recording systems.

Payroll - Graffcom £500.Up to 500 employees both weekly and monthly paid.Automatic deduction for items like company pensions

Graphics - Price depends on application.Full on -screen graphics both colour andblack and white.

Engineering - SPERT £450.Suite of programmes for PERT analysis andcivil engineering applications.

Communications - Liberator £250.Enables a micro -computer to act like a mainframeterminal and transfer data from Floppy disc toanother computer.

O

Languages - From £175.Most major computer languages are available: Basic.Cobol, Fortran. Pascal and Assembler.

Solicitors - Solace £1600.Solicitors accounting, client accounting andtime recording.

Multi -terminals - MP/M and Oasis from £350.Multi-user systems available.

KGBMICROS LIMITED

14 Windsor Road,Slough SL1 2EJ Tel:Slough (0753)38581/38319 Telex: 847111

Circle No. 13744 PRACTICAL COMPUTING May 1982

Drunken Duncan in Forth.

SCR 8 47O ( DRUNKEN DUNCAN DEMO *) 56 LOAD ( RNDM NUMBER GEN )

1 0 VARIABLE XLEN 0 VARIABLE YLEN 0 VARIABLE STAGGERS

2 : LT 0 DO 4 EMIT LOOP ; : RT 0 DO 9 EMIT LOOP ;

3 UP 1 EMIT DOWN 2 EMIT ; LEFT 4 LT ; : RIGHT 4 RT ;

4 : HOMEUP 16 EMIT : CLEAR HOMEUP 22 EMIT ;

5 : WHICH 3 CHOOSE - DUP SLEEP 2000 0 DO LOOP ;

6 : STAGGER WHICH XLEN +! DUP -1 - IF UP DROP ELSE

7 IF DOWN THEN THENWHICH YLEN +! DUP -1 IF LEFT DROP ELSE

9 IF RIGHT THEN THEN I STAGGERS +I ;

10 OFFGRID XLEN @ 0< XLEN @ 16 > OR

11 YLEN @ 0< YLEN @ 16 > OR OR ; ( leaves boolean)

12 INIT CLEAR 8 XLEN ! 8 YLEN ! 0 STAGGERS !

13 8 0 DO CR LOOP 32 SPACES ; ( CLEAR SCREEN CURSOR MIDDLE ) <

14 DUNCAN INIT BEGIN SLEEP STAGGER OFFGRID UNTIL CLEAR15 ." OFF GRID IN " STAGGERS ? ." STAGGERS" ; ;5 FD 29 1 82 <

SCR 8 56O ( RANDOM NUMBER GENERATOR1 0 VARIABLE RND HERE RND !

2 : RANDOM RND @ 31421 * 6927 + DUP RND !

3 CHOOSE ( ul u2 ) RANDOM U* SWAP DROP ;

4 ( ie 3 CHOOSE returns a number between 0 and 25

6

7

8

9

10

Drunken Duncan in Pascal.

*)

*)<

;S FD 31/01/82<

PROGRAM DUNCAN ;

CONST(* CURSOR CONTROL CHARACTERS *)

LEFT - CER(4); RIGHT - CHR(9); UP CHR(1); DOWN - CHR(2);

HOMEUP CHR(16); CLEAR - CHR(22);TIME - 200 ; (. DELAY CONSTANT .)

VAR

J,I,XLEN,YLEN,STAGGERS,COUNT INTEGER;ANSWER : CHAR ;

SEED REAL ;

FUNCTION AND INTEGERCONST

MOLT - 149;DENOM 10007 ;

VARTIMES REAL ;

BEGINSEED..SEED*MULT.IF SEED > DENOM THENBEGINTIMES:- TRUNC(SEED / DEEM) ;

SEED:. SEED - TIMES * DENOMEND;RED:.(TRUNC(SEED) MOD 3)

END; 7* RETURNS NUMBER FROM 0 TO 2 *)

PROCEDURE SLEEP ;

BEGINCOUNT: -0;FOR 1..1 TO TIME DO COUNT..COUNT + I

END;

PROCEDURE STAGGER ;

BEGIN

CASE I OFO WRITE(UP);1 : BEGIN END;2 WRITE(DOWN)

END; (* ENDS CASE *)XLEN:.XLEN+I-1;1:-RND;CASE I OF

O BEGIN FOR J:.1 TO 4 DO WRITE(LEFT) END;1 BEGIN END;2 BEGIN FOR J.. 1 TO 4 DO WRITE(RIGHT) END

END; (* ENDS CASE *)YLEN:.YLEN+I-1;

STAGGERS,STAGGERS+1END;

FUNCTION OFFGRID BOOLEAN ;

BEGINOFFGRID:.((XLEN<O) OR (XLEN>I6)) OR ((YLEN<O) OR (YLEN>16))

END;

BEGIN (* MAIN PROGRAM BEGINS HERE *)

SEED: -4999;

REPEATWRITE(HOMEUP,CLEAR); XLEN:-8; YLEN:-8; STAGGERS: -0;FOR I. -I TO 8 DO WRITE(DOWN);

FOR I:. I TO 32 DO WRITE(RIGHT);REPEATSLEEP;

STAGGERUNTIL OFFGRID ;

WRITE(HOMEUP,CLEAR);WRITELN('OFF GRID IN ',STAGGERS,' STAGGERS..);WRITELN;WRITELN('ANOTHER ONE? .):READ(ANSWER)

UNTIL ANSWER<.'Y'END.

(* CURSOR NOW AT CENTRE SCREEN *)

(continued from page 43)virtues of Basic. That is why we say keepthe best of Basic but add the good struc-tures, to get Comal - structured Basic. Itis mainly the Goto statement we deni-grate as the cause of much unnecessaryconfusion. It must be said that a sensiblecomputing system should also have gooddirect -access files as some Basics and allComal implementations have.

In Denmark, the only country whereteachers are given equal access to bothapproaches, 95 percent now preferComal. They are not a "sophisticatedelite". They work across the age -rangeseven to 19 and across the curriculum.Non -specialist teacher control of thisremarkable new learning resource is areality in Denmark in a way that we inU.K. are only struggling to achieve.

Roy Atherton,Reading.

Berkshire.

Futile dispute ?I ENJOYED Raymond Fox's " Who needsComal?" in the February issue of Practi-cal Computing, but it seems to me thatthe entire argument is irrelevant. Ifneither side can agree that a particularfeature of either language is a virtue thenit is likely that the two languages are notserving the same purpose anyway.

Perhaps an analogy exists betweencomputer languages and human ones.The French government's considerable

efforts to keep the French language"pure" have failed. Esperanto has not yetmade much impact on the world despiteits logical basis. Good old English goesrambling on, inventing new words andchanging the meanings of old ones withwhat one could once have described asgay abandon.Human language evolves to meet the

needs of the people who use it rather thanthe theories of academics, and peoplewith different needs and requirementsuse different languages or different sub-sets of the same language. Surely com-puter languages will follow the samepattern, with the ones which are mostwidely available and which offer the userthe greatest flexibility surviving regard-less of expert opinion of their worth.

Ian Soutar.Tunbridge Wells,

Kent.

Fast ForthJUDGING BY THE " Who needs Comal?"article, Raymond Fox needs Coma!, orany other language for that matter, tohelp open his mind. Languages are notrivals, they are communication tools.Why assume that a programmer uses onlyone language? Why does Mr Fox refer toother language users as "the elite"? Is itthat he knows no other language himself?

I have several Basics. I also havePascal, Common Pilot, Lisp, Forth, andtwo assemblers. I use the language best

suited to the problem in hand. That oftentends to be Forth, so I enclose a Forthlisting of Drunken Duncan. Duncanstarts in the middle of the screen and triesto get off it, the original Athertonillustration.

It took me 15 minutes to write and itran so fast that I had to slow it down withthe word Sleep to be able to see it. Itallows a diagonal step as well as thevertical and horizontal. It is scaled so thatthe whole screen is used, but with anequal probability of Duncan making hisexit from any of the four edges. As I use aCT -82 terminal, Duncan is written forcursor control rather than memory -mapped display.' My Forth has norandom -number generator so I had towrite one, and the whole thing compilesinto 543 bytes.

The program runs by typing the wordDuncan. If you add the following:0 VARIABLE SEED: 4POSTERITY RND AT SEED ! ;

: REDO SEED AT RND ;You can type 4 Posterity Duncan to see aperformance, and rerun that same per-formance by typing Redo Duncan. Forth,is a structured, compiling, interpretivelanguage all in one.

I have also included a Pascal alterna-tive, which again has to be slowed downwith a Sleep procedure. The p -code takesup 876 bytes. including Rnd and Sleep.

Frank Dale.Shepperton,

Middlesex.

PRACTICAL COMPUTING May 1982 45

BDC-600 operates inthe Unix traditionTHE BLEASDALE BDC-600 isthe first British computer spec-ifically designed for Unix -styleoperating systems. Thismachine should transformBleasdale Computer Systemsfrom a leading British com-pany into a force in the inter-national systems market.

The BDC-600 is a big microcapable of performing any tasktraditionally associated withminicomputers. It has exten-sive software and hardwaredevelopment facilities, multi-user capabilities, and can runwith a wide range of eight- or16 -bit processors. Industry -standard Multibus modulesare used but a wide range ofindustrial interface modules isavailable.

This top -line microcompu-ter is expensive but excellentvalue. Although the machinewill be mainly sold underOEM labels, Bleasdale willalso have a network of dealers.Its Leicestershire factoryshould be busy with produc-tion of 500 systems targetedfor the end of the year.

The BDC-600 uses Micro-soft's Xenix implementation ofthe Unix operating system.Unix is fast becoming thestandard on 16 -bit micros, for

Eddie Bleasdale with theBDC-600.

its flexibility and elegance aswell as its high portability.Eddie Bleasdale, managingdirector of Bleasdale Compu-ter Systems is firmly commit-ted to Unix -based systems andhopes that his firm willbecome a leading centre ofUnix know-how.

Peter Hollands who hasbeen appointed the Xenixco-ordinator at Bleasdale,explains that each Xenix sys-tem will come with a host ofsoftware including the C lan-guage and of course Basic. Thetext -processing software isfully comprehensive and acompiler writing system andspelling -checking program areincluded. Graphics andinformation -handling software

If your Vic -20 needs 35K memory, 40 -column display anda colour writer, B&B Computers' black box could be thesolution. For £220 plus VAT this expansion unit includes a32K RAM board and an additional power supply to copewith the new electronics. It comes with all connectingcables and a replacement expansion socket and isguaranteed for 12 months. The Beeline Vic Expansion unitis available from selected dealers and by mail order fromBeelines, Freepost, Bolton, Lancashire, BL3 6YZ.

are also available. Xenix's onlyproblems so far have con-cerned licensing agreements.

The Z-8000 version of thecomputer is complete with256K of user memory, eightinput/output ports, 500Kfloppy -disc system and a10Mbyte Winchester harddisc. The whole packagetogether with the softwarecosts less than £10,000.

The Z-8000 implementa-tion will shortly be followed bya 68000 version. A Z-80board with CP/M, and a 6809board with flex are available asis an 8086 with CP/M-86. Fordetails contact BleasdaleComputer Systems, FrancisHouse, Francis Street, LondonSW1P IDE. Telephone01-828 6661.

Making lightof airfreightAIRMAN SIX is an airfreightmanagement system for theApple II computer. It wasoriginally developed for theneeds of an established airoperator. The program canhandle most airfreight tasksincluding the printing ofwaybills, daybooks, back -referencing files, consolida-tions, and a number of otherfunctions.

Airman Six can be tailoredto the requirements of the userand comes complete with allthe hard- and software neces-sary and enough user supportto start operating the systemproperly. The package hasbeen developed by Type -Air,which is about to launch asimilar sea shipping and quota-tions system. Type -Air is atFarnburn Avenue, Slough.Berkshire. Telephone Slough39418.

How to give Pet achange of characterALPHA PLUS is a charactergenerator for Commodore Petmicrocomputers which insertseasily into the presentcharacter -generator ROMsocket. A length of wire con-nects the main unit to the sec-ond cassette port on the com-puter's main board, and aswitch which fits on the side ofthe Pet and the necessarysoftware are also supplied.

The standard version ofAlpha Plus contains fourcharacter sets. The first twomirror the standard Commo-dore character sets, with aBritish pound sign replacingthe dollar. This facility alonejustifies the Alpha Plus, espe-cially for British businessmen.The Alpha Plus is not solely areaction against the all-powerful dollar, since the thirdand fourth character sets cancontain virtually any charac-ters.

Character sets exist forGerman, Russian, Hebrewand Kana - the Japanesealphabet. In addition there aregraphic founts for various usesincluding games, electronics,APL, and finance. Screenfounts can be provided tomatch printer founts. This is a

facility that is especially usefulwhen a Commodore Pet isused in conjunction with adaisywheel printer which mayhave interchangeable founts.

The standard Alpha Plushas the Greek characters sobeloved of scientists andmathematicians in the thirdcharacter set, and a graphicsset in the fourth slot. Thesoftware supplied allows vari-ous character founts to bemixed on one screen, andincludes a demonstration ofthe many possibilities of thepackage - there is even afacility for user -designedcharacters. All versions of thePet are catered for, anddocumentation is supplied foreach style of computer.

Software running on astandard Pet without AlphaPlus will still run on a con-verted machine, and softwarewritten with Alpha Plus willrun on an unconverted Pet,though without the specialcharacters. Alpha Plus isavailable from Avon Compu-ter Rentals, 8 Eastbury Close,Thornbury, Bristol BS12 1DF.Telephone (0454) 415460.Enquiries about customisedfounts are also welcomed.

46 PRACTICAL COMPUTING May 1982

Printout

Accountants'competitionACCOUNTANTS should blotthose balance sheets and hurrydown to their nearestCommodore/CSM dealer toenter a competition for whichthe prizes are £6,000 worth ofcomputer goodies. Commo-dore (U.K.) and Birmingham -based Computer Services Mid-lands are running a competi-tion with a prize package of aCommodore 8032 microcom-puter, 8050 twin floppy -discunit, daisywheel printer, CSMAuditman accounts produc-tion, and time records costingprograms.

The competition closes onApril 28. 1982 and prizes wil

The CBM-8000 system.

be presented during May1982. Further informationfrom Peter Mart, ComputerServices Midlands, RefugeAssurance House, Sutton NewRoad, Erdington, Birming-ham, B23 6QX. Telephone021-382 4171.

Triumph -Adler hasdeveloped software toenable users of thisMicrowriter to transfer textto the Alphatronicmicrocomputer. TheMicrowriter is a hand-heldword-processing devicefeaturing electronichandwriting. Now text canbe generated on site -even on a crowdedcommuter train - and thentransferred to theAlphatronic at a later datesimply by plugging theMicrowriter into thecomputer's communicationport. The transfer softwareis available on disc, as is anew version of the Lexicomword processor, updatedfor the Microwriter input.For further informationon the Microwriter interfacecontact Triumph -AdlerU.K., 27 Goswell Road,London EC1. Telephone01-250 1717.

Education atall levelsEDUCATIONAL MICRO USERSboth sides of the border will beinterested in the latest issue ofthe Scottish EducationalReview. Subtitled "Microelec-tronics in Education", it isedited by Jim Howe of Edin-burgh University's ArtificialIntelligence department, andincludes articles coveringapplications of the micro ineducation from primary levelto university. In addition to anumber of general featuresthere is a piece outliningcomputer -assisted learning inthe Physics laboratory.

Microelectronics in Educa-tion costs £4, or £2 if you are amember of the Scottish Educa-tional Research Association.You can order it from theScottish Academic Press, 33Montgomery Street. Edin-burgh.

Dutch transmit softwareto serve more microsRADIO NETHERLANDS is tobroadcast another series ofsoftware suitable for a widerange of micros. This time itwill be using its own communi-cations protocol, the Hobby -scope code, which it hopes willbecome an Esperanto forcommunication betweenmicrocomputers as well asimproving the capture rate ofprograms broadcast on bothAM and FM radio.

The software will be broad-cast to Europe on April 22 at0950 and 1350 GMT on11,930, 9,895, 6,045 and5,955kHz and at 2050 GMTon 21,685, 17,695, 17,605,15,220 and 9,715kHz. Detailsof other times andwavelengths for NorthAmerica, the Pacific andAfrica can be obtained fromRadio Netherlands.

Programs are transmitted onthe normal wavelengths fromHilversum in Holland andrelayed via transmitters inMadagascar and the Nether-lands Antilles to give world-wide coverage. Experience ofthe first two broadcasts sug-gests that good results can beexpected from a simple, direct,receiver -to -cassette connec-

tion if you are within range ofthe Hilversum station. Pro-gram capture tends to be lessreliable if the signal has beenrelayed, because of differentialreflection effects. Signalsbounced off the ionosphereexperience varying reflectivityfor different frequencies,resulting in out -of -phase datacapture. Most micros will hangup and refuse to read anymore program data if this hap-pens.

Radio Netherlands and thelisteners to its Media Networkcomputer hobbyist pro-gramme have developed atransmission protocol whichalleviates this problem. Theyalso claim other advantagesfor the protocol in regularmicro -to -micro communica-tion, including, where permit-ted, the ability to send pro-grams on the phone withoutthe need for a Modem.

The Hobbyscope code isfirst loaded into the computerand then used to compile thereceived program into usableform for the host micro. Thismakes it possible to use suc-cessfully a program cassettefor one micro on another. Sofar the Hobbyscope code is

available for the Apple, DAI,Sorcerer, Nascom, OSI Chal-lenger, Philips 2000, Commo-dore Pet, TRS-80 Model ILevels 2 and 3, South-WestTechnical Products, SharpMZ-80K, Texas TI -99 andCommodore Vic -20. TheZX-81 has insufficientmemory.

Hobbyscope should alsocompact data for micros suchas the TRS-80 with a transferrate of less than 1,200 baudresulting in more storage perdisc or cassette, and continu-ous program capture off -air orfrom a telephone line, even ifsome incorrect characters arecaptured because of atmos-pheric or line noise. At presentthe transfer rate of 1,200 baudis too fast to ensure reliabletransfer from transmitter toreceiver so the latest testtransmissions will be at theslower speed of 300 baud.

A booklet containing list-ings of the Hobbyscope Basiccode and a cassette with boththe translation program andsample Basic programs, isavailable at the cost price ofU.S.$8, from Jonathan Marks,PO Box 222, 1200 JG Hilver-sum, Netherlands.

PRACTICAL COMPUTING May 1982 47

WHETHER YOU'RE A DEALER OR OEMZenith can offer a product capability that includes: Microcomputers, CP/M based with storage to 10 Megabytes Systems that start from f1795*Word processing, including letter quality printer from £2985*

(or lease from only f14 per week) A comprehensive range of Printers, VDU's, systems and

applications software 12"green screen Monitor- in Apple colours. (Dealer/OEM's only)

Equally important Zenith is a company that: Is supported by the multi million dollar Zenith Radio Corporation

of America Is committed to holding comprehensive UK stock Offers Country -wide service support Offers Dealersupport including National Advertising Campaign Offers Realistic Discount Structures

"Prices correct at time of going to press.

NEW DEALER ENQUIRIES WELCOME'Li I could be interested in a Dealership O I would like to receive details of your OEM terms

Name Position

Company Address

Telephone

PC/5/82

iwnw datasystems

The quality goes in before the name goes on.Or call Dave Taylor or Jim Detheridge at: -Zenith Data Systems Bristol Road, Gloucester. GL2 6EE. Telephone 0452 29451.

48

Circle No. 138PRACTICAL COMPUTING May 1982

Printout

Word processing forthe first -timerTHE 3007 SYSTEM word proces-sor is styled like an electronictypewriter to provide first -timers with a low-cost wordprocessor, according to itsmakers the Dictaphone Com-pany.

It is available as a stand-alone unit with its own mem-ory and processor, or as part ofa shared -resource system. The3007 has a keyboard - withQWERTY, numeric pad andfunction keys - thin window

display and 40cps metaldaisywheel printer all in onedesk -top unit. Under the deskan electronic control packageand single floppy -disc drivegives the machine 140 pages oftext storage.

The 3007 has full editing,records processing and mathsfunctions, automatic under-line, centre and bold face. Textcan be printed in 10 or 12pitch with proportional spac-ing, and one task can be inputwhile another is printed. Aspart of the Dual display systemthe 3007 can use a shared sys-tem rather than its own mem-ory. The printer can be usedby other operators while workis being keyed in. The 3007stand-alone unit costs £4,700and the shared -resource sys-tem costs a further £3,000,both available from Dic-taphone, Regent SquareHouse, The Parade, Leaming-ton Spa, Warwickshire CV324NL. Telephone LeamingtonSpa (0926) 38311.

This is the CTM 300 Colour Terminal, which offers superiorcolour clarity and resolution to a 0.3mm. dot pitch. Theterminal is serially RS -232 interfaced and is intelligent, witha standard display of 80 characters by 25 lines. It can alsobe programmed with other formats. The keyboard containsthe usual QWERTY set together with function keys and anumeric keypad. Inside the keyboard unit lies the terminal'sintelligence, a Z -80A processor. Standard features includea light -pen interface, a printer interface, American/European standards for power and video, a 256 -characterfount, and interface speeds of up to 19.2Kbaud. The termi-nal also has an automatic self -test routine and a CRT saverfeature which extends the life of the display. The Terminalcosts £1,107 and is available from Perdix Display SystemsLtd, 98 Crofton Park Road, London SE4. 01-690 1914. Ui

ZX users taste realworld with RD rangeSINCLAIR OWNERS wanting toexperience the delights ofcomputing in the real worldwill welcome the RD -8100series. The range includes twomotherboards and five inter-face modules. At £40 for abasic system unit with aMicro -Mum, anyone with aSinclair micro can begin toyingwith the interface between themachine and the real world.

The five interfaces are theRD -8110 logic input/outputinterface, the RD -8130analogue input interface, theRD -8140 analogue multi-plexor/amplifier, RD -8150analogue output port, and theRD -8180 light -pen module.These units all connect to theZX-81 via the motherboard.Super -Mum is a fully -bufferedmotherboard/console accom-modating up to eight modules,and costs £40. The Micro -Mum only takes two modulesbut costs just £15.

The RD -8100 modules canbe operated directly from theZX-81's Basic, mainly by useof Peek and Poke commands.This can be accelerated ifmachine code is used. Themotherboard is memory map-ped to the ZX-81 RAM, eachmodule having an address. Amanual gives connection

details. Prices for the modulesare: RD -8110 £27.50,RD -8130 £29.50, RD -8140£34.49, RD -8150 £29.50,RD -8180 £34.49. The mod-ules are available from RDLaboratories, 5 KennedyRoad, Dane End, Ware, Hert-fordshire. Telephone Ware(0920) 84380.

Holding datafor 100 yearsA BRISTOL FIRM hasannounced a new rival forpaper. The SGS M-120 is anonvolatile RAM device thatcan retain data without apower supply for 100 years.The device has a 256 by four -bit configuration, and uses aspecial n -channel, silicon -gate,double-polysilicon, MOStechnology. This allows thecontents of the memory to bewritten, erased, and rewrittenelectrically with maximumreliability and data retention.The M -120's internal structuremakes access times shortenough for it to be used with-out Wait statements.

The access times of thethree versions of the deviceare 450ns., 700ns. and 900ns.The 900ns. version is speciallysuited to single -chip micro-computers. All versions areTI'L compatible and come instandard 18 -pin DIL pack-ages. For further details con-tact BA Electronics, MillrookRoad, Yate, Bristol BS175NX. (0454) 315824.

PRACTICAL COMPUTING May 1982 49

Printout

HP 32 -bit system mayovertake its rivalsHEWLETT-PACKARD'S 32 -bitsystem could leap -frog 16 -bitmicrocomputers. Strictlyspeaking the 32 -bit computerwould come within the miniend of the computer market,but its price might well placesuch a machine in direct com-petition with the larger microsystems.

A custom-built 32 -bit VLSIchip will be used in conjunc-tion with five similar customchips. Hewlett-Packard iscagey about what productsmight incorporate 32 -bit tech-nology, but expects the first ofa new range of such productsto appear later this year.

The chip set comprisesmemory controller, RAM,ROM, I/O processor, clockgenerator, and a 32 -bit pro-cessor chip less than 0.25in.

Floppy disc,stiff mailerALTHOUGH AT FIRST SIGHT theMailsafe floppy mailers mightmake you reach for theorigami manual they are inpractice remarkably simple touse. The 5.25in. and 8in. discmailers are each capable ofprotecting up to four discs.

For more details about theMailsafe contact Basic Busi-ness Supplies, 50 EdinburghDrive, Ickenham, Uxbridge.Telephone Ruislip (0895)676012.

Star of filetransferFILESTAR IS a software pack-age for transferring text filesfrom one type of computer toanother. Used with the widerange of compilers, assemb-lers, cross assemblers, texteditors and so on that areavailable for CP/M systems, itis a very powerful software -development system. Alterna-tively it can enable CP/M sys-tems to offload software fromsome of the larger computers.

The package itself is writtenin Pascal and is available fromMicroSec, 49b Market Parade,Havant, Hampshire P09 1PY.Telephone Portsmouth (0705)450055.

square which contains 450,000transistors. Dana Seccombe,manager of the research labattributes the necessity of thedesign to simple physics. Theless distance a signal has totravel the quicker it reaches itsdestination, which leads tohigher processing speeds.Increased density also meansfewer chips, which cost signifi-cantly less and improve relia-bility.

The system has beendesigned from the ground up.There are no off -the -shelfchips involved; every one hasbeen designed to complementthe others. In turn theyrequired a fast data bus. It hasa transfer rate of 36Mbyte persecond. Hewlett-Packard hasalso had to develop a specialcopper -core technology toprovide dissipative cooling forthe svqem ra

Ferranti Computer Systems has developed a processingsystem which enables the user to input and processChinese text using a keyboard and a visual display unit.So next time you feel like spending an evening typesettingthe entire works of Chairman Mao or scripting a revolu-tionary ballet about the perfidious Gang of Four, you willhave over 8,000 characters in a special dictionary thatcomes on disc.

New launchby LifeboatLIFEBOAT ASSOCIATES haslaunched a new business -graphics package for micro-computer users. The softwarepublisher claims that Graftalkhas simple commands but canstill produce a variety of barcharts, vertical or horizontal,with legend and axis labels,and pie charts.

The Graftalk package costs£255 including operatingmanual, and comes with ajoystick mode with light -pensupport for graphic design.Support is also available forCRT, pen plotter, and printer.An optional digitiser is alsoavailable. Further details fromLifeboat Associates, PO Box125, London WC2H 9LU.Telephone 01-836 9028/9.

EPROM inkit formTHE MSC/A2 EPROM pro-grammer can also be used asan EPROM memory board.This easy -to -build kit is suit-able for most microcomputers,and directly fits the UK 101 orSuperboard machines througha 40 -way ribbon and plugarrangement.

Prices are £59 to £95 for thebasic kit, £4.95 for the 40 -waycable, and £6.90 for the 24 -pinZIF socket. Kits are availablefrom MCS Electronics, 9 Wil-lowfields, Hilton, Derby.Telephone 0283 733802.

U -AID is completeApple interface packTHE U-A/D complete interfac-ing system for the Apple IImicrocomputer includes aneight -channel, high-speed12 -bit A/D converter, 16 digi-tal I/O lines and timer func-tions, complete documenta-tion and example programs.Also available is the U -DTwhich, by including two 6522VIA chips, provides 32 digitalI/O lines and timer functions.For further details contactU -Microcomputers, WinstanlyIndustrial Estate, Long Lane,Warrington, Cheshire. Tele-phone Warrington (0925)54117.

50 PRACTICAL COMPUTING May 1982

more than just hardware andsoftware at good prices.We supply igaPPle hardware and software to care for your financial

modelling, accounting, word processing etc.But at Guestel that's not the end of the story. We supply GUESTELCARE -

care to ensure that the system you chose is tailored to meet your specificrequirements. We also train all operators to achieve maximum efficiency fromthe system.

After you have purchased your system Guestel care continues with nightand day technical and operational support.

Our care also extends to our prices, we take care to keep them ascompetitive as we can.

Clip the coupon or call into our showrooms and let Guestel care for youand your micro.

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41 .43 BALDWIN = E ET BRISTOL BSI IRB_EPHC", 7:

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.'I Please send me the current Guestel Ikapple systems and software price list.

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TO GUESTEL LIMITED 8/12 NEW BRIDGE STREET LONDON EC4V 6AL. PCI

A business -like problemrequires a

business -like solution

in a word SUPRBRAINAnd now the new HD version with its integral 3, 6 or

12Mbyte hard disk Winchester drive can provide the answerto business problems which other desktop machines couldn'tbegin to solve.

Superbrain HD has enough hard disk memory to carry outa word processing exercise on a complete Russian novel (andkeep a separate listing of the characters).

Or provide the finesse to send a telex using the POapproved V24 auto telex interface board. And print out theanswer unattended.

As for business software at the right price there is perhapsno better supported micro family than Superbrain. While thehardware add-ons, such as the high resolution (512 x 240pixel) 3D graphics are what every business user shouldexpect from a desktop Micro computer. But not always get!

SUMBRAIN mHD=:Ricslhe answer. From around £3,550.* based on 2$ exchange rate

Optional Extras:- SoftwareHigh Resolution Graphics Tektronix Emulation_ £140512 x 256 Pixel Graphics Surface plotting £20016K 1/0 Mapped 3-D Graphics £160Mixed text and Graphics_ Graph plotting £80£435.00 (easily installed board) Symbol generator £80True Lower Case board £50 Suite of Software £330.00Low cost £ sign (purchased with board)True descenders Inverse videoUnderline Strike throughDisc Motor offLonger media life Lower maintenance costs

Circle No. 140

ESL DealersApplied Micros Ltd. 14 Clifton Road, Heaton Moor, Stockport, Cheshire. Tel: 061-431 9390Atlantic Microsystems Ltd. 72 Honour Oak Park, London SE23. Tel: 01-699 2202Bondbest Ltd. 66 Wells Street, London WC1. Tel: 01-580 7249/6701Boyd Microsystems Ltd. 59 High Road, Bushey Heath, Herts. Tel: 01-950 0303Easi Bee Computing Ltd. 133-135 High Street North, London E6 1HZ. Tel: 01-471 4884The Electronic Office. 32 West Street, Brighton, Sussex. Tel: 0273 722248/9ISIS Computer Services Ltd. Millwood House, Middle Assendeon, Henley-on-Thames,Oxford. Tel: 04912 77735Mercator Computer Systems. 3 White Ladies Road, Clifton, Bristol. Tel: 0272 312079Micro People Ltd. 1 Union Street, Long Eaton, Nottingham NGIO IHH. Tel: 06096 69117

From the people who believe in Quality, Reliability and Support.Limited opportunities available for appointments as dealer representativesin selected areas.

&motel Systems Limited,534-539 Purley Way,CROYDON, Surrey.Tel: 01-686 96871 Telex 265605

Printout extra

Automate or dieIN THE EYES of the British Government, arobot is "a reprogrammable mechanicalmanipulator". This definition does notstand up to deep semantic analysis, butfor now it will do. In 1981 there were 371of these devices in this country. At thebeginning of this year there were 713. Tocoincide with the installation of thethousandth robot Practical Computinglooks into the U.K.'s policy on robots.

The philosophy behind the Govern-ment's policy to introduce robots intoindustry is "modernise or die". At everyopportunity the Prime Minister repeatsthe message. The trade -union movementalso recognises the need to re -equip ourmanufacturing industry in order to com-pete in today's world economy. Mr KenGraham, the Assistant General Secretaryof the TUC believes that "the surest wayfor Britain to continue losing competi-tiveness and employment potential wouldbe to pretend that we could turn ourbacks on technological advance".

Lagging behindThe robot population is steadily

increasing as more industries find a usefor them. Since Ingersoll's report for theDepartment of Industry revealed thatBritain was being left behind in robot useand manufacturing, the DoI has pro-moted and given financial aid for automa-tion.

It has made a robot film which hasbeen widely shown to industrialists.Although not exactly Star Wars - indus-trial robots are not exactly C3PO for thatmatter - the film has been enthusiasti-cally received. Robots in Industry runs forjust over half an hour and is available onfree loan or for purchase on film or videofrom the Central Film Library, ChalfontGrove, Buckinghamshire SL9 8TN.

Tangible support to industrialistscomes in three different packages. TheDoI believes that "feasibility studies are avery important exercise for investmentappraisal". So it will provide half of the

Designed by ministers, writtenby civil servants, implementedby industrialists. Bill Bennettexamines the U.K.'s policy for

robots.

costs of an outside group to study thepotential uses of robots in a particularcompany up to a maximum of 15 man -days of work. Companies must seekdepartmental approval if they chooseconsultants who are not yet on theapproved list.

The Government is also injecting cashinto the Science and EngineeringResearch Council. Here money is pro-vided to pay for fundamental researchinto automation as well as investigatingtechniques and applications. Under thisbanner come the various joint projectswhich are run by both universities andindustry. Paradoxically the universitieswhich specialise in automation researchare receiving massive cuts at the sametime, and at the hands of the very samegovernment.

Once a company decides to go aheadwith a program of robotisation theDepartment of Industry can providesome financial support both for the initialcapital outlay and the ongoing develop-ment costs. The Government attachesfew strings to the cash. There is no upperlimit to the overall size of a project butwith certain exceptions a lower limit of£25,000 will apply. Any company canapply for a grant, and may keep reapply-ing as long as each successive applicationis different.

The Government is also trying toencourage a wider robot manufacturing

base. Indigenous manufacturers arepretty thin on the ground at the moment,but this should be changing as new smallengineering companies respond to thechallenge of the robot.

Two robot manufacturers are alreadyoperating in Britain and a further two areimporting and assembling Japaneserobots under agreements. The manufac-turers are Hall - which is part of GEC -and Unimation, which is based in Telfordand is a U.K. subsidiary of an Americanconcern. The companies which will bebuilding robots under the guiding light ofthe Japanese are Dainichi-Sykes and the600 Group which has an arrangementwith Fanuc. Dainichi-Sykes is based incentral Lancashire, the development areathat includes Preston and Leyland. Aswell as manufacturing in the U.K. thecompany will be exporting to Europe amarket which is expected to grow byaround 2,500 units per year.

Insecure jobsConcern that the increasing use of

robots, especially in the industrial manu-facturing sphere will lead to massiveunemployment has been offset by fearsthat if Britain does not modernise, thenher competitors will and even more peo-ple will be out of work. So far, not oneBritish worker has been made redundantby a robot.

Those workers who have been movedto other tasks by their new, robotic col-leagues, seem to be happy. Most of themare now engaged on far more rewardingwork, both financially and mentally, andthey realise that their old jobs probablywould not have been secure for very longanyway.

PRACTICAL COMPUTING May 1982 53

THE PBM-1000 is a sturdy, cream -colouredbox that occupies an 18in. square of deskspace, allowing for the protruding con-nectors at the rear. Because its internalelectronics comprise a single horizontalboard rather than the separatevertically -mounted boards of the stan-dard S-100 arrangement, the cabinet isonly 6in. high, and no more obtrusivethan the average stereo unit. The frontface features one double -sided 5. 25in.mini -floppy Tandon drive of around800K capacity, and beside it the howfamiliar 5Mbyte Seagate mini -Winchester fixed -disc drive.

The drives each have a small LED, buton the review machine these did notfollow the normal practice of lighting uponly during disc activity. Curiously, oneLED was always illuminated, correspond-ing to the last disc accessed. It needs afine ear to hear whether a Seagatemini -Winchester is responding, and onoccasions we missed the reassurance ofthe usual flickering red glow. To the rightof the drives are the illuminated resetbutton and the on/off switch.

Access to the inner workings is a sim-ple matter of unlatching the fourattache -case clips that hold the top coverin position. This is certainly preferable tothe kind of fiddly undoing some machinesdemand - 12 small bolts have to beremoved to gain entry to the Rair, forexample.

All that the interior offers is the sightof the single horizontally -mounted mainboard, and the only reason a user wouldwant to get inside would be to set up themore -or -less permanent ribbon -cableconnections to the terminal interfaces.

Support chipsThe CPU is Zilog's Z -80A, operating

at 4MHz without wait states. Supportchips include Zilog's flexible, but costlyinput/output, PI/0 and serial input/output, SI/O. We expected to find theZilog direct memory access, DMA, chipcompleting the set, but instead a specialtwo -chip module has been assembled onthe front, left-hand side of the board todo more or less the same job.

DMA moves data around inside themachine without imposing the task on theCPU, and on the PBM-1000 thearrangement is claimed to leave 97 per-cent of the Z-80 chip available duringfloppy -disc transfer, and 70 percentavailable when accessing the Winchesterdrive. Certainly the disc access seemednoticeably faster than equivalent non -DMA hardware we have used in the past.

Field repair would typically consist of astraightforward replacement of the singleboard - something like 15 minutes'work to unhook the connecting cablesand unscrew nine bolts. The simple phys-ical construction gives little indication ofthe sophisticated logical architecture ofthe machine - the clue to that lies in thememory map - see figure 1.

MicroPro's PBM-1000 is not just another CP/Myou WordStar, DataStar and SuperSort is fightinglook at an eight -bit, 80K cream box that offers 30 percent

PBM- 1000

The PBM in action with Microline printer and TeleVideo terminal..PBM-1000 users need never know how

the extension of internal memory isachieved, but the subject is worth a closerlook. An eight -bit device like Zilog'sZ-80 cannot directly address more than64K. Bank -switching, the ability of aCPU to choose at any given momentwhich memory cells will be includedwithin the 64K limit, is used by machineslike the SuperBrain to make room formemory -consuming direct screen addres-sing without diminishing the internalspace.

Because the technique is hardware -dependent, bank -switching is usually con-fined to the deep, inner workings of thesystem's software. Even then it suffersfrom the limitation that the banked -offsections of the program are isolated fromeach other, and a further level of programcomplexity has to be introduced if itbecomes necessary to transfer data bet-ween sections.

CP/M traditionally resides in contigu-ous memory above the transient programarea, TPA, the area occupied by applica-tion software and program data. WhileCP/M lords it from on high, its represen-tative on earth, as it were, is a 100 -byteblock at the very bottom of memory -page 0 - through which the applica-tions program is expected to pass calls tothe operating system.

When the Bios disc -interface softwareis extended to drive a mini -Winchestersystem, CP/M can occupy as much as12K. With the growing use of mini -Winchesters several manufacturers havebeen developing plans to shift the operat-ing system on to a second bank.

The software that runs in the TPAmakes frequent calls to the operatingsystem, but only through two addresses inpage 0. It might, then, seem simple tooperate bank -switching code at byte 5 -the vector for most functions - and atbyte 0, where a program will typicallyjump on termination to reinitialise theoperating system and return to commandlevel.

Unfortunately there are complications.Parameters have to be passed to theoperating system and returned from it.Applications programs need some ofthese parameters to signpost file -controlblocks and disc buffers in the area that isbeing swapped in and out; normally theexistence of one bank remains unknownto the other.

Top of memoryAs the map shows, the PBM-1000

switches a pair of 16K banks at the top ofmemory. Most of CP/M resides on bankB, but it cannot set up data blocks therethat need to be accessed by user softwareon bank A. Instead it creates mirrorimages on the user bank of the datablocks to be accessed.

A user program generating, say, areference call to a disc parameter block isdirected to a quickly -constructed fac-simile of the real thing set up on bank Awhile the BShell software module handl-ing the bank switching passes its addressback from the banked -out operating sys-tem. The user program never sees thereal thing; realistic data overlays are setup for it whenever it looks for them.

To set up a disc parameter block in a

54 ' PRACTICAL COMPUTING May 1982

Review

computer: the Californian software firm who broughtback against the 16 -bit invasion. Chris Bidmead takes aextra user memory.

The computer's mainboard is easily accessible.slim multi -purpose buffer while calculat-ing its address and sending that back tothe calling program implies a good deal ofswitching between the banks. The stan-dard bank -switching arrangementstreams data via a common area. Any-where below C000H would do on thePBM-1000, but this is right in the middleof what is supposed to be the TPA.

MicroPro has cut through the inherentsoftware hazards with an ingenious hard-ware fix. The Z-80 processor has a largerepertoire of additional instructions com-pared with the 8080, some under -exploited and others best left well alone.Indirect port addressing is one of themore useful: the port whose number isheld in register C will either be read to orwritten from by the instruction

IN r, (c)OUT (c), r

where r is any register and represents thevalue in register.

If this were the whole story of the Ziloginstruction there would be noPBM-1000. What happens inside theZ-80 as a result of this instruction is thatthe chip reads the entire double registerBC and puts that word -length value on tothe 16 address lines. This is the lightly -documented "extended indirect addres-sing" offered by the Z-80. In otherwords, the chip behaves as if obeyinginstructions of the form In r, (BC) andOut (BC), r.

Ordinary hardware implementationstry to make Zilog's indirect addressing assimilar as possible to 8080 direct addres-sing by quietly ignoring the higheraddress lines. The PBM bus lives life to

the full by carrying the whole word -length address, and herein lies the secretof its bank -switching.

The bank which is switched in is seenby the processor as memory. It can accessthe switched -out bank as data by usingextended indirect addressing to fetch andcarry values as if from a 64K -sized arrayof contiguous ports. File -control blocks,disc parameters, and so forth can bepushed through the looking glass.

Unfortunately there is a price to bepaid. The PBM-1000 architecture forcesthe Z-80 to see all ports as having 16 -bitaddresses. The ports of real -worlddevices like printers and terminals alsohave to be addressed indirectly, with thesignificant eight -bit value being sent outon the high address line and an indiffer-ent value on the lower.

Data to the printer port, for example,will be sent to a port addressed as 91XX,where XX is an indifferent eight -bitvalue. Consequently the normal Intelcompatible I/O instructions In and Outare not properly supported on thePBM-1000. Neither are Zilog's auto-mated I/O mnemonics, which use adecrementing value in the B register.

Machine -independentAs a result the PBM-1000 cannot

really be called a general-purpose com-puter. Most programs written to rununder CP/M should sit happily in thePBM-1000 because they will avoidport -oriented instructions, using CP/Mcalls to keep the software machine -independent. But process -control appli-cations, and software like Bstam - used

for communicating between CP/M com-puters - that require the users to write

( their own port -oriented patches mayprove to be troublesome.

The manual also warns against prog-rams that trap calls within the operatingsystem - these are not going to find thejump table in the expected place and willcrash. A third category of potential non -runners would be programs that begin bygoing to addresses on page 0 to find outthe size of the system. Software like thissometimes has range checking that mayrefuse to believe in the PBM-1000's 63Kof user memory. Potential PBM-1000users are advised to test any CP/M soft-ware before committing themselves topurchase.

Compatibility guaranteedOne big software house will of course'

be guaranteeing compatibility, and that'sMicroPro itself.. The review machinearrived with a raft of MicroPro software:WordStar and its satellites MailMergeand SpellStar, as well as_the general-purpose database and form -generationprogram DataStar. We are also gratefulto Terodec for a chance to look at Mile-stone, a useful critical -path analysis pro-gram from a non -MicroPro source.

WordStar must be the world's best-known word-processing program. It nowoffers horizontal as well as vertical scrol-ling, so that documents of virtually anywidth can be viewed on the screen whileformatted as they will appear whenprinted. Previous versions made it poss-ible to move, copy or delete blocks oftext; enhancements to revision threeinclude the facility to do all this to indi-vidual columns of text, which is useful inthe creation of tables and "pasting up"newspaper -style pages.

The dynamic page -break feature,which shows you on screen exactly wherepagination is going to divide your text onprintout, is very valuable. The fact thatWordStar is disc- rather than memory -based has always made it theoreticallypossible to work with text files runninginto tens of thousands of words, but onnormal hardware this involves intolerabledisc -waits, to say nothing of the danger ofcrashing out with disc -full errors. On amachine like the PBM-1000 large filesbecome practical.

The large capacity of the hard discmakes a long-standing disadvantage ofWordStar more troublesome: the instruc-tion to display the directory shows everyfile, not just those whose extensiondenotes them as text files. Setting non -text files to system files with the Stattransient command will hide them fromthe CP/M Dir instruction, but WordStar'sdirectory display refuses to acknowledgethe Sys flag. At least WordStar III nowrespects CP/M's separate user levels, andno longer garbles directories on levelsother than 0.

(continued on next page)

PRACTICAL COMPUTING May 1982 55

(continued from previous page)With the addition of MailMerge and

SpellStar, WordStar becomes a verycomprehensive text -management pack-age. SpellStar is yet another orthographychecker, while MailMerge, generatesjunk mail from a mailing list, and suppliesextra facilities like multiple printing asingle block of text, linking files whileprinting. The combination is almost tootop heavy for the average mini -floppysystem, but the PBM-1000 hard disc isable to take the strain, with plenty ofspeed to handle the overlays.

The disadvantages are that the Word-Star manual is monumental, you arestuck with American spellings if you relyon SpellStar, and MailMerge becomescomplicated as you explore beyond itselementary capabilities. For many busi-ness users it may be best installed by asystems house.

Screen-based formsDataStar is a neat way of creating the

address files accessed by MailMerge. Itenables the user to design screen-basedforms that set out fields to be filled in bykeyboard entry. Extensive error checkingcan be built in, ensuring, say, that num-bers are not put in where only letters areexpected, as well as checking ranges anddoing elementary arithmetic whererequired. DataStar can also be set up toexpand automatically short entries to fulllength, such as "ABC" to "AeratedBread Company", by matching themagainst a table in a separate file.

The indexed sequential file that Data -Star builds from these entries is essen-tially a chunk of ordinary text running incombination with one or more smalllook -up files that provide a crib to pre-selected key -words in each record.

Common-sense wayOne advantage over the fixed -length

records of a more sophisticated databaseis that the DataStar text file stores thedata in a common-sense way, using aseparate line for each record and demark-ing the fields within each record withcommas. This makes it very easy to get atthe fields and records via quickly con-cocted Basic or Pascal routines.

Valuable data can be safely left perma-nently on a hard disc. It was a joy not tohgve to juggle floppies in and out of thecomputer but floppies are by no meansdispensed with once they have been usedfor entering applications software intothe machine in the first place.

Insurance against the loss of formattingon a hard disc is provided by a programcalled Backup Com, which compressesdata into a dense, non-standard format sothat the entire hard disc can be containedon six floppies.

When a floppy becomes full during theback-up process, even in the middle of afile transfer, the program interrupts andprompts for the next disc, identifying the

discs sequentially so that split files can berejoined when restored to the hard disc.Back-up offers the options of copying:

All non -system, accessed files for user(name a number)

All non -system, files for user (name anumber)

All system, files for user (name a number) All files for user (name a number) All accessed files for user (name a number) All files for all users

System files like Pip and Stat stayunchanged in an ordinary system, so it isuseful to be able to skip them whenbacking up. Similarly the back-up pro-gram is able to make automatic copies ofaccessed files that have been revised sincethe last back-up while ignoring non -system files that remain unchanged.

From the documentation Backupseemed the simplest and most flexiblesolution we have seen to the difficultproblem of backing up a high -capacityhard disc on to mini -floppies. Unfortu-nately, while trying to get the program towork as documented we ran into a varietyof problems. The disc drive would hangmysteriously in the middle of transferringa file, or the recovery module would fail

FFFF

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F500

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SWITCHABLE BANKS

A Segment B SegmentFBOO

BIOS informationBIOS linkage code 0

Mere BIOS inform- UL

BDOS linkage code r ECCP

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0400

C600

C000

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futureexpansion)

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Figure 1.

to find a file ontransferred it to.

The PBM-1000 has no built-in PROMmonitor, which made diagnosis difficult.In the case of hardware faults there isprovision for long-distance diagnosisfrom the service centre over a telephoneline, but this would require extra hard-ware. The problem may have been in theoperating system, because something likeit recurred during speed checks on thehard disc, when it proved impossible torun our standard test of filling the discwith small files. CP/M returned a no -directory -space error message, althoughfew directory entries had been writtenand Stat showed 3,196K of disc stilltheoretically available.

A second test to create a single, largefile also failed. It was impossible tooccupy more than about 2Mbyte of the5Mbyte supposedly available on the disc.

the disc we had just

With exactly the same number of discbytes remaining, CP/M returned a discwrite error.

Among the hazards of reviewing areearly versions of software and rudimen-tary documentation. We spent hours, forexample, trying to get the RS -232 readerport to perform, only to discover that thepins on the printed circuit board confi-dently engraved "Modem" had beenincorrectly marked, and should havebeen swapped with the pins labelled"Terminal".

Teething troublesApart from these teething troubles the

PBM-1000 emerged as a fast, efficientand well-built computer for general busi-ness use. It is a pity that the techniquesused by its designers to expand thecapabilities of the Z-80 chip eliminatesome of its more useful instructions, but itis a case of swings and roundabouts. Thehard-won benefit of the extended corememory presents something of a para-dox: none of the software we reviewedwith the machine took advantage of it.

Large memory is currently needed inprogram -development applications,where the compilers of high-level lan-guages like Pascal and C tend to create asqueeze in the traditional 64K; but thePBM-1000, monitorless and incapable ofsupporting the full Z-80 instruction set, isclearly not intended for intensive pro-gram development.

New 16 -bit technology is rallying in thewings, promising friendlier software withcomforts like proper error -trapping, ful-ler error message and the easing of syntaxstrictures. These are features that eat upmemory, and Zilog's 64K address limita-tion affects the amount of upholstery aprogram designer can provide. ThePBM-1000 spearheads the arrival ofextended -memory machines from othermanufacturers throughout 1982 as theeight -bit world prepares to fight backagainst the coming 16 -bit invasion. Thedesign of the PBM-1000 seems to implythat MicroPro has software enhance-ments up its sleeve that will make use ofthe big fast memory.

ConclusionsThe PBM-1000 is a new design if

Z -80 -based microcomputer with a well -implemented hard -disc facility incor-porating direct machine access. The novel architecture has some limita-tions, but these should not impinge on theordinary business user. The machine is backed by a portfolio ofwell -established general-purpose softwarethat the manufacturers have developedover the years. Although an American machine, plansare in hand for the PBM-1000 to bemanufactured in the U.K. by the currentimporters Terodec, which should help toguarantee that good -quality national sup-port is available.

56 PRACTICAL COMPUTING May 1982

I

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ult 47 fdt; er,t141

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Virtuallyno limiton nuznber

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PC1

PRACTICAL COMPUTING May 1982 57

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Review

GENIE I MICROCOMPUTER SVS EM

Genie I and II

YOU MUST have wondered about theGenie when it first came on to the marketsome two years ago. It was manufacturedby Eaca, a little-known company, basedon a small island off the coast of Chinafamous for plastic mouldings not high-technology products. Its price and cap-ability also seemed a bit too good to betrue.

Nevertheless the Video Genie System.as it was then called, has taken off andrecent new models, price reductions andadditional hardware will make it evenmore popular. With the introduction of a"professional" system, the Genie II, themanufacturer intends to break into thesmall-business computer market. AGenie II with expansion giving a total of48K RAM, two disc drives, a printer anda monitor costs around £1,700.

The Genie I differs from its predeces-sor in having a built-in sound generator,

Martin Eccles takes alook at two current

microcomputers by theHong Kong builders of

the Video Genie.

previously only available as an option,and an extra 1.5K ROM bringing thetotal to 13.5K. I was not impressed by thesound generator, but you may appreciateit if you like making up tunes or playingStar Wars.

The only drawback is the absence of avolume control. Each invader that goesdown rewards you with a perforatedeardrum. As the cassette recorder'sswitch can be used to turn off the sound,it is a pity that the playback level controlcould not have doubled as a volumecontrol.

The extra 1.5K ROM, however, addssome really useful and readily accessiblefunctions, namely Keyboard debounce,

Flashing cursor, Automatic keyboard repeat, Machine -language monitor, Program renumber, Lower-case characters, Screen contents to printer command.

Keyboard bounce has been a problemwith both the Genie and the TRS-80. Itwas solved in the original Genie by apiece of software on the demonstrationcassette that had to be loaded into pro-tected memory each time the system wasswitched on. Although it includedflashing -cursor and keyboard -repeatroutines, the new method is far simpler.One System command brings in all thefunctions, apart from the machine -

(continued on page 63)

PRACTICAL COMPUTING May 1982 61

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62 PRACTICAL COMPUTING May 1982

Review

(continued from page 61)language monitor which has a separateSystem command.

A flashing cursor is only of real valueto an experienced programmer butkeyboard repeat is useful to anyone,especially when editing Basic programlines. Nevertheless, specific editing com-mands dedicated to accessing part of aprogram line are still quicker, if you canremember them.

CommandsThere are five commands in the

machine -language monitor, each select-able by a single letter. They are,

Display Memory, Modify Registers, Modify Memory, Start Execution, Return to Basic.With these commands you can enter,modify, display and execute - withbreakpoints - Z-80 machine code inhexadecimal format.

In display -memory mode, typing in theinitial memory address displays 16 loca-tions starting from that address on thescreen. Pressing the down-arrow key dis-plays the successive 16 locations, and uparrow the preceding 16. Up to 15 rows of16 locations can be displayed at any onetime - very useful for machine code. Thecommands Modify Registers and Modify

Genie specificationsThe two models, the Genie I home computerand the Genie II business computer, havethe following features in common:

Z-80 microprocessor 16K RAM 13.5K ROM TRS-80 software compatibility lower-case characters machine -code monitor keyboard repeat program renumber flashing cursor screen contents to printer command

The business computer has a numerickeypad in place of the cassette normallyassociated with the Genie, four special -func-tion keys and an industry -standard proces-sor. A software -controllable sound generatoris standard in the Genie I.

The new "expander box" can be obtainedwith either 16K or 32K extra RAM andincludes floppy -disc controller and printerinterface. Up to four single -sided or twodouble -sided disc drives can be used andS-100 cards enable the memory capacity tobe extended by forming banks. The RS -232is an extra, but any printer with a Centronicsinterface may be connected to the expander.

The distributor also stocks a colour boardgiving six colours and 64 by 32 pixels, atelephone Modem, monitors, purchase andsales software and a "knock -down" desk forthe system. Tridata Micros is to producesoftware for the Genie business system. Inaddition TRS.DOS, VTOS, Newdos, New -dos 80, CP/M, Fortran, Pascal, APL, MicroCobol and Forth can all be run on a Geniedisc system.

Eaca's EG-602 printer appears to be identical with the Seikosha GP -80 and printsgraphics, lower case without descenders and double -width characters.

Memory speak for themselves.In Start Execution mode, you type in

the starting address and the break-pointaddress; break points are used for analys-ing and debugging programs. Themonitor inserts Call 3347H at the break-point location and this instruction, whenreached, causes all the registers to besaved and the original instruction at thebreakpoint to be restored.

For those who frequently write Basicprograms, the program Renumber func-tion is a necessity. All Gotos, etc., arerenumbered along with the program linesand the increment between each line canalso be set. The whole operation is init-iated by a letter and, if required, anincrement value.

Character displayLower-case characters with descen-

ders below the line are fine provided thatthe picture quality of the TV or monitorused is good. You have to press the shiftkey to obtain them, which is disconcert-ing. I tried to get round the problem byfitting a small lever to invert the shiftkey's operation but shift/backspacedeletes the whole line. This remedyseemed worse than the disease, so even-tually I threw the lever away. With a littlepatience, the lever's function could besimulated by software which leaves theback -space key's function unaffected; forword processing this would be essential.

Shift; down-arrow; P is the commandsequence to print out everything shownon the screen. If a printer is not con-nected to the system, the command isignored. Without an expander the Geniecan make a reset without losing the prog-ram. If you tell the computer to, say.LPrint with expander fitted but without aprinter, you will eventually have to reset

and the program can disappear. ScreenPrint is most helpful and can, for exam-ple, be used while a program is running tosave a certain stage of a game, withoutaffecting the program.

The Genie I is similar to later versionsof its predecessor. The modifiedkeyboard is used and the inbuilt cassetterecorder has the playback -level controlmeter - which worked perfectly on both

The AVT monitor's screen is smaller thanother gin. units.

Genie is reviewed. Replacing one of theshift keys with two others has greatlyimproved the functions and ergonomicsof the keyboard.

A Tab function is possible which, whenshifted, gives increased character spacing.This key has a right -arrow on it and nextto it is left -arrow, the old backspaceftinction. The former backspace key nowoperates the Clear Screen function. Theoriginal Esc and Ctrl keys retain theiroriginal functions but now have up- anddown-arrows on them, probably forgames purposes.

After running for eight hours continu-(continued on next page)

PRACTICAL COMPUTING May 1982

Review

The expander box controls up to four disc drives and a printer.

(continued from previous page)ously, the Genie I gobbled up the pro-gram and produced garbage on thescreen. No amount of resetting wouldre -boot the system. Only after the com-puter was allowed to cool down totallydid it work perfectly again. I know anold Genie with the same problem, butwhen the computer was taken back to theshop no amount of abuse - even wrap-ping it in blankets then subjecting itsvulnerable parts to freezer spray -would make the fault reappear. Lowe,the Genie's U.K. distributor, assures methat this is not a common fault and areplacement machine worked perfectly.

Genie expander1 evaluated the Ciente 1 with a new

32K expander, two disc drives, a printer,monitor and software, includingNewdos-80. The system worked perfectlyonce set up and did everything that wasasked of it. However, you need a 65cm.deep desk because the cable provided istoo short to put the expander anywhereother than directly behind the computer.Other cables for the printer. disc drivesand monitor are of ample length.

The DIN plugs for the monitor andsecond cassette recorder had their pinsmoulded in incorrectly and damage couldhave occurred if they had been forcedinto place. No polarity pin or notch isprovided on the flat cables and they canall be inadvertently inserted the wrongway round, apart from the D connectoron the printer.

Lowe now provides an attractive 9in.AVT monitor with the Genie. The screendoes not dim as it fills with characters orbloom as brightness is increased - bothproblems with the OPC monitor Loweused to supply.

Resolution and convergence are goodbut the line oscillator circuits occasionallyproduce an annoying whistle. This might

be caused by a loose fitting somewhere inthe review monitor, as the problemdiminishes as the set warms up. Unfortu-nately the screen diagonal of the newmonitor is an inch smaller than the OPC9in. monitor. A block of 127 by 47 pixelson the OPC monitor measures 154 by126mm. compared with 140 by 114mm.on the AVT monitor.

Printer problemsA logo on the front identified the

printer supplied as an Eaca EG-602, butthe manual sent was for the seeminglyidentical Seikosha GP -80. The EG-602has been slow to appear in Lowe's pricelist but the GP -80 has been advertised for£195 plus VAT, which is good value. Itpfints lower case, without descenders,and graphics. It can accept 10 controlcodes for various printing modes, includ-ing double -width characters.

Each time I tried to print graphics,the screen width was printed in a columnno more than 24mm. wide. The printeritself is probably not at fault, but youshould find out how graphics can beexpanded to cover the full paper widthbefore you buy.

Disc -drive connectionsThe two EG-400 5.25in. floppy -disc

units worked perfectly. Within minutes ofbeing taken out of their boxes they wererunning Space Invaders from Molimerx,which took about eight seconds to load.These are 40 -track drives accordingto most of the literature, though thespecification sheet says they are 35 -trackdrives. They are capable of storing 100Kof formatted data, and access time isquoted as 20ms.

Up to four disc drives may be linkedthrough a daisy -chain cable to the system.Alternatively two double -sided drivesmay be used; a double -density adapter isavailable for the new expander.

Each drive has a metal housing measur-ing 9 by 15 by 30cm. and although theyare constructed as stand-alone units, nodifficulty was found in positioning them.A one -metre cable links the expanderand drive connectors on the two -drivedaisychain cable.

The expander just sits there and co-ordinates with its on/off switch and a rowof connectors. Its large size is accept-able considering that it can control up tofour disc drives and a printer and has itsown power supply. The expander cancontain up to 32K of memory, and can befitted with S-100 cards and an RS -232interface.

Software provisionThe Genie II computer is housed in the

same case as previous models but theusual cassette recorder has been replacedby a numeric keypad and four pro-grammable special -function keys. Anindustry -standard Z-80 processor is used.As there is no mention of increased clockspeed, one can only assume that this hasbeen done for reasons of reliability. Acassette recorder output is provided atthe back of the computer.

The same expansion unit and peripher-als are used for both Genie I and II. TheII also benefits from the 13.5K ROM.

Dedicated software for the Genie II isbeing provided by Birmingham -basedTridata Micros. Titles include Stock Con-trol, Payroll, Purchase Ledger, SalesLedger and Nominal Ledger. Combinedwith the TRS-80 compatible interpreterand low prices of both the computer andperipherals they make the Genie II veryattractive as a small business computer,not to mention its communications andnetworking possibilities.

According to Lowe, developmentshave been completed and will shortly beavailable to use the Genie II as an intel-ligent terminal for mainframe computers.Genie's manufacturer, Eaca, is clearlytaking the business computer marketseriously.

ConclusionsConsidering that the number of Genie

and related products stocked by Lowe hasrisen from one to 52 in just two yearsthere is obviously a bright future aheadfor the systems. On the home computer side, andperhaps even on the business side, Eacawill eventually have to come up withsomething better than their existing col-our card. The Genie I has everything that similarsystems have and usually at a lower cost. There are interfaces available for con-necting Tandy peripherals to the Genieand vice -versa. The Genie I home computer costs £299plus VAT; the Genie II professional modelcosts £310 plus VAT. They are distributedin the U.K. by Lowe Electronics, Mat-lock, Derbyshire.

64 PRACTICAL COMPUTING May 1982

The new generationthat interfaces with

most microcomputersMannesmann -Tally's new MT100 series of matrix serial

printers for microcomputers is now available from local computershops and suppliers.

MT100 series printers are utterly reliable. They're a newgeneration of Europrinters made in West Germany with fulltechnical and service back-up from our headquarters here inthe UK.

They give high performance at a very reasonable price. Idealfor professional businesses. Or educationists. Or enthusiastswho value the latest technology.

Two basic models- MT120 and 140Main difference is in column width. The MT120 is the 80

columns version whilst the 140 features 132 columns.Both models come in three variants giving a range of standard

features which normally are beyond the scope of microcomputerorientated printers.

MANNESMANNTALLYthe source of the Europrinter

9 x 7 matrix. 160 cps high speed output - often doubled bymicroprocessor control choosing shortest possible print path ineither direction.

Selectable 18x40 matrix for high definition correspondencequality.

10 different character sets, 96 characters each.OCR A and B character fonts using 9 x 9 matrix.Four different character pitches between 10 and 20 cpi, each

of which can be printed in double width.Two colour printing.All MT100 series printers are small, quiet and highly versatile.

End user prices start at £390.For further pricing and availability use the MT100 hotlines

on Reading (0734) 586446/7/8 or look in at your computer shop.Alternatively write to us for full details.

Circle No. 146

Mannesmann Tally Limited. 7 Cremyll Road Reading Berkshire RG1 8NO Tel Reading (0734) 580141 Cables Tally -Reading Telex: 847028.

Sinclair 1X81 Personal Comthe heart of a systemthat grows with you.1980 saw a genuine breakthrough -the Sinclair ZX80, world's first com-plete personal computer for under£100. Not surprisingly, over 50,000were sold.

In March 1981, the Sinclair leadincreased dramatically. For just£69.95 the Sinclair ZX81 offers evenmore advanced facilities at an evenlower price. Initially, even we weresurprised by the demand - over50,000 in the first 3 months!

Today, the Sinclair ZX81 is theheart of a computer system. You canadd 16 -times more memory with theZX RAM pack. The ZX Printer offersan unbeatable combination ofperformance and price. And the ZXSoftware library is growing every day.

Lower price: higher capabilityWith the ZX81, it's still very simple toteach yourself computing, but theZX81 packs even greater workingcapability than the ZX80.

It uses the same micro -processor,but incorporates a new, more power-ful 8K BASIC ROM - the 'trainedintelligence' of the computer. Thischip works in decimals, handles logsand trig, allows you to plot graphs,and builds up animated displays.

And the ZX81 incorporates otheroperation refinements - the facilityto load and save named programson cassette, for example, and todrive the new ZX Printer.

New BASIC manualEvery ZX81 comes with a comprehensive, specially- writtenmanual -a complete course in BASIC programming, fromfirst principles to complex programs.

Kit:149."Higher specification, lower price -how's it done?Quite simply, by design. The ZX80reduced the chips in a workingcomputer from 40 or so, to 21. TheZX81 reduces the 21 to 4!

The secret lies in a totally newmaster chip. Designed by Sinclairand custom-built in Britain, thisunique chip replaces 18 chips fromthe ZX80!

New, improved specification Z80A micro -processor - newfaster version of the famous Z80chip, widely recognised as the bestever made. Unique 'one -touch' key wordentry: the ZX81 eliminates a greatdeal of tiresome typing. Key words(RUN, LIST, PRINT, etc.) have theirown single -key entry. Unique syntax -check and reportcodes identify programming errorsimmediately. Full range of mathematical andscientific functions accurate to eightdecimal places. Graph -drawing and animated -display facilities. Multi -dimensional string andnumerical arrays. Up to 26 FOR/NEXT loops. Randomise function - useful forgames as well as serious applications. Cassette LOAD and SAVE withnamed programs. 1K -byte RAM expandable to 16Kbytes with Sinclair RAM pack. Able to drive the new Sinclairprinter. Advanced 4 -chip design: micro-processor, ROM, RAM, plus masterchip - unique, custom-built chipreplacing 18 ZX80 chips.

Built:169.95Kit or built - it's up to you!You'll be surprised how easy theZX81 kit is to build: just four chips toassemble (plus, of course the otherdiscrete components) -a few hours'work with a fine -tipped soldering iron.And you may already have a suitablemains adaptor - 600 mA at 9 V DCnominal unregulated (supplied withbuilt version).

Kit and built versions come com-plete with all leads to connect toyour TV (colour or black and white)and cassette recorder.

ter-

16K- byte RAMpack for massiveadd-on memory.Designed as a complete module tofit your Sinclair ZX80 or ZX81, theRAM pack simply plugs into theexisting expansion port at the rearof the computer to multiply yourdata/program storage by 16!

Use it for long and complexprograms or as a personal database.Yet it costs as little as half the priceof competitive additional memory.

With the RAM pack, you canalso run some of the more sophisti-cated ZX Software - the Business &Household management systemsfor example.

ZX/316 Kings Parade, Cambridge, Cambs., CB21SN.Tel: (0276) 66104 & 21282.

Available now.the ZX Printerfor only 149.95Designed exclusively for use withthe ZX81 (and ZX80 with 8K BASICROM), the printer offers full alpha -numerics and highly sophisticatedgraphics.

A special feature is COPY, whichprints out exactly what is on thewhole TV screen without the needfor further intructions.

IL I,;AMQ LEN 1::

1-ET Rqp%64 PUKE,

98992,56 POKE

LET F95187 PET U19ssa REMTIME

989 rOF? :490 FOR991 FOR r992 POKE

K....1193 NEXTEP NEXTP N.

At last you can have a hard copyof your program listings -particularlyuseful when writing or editingprograms.

And of course you can print outyour results for permanent recordsor sending to a friend.

Printing speed is 50 charactersper second, with 32 characters perline and 9 lines per vertical inch.

The ZX Printer connects to the rearof your computer - using a stackableconnector so you can plug in a RAMpack as well. A roll of paper (65 ftlong x 4 in wide) is supplied, alongwith full instructions.

How to order your ZX81BY PHONE - Access, Barclaycard orTrustcard holders can call01-200 0200 for personal attention24 hours a day, every day.BY FREEPOST - use the no -stamp -needed coupon below. You can pay

rTo: Sinclair Research, FREEPOST, Camberley, S

by cheque, postal order, Access,Barclaycard or Trustcard.EITHER WAY - please allow up to28 days for delivery. And there's a14 -day money -back option. We wantyou to be satisfied beyond doubt -and we have no doubt that you will be.

urrey, GU15 3BR. Order

Oty Item Code Item price2

Total£

Sinclair ZX81 Personal Computer kit(s). Price includesZX81 BASIC manual, excludes mains adaptor. 12 49.95Ready -assembled SinclairZX81 Personal Computer(s).Price includes ZX81 BASIC manual and mains adaptor. 11 69.95

Mains Adaptor(s) (600 mA at 9 V DC nominal unregulated). 10 8.95

16K -BYTE RAM pack. 18 49.95

Sinclair.ZX Printer. 27 49.95

8K BASIC ROM to fit ZX80. 17 19.95

Post and Packing. 2.95

El Please tick if you require a VAT receipt TOTAL £

*I enclose a cheque/postal order payable to Sinclair Research Ltd, for £*Please charge to my Access/Barclaycard/Trustcard account no.

*Please delete/complete as applicable I I I

Name: Mr/Mrs/Miss I I I i I IIAddress. 1 1 1 1 1 1 I

I

LFREEPOST - no stamp needed.

I 1 I I 1 I 1

Please print.

1111 11I I I I I I I I

I I I I I I I I l l I l l 67PRC051

Circle No. 147

expan horizons ?

Now available from Interam, the highlyregarded North Star Horizon with mini-winchester disk drive. This integral hard diskgives you a massive 3, 6, 9 or 12 millioncharacter storage capacity sufficient forvirtually all applications. However if yourequire even further capacity then up to fourM26 Winchester hard disks can be addedexternally giving access to over an incredible100 million characters of data.

Using Starlink, our enhanced CP/M com-patible multi-user operating system this datastorage can be accessed by one or more usersin a time sharing or multi -processing environ-ment.

Starlink, - Multi -User CP/M CompatibleOperating System - Developed by Dr. Lee

of Interam, is at the heart of system expansion.Starlink logically integrates the North StarHorizon with a range of Winchester disksand/or additional I/O, memory and processors.Features include independent login and logout,print spooling, file lock and unlock for

common files, five priority levels, two-wayprivate communications, mail/news/messagefacilities etc. In all, over 20 utilities areincorporated in the Starlink package.

The followingcomponents arerecommended for usewith Starlink:-

Rodime Mini -Winchester hard disk -Thisimpressive unit achieves it's drive performancethrough elegant and reliable engineering design.The RO 100 series provides formattedcapacities from three to twelve megabytes.Fast access times enable you to obtain theinformation you require at great speed and theincreased storage capacity will give you plentyof scope for database expansion to cope withyour growing needs.

Action Computers Single Board Computer- For dedicated multi-user processor power.One DPC180 card is devoted to each user

providing exclusive use of the on -board Z80ACPU, 64K RAM and serial I/O. The obviousbenefit of distributed processing is very limitedloss of CPU time per user facilitating expansionto a larger number of users than would bepossible with timesharing.

Interam Serial I/O - Our brand new fourserial input/output card. Each board has allthe necessary features to operate in a power-ful interrupt driven, real-time, multi-usersystem. The board includes four 2661 program-mable synchronous/asynchronous serial devices

expand their systemsall these new

purchasing thupgradepackage.

for communicating with terminals, modemsor printers. Two and three serial I/O portversions also available.

North Star's 64K HRAM Memory Card -This card offers increased utilisation of theHorizon address space, increased reliabilityand lower cost. HRAM utilises individual16K x 1K dynamic RAM chips. These boardsfeature memory parity checking and bank

switching, designed to optimise operation ofNorth Star hardware and software products.

Existing North Star Horizon users canto take advantage of

products byrelevant

iloritoil is a trade mark of North Star

Computers Inc CP/M is a trademark or DigitalResearch Inc Starlink is a trademark of TTE

& Interam Ltd.

Send off the coupon today and expand yourhorizons.

illifirirn iiEMI 1Min

Microcomputer Specialists46 Balham High Road London SW12 9A0 Tel: 01-675 5325

Name

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Tel No.

PLEASE SEND ME DETAILS OF TiiiSL AND OT ER PRODI CTS

Circle No. 148

Review

Is Arfon's new light -pen an unnecessary gadget or an important tool for the seriousmicro enthusiast? Nick Laurie investigates.

ARFON L1GHT-PENOF THE TWO features of any light -penwhich are vital in determining its quality,the first is the phototransistor. Its outputis gated through a Schmitt trigger to cleanup the wave -form to meet digital -computer standards. The second compo-nent is the push-button that tells thecomputer that the light -pen is at a pointwhich is to be measured.

This measuring involves assessing theposition on the cathode-ray tube of alighted phosphor or, more often, group ofphosphors. The time interval is measuredbetween known cathode-ray tube controlsignals and the arrival of the raster scan atthe point of interest. Software is used tocalculate co-ordinate positions for thispoint.

Suitable hardwareThe answer is to use the light -pen in

conjunction with a cathode-ray tube con-troller chip which already provides astrobe pulse and timing functions. A typi-cal example of this type of chip is theHD -46505S used together with a Z-80CPU and plenty of memory in theGemini Intelligent Video Card -reviewed in the March 1982 issue. It isnot surprising, therefore, to find that thisGemini card already has a light -pen socket which matches this Arfon productperfectly.

Even those machines with video con-trollers not based on a single -chip designcan usually be interfaced to a light -pensuch as Arfon's. It took only two hours tohave the pen working on a Nascom 2, andthe Mimi 801 from British Micro also hasa suitable socket for this pen.

The Arfon pen is of a sufficiently highstandard to be used with the wide rangeof monitors, video controllers andgeneral-purpose micros now in use.

The photograph reveals the complexityof the circuit board inside this device.Double -sided glass fibre printed -circuitboard has been used to carry the circuitrywhich debounces the push -switch andturns the strobe/phototransistor signalsinto suitably -gated square waves.

Some useful thought has obviouslybeen devoted to the general design andlayout: the phototransistor has been veryneatly mounted in a separate "businessend", the circuit board clips neatly intothe body of the pen and the 4ft. ofconnecting cable is securely fastened tothe assembly. The cable is terminatedwith a five -pin DIN plug directly match-ing the British Micro Mimi 801, theGemini Galaxy 1 and the Gemini Intelli-gent Video Card.

We used a Gemini Multiboard system

- a prototype of the new Galaxy l -with the light -pen plugged directly intothe DIN socket on the Intelligent VideoCard. This provides a way of reading theposition of the light -pen directly as a pairof screen co-ordinates latched into theVideo Card's registers.

Accuracy on an 80 by 25 screen.proved to be perfect when trying todetect a single block graphic point withthe correct values being returned on most

occasions. Errors were invariably causedby failing to hold this rather heavy penperpendicular to the screen.

The Gemini Intelligent Video Cardgenerates various screen formats and itseems likely that the light -pen couldrespond to far smaller areas than weused. The manufacturer claims that singlepixels can be detected, but it is unlikelythat the same repeatability could bemaintained in this mode: backgroundnoise, bad aiming and a host of otherfeatures tend to obstruct very fine mea-surements.

Robust and reliableAll in all, though, the pen proved to be

robust and reliable when used with amenu -selecting program designed speci-ficially to test the pen. We would behappy to rely on such a well-built tool.

Unfortunately, we were provided onlywith a bare light -pen for the review: nointerface, no documentation and no sam-ple software. This makes it difficult tocomment on the full package offered byArfon which includes an interface, whererequired, and some software, all for £80plus VAT and postage and packing.

In practice, it proved simple to inter-face to the Gemini, but the lack ofdocumentation was more of a problem.Fortunately, it was possible to refer to the

Gemini Intelligent Video Card manualfor details of the software. It includes aroutine for returning the current light -pen position, neatly packaged as screenco-ordinates. Using this and some unim-aginative linking software, it was possibleto show - in principle, at least - thatthis light -pen could track the display of acathode-ray tube screen with repeatableaccuracy.

Medium -resolution graphics consisting

of a broad white line which followed thelight -pen very closely around the screenwas enough to show that everything wasfunctioning correctly.

Adapting screen menus to giveresponses to a light -pen instead of akeyboard input proved to be entertainingand gave us a very reliable way of select-ing information from the screen. If thelight -pen becomes a standard feature inthe next generation of micros, it willalmost certainly lead to some generaldesign changes in screen displays.

The software on the Gemini IntelligentVideo Card made the light -pen simpleto review. Interfacing to a Nascom 2 ledto rather more erratic results although itdid work after a fashion. Given the timeor, possibly, the documentation andsupplied software, it would not be dif-ficult to interface this pen comfortablywith most machines.

Conclusions The Arfon light -pen is a robust tool ata very reasonable price - the pen alone is£35. If you are thinking of fitting a light -pen, this device will assure you of consis-tent, reliable inputs. As with most add-ons, software, is thestumbling block which can lead to thedevice being in the bottom drawer. al

PRACTICAL COMPUTING May 1982 69

Flexible Relational Database SystemQt;r CONDOR

from M.O.M. (Systems)

For Business People Who Use English

User Friendly

Advanced

Business English commands like ENTER, LIST, DISPLAY, SORT, COMPUTE etc.

Uses relational commands like:- COMBINE, PROJECT, Et JOIN to connect two ormore datasets

Screen Formats Create your own screen formats rapidly

Processing Calculations of totals, subtotals on many keys.Sorting and selection on one or more keys

Compatible For use on any Z80 based Micro operating under CPM 2.2 eg: SUPERBRAIN,CROMEMCO, NORTH STAR, TRS etc. or A.C.T. SIRIUS (INTEL 80881

Flexible For use by Doctors, Dentists, QS, Estate Agents, Lawyers, Librarians, Engineers,etc, etc. Requires no special programming knowledge to implement systems

CONDOR is a product of Condor Computer Systems Inc. It is now available in the U.K. after extensive testingby MOM.

For prices and consultancy call or write to the main U.K. Distributor:-M.O.M. Systems Ltd.

40/41 Windmill Street, Gravesend,Kent DA12 1BA (0474) 57746

Granite Chips Ltd.21 Bon Accord Street, Aberdeen AB1 2EA

(0224) 22863(Dealer enquiries also welcome)

Circle No. 150

FINANCIAL ACCOUNTING ON THEapple computer

Logic Computers specialise in financialmanagement systems on microcomput-e rsWe provide a comprehensive servicewhich begins when we help you selectthe right system. But we don't stopthere; we also install the computer andtrain your staff. Then we provide profes-sional on going service and support.

I would like to know more about Logic Com-puters Accounting Systems

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We know that the choice of software iscrucial. We recommend only the verybest proven software. For instance .

Jarman accounting software, designedby Accountants to provide the rightinformation to help you to control yourbusiness.We offer programs for integrated sales,purchase and nominal ledgers, payrolland stock control. They are all availablefor Apple II and Apple Ill computers.For further information or a demonstra-tion simply return the coupon or phone01-222 1122/5492.

COMPUTERS31 PALMER STREETLONDON SW1H OPR

70

Circle No. 149PRACTICAL COMPUTING May 1982

Software review mom-

Grown-upFollowing the launch ofMicrosoft's extended MBasiccompiler, Chris Bidmeadprovides an evaluation of thedialect. He finds that, farfrom being a beginner'slanguage, MBasic incorporatesa number of features aimed atthe professional.

THE INTERACTIVE NATURE of Basicmakes it much the most sympathetic lan-guage for the beginner, who benefitsfrom an instant response to mistakes.However, the line -by-line executionrequired by interpreted Basic is ponder-ous compared with compiled languages,and programmed decisions and sub-routines must be routed through linenumbers and not, as is more usual else-where, by labels.

These are complications the profes-sional programmer does not need, andwould put Basic out of court for anyonebut beginners, were it not for some rapidevolution since the language was firstconceived in Dartmouth College by Pro-fessors Kemeny and Kurtz in the early1960s.

The house of Microsoft, notably, hasbeen quietly extending the language tocope with these problems. Microsoft'sBasic 80, or MBasic as it is known insome versions, is a large interpreted lan-guage of around 28K, with powerful fea-tures and some rugged corners. The codewritten and debugged in the interpretercan be compiled using Microsoft's sup-plementary Compiler and gives: Faster -running code, maybe 10 times in

some cases. Protection for your source code. More compact, executable files. More room for machine -code subroutines.

When you load Basic 80 by typing"MBasic" from CP/M command level,the screen displays the version number,copyright data and the amount of freememory left. This number is often sur-prisingly small, only 27K, for example, onPractical Computing's 64K ResearchMachines 380-Z. Any program that listsover 10 pages is pushing the limit ofavailable memory, so it is just as well thatinterpreted MBasic, like the new com-piler, has the facility to Chain from oneprogram to the next, carrying data over inan area designated as Common for thedevelopment of large business packages.

TypingMBasic <filename>

from CP/M loads Basic, then loads andruns the named program. This makes itpossible to set up a CP/M Submit file, sothat the inexperienced user need onlyboot the machine and type "SubmitAccounts", or whatever the procedure is

Mcalled. This can be made more friendlystill by renaming the Submit fileRun.com.

The CP/M command line can carryfurther instructions to define the numberof files open at any one time, the upperlimit of Basic's occupation of memory -to leave room for machine -code routines- and a redefinition if necessary of thedefault record size of 128 bytes. MBasicprograms may be written in any editorthat handles ASCII text, but the simpleline -based editor provided inside theinterpreter is adequate for most pur-poses.

To edit line 1060, for example, youtype, naturally enough,

EDIT 1060If 1060 is the last line entered, edited orlisted it will still be in the buffer, and

EDIT.is enough to evoke it. The editor lets youfind the character, delete it, change it,insert characters, delete to the end of aline and list the line again. There are alsomore elaborate line -search facilities tojump to or delete up to the nth occur-rence of a character.

Control -H (backspace) can be used onmany machines to scan backwards in thesame way that the space bar in edit modescans forward character by character.Some Bios implementations trap thisfunction and may also affect deletion inthe editor. Unnecessarily, three differentconventions handle deletion of charac-ters.

When a line is entered, the Delete keysteps the cursor to the left, erasing thelast character by removing it from thescreen. In the editor, pressing "D"deletes the character that follows to theright of the cursor with a Teletype dele-tion convention that prints <backslash><character> <backslash>. When theeditor is in insertion mode, the delete keyadvances the cursor one character at atime to the right, printing an underlinefor each press of the key.

All this is likely to be complicatedfurther by your monitor's ideas of whatthe characters should be. Practical Com-puting's 380-Z, for instance, thinks that<backslash> is best represented by "i".

Microsoft Basic is frequently thrown inby manufacturers to provide some sem-blance of animation to the raw hardware,but there is seldom any attempt to con-figure its console input/output to avoididiosyncrasies of this kind. Deletionwould be easier if the cursor movedbackwards to overwrite the last characterin all three modes.

There is a useful, if limited, Renumberfacility. Renum by itself tidies up thewhole program to start at line 10 andincrement in 10s. The command may alsobe qualified with parameters, so that, for

Basicinstance, Renum 10000, 300, 3 changesthe numbering of line 300 to 10000, allsubsequent lines being incremented bythree. Lines that precede 300 are notaffected.

Any renumbering facility has to makesure that line references within lines areproperly reordered so that Gotos andGosubs still hit their targets. MBasic ismeticulous about this, but unfortunatelyRenum insists on renumbering from anygiven line number up to the final line ofthe source file, and cannot be limited tosmall sections within the sequence. If youwant to reposition a subroutine that runs,say, from 15000, you have to put up withthe whole of the program after line 15000being renumbered as well.

The alternative is to Delete the entireprogram except for the target subroutine,renumber that, save it as an ASCII file ondisc with

SAVE " <filename >,A"reload the original program and Mergethe renumbered subroutine back into theprogram. If you need to do this often youare probably writing very bad Basic prog-rams, but even its occasional use is tire-some.

It would be more helpful if Rpnumcould be confined to a subrange of num-bers, although MBasic would probablyhave to carry a forbidding amount ofextra code to implement this securely,checking Gosubs and avoiding duplicateor overlapping line numbers.

One other apparently cumbersome fea-ture of MBasic is its file handling. Filesare either sequential - serial input oroutput - or random. The serial modes letyou write or read data from the disc as ifit were winding through the system in acontinuous strip, like a tape machine.You have to start each read or write fromthe beginning of the file, and you mustdefine the file as either read or write -but not both - at the moment of open-ing.

The alternative, random files, allowsreading or writing without these restrict-ions, and records can be accessed in anyorder as if the data were set out in anarray of numbered pigeon -holes. How-ever, MBasic's implementation takesthree stages which distort Basic's original,transparent English -like coding.

First, the file is opened for randominput/output with its record lengthoptionally specified; the default is 128bytes. The "shape" of the record then hasto be set out with the Field instruction,which means defining to the system thesize of each data segment within theoverall length of the record. This is thepurpose of line 20:10 OPEN "R", *1, "FILE", 3220 FIELD *1, 20 AS N$, 4 AS A$, 8 AS P$

(continued on page 73)

PRACTICAL COMPUTING May 1982 71

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Circle No. 151

72 PRACTICAL COMPUTING May 1982

Software review

100 NDX% = 1110 WHILE A(NDX%) <> 999120 INPUT "NUMBER"; A(NDX%)130 NDX% = NDX% + 1140 WENDListing 1.

initialise the array index

next element of the array loop, or resume here on exit

(continued from page 71)30 INPUT "2 -DIGIT CODE"; CODE%40 INPUT "NAME"; X$50 INPUT "AMOUNT"; AMT60 INPUT "PHONE"; TEL$: PRINT70 LSET N$ = X$80 LSET A$ = MKS$(AMT)90 LSET P$ = TEL$100 PUT *1, CODE%110 GOTO 30

Each field must be a string. Datatypesother than strings can only be assigned tothe record after being converted to stringformat with the special function MKS$ -pronounced "make string" - as in line80 of the example. The fields are thenconveyed to the record buffer with LSetor RSet to position them left- or right -justified within the available space. Theyare then dispatched to disc with the Putinstruction.

Retrieving information from the disc inrandom mode involves a similar processin reverse order. It is easy for the prog-rammer to go wrong: for example, thesize of the record as fielded must notexceed the size in the Open instruction,and if this in turn is greater than 128bytes, MBasic has to be given prior noticeon powering up.

Much of the unfriendliness is caused bythe uneasy interface with CP/M, whoserandom -file facility arrived in version 2.0,rather as an afterthought, and then had tobe adjusted again in version 2.2. In theversion of MBasic called Standalone DiscBasic, which requires no operating sys-tem and copes with physical file handingon its own, the distinction betweensequential and random files becomesunnecessary, enabling mid -file updatingof files otherwise treated as sequential.

Within the limited data types allowedby the original concept of Basic, MBasicpermits numerical constants and vari-ables to be defined as integer, single ordouble precision, for which the systemsets aside two, four or eight bytes respec-tively. This limits the integer range tobetween -32,768 and +32,767, or 0 to65,535 in some versions. Single -precisionnumbers are stored with seven digits witha print limit of six, while double -precisionnumbers are printed and stored with 16digits.

Arrays may have any dimensions up to255, and provided the numerical value ofany subscript does not exceed 10 thearray may be assumed as needed, with noprevious declaration. Larger dimen-sioned arrays have to be predeclared withthe Dim statement. Arrays occupy thesame space as the equivalent number ofelements, with no overhead for the arraystructure.

Strings carry an overhead. The charac-ters forming the string reside in a stack

that grows downwards from the top ofavailable memory, overwriting CP/M'scommand -line interpreter, which is not'used in MBasic. Three additional bytesare needed for each string: one to definethe length and two to act as a pointer tothe start of the string in the stack.

Programmers can define data type asthey go along by making the final charac-ter of each variable the symbols % forinteger, ! for single precision, * for dou-ble precision or $ for string.

Alternatively you can make global datadeclarations of the form:

10 DEFSNG Fin an early non -executing line thatdefines all variables beginning with theletter F - or whatever character ischosen - as denoting single -precisionnumbers. Defint, Defdbl and Defstr dothe same trick for integers, double -precision variables and strings. Thedefault takes any named variable to besingleprecision.

Num and Num! are not redefinitions ofthe same variable - a single -precisionvariable restated as an integer - but ifco -existent in a program will be known toMBasic as two entirely separate identi-fiers. Careless handling of variable defin-ition can account for many intractablelittle bugs.

Despite the default to single precision,it pays to use integers wherever possiblebecause execution speed and array sizesdepend crucially on the specified pre-cision. For example, a loop using aninteger control variable can execute up to30 times faster than one using doubleprecision.

The Dartmouth College standardallows only one form of repetitive struc-ture, the For -Next loop. It is known as a"deterministic" loop, because thenumber of times the loop will execute ispredetermined by the program.

In the MBasic interpreter a While -Wend construction is also allowed, toimplement non -deterministic loops. TheWhile statement tests the data beforeeach cycle and in the absence of a particu-lar condition, supplied by the program-mer as a parameter, the loop is skipped,and the program resumes at the matchingWend statement. This construction mightbe used in a section of code designed toaccept a previously undetermined numberof data entries from the keyboard - seelisting 1.

Basic processing must follow thesequence of line numbers except whereredirected by If -Then decision state-ments, Loop instructions or diversions viaGosub and Goto. Even so the programflow cannot escape from its numericalprison: all these redirections have to be

made in terms of line numbers, and nocalls by identifier reference are allowed.This accounts for the structural mires thelanguage leads you into, and also cloudsthe "transparency" of the code.

Gosub 7000 does little to explain itspurpose to the reader; in Cobol, on theother hand, the programmer may pre-define a subroutine in a card -playingprogram - for example, by giving it thename "Shuffle" - and call that routinefrom appropriate places in the programwith the instruction Perform Shuffle.

MBasic provides one exception to theline -number rule: the programmer isallowed to use early lines of code todefine functions that may subsequentlybe called by name, with no line numberreferences. For instance,DEF FNX(Y$) = (Y$>= 'a') AND (Y$ <= 'z')will test Y$ for the quality of being alower-case letter, returning the value -1,which is MBasic's code for "True", if it is,and 0 if it is not. Functions defined likethis cannot, as in CBasic, be extendedbeyond a single logical line, althoughthere are ways of coping with the prob-lem.

MBasic output to the screen or to theprinter can be controlled with an exten-sive set of Print Using instructions. Theseare difficult to master but make format-ting very easy. The MBasic manual takesfour pages to explain the intricacies, andits laconic style still leaves much to theimagination.

One of our Practical Computing staffcommented that he typically spends asmuch time debugging the Print Usingstatements as in making the rest of thecode work. If you find this happening toyou, watch out. The cosmetics ofMBasic's powerful individual statementsare diverting you from the real problemof turning your algorithm into code.

To a programmer brought up on thepuritan virtues of Fortran, the string -handling facilities are succulent to thepoint of indecency. In addition to theusual Right$ and Left$ functions MBasicallows Mid$(X$,I,J), which returns thestring J characters long, starting at the Ithcharacter. Omitting J makes the functionreturn everything to the right of the Ithcharacter.

Most powerful of all, Mid$ is alsoavailable as a statement for in-housestring alteration. Suppose:

L$ = "I love Susie"Then the afterthought:

MID$(L$,7) = "Rode"gives L$ as

"I love Rosie"The operators > and < can be applied

to the ASCII set and, by extension, tostrings. Logical string comparisonmatches off two strings character bycharacter, subtracting the ASCII codes. Ifthe strings are of different lengths butmatch as far as they go then the shorter isdeclared "smaller".

(continued on next page)

PRACTICAL COMPUTING May 1982 73 '

Software review

(continued from previous page)The Swap statement, a general-

purpose instruction to exchange thevalues of two variables, is particularlyuseful in combination with string com-parisons, making alphabetic sorting veryeasy.

A professional feature of MBasic is theerror -handling facility. If you put an earlyline in the program, for example,

10 ON ERROR GOTO 50000you can then, from 50000 on test for andremedy all sorts of program errors.

For instance, left to itself MBasic willrespond to a Disc Full error conditionpassed up from CP/M by posting theappropriate notice on the console andcrashing out. This On Error command, inconjunction with a matching line in the50000 error routine can divert programflow from the automatic error handlingand offer you options that keep you inthe program. It could start5000 IF ERR = 61 THEN PRINT "No room left

on the disc"50005 rem 61 = "disc full"500010 files "".DAT" rem display existing data

files500020 INPUT "Which file would you like to

delete?"; FILE$You can even set up the routine to

respond differently to the same errordepending upon the line in which itoccurred, with a statment of the formIF ERL <10000 THEN PRINT "Do you want to

start a new disc?"Once the problem has been sorted out

the program can be returned to the pointwhere the error occurred with the state-ment "Resume".

To make your error handling reallycomprehensive you can include proce-dures to deal with errors that arise in yourprogram rather than MBasic. Thus, sup-posing you expected only lower-caseletters to be typed in, you could have30 A$ = INPUT$(1) rem this statement

accepts a single key40 IF NOT FNX(A$) THEN ERROR 100

FNX(A$) is the lower-case checkingfunction we defined earlier. Error 100 isour own invention, as MBasic's systemerrors only come in 67 varieties, leavingnumbers 68 onwards to be defined by theprogrammer.

Error trapping is no fun and takes upbig chunks of code, but if you are writingprograms for the commercial market it isessential to avoid dropping the user backinto CP/M, with nothing but an obscuresystems error message to stare at.MBasic's error -handling capability givesit the edge as a professional programminglanguage.

For the rest, MBasic is not so much alanguage as a substantial dictionary ofcommands, rich enough in its vocabularlyto be patched together to do practicallyanything. But a true "language" ought togive you a tool for thinking about theproblem as well as implementing thesolution.

Well -structured, serviceable programs

can be written in MBasic, though it doesrequire the exercise of external disciplineto hold together the structure of pro-grams of any length. MBasic itself is anaccretion of patches on the originallysimple "get you started" idea. If you arenot careful the programs you write in itwill be in much the same mould.

It seems likely, for two reasons, thatthis process of accretion will continue:many people now regard the language asa standard for microcomputers; and thenew generation of 16 -bit machines willprovide the space for expansion.

An almost identical version, calledBasic 86, is already available for the16 -bit 8086 Intel chip. Later versions ofMBasic are likely to feature named subroutines, with local variables, multiline user -definable functions, local renumbering, a more extensive editor, with global string

search and replace.

Animosity to Basic runs high, particu-larly in academic circles. The Danishcomputer language expert ProfessorEdsger Dijkstra makes no bones abouthis views: "When it comes to teachingthem programming", he says, "studentswho have had prior exposure to Basic ...are mentally mutilated beyond hope ofregeneration". Nevertheless, MBasic,with its wealth of facilities immediately tohand as you build your program, conferson the hardware a vitality that no othersoftware seems yet able to offer.

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74 Circle No 152 PRACTICAL COMPUTING May 1982

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Software review simmmmEn-

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1:This is a Sa le SuperCalc Worksheet

2:

3:

4:ASSETS

5:Acct.s Receivable

6:Cash

7:Unsold Goods

8:

9:Total Assets

18:

11:LIABILITIES

12:Acct.s Payable

13:Storage Costs

14:Labour

15:Materials

16:

C

Jan Feb

1888

388

8.25415

1.85*B5

8.5*B5

0.25*C5

SUM(B5:87) SUM(C5:C7)

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58 50

180 1.05*B14

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17:Total Liabilities

18:

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11:

12:

13:

14:

15:

16:

17:

18:

19:

20:

21:

22:

I/11NDec Total

1718.34 15917.13

814.45 7483.39

427.58 3769.28

2952.37 27889.80

384.88 7776.05

50.80 680.08

171.83 1591.71

85.52 795.86

690.55 18763.62

2261.83 16326.18

100.80 1280.00

2161.83 15126.18

SUPERCALCPromising to do for CP/Musers what VisiCalc has donefor those with 6502 -basedsystems, thisfinancial -planning packagefrom Sorcim is put through itspaces by Kevin Caley.VISICALC HAS BECOME the best sellingbusiness program of all time. Apple ac-knowledges that many of its machineshave been sold just because of VisiCalc.All this is fine if you own an Apple, Pet orTRS-80 computer, but many other com-puters cannot run VisiCalc, notably thosewhich use the CP/M operating system.

Personal Software, the originator ofVisiCalc, seems unlikely to produce aCP/M version, so many other companieshave tried to fill the gap. A number ofpretenders to the throne, have all claimedto be superior, but until now VisiCalc hashad a unique advantage.

Products such as Target, T -Maker,MicroModeller and Desk Top Plan,require the user to go through a series ofsteps starting with designing the model onpaper and progressing through a series of

menus to build up the model - all beforethe user can even start to put in the data.Another common feature of these pack-ages is that the operator has to use arather complex set of instructions to setup the model.

VisiCalc was revolutionary because itallowed the computer to build up a modelin the. way that is familiar to almosteveryone who works with figures. It letsyou write down the figures as you think ofthem, and then rub them out when amistake is noticed. The computer worksin the same way as its operator ratherthan forcing users to change their waysand learn a new system.

Using the package.The program turns a computer into a

combination of:a large piece of paper,

a calculator, a pencil, a rubber, an automatic typewriter.The "paper", or screen, is divided up into63 columns labelled A,B,C and so on upto BK, and rows numbered from one to254. Thus any position on the worksheet

can be referred to by its co-ordinates, forexample the cell in the top, left-handcorner is Al. In any cell you may type atitle, a number or a formula such asA 1 +A4 which means "add the numberin cell Al to the number in cell A4 andput the answer here".

Error correctionIf you ever have to prepare sheets of

detailed figures and calculations, such asestimates or cash -flow forecasts, you willknow how time-consuming it can be.After you have spent a few hours workingon the figures and all the figures are justhow you want them, one of three thingscan happen:

Someone asks you what would happen if aparticular quantity is changed, and youhave to spend a considerable time chang-ing and recalculating the figures.

You realise that you made an importanterror early on that affects all your results.

Your typist will be faced with pages offigures to type out in columns without mak-ing mistakes - and figures are far harder tocheck than words.

This is where VisiCalc comes into its own.(continued on next page)

PRACTICAL COMPUTING May 1982 77

Software review

(continued from previous page)It cannot save you much time in buildingyour model - writing down the figures- because that is where your experienceand skill come in, but if you make amistake it can preserve your sanity byallowing you to change the figures easily.

If, for example, you decide to have asub -total half -way down a page which hasnti room for one, with VisiCalc -- andnow SuperCalc - you simply press threekeys and an extra row is automaticallyinserted. If you want to change a figure,you merely type over the old figure, andbefore your eyes the whole sheet is auto-matically recalculated.

Saving copiesYou can save a copy of your work on

disc at any time or print out your work toproduce perfectly typed copies. This isideal if you want to produce, say, a cash -flow estimate for: the most likely sales forecast, the most optimistic forecast, the most pessimistic forecast.

In this way, days of work can be com-pleted in a couple of hours! an excellentexample of the ability of the micro toincrease productivity.

The SuperCalc program for this reviewwas loaned by Croft Computers ofBramhall, near Manchester. It was run ona Panasonic JD -800 microcomputer withCP/M and twin 8in. floppy -disc drives.Though CP/IVi allows the use of a widerange of software on different computers,the software often has to be tailored tothe terminal in use. If the software pro-ducer has included an installation prog-ram for your make of computer and youknow how to enter the requested data,this should be straightforward. If eitherof these is lacking, good support from adealer is essential.

Croft. ComputerS has been quick offthe mark in recognising the importance ofSuperCalc to CP/M machines and wasamong the first in the U.K. to haveSuperCalc working. Croft's SuperCalcuser manual and quick -reference card areas good as VisiCalc's - praise indeed.The package includes the master disc, asmodified -by Croft, the Panasonicmachine, and a card to label thePanasonic's user -definable keys withtheir VisiCalc functions.

Adjusting to SuperCalcAs an experienced VisiCalc user I

found it easy to adjust to SuperCalc.Many of the operations are identical: "I"is used to indicate a command, and manyothers differ only in detail.

Though SuperCalc is, overall, a greatimprovement on VisiCalc it does havecertain disadvantages. SuperCalc takesup more memory in the Panasonic thanVisiCalc does in an Apple, but since mostApples are 48K or less and the Panasoniccomes with 64K of memory, the practicaldifference is minimised. The maximum

:A:: 1 :: I E F H I1:

2: This Title oat entered into Box 81 and autosaticallg spills over.3:4:

5:

6:

7:

9:

18:

Prod 1 Prod 2

Price 56.38 61.93+ VAT 8.45 9.29

Total 64.75 71.22

4444444 0040 t *************1****

Prod 3 Prod 4 Prod 5 TOTAL

68.12 74.94 82.43 343.7218.22 11.24 12.36 51.56

78.34 86.18 94.79 395.2711:

12:

13:

14:

15:

16:

17: Notice that columns have different widths and that 'C' is at Zero18:

19:

28:v 818

Enter B,C,D,E,F,6,I,L,11,0,P,G,R,S,T,U,11,Z or ?2/

size of the model that can be prepared isreduced, but this will only affect the mostambitious users.

SuperCalc has been written for use ona wide range of terminals, so the visualeffect will vary between computers. Forexample, some will show the position ofthe cell that is being worked on in reversevideo while others will use < > forthe same task. The Croft version usesreverse video as used by Apple VisiCalc.On many terminals, including thePanasonic, the first and last character inthe entry cell can be obscured while thecursor is over them. SuperCalc cursormovements can be slightly slower thanVisiCalc, depending on the hardwareused.

Top -class printoutsOn the positive side, SuperCalc allows

more than one model to be loaded atonce, so sub -models can be consolidated.SuperCalc allows any column to have anywidth from zero to 127 characters at thesame time, while VisiCalc sets all col-umns to the same width with a minimumof three. This makes for much neaterpage layouts.

If you are entering a heading on aVisiCalc sheet once a cell is full, any extracharacters are not shown. With Super -Cale the whole title is entered into onecell and the extra characters automat-ically overflow into the following cells,removing the need to rewrite the head-ings when the column width is changedand allowing more sophisticated head-ings.

SuperCalc allows the screen to displaynot only all the values but, alternatively,all the formulae, with or without the

borders indicating the co-ordinates. Thesheet can then be printed out in theformat shown on the screen.

SuperCalc has a unique command /Pwhich protects the contents of a cell or arange of cells from change. Commandswill operate on surrounding cells butleave protected cells unchanged. Bypressing the ? key at any time, SuperCalcwill present its user with a full screen ofinformation and hints, without losing anydata.

It is not easy to disguise the fact that anApple VisiCalc printout has been pro-duced by computer rather than a typist. Ithas no lower-case letters, no pound signon the keyboard, and it cannot drawsolid, horizontal lines. The Panasonic hasa more comprehensive character set, andSuperCalc printouts can be made to lookas if they have been typed.

Conclusions Owners of CP/M machines need nolonger feel inferior and change the subjectto WordStar when Apple and Pet ownerstalk about VisiCalc. SuperCalc is equal or superior to Visi-Calc in every important feature. Because SuperCalc and VisiCalc allowusers to apply methods with which theyare already familiar, they are both mucheasier to learn than any competing prog-ram. Anyone who has used VisiCalc willquickly feel at home with SuperCalc. SuperCalc is produced by Sorcim Cor-poration, 405 Aldo Avenue, Santa Clara,California; it is available from EncotelSystems, 530-539 Purley Way, Croydon,Surrey. Telephone 01-686 9687. Super -Cale costs £185.

78 PRACTICAL COMPUTING May 1982

HOW TOGET MORE

FROMYOURMICRO

TAKE A COURSE ATTHE COMPUTERTRAINING ANDEDUCATIONCENTRE

CP/M* (User level) 2 daysA practical course designed forthose unfamiliar withCP/M, familiarising the new userwith the operation ofthe typical hardware attached to a disc -based Z80microprocessor system, and giving an understand-ing of the facilities available and of its managementof disc files.

Advanced CP/M 2 daysThis course is designed for those who wish to modifythe standard CP/M operating system and includes adetailed investigation of BIOS and its interactionwith CCP and BDOS. Previous assemblerexperienceis essential.

Programming in BASIC 1 weekGiving a thorough understanding of the BASIClanguage and enabling the student to put thisknowledge into practical use, facilitated by hands-onsessions and practical exercises.

A professional organisation with first classtraining facilities in Central London.

*CP/M is the T/M of Digital Research Corp.t Wordstar is the T/M of Micropro Corp.

Programming in PASCAL 3 daysGiving an understanding of structured programmingtechniques as used in PASCAL and providingpractical experience on a microcomputer.

Wordstart Wordprocessing 2 daysGiving the user an understanding of the facilitiesavailable in the Wordstar/Mailmerge Wordprocess-ing System and hands-on experience which enablesthis knowledge to be put to practical use.

Al! courses are in London. A wide range ofhardware is available for practical work.

ContactThe Courses Secretary, Computer Train ing& Education Centre Ltd, 102-108 Clerkenwell Road,London EC1. 01-251 4010/4019.

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Circle No. 155

PRACTICAL COMPUTING May 1982 79

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80 PRACTICAL COMPUTING May 1982

13C1r(131111The newt APPLE-II *compatible Euro-PALcolour microcomputer now available

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The multi-user system ishoused in a standard S-100mainframe chassis enablingindividual users to run pro-grams independently andsimultaneously, while stillhaving access to sharedresources (hard disc storage,printers etc.) - via the S-100BUS Inter ProcessorCommunication channel.

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Circle No. 160PRACTICAL COMPUTING May 1982 83

How will the giantsreact to the micro?The mainframe manufacturersare finding thatmicrocomputers - so recentlyderided as mere toys - aremaking inroads into theirhitherto safe preserves. ClareGooding examines theircontrasting styles, andponders on how the giantmainframe builders will fareamong the quick-wittedbandits of the micro world.

TIME WAS when anyone working withcomputers had a hard time at socialgatherings. If you were foolish enough toadmit it, the reaction was either "Ohthat's all too technical for me, don't knowanything about it", or worse, an inunda-tion of stories about payroll computererrors and gas bills for £0.00. Nowadays amore likely reaction is, "We've got one ofthose at work, amazing little machine, wedo everything on it".

The computer, that great mystical,rather threatening beast, has become lessremote, and almost respectable. Theamazing little machine is likely to be amicrocomputer. Those who dismissedPets, Apples and Tandys as hobbyists'toys now find them so ensconced in thebusiness world that they speculatewhether micros will eventually replacethe mainframe.

The key to the rapid progress of themicro has been software availability.Instead of being limited to the programssold by their friendly dealer, people havealso written their own software.

A few years ago this would have beentantamount to blasphemy. The micro wasstill considered an experimental freak,nothing to do with real computing, exceptby an enlightened few who set aboutlinking micros with larger "host"machines to make software developmentpossible in a more familiar environment.

Amateur beginningsSoftware houses such as CAP and

Logica, who had made their killing onhuge mainframe projects, were alreadyfiddling with micros in attics and base-ments. At the same time do-it-yourselfhobbyists began to discover the joys ofBasic. Even if the results were far fromperfect, they provided an alternative tothe turnkey products at a price smallusers could afford.

As for the hardware, new potential

users thought they could afford a microwhere previously a bureau service or alarger machine of their own would havebeen out of the question.

The mini paved the way for the microas companies like Hewlett-Packard andWang offered cheaper hardware solu-tions, but the nature of software produc-tion stayed much the same. The microarrived when the pattern of the computermarket was changing in any case. Soft-ware was beginning to play a larger part,although a firm wanting to computerisewould still look first at the hardware itwanted, and then find a software house ora package through the manufacturer.

In the old days someone somewhere inan organisation would realise that a com-puter might make the company moreefficient, by doing payroll and perhapsmore specialised company -related tasks.

A consultant might move into thecompany, spending some weeks gettingfamiliar with existing routines. If thehardware itself had not been chosen it

might be his job to specify the machine aspart of the system design.

Usually an existing manual systemwould provide the skeleton, and someconstraints, for the eventual computer-ised application. The consultant wouldconfer with the systems analyst, whowould translate the entire system intoseparate modules or programs.

Ample documentationEach program had its own design

document, a specification which set outthe size and names of fields, the layout ofreport printouts, and so on. These wereprobably passed on to a fairly large teamof programmers.

It was perfectly possible for program-mers never to know the clients' originalaims for the system. They could spend allday shoving fields and values aroundwithout knowing what they represented:their prime concerns were, not surpris-ingly, far removed from those of theclient company.

84 PRACTICAL COMPUTING May 1982

Micrornarket

In the mid -seventies there were stillsome hangovers from the days whensoftware had been of secondary impor-tance and even given away free withhardware. Programmers took great pridein tweaking: devising clever routineswhich would run more efficiently inhardware terms.

The problem with clever -clever pro-gramming was that, however efficiently itran, when it came to changing it ordebugging at a later date no-one elsecould decipher what the whizz kid hadthought up.

Changing skillsAs hardware prices began to drop,

programming became increasingly impor-tant. In most large software houses prog-rammers were taught that documentationwas essential and that all developmentprogramming should bear future main-tenance in mind.

Turnkey projects became less commonas companies accepted package solutionsto data-processing problems. Tailoringpackages to individual requirements waseasier and more profitable with well -structured and documented programsthan when programmers had given vari-ables names like Fred.

All this meant a shift of skills. Special-isation had been essential before becauseof the size and complexity of systems.The jigsaw of hardware operating systemand programming language in a specificsystem design called for inside know-ledge at different levels.

With big data-processing shops the jobof operator was, and still is, a separateskill demanding familiarity with the insand outs of large-scale systems software.But in the small company - a first-timeuser or one which had perhaps relied on abureau before buying its own machine -the roles would be merged.

On every deskThe end -users might be people who

had been with the company for sometime, familiar with the business and poss-ibly the manual system which had pre-ceded the computer. Often operating themachine formed only a small part of theirduties and it would be a matter of teach-ing them to treat the new system as a tool.

The new small-business systems werewithin the reach of many more businessesthan the mainframes with their specialpremises and team of attendants. Themystique began to be dispelled as peoplesaw small computers being installed intheir own office premises - not behindclosed doors, with special under -flooringand cooling systems, but in the samecorridor, and under the care of Brenda -

who -has -been -here -for -years.When the microcomputer burst

through the pages of the Sunday coloursupplements into homes and businessesthe old mystery was really polished oft.People discovered that it was possible

t((

to learn Basic and write programs.Operating systems like CP/M meant thatpeople could manage their ownmachines, and the market realised thatapplications written for particularmachines and operating systems in themicro market were saleable.

Computers were more widely used thanever before, and end -users expectedbetter service, more for their money, andeven access to their own information -logical enough, but impossible in the dayswhen hardware had been so expensivethat the computer had to be carefullytuned to maintain performance perpenny.

Handing over power to end -users canhamper the absolute performance of themachine, but makes the people morevaluable because their time is spent moreefficiently. In the eighties, this has be-come the important part of the employ-ment equation. People are becomingmore aware of computerisation than theywere when their pay slip and bank state-ment were the closest they ever got to acomputer.

While the "Noddy programs" gatherdust, the new and sophisticated applica-tions of the micro have forced the data-processing business to take notice.Microcomputers have long been part ofthe furniture in universities and colleges,and they have already proved their worthat departmental level in large companieslike Shell.

Those in the DP industry who had beeninclined to dismiss the microcomputer aslittle more than a toy, far removed from

real computing, have had to re-evaluate.Nonetheless software houses recognisedthe limitations of Basic, the native lan-guage of the average micro.

Too many people had pushed out soft-ware which worked for them, withoutrealising how easy it is to bomb softwareif it does not cater for all sorts of errors. Itis easy enough to write a routine to do aparticular job, but much more difficult tomake it watertight, bug -free and easy forthe user to work with.

Powerful toolsMicro packages became freely avail-

able but they sometimes lacked quality.Some needed extensive testing by theuser and others were just so limited inpower that users would become exasper-ated and look for something else.

The micro software market wentthrough a similar learning cycle to themainframe and minicomputer marketsexcept that microprocessors could belinked to big host machines where thesoftware could be developed before beingrun on the micro.

This gave access to the more powerfuland sophisticated techniques of pro-gramming, particularly high-level lan-guages. The more enterprising softwarehouses concentrated on supplying thosetools to the micro, and gradually Pascal,Cobol, Algol, APL and RTL/2, all highly"professional" languages, began toemerge on micros.

The other big problem was lack ofsheer size and power. Even if -you were

(continued on page 87)

PRACTICAL COMPUTING May 1982 85

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Micromarket

OK, MICRO ././

1 -E -r5 SEE IF WE

CAN'T INORK1-06-ETHEI

(continued from page 85)lucky enough to find watertight software,the limitations of the floppy disc madethemselves apparent pretty quickly if themicro was running several applications,rather than just one.

By this time, software experts whose. roots were in the traditional data-

processing world were well aware that themicro offered opportunities which madeworking in a Cobol shop with a main-frame dull by comparison. Thoroughlyprofessional software tools, like the CISCobol compiler from MicroFocus, com-plete with development aids, had beenproduced. Far from dismissing the microas a toy, most professional programmersbecame enthusiastic and realised thattheir skills were not necessarily obsolete.

The gap narrowsEverything had grown up a little since

the original eight -bit micro. Technologyhad moved on, and hard discs solved thestorage problem for microcomputers.Winchester -type hard discs, such as Cor-vus, meant no more fiddling aroundchanging floppies and squeezing data intooverflowing spaces.

The 16 -bit machines that have beenappearing on the market in the last yearor so are not far removed from minicom-puters. As well as mass storage, operatingsystems cater for multi -users, offering thekind of facilities that used to be associ-ated more with mini and mainframemachines.

Manufacturers had learnt the impor-

tance of operating systems to machineand software sales from the immensepopularity of CP/M. In the eight -bit mar-ket, people wrote applications which ranwith CP/M simply because it had thereputation of offering a wide choice ofsoftware. The cycle perpetuated itself:people bought CP/M machines becausethey knew that there was plenty of CP/Msoftware out there, and programmers,sure of their market, went on writing it.

. Even Digital Research, the small sys-tems house which originated CP/M,admits that it was not necessarily the bestoperating system. It was ready and avail-able when people needed it, and becamerecognisable and fathiliar. Just hoW tighta grip it now has is evident in that even onthe more powerful 16 -bit machines of thenext generation, customers are asking for'CP/M to be implemented, much to theamusement of those who have nurturednew operating systems into being so thatthe new machines can make the most oftheir extra power.

There is a wealth of indepenently-written software applications on tap toCP/M, with a range and choice whichwould bewilder most mainframe pundits.As a result, the micro manufacturers haveevolved a different method of doing busi-ness from the original "here's the hard-ware and you'd better stick to us for thesoftware" technique. Most micro manu-facturers did not attempt to supplyapplications. Hardware dealers couldrefer buyers to whole lists ofindependently -written software.

This off -the -shelf method of selling

software like soap powder from a super-market works far better in the microenvironment than it ever did with thelarge machines, though there are majordifferences in the two markets.

To make a profit, micro software dis-tributors have to sell in volume, and thecustomer has to take it or leave it. Thereis no question of elaborate tailoring foreach customer, and packages have to berobust enough to stand on their own withthe minimun of maintenance. Documen-tation and operating instructions have tobe of a standard that would allow acomparatively naive first-time user to getthe package up and running entirely onhis own.

If the package does not work, or if thereare problems in sorting it out, it is prob-ably cheap enough to be thrown away.The price of the microcomputer itself hasalways put an upper limit on the cost ofthe software, however brilliantly devisedand written.

In the mainframe market there can beno question of "disposable software". Itis not unusual for a full suite of financialand payroll programs, or perhaps a set ofdevelopment aids, to cost well over£20,000. High initial prices are followedby heavy maintenance costs.

Large packages require constantmaintenance. Payroll packages needinstant updating as laws and tax regula-tions change. Most micro packages, ifthey receive any maintenance at all, willbe updated through the post.

Weak excusesOften the end -user now has control of

parameters and can do a certain amountof housekeeping maintenance, but theonus is still on the supplier to make surethat software is bug -free.

Large systems for mainframes involvea lot of high-level language program-ming, but with high-level languages nowas much in evidence on micros as onmainframes, the excuse that such pro-gramming skills are expensive can hardlyaccount for the difference in the cost ofsoftware.

Mainframe installations do demandmore skills at all the different "layers" ofsoftware. The mammoth operating sys-tems of mainframes make writing themfar more difficult than when dealing withTRSDOS or CP/M. Doctors or shop-keepers writing their own applicationscan be their own consultant, but for main-frames the role of consultant and thesystems analyst remain vital. The systemhas to run efficiently, which may involvea systems programmer as well as theoperator. No wonder it becomes expen-sive.

The mainframe market has been ham-pered by its complex and grossly ineffi-cient operating systems, conceived whengiving power to the end -user was out ofthe question, and portability to be

(continued on page 90)

PRACTICAL COMPUTING May 1982 87

Can you plan aheadfor growth?

Can you recognisea good prospectwhen you see one?

Have you a nosefor the right kindof deal?

Can you talk ourlanguage?

Are you prepared to stickyour chin out?

Haveyou got what it takesto take what we've got?

It takes a lot to become a Canon dealer.But if you've something to offer us, we'vecertainly something to offer you.

Achieve agreed targets for the CanonCX-1 computer range and we'll give you ahefty 5% additional bonus to use for extraadvertising. That's on top of your standardmargin.

Canon Computer dealers have so manyadvantages.

Limiting the number of dealers willprevent the dubiouspractices other personalcomputer dealers suffer.And make destructiveprice wars unnecessary N.

No more compet-ition from direct selling -the CX-1 range will be sold

exclusively through our chosen dealers withthe help of Canon's national Back-up team.

And heavy -weight advertising supportfrom summer onwards.

We'd welcome your application tobecome a Canon Computer dealer, but bewarned - we didn't get where we are todaywithout being choosy.

To give you the full story face to face,we've organised a Nationwide CanonComputer Roadshow. It'll be in your area

between April 28th and May 26th.Foryour free invitation please contactLiz Horsley or Alex Glickberg on01-680 7700 or write to them atCanon (UK) Ltd., Waddon House,

,...:Stafford CR9 4DD

The next step forward Circle No. 162

88 PRACTICAL COMPUTING May 1982

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Circle No. 162

89

Micromarket

-1-1-115 COULD BE

THE 5TART °FABEAun FutrRiNDSHIP././

continued from page 87)avoided, since the manufacturer was anx-ious to keep his users well and trulyocked in to his equipment.

'The micro market proved that softwareportability was likely in the long run tobenefit everyone since the more softwareis available, the more likely hardware isto sell, especially as the software decisionhas become the crucial part of buying asystem. The choice of Unix, the time-sharing operating system from Bell, forsome 16 -bit machines has opened up thepossibility of software applications port-able between micro and mainframebecause mainframe manufacturers arealso adopting Unix.

A lesson learnedMiraculously, the big boys seem to

have learnt the lessons of the micro mar-ket. IBM finally put the stamp of respec-tability on micros by launching its own16 -bit machine last year with outside -written hardware: quite a U-turn for thecompany which originated the idea oflock -in operating systems and hairy sys-tem conversions.

IBM picked CP/M-6, and promises totalcompatibility with CP/M. Other applica-tions were announced; Peachtree, forexample, was approached for its financialpackages to be supplied as the standardsoftware applications with the IBM Per-sonal Computer.

Software publishing, which gives thesame service to program authors as bookpublishers give to novelists, has becomethe in thing in microcomputing. CaxtonSoftware Publishing, which claims to bethe first such London publisher, putsenormous emphasis on 'the quality ofpresentation.

The mini and mainframe markets aretaking note, and organisations like Wangnow actively encourage independentsoftware suppliers. Even IBM looks withfavour on suppliers of "alternative"applications.

Micros have made end -users moredemanding. Data-processing managerscan no longer ignore micros. The userwho would once docilely accept a six-month wait for his application is nowmore likely to go out to buy a micro forhis department.

The idea of de-skilling the use of acomputer had already won acceptance inthe micro field: soon people wanted toget their hands on the mainframe, too.This change was really just a process ofmoving the skills one step up the line.Programmers had to write software whichwas that much more clever so that usersdid not need to be.

Now the ultimate user-friendly toolsare being developed at the mainframeend: speech synthesis and interpretation,expert systems, and natural -language sys-tems which allow the users to communi-

cate with the computer on their ownterms. Some of these products, the resultof artifical-intelligence research, arealready being sold, but they are notori-ously power-hungry and would chew upthe processing power of a micro beforeyou could do a syntactical analysis of JackRobinson.

Not forgetting the matter of existinginvestment, mainframes are unlikely tobe pushed out by micros simply becausetheir immense processing power is stillneeded for the everyday running of com-panies. The micro excels as a flexible toolfor the end -user, but the mainframe isstill needed for the dirty work: the corpo-rate processing of payroll and accounts.

The next stepThose micro users who declared UDI

with their own departmental machine arebeginning to discover that it would bevery useful to be able to tap into themainframe sometimes, for data, or sheerprocessing power. And the mainframescan get on with number crunching ordata chewing far more efficiently ifrelieved of all those specialised applica-tions. The next big issue for the computercommunity will be networking and tele-communications. If we can get it right,both micros and mainframes will findtheir niche in systems where the qualityof the job matters more than the size ofthe mill.

90 PRACTICAL COMPUTING May 1982

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PRACTICAL COMPUTING May 1982

Circle No. 16391

new Sams booksApple InterfacingJonathan Titus, David Larsen and Christopher TitusTested interfacing circuits that work are presented in this book aswell as the software (in BASIC) necessary to connect yourApple IIcomputer to the outside world. Control of electronics and electro-mechanical devices, monitoring of temperature, pressure, liquidlevel, etc., and communication with other computers, modems,serial printers and interface devices are made possible by the fullexplanations of the 6502 microprocessor, Apple and I/O inter-facing, flags and breadboarding.£7.65 206 pages 672-21862-3

Mostly BASIC: Applicationsfor Apple II. Book 2Howard BerenbonA companion volume to Book 1, this book contains 32 chaptersand 37 complete programs written in BASIC for the Apple IIApplesoft microcomputer.Twotypes of educational fantasy gamesare a new feature in Book 2. Many of the programs can be easilymodified to run in other microcomputer BASICs.£9.05 218 pages 672-21864-X

Mostly Basic: Applicationsfor Your TRS-80. Book 2Howard BerenbonWritten in Level II BASIC for the TRS-80 Model I and Model IIImicrocomputers, this book contains 37 complete programsincluding two types of educational fantasy games. Many of theprograms will run on the TRS-80 Color Computer without modi-fications; some will require minor modifications.£9.05 216 pages 672-21865-8

Available from leading bookshops and these Sams Books stockists:

Intermediate Programmingfor the TRS-80 (Model I)D. HeisermanWritten using LEVEL II BASIC, this book covers standard BASIC,machine and assembly language programming.

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92

Circle No. 164PRACTICAL COMPUTING May 1982

Games

WHITEHALL is is a game of political intrigue,written in Apple integer Basic for a com-puter with at least 8K of memory. Theplayer takes on the role of an ambitiousMember of Parliament and attempts torise from the rank of parliamentary pri-vate secretary through the Foreign Officeto Prime Minister, by judiciously decidinghow much time should be spent in parlia-ment, in the constituency, or attendingto committee or ministerial respon-sibilities.

Each decision is closely scrutinised bythe people affected. If an MP neglects hisduties he may have to contend withpublic enquiries, international scandals,or votes of no confidence. Tricky policydecisions have to be made each year, onissues such as foreign aid and acceptingrefugees. Periodically the MP has to jus-

Solve the toughestParliamentary imbrogliowith Whitehall, Simon

Goodwin's political game.tify his pay increase to the electorate -and every few years he must face a gen-eral election. A narrow defeat can bechallenged by calling for a recount - butremember you are only allowed one ateach election.

The various party names were inventedbefore the advent of the SDP so noinferences should be drawn from theassignment of the player to the Democra-tic party. It would be simple to change thelisting to ensure that you always repres-ent a favourite real political party.

An opinion poll is displayed each year,

estimating the degree of support offeredby fellow MPs and the electorate, and thestate of your morale. Sooner or later yourimmediate superior is taken ill or decidesto retire, in which case you must attemptto gain promotion. Beware of beingpushed upstairs into the House of Lordsonce you have reached respectable rank.

The Whitehall program should run,with a few modifications, on any micro-computer with a Basic interpreter andat least 8K of memory. Some of the printformatting may need to be changed if youare not using a 40 -column display. TheBasic used is integer only, so a few Intstatements may be needed to preventridiculous displays - for example, theloss of an election by 0.25 of a vote.

The Apple Rnd function is slightly(continued on next page)

Whitehall and thecorridors ofpower

,

.4.1.401.%

c4..2

'1111111'11

-

900010

20

DIM AI(10)TEXT,: CALL -936: REM CLEAR VDUPRINT "==== ***** *****=*******====...= ***** 44.*"PRINT,"=.

410420430440

F=20 -0 -P -CPRINT "REMAINDER (FAMILY DUTIES) ";F: PRINTIF A=5 OR A=4+ RND (2) THEN 1500IF AR RND (30) THEN 470

30 PRINT "* wHITEHALL 450 PRINT "CRISIS !! EARLY ELECTION FORCED UPON GlivERNmE)7.-40 PRINT ". : PRINT50 PRINT ". GAME (C) 1980 S.N. GOODWIN. 460 COTO 150060 PRINT "* 470 REM CRISIS. WHAT CRISIS ?70 PRINT -****=.). ***** (..===4== *************** 498 REM75 FOR D=0 TO 1000: NEXT D 499 REM CALCULATIONS ****.80 PRINT : PRINT "DO YOU KNOW THE RULES?" 500 H=I1*((D-5)=(P-5)=2)/50-)H-190 INPUT AI: IF AL(1.1)="Y" THEN 1800 510 IF H=100 THEN H=100- RND (15)98 REM 520 IF H=0 THEN R. RND (6)99 REM INITIALISE *4..4.* 530 E=E*((C-5).1.3.(D-5).(1.-5)+(M-50)/5)/150+E-A+C-1

200 H=40. RND (21):E=35. AND (31) 540 IF E>100 THEN E=99- RNU (10)210 M=45* RND (21) 550 IF E<0 THEN E= RND (3)220 T=0:A=0:R=1 560 M=Ms((F-5)=3.(E-401/10.(H-500/10)/100.M-A230 CALL -936: REM CLEAR VDU 570 IF M.100 THEN M=100- RND (5)298 HEM 580 IF M=0 THEN M= RND (15)299 REM MAIN LOOP 590 GOSUB 1300300 T=7.1:A=A+1 598 REM310 PRINT : PRINT 599 REM PRESET EVENTS320 TAR (16): PRINT "YEAR "IT: PRINT 600 IF D> RND (4) THEN 640330 IF T=30+13+ RND (6=R) THEN 370 610 PRINT "PARLIAMENT IS CONCERNED ABOUT YOUR MINISTERIAL PERFO340 PRINT "WELL DONE, SENILE... YOUR CONSTITUENCY PARTY 'ENCOURAGE' RMANCE."

YOUR RETIREMENT FROM PARLIAMENT." 620 PRINT "A PUBLIC ENQUIRY IS SET UP TO CHECK YOUR ACTIVITIES."350 GOTO 2000 PRINT360 PRINT "TOTAL MUST ADD UP TO 20": PRINT 630 E=E+14/15:M=M=12/13:H=H(.8/9370 INPUT "ENTER MINISTERIAL DUTIES ".1): PRINT 640 IF Cx RND (5) THEN 720380 INPUT "ENTER CONSTITUENCY DUTIES "..C: PRINT 650 PRINT "YOUR LOCAL PARTY ARE ANNOYED ABOUT YOUR ATTITUDE."390 INPUT "ENTER PARLIAMENTARY DUTIES ".P: PRINT 660 PRINT "THEY STAGE A VOTE OF NO -CONFIDENCE.": PRINT400 IF D.P+C=20 THEN 360 (listing continued on next page)

PRACTICAL COMPUTING May 1982 93

(continued from previous page)unusual. Rnd(3) returns 0, 1 or 2 atrandom, and so forth. If your computerhas a function of the form Rnd(0) whichreturns a value between 0 and 1 then youcan replace Rnd(N) by

INT(RND(0)*N)

Text in line 100 selects the display of textrather than graphics on the screen. Call-936 activates an Apple monitor routinewhich clears the screen and the hash signused in If statements corresponds to <>,meaning not equal, in standard Basic.

The vertical line in 1570 is an exponen-tial symbol, and is entered as shift -N onthe Apple keyboard. Most computers usean upward arrow or two asterisks todenote this function. The patriotic Tele-type persists in printing string variables aspound signs rather than dollars.

The only string variable used by theprogram is A$, which is declared to havea maximum length of 10 characters in line90. Most Basic interpreters will not

require this statement. The expressionA$(1,1) which returns the first characterof the string A$ could alternatively bewritten as

LEFT$(A$,1)The Apple Tab function is not used insidea Print statement. Hence the functionTab(9) causes the computer to print thenext text on the ninth column of thedisplay. Beware of integer Basic If state-ments - only the statement immediatelyfollowing the If is conditional to it, so thatthe line100A = 9 : IF A = 8 THEN A =7 :A =0

leaves A with the value zero. Other func-tions and statements in the program arein standard Microsoft Basic form.F: Family dutiesD: Ministerial dutiesC: Constituency dutiesP: Parliamentary dutiesM: Player's moraleH: Support in the HouseC: Constituency supportA$: General-purpose string

T: Year number in careerA: Year number since electionR: Player's rankJ,Y: General purposeX: Time delay

Whitehall is not intended as a serioussimulation of life in the corridors ofpower, but despite a few weaknesses Ihave found it addictive. The player isnever out of office, for instance - butperhaps he would have lost his seat if theparty went into opposition, or maybe,like Churchill, transferred allegiance atan opportune moment. Some players maysubscribe to the cynical view that politi-cians behave in much the same waywhether they are in power or not.

It seems fitting to leave the last word toa former Cabinet minister who himselfchanged parties during his career. At ameeting of constituents he was reportedto have praised the National Health Ser-vice with the words, "I have spentseveral days visiting mental hospitals,and found myself completely at home".

(listing continued from previous page) 1430 IF R44 THEN 1440: PRINT -CABINET MINISTER.": GOTO 1480670 J=31 -E43 -C: IF Jo> THEN J= RND (3) 1440 IF R45 THEN 1450: PRINT "SECRETARY OF STATE.": GOTO 1480680 PRINT "VOTES IN YOUR FAVOUR .... ":31-J 1450 IF 1746 THEN 1460: PRINT "PRIME MINISTER.": GOTO :480690 FOR X=0 TO 700: NEXT X 1460 PRINT "LIFE PEER - YOU ARE 'PROMOTED' TO THE HOUSE OF LORDS."700 PRINT "VOTES AGAINST YOU .... "(J: PRINT710 E=E*32-Jo31,mom-.(J+30)460 1470 PRINT "YOUR CAREER IS OVER.": GOTO 2000720 IF P* RND (4) THEN 760 1480 PRINT : GOTO 1200730 PRINT "MAJOR INTERNATIONAL SCANDAL OVER " 1498 REM740 PRINT "BRITISH GOVERNMENT DISORGANISATION.": PRINT 1499 REM ELECTION750 MoM*10/11:H=H*15416:E=E*13/14 1500 PRINT "A GENERAL ELECTION IS CALLED.", PRINT760 IF F. RND (4) THEN 800 1510 PRINT "WILL YOU STAND FOR 'DEMOCRAT' RE-ELECTION?"770 PRINT "FAMILY CRISIS LEAKED TO MEDIA."780 PRINT "CONSIDERABLE BAD PUBLICITY GENERATED.": PRINT 1520 INPUT AI: IF AL(1.1)4"Y" THEN 2000790 M=M*345:E=E*12/13:H=H+ RND (7)-3 1530 PRINT : PRINT "RESULTS ARE COMING THROUGH.")798 REM 1540 FOR X=I TO 6: FOR Y=1 TO 300799 REM RANDOM EVENTS ***** 1550 NEXT Y: PRINT "."1: NEXT X800 J= RND (10): IF J=0 THEN 900 1560 PRINT : PRINT810 IF J=I THEN 950 1570 A=-25000-(E*260)- RND 14001-(R 4)

820 IF J=2 OR J=5 THEN 1000 1575 IF Ao1000 THEN A=I000+ RND (1000)830 IF (J=3 AND 809) OR (J=3 AND T030) THEN 1060 1580 PRINT "LOYALIST PARTY ")01

840 IF (J=4 AND R49 AND T*6) OR (J=4 AND T'30) THEN 1070 1590 FOR Xo0 TO 500: NEXT X: PRINT850 PRINT "GENERALLY AN UNEVENTFUL YEAR.": PRINT 1600 PRINT "PROGRESS PARTY "1400+ RND (200)860 GOTO 1200 1610 FOR X=0 TO 700: NEXT X: PRINT900 PRINT "FAMINE IN THE FAR EAST.": PRINT 1620 PRINT "BIRTHDAY PARTY "125000/365910 PRINT "DO YOU SEND AID ?": PRINT 1630 FOR X=0 TO 900: NEXT X: PRINT920 INPUT AI: IF AI(1.1)4"1" THEN 940 1640 PRINT "ENTROPY PARTY "i RND (200)930 E=E*(30- RND (11))/25:m=m*1049,H=H*10/11: GOTO 1200 1650 FOR X=0 TO 1100: NEXT X: PRINT940 E=E*(30- RND (21)7/25: GOTO 1200 1660 PRINT "DEMOCRATIC PARTY (YOU) "125000-A950 PRINT "FOREIGN REFUGEE CRISIS.": PRINT 1670 FOR X=0 TO 1300: NEXT X960 PRINT "WILL YOU ACCEPT IMMIGRANTS ?": PRINT 1680 IF A012500 THEN 1700970 INPUT Al: IF AL(1.1)4"Y" THEN 990 1690 PRINT "WELL DONE.": PRINT :A=0: GOTO 500980 EoE*(30- RND (11))425:M=M*1049: GOTO 1200 1700 PRINT "YOU SEEM TO HAVE LOST!"990 E=E*(30- RND (2)»,25:H=H*13/12: GOTO 1200 1710 PRINT "DO YOU DEMAND A RECOUNT?"000 PRINT "TIME FOR A PAY INCREASE FOR M.P. S ? ": PRINT 1720 INPUT Al: IF AI(101)4"Y" THEN 2000010 PRINT "WHAT INCREASE DO YOU SUGGEST(2) ?":Jo RND (5) 1730 IF Y4300 THEN 1740020 PRINT : PRINT "ELECTORATE SUGGEST ";J*3+51" 2" 1735 PRINT "SORRY. NOT ANOTHER!": GOTO 2000030 PRINT "SOME M.P. S WANT "(J05+203" 0": PRINT 1740 Y=300: PRINT : PRINT "O.K. HERE GOES...."040 INPUT XIE=E+(J*4+6)-X 1150 FOR X=0 TO 900: NEXT X050 41=41-(J*4)+X:M=H-(J*4+6)+X: GOTO 1200 1760 GOTO 1560060 PRINT "YOUR SUPERIOR IS SUDDENLY TAKEN ILL.": GOTO 1080 1798 REM070 PRINT "YOUR SUPERIOR DECIDES TO RETIRE." 1799 REM GAME RULES *****080 PRINT "WILL YOU TAKE HIS PLACE... ?": PRINT 1600 CALL -936: REM CLEAR VDU090 FOR Xo0 TO 800: NEXT X 1810 PRINT " WHITEHALL GAME RULES": PRINT100 IF H+144.5, AND (70)+40 THEN 1120 1820 PRINT "YOU START THE GAME AS A PARLIAMENTARY PRIVATE SECRETARY110 PRINT "YOU KEEP YOUR PRESENT POSITION.": GOTO 1400 AND AIM TO RISE TO THE RANK OF"120 PRINT "YOU SUCCEED: NEW RANK "J:R=R+1: GOTO 1400 1830 PRINT "PRIME MINISTER BY MAKING DECISIONS ABOUT HOW MUCH TI198 REM ME YOU SPEND ON THESE ACTIVITIES :": PRINT199 REM END OF LOOP ***** 1840 PRINT " 1. PARLIAMENTARY DUTIES."200 IF 90100 THEN H=I00- RND (15) 1850 PRINT " 2. MINISTERIAL RESPONSIBILITIES"210 IF H+0 THEN H= RND (6) 1860 PRINT " 3. CONSTITUENCY DUTIES."220 IF E,100 THEN E=99- RND (14) 1870 PRINT " 4. FAMILY RESPONSIBILITIES.", PRINT230 IF Eo0 THEN E= RND (3) 1880 PRINT "YOU HAVE 20 POINTS TO SPLIT BETWEEN THESE EACH YEAR."240 IF 11,100 THEN M=99- RND (5)250 IF MOO THEN too RND (10)+2 1890 PRINT "YOU MAY BE CALLED UPON TO MAKE POLICY - DECISIONS AS PLAY260 GOSUB 1300 PROCEEDS.", PRINT270 GOTO 300 1900 PRINT : PRINT "READY FOR PAGE 2 ?"1: INPUT AL280 REM 1910 CALL -936: REM CLEAR VDU290 REM 1920 PRINT "WHITEHALL GAME RULES : SECOND PAGE.": PRINT298 REM 1930 PRINT "YOUR DECISIONS WILL DETERMINE THREE QUANTITIES - IF A299 REM REPORT NY ONE FALLS TOO LOW THE GAME ENDS.": PRINT300 PRINT " CURRENT OPINION POLL.": PRINT 1940 PRINT " 1.PERSONAL MORALE."310 PRINT "ELECTORATE SUPPORT ")Ei" 0" 1950 PRINT " 2.PARLIAMENTARY SUPPORT."320 PRINT "SUPPORT OF M.P. S ")114" 0" 1960 PRINT " 3.ELECTORATE SUPPORT.": PRINT330 PRINT "YOUR MORALE RATING ";M: PRINT 1970 PRINT "GOOD LUCK": PRINT340 IF M. RND (30) THEN 1370 1980 PRINT "READY TO START? "1 INPUT Al350 PRINT "URGHI.YOU DECIDE TO RESIGN FOR PERSONAL REASONS." 1990 GOTO 200360 GOTO 2000 1998 REM370 FOR Xo0 TO 1000: NEXT X 1999 REM END OF GAME360 RETURN 2000 FOR X=0 TO 1599: NEXT X398 REM 2010 CALL -936: REM CLEAR VDU399 REM RANK ***** 2020 TAB (15): PRINT "GAME OVER.": PRINT400 IF 1241 THEN 1410: PRINT "PARLIAMENTARY PRIVATE SECRETARY.': 2025 TAB (9): PRINT "YOU LASTED "IT)" YEARS.": PRINT

GOTO 1480 2030 PRINT "TYPE YE5 IF YOU WOULD LIKE TO PLAY AGAIN."410 IF R82 THEN 1420: PRINT "PARLIAMENTARY SECRETARY.": GOTO 1480 2040 INPUT AL: IF AL(1.1)o"Y" THEN 100

2050 PRINT : PRINT "PROGRAM END."420 IF 983 THEN 1430: PRINT "JUNIOR MINISTER.": GOTO 1480 2060 END

94 PRACTICAL COMPUTING May 1982

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Circle No. 16595

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96PRACTICAL COMPUTING May 1982

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PRACTICAL COMPUTING May 1982

N I trILICIE Circle No. 168

97

FAIR REPAIRThom read the screen almost as

quickly as it filled."It's worse than we suspected", he

sighed, turning away deep in thought."Shall I call up the long -stay site

recommendations, Sir"? asked Ronald."What? Yes, you'd better", replied

Thom. Sitting down gently, he paused,then slowly repeated his advice: "Yes,you better had, Ron".

Master -Captain Thom silently studiedhis thumb nails, elbows on knees, whilehis first mate keyed in call codes at theterminal. As the main screen continuedto display its gloomy report Thomremained lost in thought, Ronald in num-erical combinations.

Eventually the first mate completed hislibrary search; he entered the right codeand sat back. Somewhere, a long wayfrom the bridge a warning siren wailed.During the few seconds the page took toarrive Thom roused himself and glancedsurreptitiously at the main screen.Perhaps he had hoped for a revisionnotice, but the original message lingered,terse and authoritative:

COLLISION REPORT:IMMEDIATE SYNOPSIS

Damage by meteorbody most severe:powersections 4, 5, 7 inoperable

timeshift core fracturedRegeneration estimate: 500 hours

WARNING DO NOT ATTEMPT ANYTRAVEL OTHER THAN FREE FLIGHT***THIS IS A CLASS ONE ORDER***

"Whatever `meteorbody' means",muttered Thom. "If the damn

thing doesn't know what hit us, it shouldsay so".

Underneath the large print, the textoffered a selection of button numbers topress for various technical details alreadybeing carefully studied by the engineerselsewhere on board the ship. Here on thebridge the nuts and bolts of the situationwere of secondary interest - Thom andhis immediate companions bad other,more pressing problems.

Outside, ahead of the craft, loomed theplanet they had crossed the galaxy sectorto study. This obscure but fascinatinglittle world had been under regularobservation for several decades. Thom'sown ship had been three times before.

They had been positioning in readinessfor their six months watch - the previousship had left for home a couple of weeksearlier - when entirely without warninga large object passed clean through theworks. Why the detector systems hadfailed to discover the approach of such amassive boulder was worrying enough,what the impact meant to the vessel at theapproach stage, was something else.

Power had been lost immediately butthe collision had done nothing to

check their speed. In space there isnothing to stop a craft once it is moving- unless of course it hits a planet like theone Thom and his party were headingstraight for. With no energy for reversethrust, an entry into a controlled orbitwas out of the question. If the emergencylanding procedure failed, the ship wouldhit the surface with enough velocity to beshattered without trace.

Even with a successful touchdown,Thom would still be in trouble. A sup-reme command stated that no surveycraft must make contact with the inhabit-ants of this world. Simply landing wasenough to earn a humiliating recall.Other teams had occasionally madeemergency landings, but never for morethan a few hours.

In any case, most had already been incontrolled orbit so they were able to

by Brian Williams

choose a suitably remote region for theirrepairs. Thom would have to sit tight on amore or less randomly -chosen spot forthree weeks without attracting attention.

On top of that there was no chance ofassistance. The regulations were mostspecific. The natives - the official termwas "indigenes" - must not get theirhands on an intact craft. Survey vesselswere lightly armed, and the beings whoinhabited this planet, though otherwisetechnologically backward, excelledbeyond reason in the manufacture of allmanner of weapons.

"That's all we need", moaned Thom.The screen, instead of displaying the

expected library page about landingzones, simply stated:

Emergency landing sitesnow determined by Omnimum.

Omnimum, the latest in self -educatingcontrol systems, quietly taught itself allthe elements of the operation, manage-ment and cost-effectiveness of the craft.As it mastered each discipline it assumedcontrol. Captaincy was becoming aredundant profession.

Angrily, Thom growled: "Now wehave to sit here while that calculatordecides where to dump us".

"Message from Base, Sir", Thom wasinterrupted by Hass, the signals officer.Neither Thom nor Ronald had seen himenter; both started. The Captain grabbedthe pad and, for Ronald's benefit, read,"Report received. Enforced landing con-sidered Fair Repair. Good luck".

Handing the message back to Hass,Thom announced: "That's the first pieceof good news today. Thank -you, Hass".

Fair Repair meant the crew were in noway to blame for the accident or theconsequential down -time of the craft.Omnimum must have sent the reportautomatically; perhaps its silicon heartwas in the right place after all, encourag-ing all the right responses from a habitu-ally dour base.

"Ready when you are, Sir", promptedRonald.

"Right", came the reply. "Let's seewhat Man plus Omnimum can make ofthis lot."

Despite only having the landing trim-mers to work with, Thom's crew made afine touch -down. They approached onthe planet's day side so that their fric-tional glow would not be noticed, thenperformed a tedious routine of up-and-down spiralling until atmospheric dragkilled their speed without frying themfirst, before gliding in to a perfect land-ing.

Omnimum had dictated the co-ordinates but was secretive about theterrain. The latter stages of descent hadchannelled them into the night half of theplanet, so the external scanners remaineddark and silent.

Thom rubbed his hands over his eyes."What now"?

"We'll have to see what the morningbrings", suggested Ronald unenthusiasti-cally.

This world they were on - it had neverbeen given a name, just a cataloguenumber - was the last place any of themwanted to be. The temperature, the grav-ity and the inhabitants were all so harsh

On the third daythree natives arrived

Thom warnedof trouble.

and unpleasant. Ideal for a prison colony,maybe, but appalling as a spacecraftrepair shop.

"At least we have technology on ourside", the first mate offered, "they didn'tsee us come".

"No", said Thom, "but they still frigh-ten me".

Acouple of days had passed andautomatic regeneration was under

way. Internal systems had to be kept low,or switched off, making the ship cold andgloomy. Already a little boredom wasevident: the survey team had come toobserve the weather systems, the movingparts of this world, but the surfaceseemed devoid of interest.

No-one could decide on the function of

98 PRACTICAL COMPUTING May 1982

Fiction

their immediate environment. Next tothem stood a series of box -like structuresmade from some plants that grew on theplanet. These huts looked too frail forhabitation and, besides, nothing had stir-red since the ship's arrival.

A high, metal frame looked like acumbersome large aerial. Other equallystrange constructions were on the site,the most curious being a rough imitationof a large land animal known to haveroamed the area some millions of yearspreviously.

The crew were divided on the interpre-tation of these artefacts. Some thoughtthe compound was a religious temple,others a museum. None of the buildingsor devices had any obvious use and theplace had a fatuous air throughout. Pre-sumably Omnimum, having selected thespot, had a few ideas, but it was not goingto share its knowledge.

No -one wanted to leave the craft.They were ill-equipped for ventur-

ing into the poisonous gases, and theexterior temperature was becoming unbe-lievably low. Besides, previous surveyshad attended to all the surface samples.Nevertheless, plenty of activity was goingon elsewhere, even close by, evidencedby the microwave communications rattl-ing their antennae.

On the third day three natives arrived.Thom warned of trouble. How couldNature have developed such creatures,with their long, lanky bodies not suited toanything obvious? Probably the best shecould do in this alien world. Still, theywere relatively successful.

One of the figures stopped and pointedat the craft. The others looked briefly atit, then all three walked on towards theaerial. From there they ambled to thefront of the large land -animal facsimile,which interested them especially. All inall, the three spent almost an hour and ahalf inspecting everything on the site.They then left, passing by the space craftwithout a glance. And that was all.

After 19 days the work was complete.All parts fabricated, fashioned and

fitted by the vessel's internal repair pro-grams. Not before time. Most of the crewfelt terminally stiff either through cold orboredom.

Apart from a little excitement a fewdays previously nothing whatsoever hadhappened to break the monotony. Eventhat event was hardly stimulating, littlemore than a repeat of the earlier visit bythe same three indigenes. This time, oneof the awkward creatures had come overand tapped the hull, looked disappointedand rejoined the others who were attend-ing to the metal frame.

Warm-up, systems check, and take -off,went without a hitch. If anyone saw themgo, the crew never knew. Very swiftly theconditions aboard the ship returned tonormal; just a few miles out into spacethe involuntary groundstay was already

The men haddisposed of that

dreadful bodged -upspaceship.

history. Omnimum had delivered thegoods after all.

rr he Bentley whispered to a halt. Carl-ing looked up as the chauffeur

opened his door. Good. The new sign wasin position over the gates. In the weakApril sunshine the dapper businessmanread:

CARLING'S FUN FAIR.He rather liked his latest property

acquisition. A little run down perhaps,and seasonably bleak. But in a couple ofmonths the crowds would start buildingup in the small seaside town, bringing lifeand cash flow to his amusement park onthe outskirts.

Already his men were in action: theBig Wheel was being prepared for aninsurance inspection; the huge Bron-tosaurus was receiving a new skin ofpaint; all the stalls were having asmarten -up; and he noticed the men haddisposed of that dreadful, bodged -upspaceship to make room for the car -parkextension the local authorities hadinsisted on. Not a bad investment. Therenovation work was simply fair repair,you might say.

Funny thing, though, the spaceship. Ithad not been on the inventory or the

old insurance schedule. It had had acurious bearing, too. Massive, yet small atthe same time. Still, it had sounded per-fectly hollow, just like the fibre -glassdinosaur.

Anyhow it had looked like somethingout of a third-rate science -fiction movie,and nobody in these space -enlighteneddays would have been interested in it. CI

PRACTICAL COMPUTING May 1982 99

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Circle No. 169100 PRACTICAL COMPUTING May 1982

Applications

ONE DAY SOON the majority ofmicroprocessor -controlled devices will beoperated by voice. That, at least, was theprediction of the late Chris Evans in hisbook The Mighty Micro, back in 1979.Aspiring computer professionals whohave only lately conquered theQWERTY keyboard need not worry, forthe keyboard is likely to be pre-eminentfor many years to come in professionaldata-processing applications. Social,domestic and pleasure activities will betaken over by voice control and its corol-lary, speech synthesis, as part of the greatshift towards what artificial -intelligenceguru Terry Winograd calls "convivialcomputing".

Mimicking humansThe convivial computer will perform

like a human and participate in humanactivities through appropriate interfaces.Spoken natural -language input will reallybring the microprocessor -operateddevice, be it toy, tool or education aid,into the widest possible circulation.

Voice control and natural -languageinput still demand a great deal of work,with little prospect of short-term financialreturn. At present they are more likely tobe developed by those who feel there isan urgent human need to deploy comput-ers for social benefit or domestic andpleasure activities, rather than for trade.

Ranjit Gill leads a team dedicated tomaking computing convivial at BrightonPolytechnic's department of Computingand Cybernetics. Gill and six final -yearstudents of various nationalities havecreated the Computer -Aided Arts andAnimation Theatre, CAAAT. They aretrying to bring the magic of cartoon andcomputer together for the handicapped,who are excluded by their disabilitiesfrom a wide range of human activities.Gill's project "aims to make available tothe handicapped those facilities whichwill enable them not only to control theirenvironment better, but also find areas ofexpression and communication withothers in spite of their limitations ofspeech or personal control".

Five modulesThe project is divided into five mod-

ules. Computer -Aided Animation allowsthe user to construct cartoon shapes fromstored cartoon components, characteris-tically bits of the body such as the head,arms and trunk; to store the shapes; andto use commands such as "swim" or"run" to develop and store a story line.Commands can be made by voice orkeyboard input and in cases of severedisability or retardation this helps toimprove the user's hand -eye co-ordination and control of body move-ment. The speech -based Picture Editingmodule is an extension of the animationmodule which permits the storyline itselfto be edited, stored and played back.

On a recent visit to Brighton I saw one

Micros canhelp thehandicappedDr Ranjit Gill's team at Brighton Polytechnic is bringing togetherthe magic of cartoon and computers for the handicapped. MartinHayman looks at this application of "convivial computing".story line, "Superman", in action. Inpractice it works well, and is very easy tounderstand. A simple figure is called outof memory and those shapes conjoinedby the use of cursor commands - up,

down, left and right arrows. This is hand-led by Sinta Software's Shape Managerprogram, which was reviewed in theMarch Practical Computing. A shape,

(continued on next page)

Prakash Sinha directing an Armdroid robot arm by speech input

PRACTICAL COMPUTING May 1982 101

Applications

(continued from previous page)which may be a simple line or curve or ascomplex as, say, a gorgon's head, isdrawn freehand and laid over the screenas a transparent mask. The micro recog-nises. and "memorises" the shape, whichcan subsequently be called out andmoved around the screen.

Alternatively speech input can be used.The micro must first be trained to acceptthe defined list of commands from theuser's voice. This is specially importantfor people with severe speech handicapswho may not be able to articulate thecommands in standard English pronuni-cation. Once trained, the micro will rec-ognize semi -articulate sounds as validcommands. If the user makes a mess ofSuperman, by directing the arms off theedge of the screen for example, the software sends a personalized message outthrough the speech box: "No Martin, youcan't go that way".

Getting acquaintedIt must be said that the Microspeech 2

speech synthesiser sounds awful, thoughit is due to be replaced shortly with themore effective Wordtex. The prompts,and labels for the shapes under manipula-tion, are also displayed in big characterson the screen. This is intended to accus-tom the user or pupil to instructions, andto aid the teacher in familiarising thepupil with more conventional methods ofinstruction. To this extent, it is animproved communication device forthose who have to instruct pupils withsevere learning problems.

Gill started in mid -1981 and the worksoon expanded to take up his summerholiday, weekends and evenings, as wellas the attention of his two children, whocreated some of .the first "designs" forfigures used on the screen. Gill extendedthe design exercise into local schools,where he ran a competition to generategraphical material expressing the experi-ence of the disabled.

Gill, who has lectured at Brighton for10 years, compares his interest in com-puters for the disabled to his involvementwith language schemes for Asians, whoare also disadvantaged in English society.They may not be able to speak Englishwell, or at all, and they are culturallyisolated from English life. The problem isriot merely one of teaching English but ofconveying some grasp of the culturalmeaning of the language. Any humanlanguage enshrines the concepts of itsown culture, unlike a computer language.One of the "convivial" uses which Gillforesees for the coniputer is to act as apupil/teacher interface to improve themethods by which culture is "taught"along with language.

Gill feels that research in computing istoo narrowly directed either to specificindustrial ends or to academic research,with too little emphasis on the middleground of social and educational applica-

tions. He is struck specially by the drylinearity of conventional teaching, bothfor adults and children. He wants to seemuch greater creativity by using graphics,sound, speech and text together to makethat communication a more creative.interactive process.

The disadvantaged find it difficult toexpress their experience of the world,though that experience may in itself behighly developed. This new tool, themicro, should help them to communicatetheir experiences to those in the "outsideworld", resulting in a better and fullerexchange of experiences and, Gill hopes,better mutual understanding. So themicro is here conceived of as an interac-tive teaching and learning tool capable ofimproving human communications viaprogressively more sophisticated inter-faces. To complement the keyboard, itwill use speech and visual inputs, eventouch in the form of a screen light -penand digitising tablet.

I saw some students developing thespeech program to instruct a robotarm, and invited Prakash Sinha todemonstrate the arm. The task set was to

pick up a small carton under speechinstruction. First he showed me how theApple is trained to recognise the menu ofcommands from a particular voice -obviously the speech box recognizessounds rather than identifying words.

Consistent pronunciationOnce the arm is trained to recognise

the particular voice vocabulary, the usercan go ahead and manipulate the arm byissuing commands, either for half- orfull -step operation, software-switchableat the start of the operation, to each partof the arm he wishes to move. Occasion-ally the screen fails to respond, but solong as you pronounce each commandwith more or less the same stress andintonation as used when training the voc-abulary, the computer issues signals tothe stepper -motor driven arm quite reli-

ably. The arm itself, described as Arm-droid and built by Colne Robotics, wasunfortunately suffering from drive -beltslippage at the shoulder.

Module 3 is Speech/Sound-BasedText Processing, allowing disabled usersto use their own sound or speech togenerate text from stored words, phrasesor text, to write it to screen or printer,and to edit, insert or delete in the normalway. The advantages of being able towrite and draw are obvious for the mostseverely disabled, who may lack articu-late speech as well as muscular control.

International prospectsModule 4 may hoist Gill on to the

international circuit. It uses inferencerules for natural language processing,visual literacy, speech understanding; todevelop an intelligent teaching, monitor-ing and assessment system on a mic-rocomputer. This work should lead to anew direction for computer -aided learn-ing and teaching. Gill hopes to human-ise AI techniques and popularise themfor human communications. The exampleof the robot arm vocabulary is useful

here: at primary -school level you can doa great deal with a vocabulary of 64words.

A future expert system for learningmight contain various modules with rulesof teaching, learning and personal com-munication, together with a module ofrules for monitoring and assessing thepupil's progress. Specific techniquesmight include those of the linguist, theartist and the speech therapist.

American Express has endowed Gillwith sufficient funds to buy the twoApples used by the unit but he now hopesto get backing from a big trans -governmental agency such as UNESCO.On that basis he believes that his teachingsystem could be implemented as aspeech -training scheme for people in theThird World, to convey language in itscultural envelope.

102 PRACTICAL COMPUTING May 1982

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Circle No. 170PRACTICAL COMPUTING May 1982 103

Putting lifeinto sketchesMicro technology is freeing cartoonists ofmuch of the drudgery of their work,

allowing more timefor creativeendeavours.Lodge/Cheesman'scomputer -drawnanimation for KPOuterspacers (left)has become afamiliar sight on cinema and TV screens.John Lewell tried out some of the latestequipment in a computer -based animationworkshop led by Co Hoedeman (above),the animator who won an Oscar for Sandcastle

DEDICATED FILM -GOERS, still reeling fromover -exposure to film at the festivals ofDeauville and Venice, converged onCambridge last autumn for the biannualCambridge Animation Festival. For sixdays, professional film-makers, studentsand animation buffs attended screeningsof nearly 200 animated films.

The main themes of the festival werejazz and computers. If this seems like anunlikely combination, they were at leastlinked very cleverly in a title sequencemade specially for the event. Though aretrospective of historical films with jazzsoundtracks was probably the moreentertaining of the themes, the full day ofdiscussions, lectures, product demonstra-tions and screenings of computer imageryseemed more relevant to the contem-porary animation scene.

Certainly, computers attracted plentyof attention, even from animators whowere steeped in the more traditional skillsof their medium. Antoinette Moses, thedirector of the Festival, commented: "Wehave brought together the world of Cam-bridge scientists and the world of Londonfilm-makers. I think we have brokendown some barriers this time".

This was an accurate, if perhaps anover -modest observation. Many peopleat the event had come from overseas, asindeed had some of the products on dis-play. Speakers on computer graphicsincluded Andre Martin of the Institut

National de l'Audiovisuel in Paris. Heclearly spelled out some of the implica-tions of the new technology, saying: "Ifanimators do not appreciate the newtechniques they will find themselvesbeing replaced by those who do".

It was interesting, therefore, to hear thecomments of the animators themselves,after they had had a chance of a hands-onsession with some computer -based equip-ment. A workshop was formed, under theguidance of Co Hoedeman, the Oscar -winning director of Sandcastle, and visit-ing animators were able to see their off-the-cuff pencil sketches brought to lifewith the NAC Advanced Animation andGraphics System.

Vigorous sellingNAC is a Japanese company which spe-

cialises in motion -picture instrumenta-tion. Its home market for equipment mustbe substantial, bearing in mind thehealthy state of the Japanese animationindustry. None the less, NAC's system isbeing marketed with some vigour in theUnited States, and in the U.K. is distri-buted by International InstrumentationMarketing, based in Thame, Oxfordshire.

The NAC system is what it claims to be:a complete system. Only the quick -actionrecorder was prominent at Cambridge,but the system also includes a video actiontracer, a film action tracer, a video anima-tion stand and a video animationrecorder. The system claims to add up to amajor additional tool for the animator.

The quick -action recorder is designedto replace the existing methods of making

a pencil test. A test from the originalsketches by conventional means can be

time-consuming as shooting thefinished cel animation. To see if an ani-mated sequence will work, the pencilsketches are filmed, often several timesover, with different timings in each ver-sion. A combination of computer andvideo technology is ideally suited to mak-ing this task easier. Not only do you getinstant replay, you can also adjust thetimings until the optimum set isdiscovered. Drawings are stored frame byframe in a computer memory, allowingaccess for editing, replay, or repeatingselected sequences.

Apart from the video camera and table,there are four main components of thequick -action recorder: a rack -mountedCPU, a viewing monitor, a menu monitorfor showing modes, commands and expo-sure information, and a small, neatly -designed keyboard for entering instruc-tions. The recorder can be connected to aVTR for storing sequences which are toolong to be held in memory.

Several memory options are available,. including those for storing 30, 60, 120and 240 line drawings. Playback speedcan be preset or varied at any ratebetween three and 60 frames per second.A picture has to be entered into thememory only once, because the repeatfunction can hold the sketch for as manyframes as are required.

Operating the quick -action recorder issurprisingly simple and flexible. It is cer-tainly more efficient than using conven-tional photography, and it does not make

104 PRACTICAL COMPUTING May 1982

Animation

any of he traditional skills redundant.Able to interchange frames, to eraseframes, or to put others through a varietyof loop sequences, this machine makes auseful addition to the animation studio.

Of the other products in the NACrange, the video and film -action tracersare used for rotoscoping - that is, tracinglive action into outline drawings or com-bining live action with animation. IfRalph Bakshi's American Pop has notpermanently killed the desire to roto-scope, there may be a market for thesesystems.

Both tracers, together with the videoanimation stand are designed for the pro-fessional animator, while the video ani-mation recorder is a more down-marketmachine. It is VHS cassette -based, with aremote -control panel for operating in aframe -by -frame mode. Of this productthe NAC brochure says: "Anybody canmake video catalogue. Feel more free totry new idea and feel more easy to ventur-ing." Though this may sound like adubious invitation to downtown Tokyo,the NAC equipment deserves to be takenseriously.

Suiting every pocketAnother system on display at Cam-

bridge was an Apple -based rostrum -con-trol system from Animation EquipmentEngineering. This company offers a widerange of studio equipment - from theirGrand Stand rostrum, priced at £9,320,all the way down to filters, peg -bars, dim-mers and switches.

The Apple system, called Caro - forcomputer -aided rostrum operation - isdesigned to control the complex rostrummovements which are necessary in full-scale animation. With the addition ofstepper:motor drives and interfaces, thecomputer will handle the calculations forpans, zooms, tracks and rotations: Otherdrives are available for focus, fades anddissolves. The package comes with dualfloppy discs and a monitor which showsrelevant information: camera poSition,frame numbers and the exact positions ofeach axis.

Of the speakers at the Cambridge mini -teach -in on computer animation, onlythose who had seen the recent computerfilms at the Siggraph convention wereguilty of holding out big promises for thefuture. By contrast, Neil Wiseman fromthe Cambridge University ComputerLaboratory, noted ironically: "Interac-tive computing is such fun we often like touse it even if it makes things worse". TomSancha, of Cambridge InteractiveSystems, an expert on computer -aideddesign, gave a clear explanation of thetechniques used in his branch of themedium, but said: "Most computer -generated pictures have a Hockneyesquecharacter". I am not sure where thatleaves computer graphics - or, for thatmatter, David Hockney - but I am sure

(continued on next page)

Modes and commands are displayed onthis monitor.

Actions as per your commands areplaybacked on this monitor.

Compact Key Board containsall switches forcommunication and

commands of actionmodes.

Rack to contain allelectronics andmemory devices.

Conveniently designedside -table type rackwith casters.

OR

Video camera(B/W)

VTR

The NAC quick -action recorderis intended to replacetime-consuming conventionalpencil tests. An animator (right)can call up frames frommemory and vary the order ofshots or the "perceived speed"of the film at will. Usingconventional photographictechniques this could takehours. The whole unit consistsof a rack -mounted CPU,viewing monitor, menu monitorand keyboard, linked as shown(above). The keyboard (below)allows full access to theelectronics which are tuckedaway in a side -table style rack.A wealthy animator could alsobuy NAC's video action tracer,video animation stand andvideo animation recorderwhich are fully compatible.These NAC machines areintended to speed existingmethods of animation ratherthan create "computercartoons".

Endless playback mode(continuous loop of preselectedsegment) and Repeat mode \(repeating from preselectedStart frame)

Memory Clear key

Indicator for Used /Remainingmemory capacity.

Picture to be recorded can beeither from VTR or AnimatedDrawings on papers takenby TV camera.

Memorized pictures andfinished actions aretransferable to VTR.

Basic commands of playback :Stop, Forward, Reverse,Single Frame, Return toStart frame, etc.

Pictures of both VTR and Memory can bedisplayed on Video Action Tracer.

Picture to be displayed canbe selected either from ownmemory, or TV camera,or VTR.

Correction of action bymeans of Erasing ,Adding,and Interchanging frames.

Preset of Start frameand End frame.

Playback speed can be eitherpreset, or varied duringplayback at rate of 3 to60 fps.

Playback modes are-Normal : 24- fps- Preset Variable exposure: shooting - on- ones to -fives,

and 6's 12S ,and-Strobe : 8 pictures maximum

PRACTICAL COMPUTING May 1982 105

Animation

(continued from previous page)that most of the audience were unawarethat the three-dimensional pictures whichwere used to illustrate the talk were in factmerely stills from fully -animatedsequences.

The workshop session produced aninteresting, if somewhat incoherent, film.No doubt, animators learned some newtricks, but neither computer -controlledrostrums nor systems for animating pencilsketches are truly representative of themajor changes which will be taking placein the animation industry. Neverthelesssystems such as these help to introducesome of the basic principles of the com-puter. More exciting are the paint systemswhich are currently under developmentby Logica and Quantel, and the workbeing done on three-dimensional com-puter imagery.

A warning to hopeful manufacturerstrying to cash in at the early stages ofdevelopment came from Co Hoedeman:"Today we have this, tomorrow we havesomething else. When I am ready, as anartist, to use a computer for creating theimage - or on some other part of makinga film - there will be something quitedifferent available. Computer animationis just a child growing up".

Animators, despite their sometimesnotorious sense of humour, tend to bevery serious and cautious about theirwork. After all, it takes them a long time

Recording

Series of picturesongirally recorded Playback

1 2 3 4- S 6Variablespeed mode Variable

,odeRepeat orEndless mode Erase or Addition Interchange

4.AP1,ttSet ofline drawings

W24

animated

40

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V#

te:le

fr"srisec

.* .,PAP

= ."frUArPfr + 5AltP .6

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7

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Variable from

3iPs to Weslot shooting -on-twos exposure)

Preset ofvariableexposuresto individualframes from

Eta 5.6.12,and 24

Desiredsegment

Discretionalcorrection as desired

Any pair offrames arefreelyexchanged

Functions of the quick -action recorder.

to become fully competent in their art.The use of computers in animation will

find general acceptance only when manu-facturers can demonstrate real commer-cial or creative advantages in using their

products. NAC and AEE are quite con-vincing at a very modest level. It nowremains to be seen whether more power-ful packages can be marketed success-'fully.

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Circle No. 171PRACTICAL COMPUTING May 1982

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PRACTICAL COMPUTING May 1982 107

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Circle No. 173108 PRACTICAL COMPUTING May 1982

Education

Making it fun tolearn tables

AFTER READING Nick Hampshire's articleon Pet graphics in Practical Computing,June and July 1981, I decided to usesome of his subroutines in place of mynormal methods. The first opportunitycame when my youngest son started tolearn multiplication tables at school, andrequested a program that would test hisknowledge of them.

The program asks first for the highestnumber of tables to be tested on, thengives the option of studying the tablesbefore answering any questions. Thequestion is displayed, and if the correctanswer is entered it is "ticked" and thenext question is displayed. If the answeris wrong, the tables are displayed with thecorrect answers highlighted in reversevideo; after a pause the question is thendisplayed again. To finish the session, a *is entered as the answer and the pupil'sscore is displayed.

I found the most convenient way ofusing the graphic subroutine was to usevariables for the start -line number, col-umn number and other parameters

When his youngest son came home and asked tobe tested on his multiplication tables John Craigseized the opportunity to write a clear and con-cise program for his Pet.required by the subroutine and thenassign values to the variables before cal-ling up the subroutine.

The program was written on a 3000series Pet but if you have converted NickHampshire's program to run on your Petthis program will also run satisfactorily.

Screen graphicsThe screen graphics program given in

Nick Hampshire's articles is first loadedand run. There is a mistake in Hamp-shire's version: line 310 of the Basicprogram should be amended to read

DATA 48, 98, 48, 8A, 48, 20, 00, 74, A4, 58,A5, 00.

The pupil's name is printed by line1760. If the program is to be used with

several pupils, the pupil's name can beleft out or an additional input added byadding Gosub 2050 in line 500, betweenGosub 1970 and Goto 760, then sub-stituting line 2160 as line 1760.

My normal method of placing the cur-sor at a screen location is to key a screenhome, followed by the required numberof cursor -down and cursor -right opera-tions. To save space and for ease of useduring programming, in the initialisationpart of the program I would haveSP$ = 39 blanksSD$ = 24 cursor -downsSU $ = 24 cursor -upsSR $ = 39 cursor -rights' The cursor -up was sometimes used4fter printing error messages or prompts

(continued on next page)

100 REM110 REM120 REM1:30 REM140 REM150 REM160 REM170 REM180 REM190 REM200 REM210 REM220 REM2:0 REM240 REM250 REM260 REM270 REM280 REM290 REM300 REM31A REM320 REM330 REM340 REM350 REM360 REM370 REM380 REM390 REM400 REM410 REM420 REM4:30 REM440 REM450 REM460 REM

************************************ MULTIPLICATION TABLES *4*44* COPYWRIGHT JOHN CRAIG 1981 *44**********************************

*44 LIST OF VARIABLES 44*

A3S=KEYBOARD INPUTA3=VALUE OF KEYBOARD INPUT

EMVI)=ERROR MESSAGEA2=TIMER DELAY

1=FLAG FOR WRONG ANSWERERROR MESSAGE NUMBER

Z5=CHECK IF QUESTION REQUIRES DISPLAYING AGAIN26=ERROR FLAG FOR KEYBOARD INPUT.27=FLAG IF ERROR MESSAGE WAS DISPLAYED

D=TABLES NUMBER COUNTERE=TABLES POSITION COUNTER0=QUESTION NUMBERT=PUPILs8 ANSWER TO QUESTIONW=CORRECT ANSWER TO QUESTION

F4:=STRING EQUIVALENT OF WY=HIGHEST TABLES NUMBER TO BE TESTED ONV=FIRST NUMBER GENERATED2=SECOND NUMBER GENERATEDH1=WRONG ANSWER COUNTERH2=CORRECT ANSWER COUNTER

***********************************************************44* Al VARIBLES LIED IN SCREEN GRAPHICS SUBROUTINES *44*44 B1 : THE SUBROUTINES ARE FROM "PET GRAPHICS" *4*44* Cl BY NICK HAMPSHIRE 44*014 DI : PUBLISHED BY COMPUTABITS *4**44 El : 444***********************************************************

(continued on next page)

PRACTICAL COMPUTING May 1982 109

(continued from previous page)at the bottom of the screen, and the SP$used to blank out the error message orprompt. It is then a simple matter to placethe cursor at any position byPRINT '(home)'; LEFT $ (SD$, 10); LEFT $(SR$, 20)

which will place the cursor 10 lines downand 20 columns across.

For simple single movement of the

cursor, I still prefer this method, but inthe listing of the multiplicatiori program 1have only used Nick Hampshire'sroutines. The program starts at line 490with Poke 59468, 14 which changes thecharacter set to lower case. The Gosub1970 at line 500 initialises the error mes-sages; I hold the error messages in thearray EM$ (I) so they can be called up asrequired by printing EM$ (1).

470 REM (continued from previous page)480 REM490 POKE59468;14:REM POKE59468;12 RETURNS UPPER CASE500 008UB1970:0010760510 REM520 REM530 REM *** SUBROUTINES *4540 REM KEYBOARD INPUT550 OPENI;O:INPUT#1413$:CLOSE1560 IFA3$="*"THENGOT01800570 RETURN580 REM590 REM CHECK IF KEYBOARD INPUT NUMERIC600 A3=VAL(A3$):IFFI3=0THENZ3=3:82=90:GOSUB630:26=1610 RETURN620 REM630 REM DISPLAY ERROR MESSAGE FOR TIME A2640 A1=2341=0:00SUB1540650 PRINTEM$(Z3)660 T6=TI+A2670 IFTI<T6THEN670680 1F27=0THENR1=2341=0 C4=35:D1=32:00SUB1580690 RETURN700 REM710 REM WAIT FOR KEY DEPRESSION720 GETA3$,IFA3$=""THEN710730 RETURN740 REM750 REM760 REM DISPLAY INSTRUCTION TEXT770 PRINT"n":A1=8:BI=0:GOSUB1540780 PRINT"IHIS PROGRAM WILL TEST YOUR KNOWLEDGE "790 PRINT800 PRINT"OF MULTIPLICATION TABLES."810 PRINT820 PRINT" -TITER THE HIGHEST NUMBER OF TABLES"830 PRINT840 PRINT"YOU WISH TO BE TESTED ON ";850 GOSUB540:00SUB590:IFZ6=0ANDA3<11THEN910860 IFZ6=0THENZ3=2:A2=90:00SUB630870 Al=14:B1=24:C1=3:111=32:00SUB1580:A1=14:B1=25:GOSUB1540880 Z6=0,00T0850890 REM900 REM DISPLAY TABLES QUESTION910 Y=A3:PRINT"7"920 A1=10:B1=0:00SUB1540:PRINT"-0 YOU WISH TO STUDY THE TABLES FIRST "930 PRINT940 PRINT" -LEASE ENTER I OR / ";:GOSUB540950 IFA3$="Y"THENGOSUB1220:A1=23141=0:00SUB1540:PRINTEMS(6):GOSUB710:0070980960 IFA3$0"N"THENZ3=7:A2=90:00SUB630:A1=12:B1=21:C1=3:D1=32:GOSUB1580:0070920970 REM980 REM LOOP TO GENERATE QUESTIONS990 Q=Q+11000 V=INT(Y*RND(1)+1)1010 Z=INT(10*RND(1)+1)1020 W=V*Z1030 IFZ5=1THENGOSUB14301040 GOSUB14101050 REM1060 REM INPUT ANSWER1070 GOSUB540:GOSUB5901080 IFZ601THEN1100iop Z6=0:A1=12:B1=24:C1=4:D1=32:GOSUB1580 A1=12:B1=25:GOSUB1540:007010601100 T=A31110 IFTOWTHENGOSUB1480:00T010601120 A1=12:B1=28:GOSUB1540:PRINTCHR$(186)1130 A2=90:Z7=1:GOSUB660:27=01140 IFZI=OTHENH2=H2+11150 Z1=01160 REM1170 REM CLEAR WORKING AREA1180 Z5=1:A1=8:B1=24:C1=2:D1=32:00SUB15801190 Al=12:B1=0:C1=39:D1=32:00SUB15801200 G0T09801210 REM1220 REM GENERATE TABLES1230 GOSUB17501240 A1=1:D=0:J=01250 J=J+I:IFJ=11THEN13901260 D=D+11270 AI=A1+21280 E=0:B1=11290 FORI=170101300 E=E+11310 B1=B1+31320 G0SUBI540

GOT01060

(continued on next page)

I have located the data statement at theend of the program as it is only read once.The Goto 760 skips past the KeyboardInput, Time Delay and Hold subroutineswhich are part of my standard repettoireand are stored at the start of the program.On the Gosub command, the Pet looksfrom the start of the program until it findsthe tequiredGOsub.

I could also have placed the screen

graphic routines at the start of the pro-gram after they were developed. Line770 clears the screen with Print "CLR"then sets the variable Al with 8 and I31with 0.

The Gosub 1540 is the cursor -place

routine which will place the cursor at line

8 column 0 ready to print the instructiontext, lines 780 to 840. The ";" at the endof line 840 is used to keep the cursor on

the end of the printed text. lithe ";" is

omitted, the cursor will fall to the line

below. At line 850, Gosub 540 is used

instead of Input A3$; this subroutine

treats the keyboard as an input device,

the device number of the keyboard is 0.

Therefore OPEN 1,0opens the keyboard for an input, after theinput the keyboard is closed, with

CLOSE 1,0.This routine prevents the program end-

ing prematurely if Return is depressedwithout any data being entered.

Input checkGosub 590 then checks that the input is

numeric by assigning to A3 the Val of

A3$. If A3 is 0 then A3$ is not numeric,

therefore Z3 is set to 3, and A2 to 90.

The Gosub 630 at line 600 displays error

message 3 for time A2. On returning to

line 600 Z6 the keyboard -input error flagis set to 1. Then on returning to line 910,if Z6 is 0 and A3 lesS than 11, control is

transferred to line 910, otherwise the

input is blanked out by line 870 andcontrol is transferred back to line 850 by

the Goto at line 880 after cancelling the

error flag Z6. Lines 900 to 960 follow thesame pattern of events for the option of

studying the tables.

Lines 980 to 1040 form the loop that

generates the question. Line 990 indexes

the question number counted Q. Lines

1000 and 1010 generate the numbers to

be multiplied together, and line 1020 setsW with the correct answer. Line 1030checks whether the question is new or a

reprint .of a wrongly answered question.

It enters the Display Question routine at

1410 to display the title block by Gosub

1750 and printsEMS (1)

If you are finished enter "*" at the

bottom of the screen. Alternatively it

enters the routine at 1430 to display the

question.

Line 1070 is the answer input, with a

check that it is numeric. If the input is notnumeric, 1090 erases the input andreturns the cursor to the correct position

to wait for a numeric input, when Goto

110 PRACTICAL COMPUTING May 1982

Education

1060 is executed. Line 1100 checks thatthe answer is correct; if so, line 1130"ticks" the answer.

Line 1130 gives a time delay withoutprinting an error message by settingZ7 to 1. Line 114(1 indexes thecorrect -answer counter H2 if the wrong -answer flag Z1 is not set. Line 1150clears the wrong -answer flag.

Lines 1180 to 1200 clear the workingarea ready to display the next questionafter Gbto 980. 1 clear the working areaby this method rather than by clearing thescreen and re -displaying the title block asI dislike the flashing effect this gives.

Wrong -answer counterIf the answer given to the question is

wrong, line 1170 calls up the displaytables routine with Gosub 1480. Line 1490indexes the wrong -answer counter H I . Itshould be noted that no flag is used tocheck if this is the first attempt at thequestion: the total of correct and wronganswers is greater than the number ofquestions if more than one attempt hasbeen made at any question.

Gosub 1220 generates the tables. Line1240 initialises the variables. Lines 1250and 1380 are used in place of a For -Nextloop - my Pet has a fault, and will notaccept nested For -Next loops. Line 1260indexes the table -number counter D.Line 1270 sets the line number to start toprint the line of tables.

The loop 1290 to 1370 prints the lineof tables on the screen by indexing E andincreasing the column position B 1 . Line

780 This program will test your know-ledge.

820 Enter the highest number of tables.920 Do you wish to study the tables first?940 Please enter Y or N.

1430 Question number.1760 John Craig Tables.1830 RESULTS1860 Correct Wrong1870 Answered1980 If you have finished, enter *.2010 Type any key when ready. Try again.

Table 1

1320 moves the cursor to the correctscreen position, line 1330 calculates thenumber to be printed and assigns it to F$.Line 1340 builds F$ up with leadingblanks to a length of 3 digits. Line 1350checks whether F$ is the correct answerto the question and if it is, prints F$ inreverse video. Line 1360 prints F$. Whenthe table is printed the return is at line1390 to line 1490. The cursor is thenplaced at the bottom of the screen andprints the prompts EM$ (4) and EM$ (5)for time A2 set in line 1500. Line 1510displays the question again then returnsto line 1110, then back to line 1060 for asecond attempt.

When a * is entered, the finish routineis called up, starting at line 1540. Thisroutine prints the tables of results usingthe screen -graphic subroutines. Line

1810 prints the title block. Line 1820prints the block of *. Line 1830 prints"RESULTS". Lines 1840 to 1870 printthe headings, and line 1880 prints theunderlining of the heading.

Line 1890 checks that the last questionhas been answered.

Lines 1910 to 1930 print the border.Line 1940 places the cursor at the

bottom of the screen.

This program was written in lower caseas I wished to use the "tick" symbol,which is only available in the lower-casemode as CHR$(186). This does, unfortu-nately, create a problem when the pro-gram is listed in upper case, as graphicsymbols are printed where capitals areused. If address 59468 is Poked with 14before the program is entered; the text tohe entered is shown in table 1.

(continued from previous page)1330 F$=STR$(D*E)1340 IFLEN(F$)<3THEMF$=" "+F$:GOT013401350 IFVRL(F$)=WTHENIFDTHENC1=2,D1=1TRINTF$.00SUB1670,001.013701360 PRINTF$1370 NEXTI1380 GOT012501390 RETURN1400 REM1410 REM DISPLAY QUESTION1420 GOSUB1750,A1=23,B1=0 GOSUB1540PRINTEM$(1)1430 A1=841=10:00SUB1540 PRINTWESTION NUMBER ";Q1440 PRINT:PRINT:PRINT1450 PRINT" ";V"*":e7"= ";1460 RETURN1470 REM1480 REM DISPLAY TABLES IF ANSWER IS WRONG1490 H1=H1+1:130SUB1220,A1=23,B1=5:00SUB1540:PRINTEM$(4) Q;EM$(5),Z1=11500 A2=300:GOSUB6601510 GOSUB14101520 RETURN1530 REM1540 REM * CURSOR PLACE * Al=LINE B1=COLUMN1550 POKE84,A1TOKE85,B1:SYS(31.243)1560 RETURN1570 REM1580 REM * DRAW A HORIZONTAL BAR * Al=LINE B1=COLUMN C1=LENGTH D1=CHARCTER1590 P0KE86,B1:POKE87,A1TOKE88,C1:P0KE00,D1:SYS(30029)1600 RETURN1610 REM1620 REM * DISPLAY BLOCK OF CHARECTER El *1630 REM Al=LINE B1=COLUMN CI=WIDTH OF BLOCK D1=HEIGHT OF BLOCK E1=CHARACTER

1650 RETURN1660 REM1670 REM * DISPLAY BLOCK: IN REVERSE VIDEO *1630 REM R1=LINE B1=COLUMN C1=WIDTH OF BLOCK D1=HEIGHT OF BLOCK1690 POKE86,(B1+1):POKE87,Al:POVE38,CITOKE89,D1,S4S(30510),RETURN1700 REM1710 REM * OUTLINE BORDER *1720 REM Al=LINE B1=COLUMN CI=WIDTH OF BORDER D1=HEIGHT OF BORDER1730 POKE86,B1TOKE87,Al:POKE88,C1:POKE89,111SYS(30090):RETURN1740 REM1750 REM TITLE BLOCK1760 PRINT"D 'OHM -PAID IABLES"1770 Al=1:B1=7C1=25,111=61:GOSUB15801780 RETURN1790 REM1800 REM FINISH ROUTINE1810 GOSUB17601820 Al=441=10:C1=11=3,E1=42 GOSUB16201830 A1=5,B1=12:GOSUB1540:PRINT" --0 (LI "

1840 A1=9:B1=6:00SUB15401850 PRINT"0LIESTIONS"1860 PRINT" -ORRECT ORONG"1870 PRINT" +NSWERED"1880 A1=12:B1=5C1=28:D1=61:GOSUB15801890 PRINTAFZ1=1THENO=Q+11900 PRINT" ";0-1;" "H2;"1910 Al=8:B1=4:C1=11,111=8,GOSUB17101920 Al=8:B1=15:C1=10,111=3GOSUB17101930 Al=8,B1=25:C1=10:111=8,130SUB17101940 Al=201I1=0:GOSU615401950 END1960 REM1970 REM INITIALIASE DATA1980 DATA" YOU ARE FINISHED ENTER * "

1990 DATA" PLEASE ENTER A NUMBER BETWEEN 1-10"2000 DATA" IUCK UP YOU MUST ENTER A NUMBER":"TRY QU1GTION "," AGAIN PLEASE"2010 DATA" *** IYPE ANY KEY WHEN READY ***"," *** IRY AGAIN ***"2020 FORI=11.07,READEM$(I):NEXT2030 RETURN2040 REM2050 REM INPUT NAME2060 PR.INT"3":A1=8:B1=0,GOSUB15402070 PRINT "PLEASE ENTER YOUR NAME UNDER THE STARS"2080 PRINT2090 PRINT" ******************"2100 A1=1241=5:00SUB15402110 GOSUB540:IFLEN(A3$)>18TNEN21402120 IFLEN(A3$)<18THENA3$=A3$+" ":00T021202130 N$=" "+A3$:1507021502140 A2=9023=7:00SUB630:A1=1241=4,C1=35:D1=32'GOSUB1580:00T021002150 RETURN2160 PRINT"n";NC"TABLES"2170 GOSUB1970:GOSUB2050:0010770

PRACTICAL COMPUTING May 1982 111

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Circle No. 175PRACTICAL COMPUTING May 1982

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1114'1-'ft4

PRACTICAL COMPUTING May 1982

Circle No. 176 113

Dual floppy disk drives. Two 5/4" floppy diskdrives provide 100,000 characters each of datastorage, or about 60 pages of typed,doublespaced text.

Diskette storage. The floppydiskettes can be removed,providing infinite permanentinformation storage. Twocompartments provide storage forup to 25 diskettes.

RS -232C Interface. Enables theOSBORNE 1 to connect with serialprinters, or other devices using thispopular industry -standardinterface.

IEEE 488 Interface. Connects theOSBORNE 1 to the standardinstrumentation bus, for datacommunication with test instruments.

B C

Osborne 1.It doesn't need a room of its own.Or even a desk of its own.With its optional battery pack, in fact, it doesn't need mains

electricity for up to two hours.It's - as you can see - portable.Weighing under 241b in its weatherproof case, it can be carried

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business computers several times as big and twice as expensive.The Osborne 1 will achieve in seconds commercial,

engineering or scientific calculations which, without a computer,would take days.

And store a whole library of data for instant retrieval and useany time.

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You can see an Osborne 1 - and try it out - at any of thedealers listed below.

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For E1,250' the only personal business coneexcluding VAT.See the Osborne 1 at any of these authorised dealers.

LONDONAdda Computers Ltd. Mercury House. Hangar Green. Ealing,London W5 3BA. Tel: (01) 997 6666

Business Computers (Systems) PLC, The Pagoda,Theobald Street, Borhamwood, Herts WD6 4RT.Tel: 101) 207 3344

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Digitus Limited, 10/14 Bedford Street, Covent Garden,London WC2E 9HE. Tel: (01) 379 6968

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Microcomputers at Laskys, 42 Tottenham Court Road.London WI 9RD, Tel: 101) 636 0845

Lion Microcomputers, Lion House, 227 TottenhamCourt Road, London WI. Tel: (01) 637 8760

Star Computer Group PLC, 64 Great Eastern Street,London EC2A 30R. Tel: (01) 739 7633

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B ELFASTNorthern Ireland Business Systems Ltd, 7/9 Botanic Avenue,Belfast' BT7 1JH. Tel: (0232) 48340

B IRMINGHAMMicrocomputers al Laskys, 19/21 Corporation Street,Birmingham 82 4LP. Tel: (021) 632 6303

Byteshop Computerland, 94/96 Hurst Street, BirminghamB5 4TD. Tel: (021) 622 7149

B RISTOL Microcomputers at Laskys, 16/20 Penn Street, BristolBSI 3AN. Tel' (0272) 20421

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CHESTERMicrocomputers al Laskys, The Forum, Norlhgate Street.Chester CHI 2BZ. Tel: (0244) 317667

DERBYDatron Micro Centre, Duckworth Square, Derby DE I 1JZ.Tel: (0322) 380085

EDINBURGHMicrocomputers at Laskys, 4 St James Centre, EdinburghEHI 3SR. TeL (031) 556 2914

GLASGOWMicrocomputers at Laskys, 22/24 West Nile Street, GlasgowG7 2PF. TeL (041) 226 3349

Byteshop Computerland, Magnet House, 61 Waterloo Street,Glasgow G2 7BP. Tel: (041) 22t 7409

GUILDFORDSystematic Business Computers, Braboeul House.64 Portsmouth Road, Guildford. Surrey GU2 5DU.Tel: (0483) 32666

LIVERPOOLMicrocomputers at Laskys, 14 Castle Street, LiverpoolL2 OTA. Tel: (051) 227 2535

MANCHESTERMicrocomputers at Laskys. 12/14 St Mary's Gate.Market Street, Manchester Mt 1PX Tel: (0611 832 6087

Byteshop Computerland, 11 Gateway House.Station Approach, Piccadilly, Mancnester 1.Tel' 10611236 4737

NEWCASTLESage Systems, Hawick Crescent, Newcastle upon TyneNE6 1AS TeL (0632) 761669

NOTTINGHAM Microcomputers at Laskys. 1/4 Smithy Row, NottinghamNG1 2DU. (0602) 415150

Byteshop Computerland. 92A Upper Parliament Street,Nottingham NG1 6LF Tel (0602) 40576

PRESTONMicrocomputers at Laskys, 1/4 Guildhall Arcade. PrestonPhi 1HR Tel (07721 59264

114 PRACTICAL COMPUTING May 1982

Ft 1\1 E

Standard softwareFive outstanding softwarepackages, with a retail value ofover £800 are included:GP/M ® Operating SystemWORDSTAR ® with

MAIL MERGE® SUPERCALO TM MBASIC®CBASIC®

Circle No. 177

puter you can take anywhere.

Internal electronics. Z8OATM CPU, 64K bytes RAMmemory (60K available to the programmer; 4K used to runthe screen.) System software is held in ROM in a separate

address space.

Screen. Clear, 5", 24 -row screen displays a 52 -characterwindow on a 128 -character line with automatic horizontal

scrolling.

Monitor Interface. Connects the OSBORNE 1 to anymonitor screen.

Keyboard. A standard typewriterkeyboard plus numeric, adding -

machine keypad for fast entry,and cursor control keys for easy

cursor movement.

Case. The plastic casesnaps together to form a

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underneath the standardairline seat.

Optional extras Modem cable for use with

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Battery pack Double density disk drives

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SHEFFIELDDatron Micro Centre, 2 Abbeydale Road, Shelled S7 I FDTel: (0742) 585490Microcomputers at Laskys. 58 Leopold Street, SheffieldSL1 252. Tel: 0742) 750971

SLOUGHThe Xerox Store, 3/4 William Street, Slough, BerkshireSL1 1XY. Tel: (0753) 76957

SOUTHAMPTONXitan Systems Limited, 23 Cumberland Place,Southampton SOI 2B13. Tel: (0703) 38740

TORQUAYCrystal Electronics, 40 Magdalene Read, Torquay, Devon.Tel: (0805) 22699

Opening shortly

Trademarks: SUPERCALC: Sorcim Corporation; Z8OA: Zilog Corporation.Registered Trademarks: OSBORNE 1: Osborne Computer Corporation; CP/M Digital Research; WORDSTAR,MAILMERGE: MicroPro International; MBASIC: Microsoft; CBASIC: Compiler Systems, Inc.

For further information and full specification, return the coupon to TheMarketing Manager, Osborne Computer Corporation (UK) Ltd, 38 TannersDrive, Blakelands North, Milton Keynes, Buckinghamshire MK14 5BW.Telephone: 0908 615274. Telex 825220More information on Osborne 1, please.

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PRACTICAL COMPUTING May 1982 115

THE MICRON -if CHALLENGE:FIND A COMPUTER TO COMPARE

WITH THE WW1 . . . NEVER.

. Because the SIG/NET offers the price advantage ofthe low cost systems together with the flexibility andinfinite expansion capabilities of the high cost systems.

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For just £1,299.00 the standard SIG/NET offers theflexibility to choose the terminal best suited to yourrequirements, the printer to give the speed and qualityyouneed and disk capacity from 400,000 to 40 Millioncharacters.The standard SIG/NET 2025 E1,299.005 Megabyte hard disk system £3,100.0010 Megabyte 4 User £6,000.0010 Megabyte 10 User £9,500.00FOR FURTHER TECHNICAL DATA AND THE NAME OF YOUR NEAREST DEALERSEND THE COUPON NOW1

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Circle No. 178

116 PRACTICAL COMPUTING May 1982

Programming

WHILE THE BASIC residing in the PetROM is adequate for most tasks, theprogrammer may wish to accessmachine -code routines either becauseBasic is too slow for a required task, orbecause a particular function is notimplemented in Pet's version of the lan-guage.

An interpreter like Basic consists ofmachine -code subroutines to performspecific tasks. The required task isspecified in the higher language, stored asa program, and then interpreted by scan-ning program lines. When a keyword isrecognised, the appropriate machine -code subroutines perform the desiredfunction.

The interpreter first finds the end ofthe line. It then starts to interpret thecode to find tokens which the interpreterrecognises. Default is the Let command.

The Pet makes machine -code sub-routines available from Basic by the useof the Sys(x) command where x is thedecimal start address of the subroutine.Most of the resident machine -code sub-routines are of little use when calleddirect from Basic since routines usuallyassume certain values in the micropro-cessor registers. The most effective wayto access them is from a machine -codeprogram.

Different entry pointsThe examples in this article are specific

to new -ROM Basic 2.0; Basic 4.0 userswill probably find that the entry points tothe machine -language subroutines aredifferent.

Old -ROM users have this problemand, in addition, the references to theTim monitor are not applicable to them.

Many readers uninterested in details ofmachine -language programming willhave dabbled with the monitor, and mayeven have used some of the interestingshort routines submitted by readers.Usually these instructions include thestatement that "the function is initiated

Figure 1. Monitor Basic line.

Machine -codesubroutineson the Pet

Judiciously -placed machinecode can make a huge

improvement to the speed atwhich a program runs. P H

Richards reveals the secrets ofthe Pet's interpreter and shows

how it can be harnessed topowerful machine -code

routines for use within yourBasic programs.

by Sys 826" or thereabouts. Most ofthese routines are designed to reside inthat area of memory reserved for thesecond cassette buffer, which starts atmemory location 826 decimal. This areais unaffected by Basic, unless you areusing two cassette drives; it cannot beaffected by the Basic editor and the Newcommand leaves it untouched.

Furthermore, if a momentary powerfailure occurs - like switching your Petoff then on - the chances are that any-thing in the buffer will survive providedthat the interrupt is less than one second.There are, however, problems with thislocation. Some commercial add-ons usethe area. Basic 4.0 uses it, and if you wishto use more than one routine the totallength of the machine code may exceedthe available space.

If the second cassette buffer area is notavailable the machine code must be heldin the main user area of memory. Protect-ing the machine -code program from the

a

a

a

Pi: IRO Al_: XR YR

Ef-72E 2C 34 FA

,n4n1 51 n4 OA n0 S =,-LF .1 45 4D

04n. 2A 2A 2A 2A 2A 2A 2A 2A0411 2A 2A 2A 2A 2A 2A 2A 2A0419 2A 2A A 2A 2A 2A 2A 2A0421 2A 2A 2A 2A 2A 2A 2A 2A0429 2A 2A 2A 2A 2A 2A 2A 2A0431 *:"A 2A '-,19 2A 2A 2A 2A 2A`- 2A 2A *2F1 2A 2A 2A 2A 2A0441 2A 2A '7,A 2A 2A 2A 2A 2A0449 2A 2A 2A 2A 2A 2A 2A nO0451 00 00 AA AA AA AA AA AA

Basic interpreter is possible by writingthe machine code to reside at the top ofmemory, and then fooling the Pet intothinking that the top of memory is lowerthan it is.

This is easy because Basic uses a two -byte pointer held in decimal addresses 52(low byte) and 53 (high byte) toremember the top of memory. In a 32KPet these pointers would contain zero and128 decimal respectively, indicating amemory total of 32,768. Addresses zeroto 1024 are reserved for Basic so thatuser memory is 32,768-1,024=31,744.

Poking these address pointers withlower values will protect an area of mem-ory. If you poke 52 with zero and 53 with80 then approximately 12K will be pro-tected.

A number of commercial programsdesigned to run in conjunction with auser's own Basic program are located totop of memory in this manner. I use thismethod when writing large blocks ofmachine code. The only problems occurwhen I lose, or have to rewrite, a favour-ite block because my latest add-on usesthe space I need.

Routine treatmentWhat I needed was a way of treating

short routines as part of a Basic program.The ideal would be to make the machinecode part of the Basic program with linenumbers so that the Toolkit could beused when building up a program fromsubroutines for Renumber, Find andDelete.

This can be done by using the RemBasic statement to protect the machinecode following from the interpreter. Foreach program line about 70 bytes ofmachine code can be incorporated.

To follow the examples exactly youshould have the Pet reset either byswitching it off then on, or by the com-mand Sys 64721. Now enter the line10 REMREMentering the * symbol to the end of theBasic line. Also note that the secondappearance of Rem is not a printingerror. You should have managed to get71 * symbols m your line.

Clear the screen and enter the monitorwith Sys 64785 and request memory loca-tions 0401 to 0453. If everything is inorder you should see the information asshown in figure 1. Exit the monitor bytyping X then return.

(continued on page 119)

PRACTICAL COMPUTING May 1982 117

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We were established in 1969 as a consultancy and softwarehouse, our consultants are well qualified and members ofseveral professional institutes.We undertake consultancy and contract work at a veryreasonable fee and our systems can be tailored to meet yourrequirements at a nominal fee.Other micro manufacturers, distributors and dealer enquiriesare welcomed.Also we are looking for distributors abroad and commissionagents in the U.K. Please ring for details Watford 48580.

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Circle No. 179

118

Circle No. 180

PRACTICAL COMPUTING May 1982

I

Programming

(continued from page 117)Location 0401, or 1025 decimal, is the

start of the RAM for user programs. Thefirst two hex numbers 51 and 04 are thelow and high bytes of the address whereBasic expects to find the next line forinterpretation. The next two bytes OAand 00 are the low and high bytes of theline number; 00A0 hex is 10 decimal.

Next comes the byte 8F, or 143 deci-mal. As the Basic interpreter enters aprogram line from screen to memory itlooks for instructions such as Rem orRead and if they are recognised they areconverted into single -byte tokens withASCII values of 128 - End - orgreater; 143 is the value of the token forRem. Once the Basic interpreter has rec-ognised the Rem token, following charac-ters are stored exactly as received, whichis why the following three bytes contain52, 45 and 4D respectively - the hexrepresentations of decimal 82, 69 and 77.They are the ASCII values of R, E andM. The second Rem entered has beentreated as received and not tokenised.

End of programThe rest of the line to memory 044F

consists of 2A which represents the *

character. The three 00 bytes followingsignify the end of the program since thefirst two bytes signify that no further linesfollow, and the third that the current lineis ended.

Now re-enter the monitor and placethe cursor over the first of the 2A bytesand alter it to 8F, which is the token forthe Rem statement. Now exit the monitorand List. The List command reverses theprocess of the line entry, with the excep-tion that the program assumes that if abyte has a token value then it is a token,and the appropriate command is printed.If you were to alter all of the 2A bytes to8F via the monitor then a List wouldproduce a very long program line.

Enter the monitor and change the sec-ond 8F back to a 2A and then exit themonitor and List. Now place the cursorover the line number 10 and edit to 99.Delete line 10 by typing 10 then pressingReturn. Now enter and examine the linefrom the monitor. Nothing has changedapart from the line number and the factthat you probably lost one of the * sym-bols during your line edit.

It appears possible to alter the line viathe monitor to include a machine -coderoutine. If the line starts with a Remstatement then the line can be renum-bered, and can be stored on tape or disclike any other line.

However, an important snag in thisapparently simple approach can bedemonstrated by trying to make the Petbreak to the Tim monitor. When the6502 processor meets a 00 byte instruc-tion it causes a software interrupt whichon the Pet calls the monitor.

Using the monitor alter the first of 2Abytes to 00. Then exit the monitor and

d

N

Pr IRO SF. AC XR 'r F' SPCGFE EIS2E 34 37 38 35 FA

0401 FIA n4 nn AA SF 45 4D0409 An Al A2 01 BD FF 7F 180411 6,7i RA 9D FF fF ES EO FFn419 Dn F2 ES 18 BD FE Sn 1R0421 F.'"; Rn 9D FE Rn ES Efi FFn4:=P;1 Dn F2 ES 18 TiD FD 81 180431 AC' Rn 9D FD 81 ES Efi FFn 39 Do F2 ES 18 BD FC 82 180441 1,7,c1 Rn 9D Fr Rs' ES Efi EC

n449 Do F2 Fin s':,f no On0451 on AA AR' AR RA AR AR AR

Figure 2. Screen -image reverse routine.

type Sys 1033. You should have enteredthe monitor via a break signified by a Et*at the start of the monitor listing. Nowlook at the program by typing M 04010530. The zero byte is now in the place ofthe first 2A.

Exit the monitor and List the line. Seethat the listing does not include any of the* symbols. The Basic interpreter alwayssees a zero byte as meaning the end of a

Figure 3. Code for reverse screen.

AO 01A2 01BD FF 7F

1869 809D FF 7F

E8E0 FFDO F2E818BD FE 801869 809D FE 80E8E0 FFDO F2E818BD FD 811869 809D FD 81E8EO FFDO F2E818BD FC 821869 809D FC 82E8EO ECDO F260 RTS

Load Y reg with 1Load X reg with 1Load Accumulator from$7FFF + X reg contentsClear Accumulator Carry FlagAdd $80 to accumulatorStore in $7FFF+ X regcontentsIncrement X registerCompare X reg with $FFBranch if not zeroIncrement X RegisterClear CarryLoad from $80FE + X

Store in $80FE + X

Load from $81FD + X

Store in $81FD + X

Load from $82FC + X

STORE in $82FC + X

program line, hence it assumed that thezero byte meant the end of line 99. Itthen moved on trying to make sense ofthe rest. It failed because it tried tointerpret the following symbols as beingpresent in the expected format.

Now try to run the line. Rememberthat the Run command was followed byReady, indicating that the Rem statementhad been ignored. If you are lucky, andhave a 32K Pet, then the return messagewill be

?SYNTAX ERROR IN 10794The Basic interpreter ignores the Remstatement but assumes that the singlebyte means the end of the line. Theaddress of the next line given at the startof the line is not used in normal execu-tion.

Major faultThe Interpreter assumes that the next

line starts immediately after the singlezero byte. It ignores the next two bytes -2A,2A - and sees the following twobytes - 2A,2A - as the current linenumber, in this case 2A2A hex or 10794decimal. The interpreter then parsesalong this line looking for an instructionuntil it gives up and exits via the syntaxerror message. Thus we cannot incorpo-rate a machine -code routine into a Basicline if it has a zero byte in the listing.Even with this major fault, however, youcan write a number of useful routines.

Figure 2 shows how a routine forreversing the screen image would appearin the Basic line. First clear Basic with Sys64721 and then enter the line

0 REMREMfollowed by the rest of the line in itsymbols, to duplicate the exampleexactly. Start altering, via the monitor, tothe codes shown in the listing. Note thatthe AA bytes following the three zerobytes are not part of the required routine.

Once you have entered the code, exit(continued on next page)

PRACTICAL COMPUTING May 1982 119

Programming

,.:2000 REM TO LOCATE UP TO '14/ MACHINE CODE SUPROUTINES IN REM STATEMENTS IN ORDERF2002 REM OF THEIR APPEARANCE623_104 REM THIS ROUTINE SHOULD BE CALLED AT THE START OF THE PROGRAM USING THE C

ODEc2A01; REM THE SUBROUTINE SHOULD BE ENTERED WITH SY SET TO THE MAXIMUM NUMBER OF6200R REM ROUTINES AVAILABLE AND SUBROUTINES STORED IN LINES BEGINNING REMREMA2A1O DIMSY(SY):SS=PEEK(43)+256+PEEK(42):N=1:FORI=1024TOSS82012 IFFEEK1:I)=143ANDPEEK(I+1)=S2ANDPEEK(I+2)=89ANDPEEK(I+3)=77THENSWN)=I+462014 IFSWN)=I+4THENN=N+1:IFN>SYTHENI=SS62016 NEXT:RETURN

Figure 4. Basic program to find machine code in RemRem lines.(continued from previous page)the monitor and type Sys 1033 followedby Return. The screen should reverse toblack on white. Type Sys 1033 again torecover the normal screen. When you aresatisfied that the routine works then savethe line to tape or disc. The logic of theroutine is given in figure 3.

The routine examines screen memoryin four blocks; three of 255 bytes and oneof 236 bytes. The routine could havebeen much shorter were it able to residein a fixed location. Each location on thescreen memory has 128 decimal added toits value and this provides the reversal.Indirect addressing of the screen is via theX register, which is incremented in thefirst block from 1 to 255 and thereafterfrom 0 to 25'5.

This program demonstrates one wayround the problem of not having a zerobyte. If it is particularly desired to initial-ise a register with 0 then you could loadthe register with 1 and then use a decre-ment instruction. The call Sys 1033 wasused to activate the machine -code sub-routine because it is known exactly wherein memory the program was located. Tobe completely portable, however, theroutine must be able to be at any point inmemory.

All of the routines so far have startedwith two typed Rems of which only thefirst was tokenised. Thus each line startswith the decimal numbers 143, 82, 69,77. This pattern can be used to identifythe start of a machine -code routine.If Peek(x)=143, Peek(x+ 1)=82,Peek(x +2)=69 and Peek(x+3)=77 thenPeek(x +4) is the start of the routine. Acontinued search would find any otherroutines hidden in this way.

Figure 4 gives a Basic subroutine tolocate up to N machine -code subroutinesin this way and tO put the start addressesinto the array SY(N). If this subroutine iscalled at the start of a program, thesubroutines can be called by Sys(SY(X))where X is the number between 1 and Nof the routine required. The subroutinemust be entered with N set. The methodof identification precludes the inclusionof such program lines as

100 REMREMOVE THE ...The method is easily modified to otheridentifying sequences. For instance youmay wish to use Rem followed by ashifted graphic character.

These routines may be renumbered bysoftware such as Toolkit without any illeffects. If you have attempted a Basic Listof the screen -reverse program you will beaware that the screen editor may not beused. If you have not yet listed them, doso now.

The line 0 when listed occupies aboutfive screen lines on a 40 -column Pet. Anyattempt to change the line number usingthe screen editor will truncate theroutine. You can renumber a line via theTim monitor to change bytes 3 and 4 ofthe line to the desired value. Assumingthat the screen -reverse routine is still inmemory, try the following:

20 IF X=0 THEN X=1:GOTO 4230 IF X=1 THEN X=2: GOTO 4240 PRINT X

Now enter the monitor and look at line0. The line number is given in the thirdand fourth bytes of the line which, at themoment, read 00 00. Change the firstbyte to read 2A then exit the monitor andList. Although the line number of theroutine has been changed it is still in thesame place in the listing. Running theprogram will give a value for X of 2 onthe screen, proving that Basic accepts thenew line number as valid.

This also demonstrates how Goto

works. The interpreter starts from thefirst location in Basic and looks for a linenumber match, without reference to thepresent line number. If the interpretermeets a higher line number than that forwhich it was searching then anunidentified -statement error is issued.Change the 42 in line 20 to 20, and theprogram will give an error.

This only works if you enter the wholething again. The modification to the linenumber must be the final edit. If you havenot got a Toolkit or similar then youshould reserve some line numbers exclu-sively for these machine -code routines.

Short routines of this type give accessto the wealth of machine -code routinesforming the Basic interpreter. Figure 5shows how to access a number of theseroutines and it provides, on call, thecurrent value of the variable I to thetop -left corner of the screen. The routinecalls subroutines in the Basic interpreter.

First it calls CFC9 hex which locates avariable, then E25D hex which positionsthe cursor' for printing, before DAAEhex loads the current value of the vari-able into the floating-point accumulatorand DCE3 hex prints it on the screen.The final call to E25D hex resets thecursor position.

Figure 5. Program to access routines from Basic interpreter.

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120 PRACTICAL COMPUTING May 1982

In fact it leads to many others! Joining the amazing successof our PAL Encoder Card, these four new expander cardsall featuring the unique 'Digitek Safety Tab' are ready toplug straight into your Apple Computer.Pal Colour Encoder Card £105 This amazing card with it's on -boardmodulator, displays exceptional colour graphics to your TV.16k Ramcard £91 Insert the card straight into slot 0, and increase .,the memory capability of your Apple without having to removeany memory chips.Z80 Expansion Card £110 Installing the Z80 into yourApple gives you two systems in one, which enables you torun the popular C P M operating system.

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The PRINT -MASTER accepts Appleprotocols,15+ software commands andhas on -board graphics dump capabilityto all popular graphics printers. Noneed to load clumsy softwareroutines - it's all at your fingertipson the PRINT -MASTER - choice ofinverse printing, double sizepicture, 90°picture rotation,many word processor typetext commands, plusmany more.Apples the hodemorkof Apple computers IncDulek arld Fir} -masterore the trademarks ofNook (ntemotonal)

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122

Circle No. 183

PRACTICAL COMPUTING May 1982

Make the most of yourSinclair ZX Computer...

Sinclair ZXsoftwareon cassette.23.95per cassette.The unprecedented popularity ofthe ZX Series of Sinclair PersonalComputers has generated a largevolume of programs written by users.

Sinclair has undertaken topublish the most elegant of theseon pre-recorded cassettes. Eachprogram is carefully vetted forinterest and quality, and thengrouped with other programs toform a single -subject cassette.

Each cassette costs £3.95(including VAT and p&p) and comescomplete with full instructions.

Although primarily designedfor the Sinclair ZX81, many of thecassettes are suitable for runningon a Sinclair ZX80 -if fitted with areplacement 8K BASIC ROM.

Some of the more elaborateprograms can be run only on aSinclair ZX Personal Computeraugmented by a 16K -byte add-onRAM pack.

This RAM pack and thereplacement ROM are describedbelow. And the description of eachcassette makes it clear whathardware is required.

8K BASIC ROMThe 8K BASIC ROM used in theZX81 is available to ZX80 ownersas a drop -in replacement chip.With the exception of animatedgraphics, all the advanced featuresof the ZX81 are now available on aZX80-including the ability to runmuch of the Sinclair ZX Software.

The ROM chip comes with anew keyboard template, which canbe overlaid on the existingkeyboard in minutes, and a newoperating manual.

16K -BYTE RAM packThe 16K -byte RAM pack provides16 -times more memory in onecomplete module. Compatible withthe ZX81 andthe ZX80, it can be usedfor program storage or as a database.

The RAM pack simply plugsinto the existing expansion port onthe rear of a Sinclair ZX PersonalComputer.

Cassette 1 -GamesFor ZX81 (and ZX80 with 8KBASIC ROM)

ORBIT-your space craft'smission is to pickup a very valuablecargo that's in orbit around a star.

SNIPER- you're surroundedby 40 of the enemy. How quicklycan you spot and shoot them whenthey appear?

METEORS -your starship iscruising through space when youmeet a meteor storm. How long canyou dodge the deadly danger?

LIFE-J. H. Conway's 'Game ofLife' has achieved tremendouspopularity in the computing world.Study the life, death and evolutionpatterns of cells.

WOLFPACK - your navaldestroyer is on a submarine hunt.The depth charges are armed, butmust be fired with precision.

GOLF-what's your handicap?It's a tricky course but you controlthe strength of your shots.

Cassette 2 -JuniorEducation: 7 -11 -year -oldsFor ZX81 with 16K RAM pack

CRASH- simple addition -withthe added attraction of a car crashif you get it wrong.

MULTIPLY-long multi-plication with five levels ofdifficulty. If the answer's wrong-the solution is explained.

TRAIN-multiplication testsagainst the computer. The winner'strain reaches the station first.

FRACTIONS -fractionsexplained at three levels ofdifficulty. A ten -question testcompletes the program.

ADDSUB - addition andsubtraction with three levels ofdifficulty. Again, wrong answersare followed by an explanation.

DIVISION-with five levels ofdifficulty. Mistakes are explainedgraphically, and a running score isdisplayed.

SPELLING-up to 500 wordsover five levels of difficulty. Youcan even change the words yourself.

Cassette 3 -Business andHouseholdFor ZX81 (and ZX80 with 8KBASIC ROM) with 16K RAM pack

TELEPHONE - set up your owncomputerised telephone directoryand address book. Changes,additions and deletions of up to50 entries are easy.

NOTE PAD-a powerful, easy -to -run system for storing and

retrieving everyday information.Use it as a diary, a catalogue, areminder system, or a directory.

BANK ACCOUNT -asophisticated financial recordingsystem with comprehensivedocumentation. Use it at home tokeep track of 'where the moneygoes,' and at work for expenses,departmental budgets, etc.

Cassette 4 -GamesFor ZX81 (and ZX80 with 8KBASIC ROM) and 16K RAM pack

LUNAR LANDING-bring thelunar module down from orbit to asoft landing. You control attitudeand orbital direction-but watch thefuel gauge! The screen displays yourflight status-digitally and graphically.

TWENTYONE -a dice versionof Blackjack.

COMBAT-you're on a suicidespace mission. You have only 12missiles but the aliens haveunlimited strength. Can you take12 of them with you?

SUBSTRIKE - on patrol, yourfrigate detects a pack of 10 enemysubs. Can you depth -charge thembefore they torpedo you?

CODEBREAKER-thecomputer thinks of a 4 -digit numberwhich you have to guess in up to 10

Cassette 5 -JuniorEducation: 9 -11 -year -oldsFor ZX81 (and ZX80 with 8KBASIC ROM)

MATHS- tests arithmetic withthree levels of difficulty, and givesyour score out of10.

BALANCE -tests understandingof levers/fulcrum theory with aseries of graphic examples.

VOLUMES-`yes' or 'no'answers from the computer to aseries of cube volume calculations.

AVERAGES -what's the averageheight of your class? The averageshoe size of your family? The averagepocket money of your friends? Thecomputer plots a bar chart, anddistinguishes MEANfromMEDIAN.

BASES - convert from decimal(base 10) to other bases of yourchoice in the range 2 to 9.

TEMP-Volumes, temperatures-and their combinations.

How to orderSimply use the order form below,and either enclose a cheque or giveus the number of your Access,Barclaycard or Trustcard account.Please allow 28 days for delivery.14 -day money -back option.

tries. The logical approach is best! IIMI=111111MAYDAY-in answer to a distress

call, you've narrowed down thesearch area to 343 cubic kilometersof deep space. Can you find the Sinclair Research Ltd,astronaut before his life-supportsystem fails in 10 hours time?

ZX SOFTWARE6 Kings Parade, Cambridge,Cambs., CB21SN. Tel: 0276 66104.

rTo: Sinclair Research, FREEPOST, Camberley, Surrey, GUI5 3BR. Pleaseprit7t1Please send me the items I have indicated below.

Qty Code Item Item price Total

21 Cassette 1 -Games £3.95

22 Cassette 2 -Junior Education £3.95

23 Cassette 3 -Business and Household £3.95

24 Cassette 4 -Games £3.95

25 Cassette 5 -Junior Education £3.95

17 *8K BASIC ROM for ZX80 £19.95

18 *16K RAM pack for ZX81 and ZX80 £49.95

'Post and packing (if applicable) £2.95

Total L

*Please add £2.95 to total order value only if ordering ROM and/or RAM.

I enclose a cheque/PO to Sinclair Research Ltd fork

Please charge my Access*/Barclaycard/Trustcard no.

1 I 1 1 I1 I I I I I I I I 1 I I

*Please delete as applicable.

Name: Mr/Mrs/Miss I 1 I I I I 1 I

Address. I 1 I I I 1 I I I I I

LI 1 1 1 1 1 1 1 1 I I 1 1

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PRACTICAL COMPUTING May 1982 Circle No. 184

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Statistics

Finding the significance of the differing averages of two sets of data is a commonproblem. Malcolm Mountford demonstrates an improved randomisation test.

CorrelationTHE EXCELLENT ACCOUNT Of the I sation test given by Owen Bishop inrationale of Fisher's two -sample randomi- I Practical Computing, February 1981 is

0010 REM FISHER'S TWO -SAMPLE RANDOMISATION TEST FOR IDENTICAL POPULATIONS.0020 REM SENSITIVE TO UNEQUAL LOCATIONS.Q030 REM0040 REM PROGRAM RETURNS PROBABILITY LEVELS FOR ONE TAILED AND TWO --TAILED TESTS.

0050 REM0060 DIM X(20) rY(20) '2( 40) rJ(20) rT(3) rPi310070 PRINT TABT18Ti!RANDOMISATION TEST'0080 PRINT0090 LET N1=00100 LET N2=00110 REM INPUT VALUES,XTPrOF FIRST SAMPLE AND COMPUTE SIZE OF SAMPLE.0120 REM0130 PRINT 'ENTER VALUES OF FIRST SAMPLE EACH FOLLOWED BY EOL'0140 PRINT 'AFTER FINAL ITEM TYPE END'0150 PRINT0160 FOR I=1 TO 10000 STEP 10170 DISP 'ENTER VALUE.IF NO MORE TYPE END',0160 INPUT X$0190 IF X$='END' THEN 2300200,,ASSIGN X$,X(I);320210 LET N1=F11+10220 NEXT I0230 PRINT 'VALUES OF FIRST SAMPLE'0240 PRINT0250 FOR I=1 TO Ni STEP I0260 PRINT X(I)0270 NEXT I0280 REM INPUT VALUES,Y(I),OF SECOND SAMPLE AND COMPUTE SIZE OF SAMPLE.0290 REM0300 PRINT 'ENTER VALUES OF SECOND SAMPLE EACH FOLLOWED BY EOL'0310 PRINT 'AFTER FINAL ITEM TYPE END'0320 FOR I=1 TO 10000 STEP 10330 DISP 'ENTER VALUE4IF NO MORE TYPE END'r0340 INPUT Y$0350 IF YWENIT" THEN 3900360 ASSIGN Y$,Y(1)T320370 LET N2=N2+10380 NEXT0390 PRINT 'VALUES OF SECOND SAMPLE'0400 PRINT0410 FOR I=1 TO N2 STEP 10420 PRINT Y(I)0430 NEXT I0440 PRINT0450 REM CALCULATE OBSERVED DIFFERENCE BETWEEN MEANS.0460 LET S1=00470 LET S2=00480 FOR I=1 TO N1 STEP 10490 LET S1=S1+X(I)0500 NEXT I0510 FOR 1=1 TO N2 STEP 10520 LET S2=S2-TYTI10530 NEXT I0540 LET 0=10550 IF N2>N1 THEN 6000560 LET R=N20570 LET M=N10580 LET 0=20590 GOTO 6200600 LET R=NI0610 LET M=N20620 LET D1=S1/N1'-S2/N20630 LET D=ABS(D1)-1E-300640 REM THE TWO SAMPLES ARE MERGED.0650 LET N=N14.N20660 LET S3=(514.52)/M0670 FOR I=1 TO N1 STEP 10680 LET Z(I)=X(I)0690 NEXT I0700 FOR I=1 TO N2 STEP 10710 LET Z(N144)=Y(I)0720 NEXT I0730 REM GENERATION OF ALL PARTITIONS BY THE ALGORITHM PROVIDED0740 REM BY JANE GENTLEMAN IN APPLIED STATISTICS 1975.P374.0750 REM0760 FOR 1=1 TO 3 STEP I0770 LET T(I)=00780 LET P(I)=00790 NEXT I0800 LET 11=10810 IF (R<1) OR (FM) THEN 13100820 LET 11=00830 LET N0=00840 LET M=N -R0850 LET I=1

(listing continued on next page)

marred by an erroneous procedure andan incorrect algorithm. The test is basedon the following argument.Suppose that N individuals are drawn ran-

domly from one population and M individualsare drawn randomly from a second popula-tion.

Each individual is weighed.If the two populations are identical all partitions

of the total of (N+M) individuals into twogroups of N and M individuals are equallyalike.

Let X be the mean of the first sample and Y themean of the second sample.

For each of the (N+M)!/(N!M!) partitions thereis a corresponding value of X -Y.

The probability level of the observed differencebetween means is the proportion of possiblevalues of X -Y that are greater than or equalto the observed value of X -Y.

Bishop argues that to calculate this pro-portion it is not necessary to consider all(N+M)!/(N!M!) partitions, and that it issufficient to consider merely the inter-changes of values in the region of overlapof the two samples. To illustrate the point,,the numerical example given by Bishop isrepeated here. He considers the compari-son of two samples of weights:Sample A has weights 495, 490, 497, 493, 500;

means = 495Sample B has weights 499, 500, 502, 496, 503:

mean = 500.The two samples are then separately

sorted in ascending order and thenarranged as shown in Table 1.

Owen Bishop then argues that if wewant to make the sample with the largestmean, sample B, even larger, it is a wasteof time to consider swapping any memberof B for the three smallest members of A,490, 493, 495. Similarly we would notconsider swapping the two largestmembers of B, 502 and 503, for any in A.The only values which are concerned withthe selection process are those of theoverlap group.

This argument is correct only ifexchanges are made one at a time.However, let us consider what may hap-pen when exchanges are made two at atime. In particular consider swapping thetwo values 495 and 500 of sample A withthe two values 496 and 499 of sample B.The resulting partition has the same meandifference, and should therefore be takeninto account.

Evidently it is incorrect merely to con-sider exchanges one at a time; it is alsonecessary to consider swapping memberstwo at a time, three at a time and so on. Tofollow the correct procedure it would be

(continued on next page)

Table 1.A 490 493 497 500

495B 496 499 5p2 503

500smaller overlap larger

PRACTICAL COMPUTING May 1982 125

Statistics

(continued from previous page)

necessary to sort paired values in ascend-ing order to establish the overlap formembers exchanged two at a time, then tosort in ascending order values taken threeat a time, and so on. This method leads tolarge demands on sorting procedures andalso to large storage requirements. Thus ifa sample has 15 members, storage capa-city of 15!/(8!7!) = 6,435 values isrequired. The sorting procedure neededto cope with this number is correspond-ingly expensive.

These problems of storage, sorting andindeed of programming are avoided bysimply evaluating the values of the dif-ference between means X- Y for all poss-ible (N+M)!/(N!M!) partitions. It is thena straightforward procedure to evaluatethe probability levels for one -tailed andtwo -tailed tests.

In outline, the Randomisation programis as follows:Lines 70-350. The data for the two samples is

entered.Lines 370-540. The observed difference is

computed.Lines 550-620. The values of the two samples

are merged.Lines 670-1010. All partitions are generated by

the algorithm provided by Jane Gentlemanin Applied Statistics (1975), page 374. Thevalues of X -Y for each partition calculatedin lines 800-940.

Lines 1020-1300. Printout of probability levelsfor one -tailed and for two -tailed tests. In

0950096009700980099010001010102010301040105010601070108010901100111011201130114011501160117011801190120012101220123012401250126012701260129013001310

(listing continued from previous page)0860 LET J(1)=10870 IF I=R THEN 9200880 LET P1=I+10890 FOR L=P1 TO R STEP 10900 LET J(L)=J(L-1)+10910 NEXT L0920 LET K0=K0+10930 LET S=00940 POR I=1 TO R STEP 1

LET L=J(I)LET S=S+Z(L)NEXT ILET S=S*N/(R*M)-S3REM NOTE THAT THE DIFFERENCE BETWEEN MEANS=S.IF 0=1 THEN 1020LET 8=-SIF S<D1-1E-10 THEN 1060REM COMPUTE THE NUMBER OF PARTITIONS IN THE ONE -TAILED AND TWO --TAILEDREM CRITICAL REGIONS.LET T(1)=T(1)+1IF S>D1+1E-10 THEN 1080LET T(2)=T(2)+1LET S=ABS(S)IF S<D THEN 1110LET T(3)=T(3)+1LET I=RIF J(I)<M+I THEN 1160LET I=I -1IF I<=0 THEN 1180GOTO 1120LET J(I)=J(I)+1GOTO 870

FOR I=1 TO 3 STEP 1LET P(I)=T(I)/K0NEXT I

REM PRINT-OUT OF PROBABILITY LEVELS OF' ONE --TAILED AND TWO -TAILED TESTS.PRINT 'MEAN OF FIRST SAMPLE=';S1/N1PRINTPRINT 'MEAN OF SECOND SAMPLE=';82/N2PRINTPRINT 'PROBABILITY LEVEL FOR A TWO -TAILED TEST=';P(3)PRINTPRINT 'PROBABILITY LEVEL'FOR ONE -TAILED TEST(1ST>2ND)="iP(1)PRINTPRINT 'PROBABILITY LEVEL FOR A ONE -TAILED TEST(2ND>ISI)=';F(2)END

WHY YOU NEED LOCKSMITH.you've invested some money and a lot of time in a

commercial software program for your Apple. It workswell, to the point that you are dependent on its day-to-dayfunctioning. But the disks are copy -protected. So you arealso dependent on the vendor's back-up (if furnished), onhis living up to vague promises of support, even on hisability to stay in business.

o computer user can live with that. So until thesituation changes (and it will), you need Locksmith.

ocksmith (new 4.0 version) will copy almost all"protected" diskettes for the Apple. It is the most reliable

nibble -copy program you can buy. Locksmith is suitableonly for backups, because the copiesinclude all serial numbers, codesand protection features of theoriginal (under the new copyrightlaw, you'd have to be prettyfoolish to try bootlegging

software that is traceable back to the purchaser).

Locksrnith includes nine other utilities, of which thesefive are vital to the integrity of your system: 1. Media

surface check- Never commit data to a flawed disketteagain. 2. Disk -drive speed calibration - the most frequentcause of communication bugs between Apples. 3. Degaussand Erase - Make sure no stray data is left over. 4.Nibble -Editor - sophisticated read/write tool for repairingblown disks. 5. Quickscan -Check for unreliable data, findused and unused tracks.

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ESSEX SS 13 1LPTEL: (0268) 728484Apple is a registered trademark of Apple Computer. Inc

Circle No. 186126 PRACTICAL COMPUTING May 1982

Art

In these pages Brian Reffin Smith keeps you up to date with computer -based art and design and lays the foundations for graphics routines touse on your own micro.

All-purpose graphicsroutines frow GinoSQUEEZING GINO into a micro is the artis-tic equivalent of putting all the Pen-tagon's cornputers onto a single chip. TheComputer -Aided Design Centre, CADC,at Cambridge, originally designed Ginofor large mainframe computers and it hasbecome the best-known general-purposegraphics package around. This library ofFortran subroutines has traditionally costthousands of pounds to buy or even hibecause it can perform tasks ranging frominformation graphics to map making, andfrom equipment design to architecture.

Machine -portableNow Research Machines has made all

this available to micro users for a fewhundred pounds. The general-purposeGino -2D comes on a 5.25in. mini -floppy.It is also available on 8in. disc, as areGino -zone for mapping, Gino -graph forinformation graphics, and even the mas-sive Gino -F which can perform two- andeven three-dimensional routines. Theseall run under CP/M, and of course needFortran, and a text -editor to write theprograms.

Gino is device -independent, and so willdrive a Tektronix display, plotter orprinter as well as the 256 colours of theResearch Machines 380 -Z's high -resolution graphics. The CADC hasroutines to drive a huge range ofperipheral equipment. The packages costno more than many word-processingpackages.

The transition from Basic to Fortran isnot hard, because the two languages areclosely related. Details from ResearchMachines, Mill Street, Oxford OX2OB W.

iii 26 24691111 90800.56 48 69520

D>CHORO

OCINO-F MARK 2 6

When a student walks into the compu-ter studio raving about a dictionary youtend to think "What has all this got to dowith computer graphics"?

Visual thesaurusThe answer lies on every one of the

820 pages of the Oxford-Duden PictorialEnglish Dictionary published by OxfordUniversity Press in September 1981 for£7.50. The book, with over 28,000 illust-rations, is a kind of pictorial equivalent ofRoget's Thesaurus.

Each page is reminiscent of a screen -full of information, with a picture in theupper half and a numbered key in thelower portion. Each image is a story orscenario, combining all the elementsthought relevant to some topic - andtopics range from information technologyto reptiles, from printing processes topolitical meetings. You can look upalmost anything in the huge index andfind a picture of it, in context: e.g., gar-ters appear under "night club", completewith strippers and tired businessmen. a]

BBC soundTHE BBC COMPUTER is far more powerfulthan expected. The designers have beenso clever with the graphics and the Basicthat they have probably also put a lot ofthought into the operating system, sound,and so on.

To give an indication of just how usefulthis machine can be for artists suffice it tosay that the FX commands and the VDUdrivers allow a user to roam aroundinside the system thus making themachine doubly powerful. The soundroutines that are built into Basic giveanyone who buys a BBC machine a freemusic synthesizer. The two relevantkeywords are Sound and Envelope.

Sound causes the internal loudspeaker toemit a tone whose frequency, volume andlength can be specified. The machine canplay up to four sounds simultaneously,using four channels, the first of which is anoise generator. The command looks like

SOUND 1,-15,100,50where the 1 is the channel, and -15 thevolume; 15 is the maximum value, whichis always given a minus sign to distinguishit from more complex sounds. Parameter100 is the pitch and 50 the duration of thenote in units of 0.05s. Each increase ofthe pitch by one gives a rise of one -quarter of a semitone. The duration and

(continued on next page)

PRACTICAL COMPUTING May 1982 127

Art(continued from previous page)pitch can take any value zero to 255, witha duration of 255 playing for ever.

The noise generator on channel 0 hasthe following properties - the numbergives the pitch setting.0 high -frequency periodic noise1 medium -frequency periodic noise2 low -frequency periodic noise3 periodic noise whose frequency is

determined by the pitch setting4 high -frequency white noise (many fre-

quencies at once)5 medium -frequency white noise6 low -frequency white noise7 noise whose frequency is continuously

determined by the pitch of channel 1The first, channel, number can be afour -digit hexadecimal number, precededby &, enabling notes to be synchronised,to wait for each other to die away, and so

on. The second parameter, normally con-trolling volume, can instead be given apositive number of one to four, specifyingan Envelope to be used for that sound.Envelope controls to a remarkable extentthe sort of sound that is produced; itdetermines, for instance, whether a soundis piano -like - starting loud, then dyingaway - or more like a violin, or amotor -bike.

In this example there are 14 paramet-ers to the Envelope command, which arethen used by Sound at line 20:

10 ENVELOPE 3, 25, 16, 12, 8, 1, 1, 1, 10,-10, 0, -10, 100, 50

20 SOUND 1, 3, 100,100

The first parameter, 3, gives the envelopenumber. The next, 25, gives the length ofstep in 100ths of a second, used by later

BEGINNING GRAPHICS

parameters. It is these that control theEnvelope of pitch, the values 16, 12, 8, 1,1, 1, and that of amplitude or volume, thefinal six. The attack, sustain, decay andrelease of the note are determined bythese values.

The pitch of the note can be changed inthree sections, and for each of them thechange in pitch for each step is given. Inour example the three sections have pitchchanges of 16, 12 and 8 units. All threesections have only one step. The finalvalues should be played with to see whatthey do. They can take values as follows:The 9th can be

10th11th

the 12ththe 13ththe last one can be 0Good luck.

-127 to 127-127 to 127

-127 to 0-127 to 127

0 to 126to 126.

Ever-increasing circles100 REM***SPIRALS FOR RESEARCH MACHINES

380Z WITH HI-RES GRAPHICS110 CLEAR100120 CALL"PESOLUTION",0,2:PUT12130 RANDOMIZE140 FORI=0T03:CALL"COLOUR",I,INT(255*RND(1)):NEXYI150 I=0160 INPUT"CENTRE X,Y";HS,VS170 INPUT"RADII A,B";A,B180 INPUT"NUMBER OF SIDES";N190 INPUT"CONE GENERATION Y/N)";ZCS:IF ZCS="N"THEN220200 INPUT"POINT OF CONE X,Y";PX,PY210 INPUT"LINE OR POINT EDGE (L/P)";Z$:IF Z$="P"THENSU=99220 ANGLE=2*3.142/N230 C=COS(ANGLF-.04):S=SIN(ANGLE)240 XA=1:YA=1250 I=I+1260 COL=INT(I/N)+1:IFCOL=4THENI=1270 X=XA*C-YA*S200 Y=XA*S+YA*C290 XA=X:YA=Y300 IFI>1THENPS="LINE"ELSFP$="PLOT"310 IFSW=99THENP$="PLOT"320 CALLP$,A*XA+HS,R*YA+VS,3330 IF ZCS="N"THEN350340 CALLP$,PX,PY,COL:CALL"PLOT",A*XA+HS,B*YA+VS,16350 COT0250

ANALOGYBOX

What would the competitiondictionary be like if it usedsounds instead of pictures?Could it be simulated on ascreen using a computer withbuilt-in sounds such as theBBC, Atari or DAI?

OCNTR8` X, '0160;100a, ;RADI I A, 87NUMBER OF SIDES'? 55CONE GENERATION Y/N)? YPOINT OF CONE X,Y? 160,100LINE OR POINT EDGE (L/P)? L

HERE IS AN EXTENSION to the Cones pro-gram for the 380-Z, that spirals overoutwards. You can put the point of a coneinside its own rim, thus making a floweror spoked wheel. This program alters theangle to make a never-ending polygon.©

CompetitionWE WERE inundated with high -

quality entries for the For -Next

loop artwork competition. Half of

them were for bizarre machines

but John Hardman's winningentry was a simple concise prog-

ram for a 380-Z. If you want to

win this month's prize, the

Oxford-Duden Pictorial Diction-

ary, try writing a program to draw

a few simple objects on thescreen. Refer to them by a num-

bered key, 1=Car, 2=Frog. NoW

scramble objects and descriptions

so that the "wrong" ones arematched -a Car may be labelled

as a Frog, for example. The win-

ning entry will not only be amus-

ing but will shed a new light on

ordinary objects. Send your entry

which cannot be returned, to Art,

Practical Computing, RoomL306, Quadrant House, TheQuadrant, Sutton, Surrey, SM25AS.

128 PRACTICAL COMPUTING May 1982

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PRACTICAL COMPUTING May 1982 129

Telesoftware

BBC: sky is the limitANYONE who threw caution to the windsand, on inspecting the spec of the BBCMicro last year decided there and then toput in an order will now be indulging insome smug self-congratulation. A cun-ning entrepreneur who ordered up sev-eral will be even more pleased at theprofits to be taken from immediate resaleof this machine, which looked from thestart to be exceptionally good value,despite the Ferranti ULA chip malfunc-tion.

Acorn is said to have licked this prob-lem now; certainly at the launch party forthe Micro and for the TV series, TheComputer Programme, which accom-panies it, there was a good score of themachines being bashed by skilled andnot -so -skilled operatives. Among them,tucked away in the corner, was one with aprototype videotex extension. It was adevelopment job, to judge by the quan-tity of surrounding test gear, but it was,nevertheless, capturing data off -air fromthe BBC's Ceefax teletext service, as wasdemonstrated when someone unconnec-ted with the computer's launch un-plugged the aerial on the roof.

Teletext biasThe main thrust of the BBC Micro's

videotex development work is going intothe teletext side - not surprisingly as theBBC is a broadcasting organisation. Butthe development team, headed by aubiquitous figure who declines anyfurther mention in these columns, isextending maximum co-operation to Brit-ish Telecom in attempting to maintaincompatibility with its Prestel system.

It is not an easy task: as a marketingexercise it might seem redundant, forPrestel has climbed now to only around15,000 registrations, while by the end ofthe year, it is confidently predicted, therewill be more than 1,000,000 teletext setsin use in the U.K.

But is all as it seems? The Govern-ment's own document, InformationTechnology, devised by the AdvisoryCommittee for Applied Research andDevelopment, ACARD, alludes withsome sympathy to the drudgery of draft-ing standards in electronic com-munications, and who would blame anengineer for assigning priority, whendrafting standards, to his own area ofinterest? It is cheering, then, to find thatCeefax enhancements will make it appearto the user more like Prestel.

Such a structure could be useful fordata within a telesoftware program, or fordocumentation. Equally it would be suit-able for magazine -type editorial contentwhere news in brief could be followeddown the tree to its more detailed report.These hooks in the structure of teletext

Is Acorn bidding tobecome the IBM of 1984?Martin Hayman looks atthe progress being madeby BBC and Acornengineers towardssoftware -programmable"data grabbers".were built in by the system's technicaldesigner, John Chambers. They are toexploit fully the increasing capacity ofteletext, which now transmits on fourblanking lines instead of two, and tomake it, so far as possible, "futureproof".

Chambers explains that teletext filesare sent in block of 1K with a "cyclicredundancy check" signalled by a flag bitwhich, in his words, is to "check the pageis OK without having to eyeball it tomake sure it makes sense". Teletext isprone to errors caused by atmosphericdisturbance - low -flying aircraft, forexample - so its need for error detectionis no less than Prestel's, as any viewer ofstandard "editorial" teletext will attest.

Used as a medium for software trans-mission, teletext may offer some realadvantages over Prestel though convert-ing broadcast, i.e., teletext -formattedprogram files into executable code withinyour own machine via the TV screen mayinvolve some delicate hedging aroundHome Office rules on subliminal broad-casting.

It is hard to know whether the samerules would apply. to a "data grabber"between a TV aerial and a micro-computer. Such a box, first mooted inthese pages in July 1980 by Oracle's JohnHedger, would be dedicated to de -formatting and checking broadcast tele-software and would squirt the codestraight into your machine.

Why not radio?In March 1980 Hedger put the break-

through price for such a device at £100,and Chambers now reckons that the BBCdesign could. be sold for £115. A Labgearadaptor, which admittedly has its ownpower supply and infra -red control, costsabout £200. A further advantage of sucha data grabber is that it would be able toaddress pages outside the range of thestandard teletext decoder. So why notjust use the radio? Indeed, as we reportedin January 1982, this is perfectly possibleand being done in Holland - and, so wehear, by the Open University here.

In this context the BBC Micro's systemis little different from an adaptor, thoughits error detection is, according to Cham-bers, slightly different from his. However

- and here we come to the nub of theargument - he refers to its operation as"software -programmable". On firstinvestigation, it seemed that what wasintended was a portable system: theteletext/Prestel receiving part of themachine could be programmed to under-stand any protocol sent to it.

Emulators seem to be in vogue at themoment, as you will know from Commo-dore's recent news that it is to marketplug-in circuitry to make the Commodore64 behave as its rivals Apple, Tandy andIBM. ITT's Business Systems' "Informa-tion Transfer Technology" proposes toinsert some local intelligence into a net-work to act as an interpreter in front ofthe terminal, and can appear as a tele-phone, teleprinter, VDU or what -have-you.

Seeking portabilityThe BBC Micro is different. The

hitherto anonymous consultant to Acorn,Mel Pullen, is a proponent of machine -independent programs and argues thatlittle has been done on this front sinceAlan Turing discussed it 20 years ago,and suggests that portable compilers suchas Forth and Mint are the answer. Hisobject appears to be to implement somesuch system on the BBC Micro, wherebythe protocol in which a teletext/Prestelprogram is sent is indicated at the start oftransmission: in plain terms, the rulesprecede the program. The machine firstloads the rules, and then converts its frontend to decode the program which followsaccording to the rules of that protocol.

Chris Oswald, a resourceful under-graduate at Cambridge University, whoseems to spend his holidays working forLogica and CET, has written a paper forAcorn in which he outlines in some depththe case for, and implementation of, "ARedefinable Telesoftware Format". Sucha format would, he claims reduce the arguments over the choice of a

standard to an agreement on the defaultformat,

encompass a wide range of fixed telesoft-ware formats,

provide for future expansion.But other experts are not so sure. How doyou instruct a receiving machine, i.e., aBBC Micro, with new rules for a formatunless it already understands themachine -level language of the machinewhich is sending the formatted programfile? Would the Acorn product be able totalk to a Research Machines 380-Z with-out the undesirable hardware fix?

It seems rather like trying to teach acomplex system of contract bidding tosomeone who doesn't know how to playbridge. Or is this Acorn's bid to becomethe IBM of 1984?

130 PRACTICAL COMPUTING May 1982

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PRACTICAL COMPUTING May 1982 131

Y6 bit mien).At last! A 16 bit micro computer to

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Survey

The microcomputer market is so big, fast-moving and disorgan-ised that information about it is hard to come by. We would liketo know more so that we can plan Practical Computing better.Industry and government need to know so that products andservices can be provided to satisfy microcomputer users' needs.

We would be most grateful for your answers to the question-naire below. Please send it to The Editor, Practical Computing,Quadrant House, The Quadrant, Sutton, Surrey, SM2 5AS. Asan inducement to our busy readers three cash prizes will beawarded - one of £50 and two of £25 - to the first threecompletely answered questionnaires drawn on May 17, 1982.Employees of IPC and their families are not eligible.

Please place a tick in the boxes provided - you may need to tick more than one box in somequestions - or write your answer in the space provided.

0. Into which of these ranges does your age fall?

under 211

21 to 30 0 31 to 403 4E 41 to 50 E 51 to 60

E5over 60

1. Do you read Practical Computing mainly because of your: Job y Formal study

Hobby/self-education rgl?-1-81

2. If you read Practical Computing for your job or formal study please indicate

a) Your job-title/occupation

b) The nature of your organisation

c) The number of people employed at your establishment:

under 10 1;13 10 to 24 E] 25 to 99 g 100 to 249 c; 250 to 1,000 pi over 1,00011 15

3. Do you regularly use a microcomputer? Yes 0 No Li17

4. If you answered yes to question 3, what type of machine is it?

Pet CI Apple U Tandy CI CP/M LJ22

Acorn ZX - 80/81 g BBC g18 20 21

Vic -20 Nascom CI Other g If "other", please specify25 26

Plotter [1 High -resolution graphics

6. What is the approximate value of the system you use most?

Under £100 1;5] £100 to 299 36

£300 to 699 l; £700 to 99938

£1,000 to 1,499 L3,_1

£1,500 to 2,999 ;) £3,000 to 5,999 c.71 £6,000 to 9,999 El over £10,000

ReaderSurvey

5. Do you regularly use any of these peripherals?

Cassette I;31 Printer 1_2 Discs 5.25 in.30

Discs 8in. E Hard discs329 31

7. What regular use do you have for a micro?

Accounting, pay, etc. g Stock, production control Costing CI46

Business/financial planning ;I Engineering calculation ,3. Science calculation gData collection CI Self -education C Games g Other LJ .

50 51 53

If "other" please specify

8. Do you regularly use software package(s) that you did not write?

Word/text processor 11 Database manager Languages ;IAccounting, pay, etc. H Planning ;I Other

If "other" please specify60

Assembler E57

(continued on next page)

PRACTICAL COMPUTING May 1982 133

Survey

(continued from previous page)

9. How much did you spend on software in the last 12 months?

Under £100 Fl £100 to 249 g £250 to 1,000 over £1,000 F671,61

1163

10. Which of the following types of article are important to your interest in Practical Computing?

News in brief El Hardware reviews E Software reviews H Applications 1:365 66 67

Programming techniques 1_0] Readers' letters El Readers' programs Games Li Education 1-770 73

Buyers' Guide (Software) 0 Buyers' Guide (Microcomputers) Buyers' Guide (Peripherals) I;1

11. How do you normally get your copy of Practical Computing?

Own subscription 0 Company subscription Computer club [E;13 School friend 0Buy at W H Smith or Menzies El Buy at another newsagent PI Buy at computer shop El

82 74 83

12. What publications do you read regularly for information on computers and related subjects?

Your Computer C Personal Computer World 0 Computing Today

Computer and Video Games 0 Electronics and Computing Windfall

Kilobaud 0 '80 Microcomputing95

Electronics and Music Maker E99

Byte ;10 Elektor i; Computer Weekly p) Computing irc)3 Computer Talk 11 Datalink

Informatics 1LoIsComputerworld UK 11071 Micro Forecast icj Office Systems P1 Microdecision 1;31

Which Computer? pi Computer Management 14421 Data Processing ; Systems International ;14

New Scientist 0 Omni 0 Science Digest 0 Scientific American Technology Week 11115 116 117

Practical Computing 11

Microcomputer Printout L;

Educational Computing ij

Wireless World 97

Interface CBM User 1;4193

Electronics Today International 1:

13. Do you intend to buy a micro in the next six months?

Yes No120 121

If so, what will it be?

Pet 122Apple g Tandy ; CP/M 10

Vic -20 Nascom A 16 -bit micro 0131

II129 130

Acorn ; ZX-80/81 H BBC128

Any other, please specify

15. Do you intend to buy peripherals in the next six months?

Yes ; No igIf so, will they be?

Cassette El Printer 0 Discs 5.25in. [i;;1 Discs 8in. El134 135 137

High -resolution graphics .1401

Hard discs El Plotter 0138 139

16. What daily newspapers do you read regularly?

The Times pm Daily Telegraph 1-1 Guardian 111 Daily Express Fl Daily Mail 145142 143 144

Daily Mirror146

Sun H Other147 148

If "other", please specify

Your name and address:

134 PRACTICAL COMPUTING May 1982

IDSBORNEIThe portable business computerwith a difference

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PRACTICAL COMPUTING May 1982

Circle No. 190

135

Open file: 6502

OpenFileThis regular section ofPractical Computingappears in the magazineeach month, incorporatingTandy Forum, Apple Pie,ZX-80/81 Line-up and theother software interchangepages.

Open File is the part ofthe magazine written byyou, the readers. All aspectsof microcomputing arecovered, from games toserious business andtechnical software, and wewelcome contributions onCP/M, BBC Basic,Microsoft Basic, ApplePascal and so on, as well asthe established categories.

Each month the bestcontribution will beawarded £20; othersreceive £6. Sendcontributions to: OpenFile, Practical Computing,Quadrant House, TheQuadrant, Sutton, SurreySM2 5AS.

Real-time clockMANY MICROPROCESSOR applications,such as data collection, security systemsand some business uses, call for programsto know the time of day, notes Peter

6502 Special: Aton real-time clock; Dual monitor chips forSuperboard; UK 101 scroll stopper 136

Pet Corner: Petvoice; Screen -print routine; Calculating the stressin a beam; Machine -code sort 140

ZX-80/81 Line-up: Renumber; Zombies in 2K; 1K dexteritygame; Not -equal operator; Logic game; Programmingtips; Comment messages on screen; Garrulous Godfrey; Fueleconomy 145

Tandy Forum: Astrological star signs; Life and Breakoutgames; Fireworks one-liner 148

Z-80 Zodiac: Nascom hard -copy graphics with IOSL board 152

Disc Dialogue: Amendments to Qera routines; File -sizecounter 155

Apple Pie: Musical moments; Letter Shuffle game; Screen dump;Print formatting for accounts 156

Guidelines for contributorsPrograms should be accompanied by

documentation which explains to otherreaders what your program does and, ifpossible, how it does it. It helps ifdocumentation is typed or printed withdouble -line spacing - cramped orhandwritten material is liable to delay anderror.

Program listings should, if at all possible, beprinted out. Use a new ribbon in your

printer, please, so that we can print directlyfrom a photograph of the listing and avoidtypesetting errors. If all you can provide is atyped or handwritten listing, please make itclear and unambiguous; graphicscharacters, in particular, should beexplained.

We can accept material for the Pet, Vic andSharp MZ-80K on cassette, and materialfor the larger machines can be sent onIBM -format 8in. floppy discs.

Keogh of Luton, Bedfordshire. The real-time clocks required for this purpose areusually expensive electronic accessoriesrequiring an additional circuit board. Forthe Acorn Atom, however, it is possibleto set up a real-time clock using one of thetimers on the 6522 VIA chip. Since thischip is needed to operate the printerinterface, the real-time clock facility isusually available.

The VIA is set to interrupt the 6502CPU at regular intervals. Note that link 2on the Atom circuit board must be con-nected to enable this modification. Ateach interrupt, a register is incrementedand any carry-over goes into the adjacentseries of registers. Examination of theseregisters gives an indication of lapsedtime.

A problem arises because the registersmust be examined one at a time. A signifi-cant error may be introduced if carry-over occurs at the wrong moment, though

the clock will continue to run. To enablethe registers to be interrogated reliably,the interrupt service routine itself mustrecognise when a time request exists andcopy the registers to a second set whichremains unaltered until the next timerequest. The program shows the differentprocesses involved and how they inter-connect.

The least -significant register, 84H, isincremented by eight, 32 times persecond by the assembler -interrupt serviceroutine. Carry-over is held in registers83H to 80H which show integer seconds.The interrupt rate is controlled by theVIA timer one -count cycle, which here isset to 31,250 clock pulses. The subtract-ion of two in the program is to allow forthe period between the end of one countcycle and the start of the next.

The interrupt rate will be precise if theAtom circuit -board crystal is running at

(continued on page 139)

136 PRACTICAL COMPUTING May 1982

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LICILLLLCILMATRIX. LINE OR LETTER QUALITY

DYNABYTE5000

1 1

CPIM MP M CPINET I

OPERATING SYSTEMS 5114 in. DISKETTE 8 in. DISKETTE

CARTRIDGE TAPE

6MB10MB16MB

in. WINCHESTERFIXED DISK

(ONLINE STORAGE'11MB23MB45MB

8 ,n. W NCHESTERFIXED DISK

2MB 3.2MB1MB 1.6MB

All Dynabyte 5000 models include standard features ofan S-100 bus architecture, 64K of RAM, a 4 MHz Z80A,

one parallel and two serial ports. All systems run onCP/M, MP/M and CP/NET.

37

ItElin one second

THE RICOH 16005If It's high performance you're

looking for, the Ricoh 16005 is for you,offering an amazing 60 characters injust 1 second. An updated version ofthe tried -and -tested 1600, the new Smodel has been re -designed and fittedwith all sorts of extras. Yet one thinghasn't changed - the price, makingthe 16005 cheaper than any equivalentmodel on the market. This superbperformer Incorporates the 280 micro-processor, auto bidirectional printingand look -ahead logic, increasing speedand efficiency. Other capabilitiesinclude proportional spacing, graphplotting and word processing enhance-ments. The printer includes a standardcentronics interface, and RS232 andIEEE options are available.

The Ricoh 1600S is available onlyfrom Micropute and their authoriseddealers, all backed up with a nation-wide service network. If you'reinterested in the 1600S either as acustomer or as a dealer, send thecoupon now."Picture shows 1600s fitted with tractor feed option"

174:117:7,7d7,11%.,"ThrRTh7:07s

'Company

Tel No

-RICOH 16005 THE PERFORMANCE HAS`,RISEN -THE PRICE HASN'T

/11

FEATURES COMPETITORS

DIABLO QUME SPIN- RICOH RICOH630 SPRINT 5 WRITER RP.1600 RP.1600S

(10 DATA)

PRINT SPEED(CPS) 40 45/55 55 60 60

PRINT ELEMENT DAISY- DAISY- THIMBLE DOUBLE DOUBLEWHEEL WHEEL DAISY- DAISY-

WHEEL WHEEL

AUTOBIDIRECTIONAL Yes No No No Yes

AUTO LOGICSEEKING Yes No Yes No Yes

PROPORTIONALPRINTCAPABILITY Yes Yes Yes No Yes

EXTENDEDCHARACTER SET No No Yes Yes Yes

LETTER QUALITYPRINT Yes Yes Yes Yes Yes

CUSTOM INTER-FACE OPTION No No No No Yes

PRICE £1675 £1950 £1950 £1450 11450

The above information was gathered from distributors andabstracted from their current literature. Prices shown are thoseadvertised at the present time.

Circle No. 192

MICROPUTEmicrocomputer sysiems

Catherine Street, Macclesfield, Cheshire.SK11 6(1Y. Tel: Macclesfield 612759

138 PRACTICAL COMPUTING May 1982

Open file: 6502

(continued from page 136)exactly 1MHz - but some adjustment ofthe count size will normally be needed. Inthis program, a consistent accuracy ofbetter than about one second per day canbe achieved.

The subroutine at line 610 onwards isused to extract the time itito the VV array,signalling a request for time by settingregister 89H to one. It is reset by theinterrupt service routine.

Use of the VIA timer keeps the time-keeping function quite independent ofany program operations, unlike the use ofWait, and it can be adjusted to a widerange of time intervals very easily.Among some minor snags, the clock willbe stopped by Break, since the interrupt -request disable flag in the CPU statusregister is reset. Tones are modified bythe clock and acquire a distinct warble.

Surprisingly, tape transfers seem unaf-fected and it is possible, having set up theclock, to read in a further program from acassette. Printer functions are unaffectedtoo, and the CPU is slowed by a negligible0.3 per cent. Note that the interrupt serv-ice routine has been optimised for speed.

Monitor selectNO DOUBT other readers who have pur-chased new monitor chips for the Super -board find that some programs need to berewritten because the new chip utilisespreviously unused page -two space, writesM J Bedford of Bradford, West York-shire. One way to overcome this problem,which is particularly relevant to somemachine -code games is to fit both ROMs.

The different chip -select polarityrequirements of the old ROM and thenew EPROM, a. 2716, make it possible touse a simple DPDT for enabling eithermonitor. The old monitor chip requiresthe chip -select line to go high, whereasthe replacement EPROM monitorrequires the chip -select line to go low.The new monitor chip should be soldered

Real-time clock.10

100110120130

REM PM KEOGH 1981DIM VV4A=E280003=EB002,V=EB800F=256;G=60V?14=E7F

390 PRINT $30 '''4VV2" HOURS"'VV1"MINUTES"'VVO" SECONDS"400 K=1085410 GOTO s420aREM assembler

140 PRINT $21 430 P=A150 GOSUB a;GOSUB a 4401160 PRINT S6 450 STX £8A170 ?E204=A; ?£205=A/F; LINK VV4 460 LDA £B804180 K=31250-2 470 LDX @4;LDA @8; CLC190 V?4=K 480:VVO ADC £80,X; STA £80,X200 V?5=K/F 490 LDA @0210 V711=£40 500 BCC VV1220 1/714=£C0 510 DEX; BPL VVO230 REM timer routine++. ...... - 520: W1 CMP £89;BEQ VV3240 PRINT $12 ''"WHAT START TIME?"' 530 LDX @0; STX £89250 INPUT "HOURS"H 540 STY EBB; LDY @3260 INPUT "MINS "M 550:VV2 LDA E80,X; STA £85,Y270 H=(H*G+M)*G 560 INX; DEY; BPL VV2280 PRINT ''"TAP Q TO START"" 570 LDY EBB290eIF ?£8001=EFF; GOTO e300 ?E84=0310 FOR I = 3 TO 0 STEP320 I/£80=H8F; H=H/F; NEXT330 REM clear screen340zCLEAR 0; ?£E1=0350 K= -1360sGOSUB c370 IF 1£85<=K; GOTO s380 ?8=4;78=0; REM TICK

580: W3 LDX £8A; PLA; RTI590:VV4 CLI; RTSH600 RETURN610cREM time extraction -.**.t..620 ?E89=1630dIF ?£89=1; GOTO d640 C=1£85650 VVO=C8G; C=C/G660 VV1=Q%G; VV2=C/G670 RETURN

piggy -back fashion to the original chip,apart from pins 18 and 20 which are bentout. Pin 18 should be tied to MCS at pad7 and pin 20 is connected to the selectorswitch - see figure 1. Pin 21 should betied to +5V. This method cannot be usedfor WEMON, which occupies a 4K blockand thus has different fitting require-ments.

Switching between monitors is notadvised when a program has been loaded,as the system crashes rather badly. Basic1 chips can also be piggy -backed in asimilar fashion. I found, however, thatonly an SPDT was necessary in this case.The new Basic 1 is soldered piggy -backfashion on to the old Basic 1 chip, apartfrom pins 18, 20 and 21 which are bentout and connected as shown in figure 2.

This fitting method allows the Nullcommand to be retained by those fortu-nate enough to have found a use for it.The chips can be selected at will bypressing the Break key, selecting the chipand then performing a warm start.

Scroll stopper.

I 01214161;=

21

;s3

24

34,1

40464850

54

REMREMREMREMREMREMREMREMREMREM

SCROLL STOPPER FOR CEGMON UK101ADAPTED FROM PRACTICAL COMPUTINGDECEMBER 1981prosiram should reside at -location 560(0294 hex) since the Control -C routineis at FB94 he>, with its vector at541 (0217/8 hex).There+ore: line 54 - 155 chan.Fied to 148

255 chan-Fied to 251line 56 - 667 chansied to 660

REM To invoke POKE 541,2REM To disable POKE 541,251

DATA 173,5,2,208,20,165,19,201,153DATA 208,14,169,253,141,0,223,173,0DATA 223,7G, 255,240,244,48,3,76DATA 148,251,24,76,79,166A=660: FOR N=0T031:READ D: POKE A+N,D NEXTEND

Monitor select - figure 1.

MCS5V

NEWMON

2018

21

U18MCSSa

OV

02We

Figure 2.

NEW OVBASIC 1

21

201918

OLDMON

2018

21

9.-- PIN 7 1117

+5V

11(0

+5V

11(0

Sb

I fitted both chips because the newBasic 1 would not load programs. Thisfunction had been displaced upwards onebyte in the new chip and was not beingfound by the monitor. I now load pro-grams using the old chip and then switchto the new chip for normal runningbecause of the improved facilities itoffers, e.g., understandable syntax errormessages, Ctrl -Z gives a fast screen clear,etc.

Scroll stopperTHIS SCROLL STOPPER program for UK101 with Cegmon comes from J MWilson of High Wycombe, Buckingham-shire. It is adapted from Derek Aston'sprogram in the December 1981 edition of6502 Special.

The program should reside at location660 (0294 hex) since the Control -Croutine is at FB94 hex. In line 54, 155becomes 148, and 255 becomes 251. Inline 56, 667 becomes 660. To invoke theroutine Poke 541,2; to disable, Poke 541,251.

PRACTICAL COMPUTING May 1982 139

PetvoicewITHouT satisfactory I/O capabilities, theapplications to which even the mostpowerful computer may be put areseverely limited, writes N J Bailey ofBristol. Most computers rely on akeyboard for input. Output is via amonitor, domestic television set andmodulator, or printer.

The most flexible and user-friendlyform of output is speech - humans use itall the time - but speech synthesis iscurrently very expensive and availableonly on a few systems. It was thereforedecided to write a machine -code sub-routine to store and, later, replay speechat will from any point in a program.

Possible methods of storing suchinformation that were considered were:To attach a digital -to -analogue converter,

DAC, to an eight -bit parallel port, samplethe input waveform at regular intervals, andthen store the values byte -by -byte in mem-ory to be replaced via an analogue -to -digitalconverter, ADC, connected to the sameport.

To digitise the input signal into a stream ofones and zeros, read the resulting data bitby bit, and then replay the data in a similarfashion.

The first method has the advantagethat the playback quality of the recordedspeech is potentially very good, and thesoftware easy to write. However, it hasthe disadvantages that it entails the con-struction of two relatively expensive units- the DAC and ADC. It would also useup available memory at eight times therate of the second method.

The second method, on the other hand,is extremely economic with availablememory and is relatively cheap and easyon the hardware side. The system was tobe developed and used on a 32K Petfitted with new -ROM Basic 2.0. Thismachine is fitted with a 6522 VIA chip,so the serial -parallel and parallel -serialconversion may be performed entirely bythe machine's hardware using the CB2pin on the user port in conjunction withon -chip eight -bit shift register, furtherlowering the software requirements.

This pin is frequently used by Pet usersto generate music and sound effectsinside Pet programs. Many users willtherefore already have a soundbox - asmall loudspeaker and amplifier - con-nected to this pin which may be used asthe output device.

These two programs reside in thesecond cassette buffer of the system033A to 03F9 hex, providing facilities forspeech input and output as detailed.Since calls to the Basic ROM are made,the program as it stands will only run on

Basic 2.0 machines. Details of conversionfor old ROMs are given in table 1.

As it is essential that the analogueinput voltage from the speech source beconverted to a level of either +5V or OV,the circuit in figure 1 was constructed. Itwas converted to the external loud-speaker output of a standard mono cas-sette recorder, on to which the speechwas recorded. The output signal shouldbe connected to the CB2 input on the Petuser port, and sufficient memory shouldbe reserved for the storage of the speech.Two seconds will fit into each 1,000bytes.

This may be done by lowering thetop -of -Basic pointer in memory locations52 and 53 -134 and 135 for old ROMs.

The direct command SYS871, SA, EAmay then be given, where SA is the startaddress and EA the end address. Speechinput will then begin.

On pressing return, the cursor will dis-appear and the cassette should then beplayed. The data will be input from thecassette recorder into the specified mem-ory locations at 4,000 bits per second.

Connecting the soundbox to CB2 andentering SYS909, SA, EA reverses the pro-cess.

Speech produced by this method is notof particularly high quality, and althoughvowel sounds are easily distinguished, it isrecommended that the message is printedon the screen while the speech is being

Table 1: Equivalent old -ROM memory locations.Hex Dec Usage Old -ROM equivalent

address$Lines CB/CC 203/204 Program's temporary storage. $EE/EF (238/9)Lines $11/12 17/18 Returned integer from ROM sbr. $08/09 (8/9)Lines $CDF8 52728 ROM sbr. : confirm comma in text $CE11 (52753)Lines $CC8B 52363 ROM sbr.: evaluate expression $CCA4 (52388)Lines $D6D2 54994 ROM sbr.: convert FPACC to an integer $D6D0 (54992)Lines $E848 59464 Timer 2 latch of VIALines $E84B 59467 Shift register control same for old ROMsLines $E84D 59469 Interrupt flag register

Petvoice

r'ET-MO I CE 1 -174

PC IR0 SF: AC XR YR SP771.74R Er, E RO AA 7A 09 ES

033A ES CB INC SOB0330 DA 02 BNE $0340033E ES Cr INC $r00340 A5 0B LDA $0B0342 05 11 CMP $110344 DO A4 BNE $@34A0345 A5 rC LDA $r00348 05 12 0MP $12034A SO RTS934B 2A 55, 03 JSR $0356024E A5 11 LDA $112050 55 CB STA $rB0352 A5 12 LDA $120354 R5 CC STA $000351; 2A FS CD JSR $0DFS0359 2A 8B 00 JSR $008B

025F

0354oRrac.

035A171241-,c

93530.36E

0:7172

A275077171-77q

OR709.37F0-7:Ro

ARR-7;

07-1RR

03R9RFT

o:74R

038D

40AD

FA1,70

-)171

AA AO78A9 7DSD 48 ESAD 4B ES2g E3Og 04SD 4B ES

3A0829 SFAD 4A ES91 CB

DA E25R60'9 4B

D2 DS JMP $D6324D ES LDA $E84D04 AND #504F9 DEO $035F

RTS4B AR JSR $034B

LDY #$A0SEILDA #57DSTA $E845LDA SENDAND #$E3ORA #$04STA $E84BJSR $.033APHPJSR $035FLDA SES4ASTA ($0B),YPLPBNECLIRTS

03 JSR

50:3 All

03gA4712:92

03980:39 B

;71:74911

17139E

03A2

171:74Ar.

03AB03AEARAF(7-IRB1

03B2ARD5nRE703BAORBB

$0:348 READY.

A0 007RA9 7D811 4SAD 4B29 E309 14SD 4Bs'A 3AORB1 CI:811 4As=171 5F

2RDA E25RAD 4B2q E3RD 4B

AO

LDY #$AASE I

LDA $l$7DES STA $E848ES LDA $E846

AND #$E3ORA #514

ES STA $E84B03 JSR $033A

PHPLDA ($010,Y

E8 STA $E84AoR JSR $035F

F'LP

BNE $0393CLI

ES LDA $E :4BAND #$E3

ES STA $ES4BRTSBRK

140 PRACTICAL COMPUTING May 1982

Open file: Pet

Figure 1.

Semiconductors:BC108 transistor1N4148 silicon diode or equiv.3.9V, 400mW Zener diode

Resistors:8.211 (value to suit source)10 kfi 0.25W150 la/ 0.25W2.7 la10.25W

Miscellaneous:Matrix boardConnector to suit Pet user portConnector to suit sourcePP3 battery and connectorWire, solder, etc.

L.S. inputfromtaperecorder

Corn CB2to PET user -port

Power rating > amplifier power

-r-PP3

output. The values of SA and EA may bevanables, constants or expressions, soSYS909, 1000*SQR(144), 10000*SIN(0.3)for instance is perfectly allowable.

The program may be divided into sixparts.$033A - $034A increments a two -bytepointer stored in $11/12 (low/high).$034B- $0355 evaluates the start address.$0356 -$035E evaluates the end address.$035F - $0366 waits until eight bits have

been shifted in or out by the 6522 VIA.The remaining two subroutines.

$0367 - $038C and $038D $03BA per-form data input and output respectively.The input and output routines are simi-

lar in operation: the "from" and "to"addresses are evaluated in zero page; theinterrupt is disabled to prevent any inter-ference with the routines; the appropriateVIA registers are set up and data transferbegins. The PHP instruction after theJSR $033A remembers whether the sub-routine should be terminated until afterthe last byte has been transferred.

HEX D P1 F3*

PC7074R

022R0242034A

i335An352

cy4;2

036R6372037R0382p3RApnel2

03A203FIA

O3BA

DERBY.

I RQ SR AC XR YR SPE62E 30 00 70 00 F4

E6CS

AS

2ci

Fi0AD4B02E273ES213

ESAD60

CE DID 02 EE Cr AS11 DA 04 AS CC CS243 56 02 AS 11 R512 R5 CC wi FS CDCC 4C D2 DE AD 4D04 FO F9 60 T,A 43AO 78 R9 7D RD 484B ES E3 09 A4ES 20 3R A3 ri2 2AAD 4A ES 91 CE 2258 60 271 43 03 AO99 7D SD 48 ES AD

E3 n9 14 RD 433R 03 OS El CE SD20 5F 03 28 DO E24E ES E3 SD 4300 On 00 0A 00 FE

CE12CB20ES03ESSD5FDO0043ES4A

ESFF.

In use, the voice may be input and thenmanually compacted. After entering themonitor and observing a hex dump of thearea of memory involved, the bytes con-taining no information will be seen tocontain Hex FF. Re-entering Basic, theblock of memory containing useful datamay be moved down so as to "butt up"against the next piece of useful data thus:FORI = [start of useful data] TO [end] :

POKE I-N, PEEK(I) :POKEI,255 : NEXTwhere N is the number of unused bytes.In this way all the available space may beutilised, realising a storage capacity oftwo seconds per K.

With a cassette system, the generatedvocabulary is best saved in a program fileby the monitor before the program whichis to use it. Then enter the followingsequence of direct commands:LOAD '[name of vocab file]'NEWLOAD '[name of main program]'RUN

The first line of the Basic programshould lower the top -of -Basic pointer aspreviously described, and then immedi-ately CLR all variables. This will ensurethat all the other Basic pointers arereinitialised. This line should make noreference to any variables.

If a disc drive is available, the vocabu-lary program file may be read by openingthe file and assigning a secondary addressof zero. After ignoring the first twocharacters by using Get* twice so as tomiss the start address, Get* may then beused repeatedly. Poking the ASCII valueof the resulting string into memory untilan end -of -file, ST=64, is detected. Usingthis system, vocabulary may be passedfrom disc to reserved memory.

If you have a Pet fitted with a different'version of Basic, of another machine fit-ted with a 6522 VIA device, details of thePet memory are shown in the table.

Screen printingON UPGRADING to CBM Basic 4.0 fromBasic 3 I found the Screen Print routine- Pet Corner, June 1981 - would nolonger work, writes M J Valentine ofRotherham, South Yorkshire. Closeinspection via the Pet monitor revealedthat yet again, on upgrading, that therehad been a major reorganization of firm-ware. After many hours of searching Ifound the corresponding entry points toBasic 3, and was then able to modify theprogram accordingly.

The upgraded screen print will work onCBM Basic 4, 40 -column machines.

Screen printing

1 POKE59468,12:POKE59468,14,POKE59468,12PRINT"OWAS4032- 4022 SCREEN PRINT2 PRINT"044WIT ANY KEY WHEN 4022 ON & LOADED3 PRINT4DWRIGINALLY BY JOHNANTHEN DICK4 PRINT"ODIPPACTICAL COMPUTING (C) OCTOBER 19805 PRINT"WOMODIFIED M VALENTINE NOVEMBER 19816 GETC4'IFOS=""THEN67 PRINT"'I.9S4022 SCREEN PRINT LOAD IN PROGRESS"8 POKE53,(PEEK(53)-1),S=PEEK(53)*256,G3SUB179 PRINT"UPOUTINE CALLS WSW10 PRINT"gRURCIUTINE DISABLE U POKE 0,9611 PRINT"NAMPONTINE ENABLE POKE 0,7612 PRINT"ODLINE SPACE(SA=6)! POKE"S+66",24"13 PRINT"DIMIGRAPHICS MODE P POKE 59468 ,12"14 PRINT"MMLOWER CASE MODE i POKE 59468 ,14"15 SYSSlIEW16 RE="80,4022SCRTOP"SAVEAC8,SAVEA4.8:VERIFVA4,817 FORI=STOS+256,READAE:C=LEN(Afi:IFAS="*"THENRETURN18 A=ASC(F4)-48,B=ASC(RIGHTCA4,I))-4819 N=B+7*(B>9)-(C=2).<16*(A+7*(A>9)))20 IFAWSS"THENN=(S/256)21 IFAS="XX"THENN.PEEK(53)22 POKEI,N,NEXT.RETURN23 PRINTuBVTE"L"=C"Arl ???"24 CLR:POKE53,(PEEK(53)+1) (listing continued on next page)

PRACTICAL COMPUTING May 1982 141

Open file: Pet

(listing continued from previous page)

25 DATAR5,35,85,02,09,00,85,0126 DATA20,18,XX,20,30,XX,ER,EA27 DATA20,18, XX, SO, EA. EA, EA. EA28 DATAA9,04,20, E2, F2,09,06,2029 DATAE2, F2,05,35,85,02,60, EA30 WIRER , EA, EA, EA, EA, EA , EA, ER31 DATREA, EA: EA, EA, EA, EA: EA , EA32 DATAEA , EA33 DATRA9,06,02,06,20, E5 XX0A934 D01'818,20,46, DB, 20,06, F2, A935 DATA04, A2,00,20, E5, XX, A9,0036 DATA85,01,09,80,85,02,0000037 DATAA2,00, AD, 4C, E8,89,00, FO38 DATA05,09,11,20,46, DD , D139 DA TA01 C9,1F, DO, 05,69,40,4C:40 MIRK , XX, C9,80,90,09, C9, BF41 DAMN, 05, E9,3F: 4C, B6, XX, C942 DATAC0,90,07, C9, DF, BO, 03,4C43 DATAB6, XX , C9, EC', 90,05, E9,4044 DATA4C,116, XX,C9, 40,90,09, C945 DATA60, BO, 05,69,80,4C , AC:, XX46 DATAC9,61,90, OS, C9,7F, DO, 0247 DATA69,40,85, OF, 09,92,20,4648 DATADD, 4C , BD, XX, 85, OF , A9,1249 DAT020,46, BB: 05, OF, 20,46, BB50 DATAC8, DO, 02, ES, 02, ES, EO,2851 DAMN: 9C, 20, U . BA. A2: 00,0552 DATA02, C9,83, FO, 03,4C, 5C: XX53 DATACO, E8 , FO, 03,4C, 5C, XX, 2054 DATAA6 F2,60,85, D2,86, D3,0955 DATA00,85, D1,89,04,85, D402056 DATA63 , F5, AS, D2,20, FE, F7,6057 DATA*, 00, 00, 00, 00000, 00, 00

Stress calculationSIMPLE BENDING THEORY for structuralcomponents leads to the formula:Q M- = -ywrites A L Milnes of Portsmouth,Hampshire. Q is the stress existing in thecomponent at a distance y from theneutral axis when the component is sub-jected to a bending moment of M; Irepresents the second moment of area ofthe cross-section of the component aboutan axis through the centroid of the sec-tion - the neutral axis - the axis beingperpendicular to the plane of the bendingmoment.

This short program calculates the posi-tion of the neutral axis relative to thebase of the section, and the secondmoment of area of the section about thisaxis. The program assumes that the weband flanges can be approximated withsufficient accuracy by rectangles. Inactual sections, there are fillets at thejunction of the flanges to the web, andthe toes of the flanges are radiused. Inaddition, the flanges are tapered if thesection has been produced by a rolling

process, but these approximations are notsignificant in many practical situations.The program is quite useful for simplesections which can be considered to bemade up of three rectangles.

Machine -code sortTHE MACHINE -CODE sort routinedescribed by Simon Letts in Pet Corner,May 1981, has proved useful to MervynBroadway of Slough, Berkshire. Usuallyhe needs to search an array for a match oftwo strings, but since the sort routine islimited to 256 bytes it is far quicker tosearch through an array in its unsortedformat at machine -code speed.

This routine is used in much the sameway as Letts' sort routine. The string tobe matched is entered into the zero ele-ment of the array to be searched. Conse-quently the array must start from element1. The length of the array is Poked into180, and the array is set equal to itself.Finally SYS634 completes the operation.

The matched output - in the form ofthe array element numbers that matched- are displayed in Pet screen -code for-mat on the screen top left. This is fordisplay only. Setting the top of memory,however, allows the area $7F00 onwardsto be used, and leaves the screen free tobe used in any way. If the screen isscrolled while the information is dis-played, then the information is lost.

Finally, the arrays may be found by

Line -clearing routine.. ,

.03840385

0848

PHPPHA

tn36 8A TXA. . 0387 48 PHA^ , 98 TYR

0989 48 PHA038A FI9 20 LDA 020

. 09A8 04 C6 LDY P36038E 91 84 STA $04) Y

, n990 89 INY1

0391 CO 28 SPY St$281 0393 DO F9 ENE $038E. 0395 :;3 PLA1 A8 TAY

Pn97 PLA1 171,718 AA TAX

. . 0399 PLA

. .1 0390 28 PLP

. .1 rpqE

Peeking their locations until a zero isfound, for example

PRINT A$(PEEK(32768))The zero indicates the end of thematches; a zero by itself indicates that nomatches have been found.

The line -clearing routine is useful ifyou have to overprint a line but do notwant any of the previous line left on thescreen if the new line is shorter than theold one. Its syntax is

PRINT A$;: SYS900

Machine -code sort routine.

0270 ,188278 480278 8A027D 48027E 98027F 480280 D80281 A5 440283 870285 A585 450287 85 880289 A2 010288 R9 00028D 8D 000290 85 850292 AO 020294 81 870296 99 BB0299 380290 10 F80298 18023D A5 B7

029F02A102A302A502A7028902A802RD028002810288028502870283

6985A569859081998

10 F8R5 BEro 0888C4 88

03878800880287BE

023A FO 12023C: 81 BF02BE DI BC021:0 FO F50282 ES0283 E4 840285 80 850287 68

PHPPHATXAPHATVAPHACLDLDO $44STA $87LDA $45STA $88LOX #$01LDA #$00

80 STA $8000STA $85LDY #$02LDA ($87),Y

00 STA $00B8,YDEYBPL $0294CLC.

LDR $87

ADC #$03SIR $87LDA $38ADC #$00STA $88LDY #$02LDR ($37),Y

00 STA $00BE,YDEYBPLLDABEGINYCPYBEOLDACMPBEG

0288 980289 6802CA AA0288 680288 21:02CT 6002CE A4 850200 8R0281 99 00 :3002D40285 84 850287 R9 000289 99 00 8002DC 4C C2 02

$0201:$BE$0282

$88$028E($8F),Y($8C),Y$0237

INXCPX $24BNE $029C:PLR

TRYPLATAXPLRPLPRTSLDY $85TXASTA $8000,YINYSTY $85LIA #$00STA $8000,YJMP $0282

Stress calculation.100 PRINT"n"110 PRINT"SECOND MOMENT OF AREA OF A SECTION120 PRINT"130 PRINT" A(1)"140 PRINT"150 PRINT" I N I

160 PRINT" B(1)0 I

170 PRINT" ->MK A(2) "

180 PRINT" 3 I

190 PRINT" I 33(2)200 PRINT" I I

210 PRINT"220 PRINT" --->sistiamossamaima<---11(3)"230 PRINT"240 PRINT"250 PRINT" B(3)260 PRINT270 INPUT"TYPE R(1),A(2),A(3)",A(1),R(2),A(3)280 INPUT"TYPE B(1),B(2),B(3)",B(1),B(2),B(3)290 REM FIRST CALCULATE THE AREA OF THE SECTION300 LET AR=A(1)*B(1)+A(2)*B(2)+A(3)10(3)310 REM NOW CALCULATE THE FIRST MOMENT ABOUT THE BASE320 LET MI=A(1)*B(1)*(8(3)+B(2)+.5*B(1))

330 LET MI=M1+A(2)448(2)*(E(3)+.5*B(2))340 LET M1=14103(3)*B(3)*(.50(3))350 REM CALCULATE THE DISTANCE OF THE CENTROID ABOVE THE BASE360 LET VB=M1/AR370 REM NOW THE SECOND MOMENT ABOUT THE BASE380 LET M2=(A(1)*B(1))*(03(3)+B(2)+.5*B(1))t2)+C(A(1)*(8(1)t3))/12)390 LET M2=M24.(A(2)*B(2)*(a(3)+.5*B(2))T2)+(A(2)*((8(2)1.3)/12)))400 LET M2=M2+((A(3)*(B(3)T3))/3)410 REM M2 NOW HOLDS SECOND MOMENT OF SECTION ABOUT THE BASE420 REM CALCULATE SECOND OF SECTION ABOUT AN AXIS PARALLEL TO BASE THROUGH430 REM THE CENTROID OF THE SECTION440 LET MI=M2-(YB*YB*AR)450 REM NOW OUTPUT THE RESULTS460 PRINT470 PRINT"AREA OF SECTION=",AR480 PRINT490 PRINT"CENTROID OF SECTION ABOVE THE BASE=,"YB500 PRINT510 PRINT"SECOND MOMENT OF THE SECTION ABOUT THE BASE=",M2520 PRINT530 PRINT"SECOND MOMENT OF THE SECTION ABOUT AN AXIS THROUGH THE CENTROID AND":540 PRINT" PARALLEL TO THE BRSE=",MI550 PRINT PRINT560 PRINT"YOUR DATA WAS 8(1)="A(1)"A(2)"A(2),570 PRINT"A(3)"A(3)"AND B(1)13(1)13(2)"8(2)93(3)93(3)

142 PRACTICAL COMPUTING May 1982

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Circle No. 196144 PRACTICAL COMPUTING May 1982

Open file: ZX-80/81

ZombiesTHIS GAME by Richard Hooper of Ger-rards Cross, Buckinghamshire occupiesabout 2K of memory on the ZX-81.When it is run, a pot -hole, represented bya black square, appears in the middle ofthe screen. Five randomly -placed zom-bies represented by grey squares, and arandomly -placed player, represented byan 0 also appear.

The Zombies immediately start movingtowards you, and will follow you roundthe screen. By pressing 5, 6, 7 or 8 youcan move in the direction of the arrow onthe key. If one of the Zombies catchesyou, the program stops and your onlychance to escape is to lure it into thepot -hole.

When all of the Zombies have fallendown the hole a congratulatory messageappears at the top of the screen. TheZombies only move at half your ownspeed, so it is possible to outrun one onits own. You are in danger of beingcaught if you become trapped betweentwo or more Zombies.

The arrays X and Y contain the co-ordinates of the Zombies and the player,whose co-ordinates are stored in X(6)and Y(6). The array Z is used to find outwhether a Zombie is active or not, i.e.,whether it has fallen down the pot -hole.Lines 40 to 70 generate the positions ofthe Zombies and the player. Lines 80 to120 print the Zombies and the pot -holeon the screen.

Lines 130 to 180 test whether a Zom-bie has fallen down the pot -hole orwhether one has caught you, and alsomove them all towards you. Lines 190 to250 move the player and check that youare still on the screen. Then the screen is

Zombies.

10 DIM X(6)20 DIM Y(6)30 DIM 2.'5)40 FOR 1=1 TO 65n LET X(I)=1NT (22+RND)

LET Y I)=INT(32*RND)'0 NEXT IRA PRINT AT 10,15CHR$ 12890 PRINT AT X(6),Y(6);"0"100 FOR 1=1 TO 5110 IF Z(1)=0 THEN PRINT AT X(I),Y(1);CHR$ 8120 NEXT I

1:,:0 FOR I=1 TO 5140 IF X(I)=10 AND Y(I)=15 THEN GOSUB 280150 IF Z( I)=0 AND X(I)=X(6) AND Y(I)=Y(6) THEN nOTO .70n160 LET X(I)=X(I)+SON(X(6)-X(I))/2170 LET Y(I)=Y(I)+SON(Y(6)-Y(I))/2180 NEXT I

19-40 LET A$=INKEY$:,nn IF R$="5" THEN LET y(6)=Yoso-i214_1 IF A$="6" THEN LET X(6)=X(6)+1220 IF A$="7" THEN LET X(6)=X(6)-1330 IF A$="8" THEN LET Y(6)=Y(6)+1240 IF X(6)=-1 OR X(6)=22 THEN LET X(6)=X(6)+SON(10-X(6))250 IF Y(6)=-1 OR Y(6)=32 THEN LET Y(6)=Y(6)+SGN(15-Y(6))260 CLS770 GOTO 80280 LET 2(1)=1290 IF 2(1)42(2)*Z(3)*Z(4)*2(5)=0 THEN RETURN300 PRINT AT 0,0"WELL DONE."31n STOP320 PRINT AT 0,0;"THEY GOT YOU."

cleared and the program returns to line80.

If a Zombie falls down the pot -hole,the program goes to line 280 and theZombie concerned is rendered inactive.The subroutine also checks whether anyZombies remain.

To make the game harder you couldhave more Zombies or make them moveat the same speed as the player, by takingaway the "/2" from the end of lines 160and 170. To stop the game if the playersteps into the pot -hole, add185 IF X(6) = 10 ANDY (6) = 15 THEN STOP

The program is quite slow, but fun andaddictive.

Renumber routineTHIS RENUMBER program from MangulSingh of Slough, Berkshire will fit into 1Kon ZX-81. It also runs on the ZX-80 withnew, 8K ROM. It will provide new linenumbers for your programs in steps of 10.

You can increase or decrease the sizeof the steps by changing line 9080 to

LET B = B +Nwhere N is the size of the step required.The new line numbers will start at 10; ifyou wish to start at a different linenumber, alter line 0910 accordingly.

Renumber routine.9000 LET R=165099010 LET B=105020 POKE AANT(B/256)9030 POKE A+14-(INT(B/256))*2569040 LET A=A+19050 IF PEEK (A)=118 THEN GOTO 90709060 GOTO 90409070 LET A=A+19080 LET B=B+109090 IF NOT PEEK(R)*256+PEEK(R+1)=9000 THEN GOTO 90209100 LIST.

Substitute operator.

10 CLS20 PRINT"ENTER A NUMBER TO BE

COMPARED WITH TWO"30 INPUT A'40 IF A - 2 THEN GOTO 7050 PRINT" EQUAL"60 STOP70 PRINT" NOT EQUAL"80 GOTO 10

Substitute operatorTHE ABSENCE of a "not equal to" logicaloperator is a major source of disappoint-ment in the ZX-80, writes Michael Taylorof Bishop's Stortford, Hertfordshire. I

have noticed, though, that a minus signwill do the job.

40 IF NOT A = 12 THEN GOTO 150

has the same effect as40 IF A - 12 THEN GOTO 150.

Sinclair Basic appears to assume "isnot equal to zero" after any If -Then state-ment with no comparator and secondexpression. So if A-12 is not equal tozero, then A cannot be zero. This sampleprogram demonstrates:

Operating tipsMAY I pass on a few hard-won practicaltips to other ZX-80/81 users, especiallythose who have added the 16K RAMpack, offers A H Davies of Coventry.After prolonged use - whether intermit-tant over a period of several months or ina long, single operating session - myZX-80+16K seems to get bored or tiredand develops some bad habits.

The most annoying of these is a pro -(continued on next page)

PRACTICAL COMPUTING May 1982 145

Logic puzzle. 270 IF X = 3 THEN PRINT " 739"

10 DIM A(9) 280 PRINT240 FOR X = 1 TO 9 290 NEXT X30 LET A(X) = 0 300 PRINT40 NEXT X 310 PRINT "FROM50 LET A(5) = -37 320 INPUT F50 FOR X = 1 TO 9 330 PRINT F70 IF x = 5 THEN GOTO 130 340 IF F> 9 THEN GOTO :31030 LET F = RND(8) 350 PRINT90 FOR Y = 1 TO 9 360 PRINT "TO100 IF A(Y) = P THEN GOTO 80 370 INPUT T110 NEXT Y 280 PRINT T120 LET A(X) = P 390 IF T> 9 THEN GOTO 360130 NEXT X 400 IF NOT A(T) =-37 THEN GOTO 360200 FOR X = 1 TO 3 410 IF AFS(F - 7)=1 OR APS(F - T) =3 THEN GOTO 430210 FOR Y = 1 TO 3 420 GOTO 310220 PRINT CHR4( A( Y + (X -1)+3 ) +37);" 430 LET A(T) = A(F)240 NEXT Y 440 LET A(F) = -37250 IF X = 1 THEN PRINT " 123" 450 OLS260 IF X = 2 THEN PRINT " 455" 450 GOTO 200

(continued from previous page)pensity to drop lines from the programwithout apparent cause or warning. It isalso inclined to input lines with one digitof the number omitted so that they areshunted off into quite different parts ofthe program. I have found that the bestway to deal with this is to write linenumbers in blocks, giving one blockonly odd numbers, and the next blockeven numbers. Misplaced lines then standout more readily.

An off-putting quirk it has developedon Load concatenates lines into a con-tinuous single line, e.g.

100FOR1=1TON110PRINT120NEXTIwhich can produce some very unnervingprintouts. Sometimes it just leaves linesout. I have been able to cure these errorsby always keying in New after switchingon and before keying in Load.

One of the program -writing problemsthat eluded me for a long time was whatto do with that irritating 5/n error mes-sage while inputting instructions or out-putting long strings of answers. A simplesubroutine solves the problem:

9000 LET A = PEEK(16421)9010 LET B = A -29020 FOR C = 1 TO B9030 PRINT9040 NEXT C9050 PRINT "PRESS NEWLINE TO

CONTINUE"9060 INPUT A$9070 IF A$ = " " THEN GO TO 90809075 IF A$ = "9" THEN GO TO 99999080 CLS9090 RETURN9999 STOPThe subroutine is called by a Gosub

9000 at the end of the "page" of mater-ial, which should be limited to a maxi-mum of 18 or 19 lines of printout. ThePeek establishes the last line printed,reading from the bottom upwards, and soB tells you how many blank lines youhave to fill to the penultimate line of thepage of 22 lines. Line 9020 to 9040 thenPrint space's to fill up any difference.

Once you press Newline the nil -string(9070) moves you on to CLS and thenback into the main program and the next"page" of printout. Line 9075 enablesyou to climb out of a long series of pagesand quickly return to List for debuggingor simply to change a spelling mistake.

Logic puzzleAN ARTICLE in 6502 Special, May 1981.prompted me to write a simple programfor the ZX-80, explains E Mullinger ofWindsor, Berkshire. The game representsthe little squares in a frame that areshuffled around until they are in a logicalorder. This version has nine "squares"labelled with alpha characters, though thenumber can be increased simply bychanging the size of the array and itsaccompanying subscripts.

Lines 10 to 130 set up the array withthe central square blank and the otherslabelled A to H. Lines 200 to 300 displaythe values of the subscripts as alphacharacters and print a square containingthe relative location of the array sub-scripts used to move a "square" into theblank space. Lines 300 to 420 accept themove locations, and validate them toallow a move to be made only into ablank space; horizontal and verticalmoves only are allowed.

The program does not prevent invalidmoves from 4 to 3 and from 7 to 6, whichyou could try.

Message displayIT IS OFTEN necessary to reserve one lineof the screen for comment, instructions,scores, etc., while leaving the upper partundisturbed, notes D M Bennion of New-castle, Staffordshire. When a shortermessage overwrites a longer one, spacesmust be included to obliterate the oldmessage completely.

This can be tedious and time-consuming, especially when an extra mes-

sage is inserted during program develop-ment and all extra spaces must beadjusted accordingly. This shortmachine -code routine, which may bePoked into an initial Rem of 22 charac-ters, and called by

RAND USR 16514will clear the screen from the currentPrint position to the end of screen, and soremove all characters after a particularprint statement.

A typical use could be as follows:500 PRINT AT 12,0; "SORRY, THAT

SQUARE IS FULL."510 PRINT "PLEASE RE-ENTER YOUR

MOVE."followed by:600 PRINT AT 12,0; "YOU GAIN ONE

PIECE."605 RAND USR 16514which will remove all traces of the twoprevious lines.

Garrulous GodfreyFANS OF The Hitch -Hiker's Guide to theGalaxy will remember Eddie, thefriendly shipboard computer on theHeart of Gold. This program from TimJohns provides you with all the worstaspects of Eddie's maddeningly incessantchatter, passing randomly -composedgreetings of appropriate fatuity from oneside of the TV screen to the other.

A short program first loads the twoarrays:

10 DIM D$ (9,8)20 DIM E$ (9,8)30 FOR N =1 TO 940 INPUT D$(N)50 PRINT N; " "; D$(N)60 NEXT N

Message display.

LB B,DEC BDEC BLD HL, (16398)DEC HLINC HLLD A, (HL)CF 118JR2 4LD(HL),0JR 246DJNZ 244RET

(IY+58)

42,14,6443

126254,11840,436,024,24616,244201

Lines to bottom o4 screen

Allow tor-' the two bottom linesGet current print position

Move on

Cheo1 i'or end o+ line

Print a sPaoeMove on:=;tArt new line

146 PRACTICAL COMPUTING May 1982

Open file: ZX-80/81

After running the loading programs,type in the following, taking care of theleading spaces necessary to maintain thejustified right-hand margin:

"HI THERE""SO LONG""EVENING"

"HAVE FUN""HULLO"

"CHEERIOH""COOL IT"

"BONJOUR""ADIOS"

Next Edit lines 40 and 50, substituting Efor D, then type in Goto 30 as a directcommand and enter the following words,which are left -justified:"EVERYONE""FRIENDS""GORGEOUS""GIRLS""SAILOR""CHEEKY""HANDSOME""MON AMI""AMIGOS"

Lastly type in the main program - whichk ill overwrite the array -loading program

Garrulous Godfrey.10 RAND20 LET A$=" "+DCINT(RND*9)+1)

+" '-f-E$(INT(RND*9)+1)+" "

30 LET R=INT(RND*2)40 FOR N=1 TO R+5050 LET A=(31 -N AND R)4 -(N-19 OR R)60 IF A<0 THEN LET A=070 LET B=(N-32 AND -R)+(20-N OR R)80 IF BO THEN LET B=190 LET C=(N-1 AND R)+(51 -N OR R)100 IF C>19 THEN LET C=19110 PRINT AT 11;A; A$(8 TO C)120 NEXT N130 GOTO 20

- and store it. To start the program typeGoto 10 as a direct command. You canexperiment with the program, for exam-ple by arranging that the chatter passingfrom left to right on the screen has adifferent "personality" from the chatterpassing from right to left.

Digital exerciseTHE OBJECT of this game for 1K ZX-81 isto place the cursor over as many randompoints as you can in the set time, writesDavid Clifton of Doncaster, South York-shire. You move by pressing 5. 6, 7 and 8 tomove left, down, up and right respec-tively. To start, you set the number ofseconds you wish the game to last andpress New Line. When your time is up,your time and score are displayed on thescreen.

Friel economyI HIS PROGRAM by John Gent of Crook.County Durham runs on a 16K ZX-80with 8K ROM to calculate fuel consump-tion and costs for a car.

When the program has been entered,type Run 30, and the computer asks forthe number of entries to be made. Foreach entry number you are asked to enterdate, mileage, price per gallon and totalcost of the petrol refill. When all entrieshave been made, an input of either 1 or 2displays a list of seven dates or sevenmileages which may be scrolled forwardsor backwards.

By entering 400 and two entry num-

Digital exercise.10 INPUT K20 LET 3 = K * 630 LET B = 040 LET 8 = 1

50 LET N = Q60 LET 2= INT(RND*60)70 LET X = INT(RND*40)80 LET C = 3090 LET V = 20100 PLOT CV110 LET N = N+Q120 PLOT 2, X130 IF INKEY$ = "5" THEN LET C = C-8140 IF INKEY$ = "6" THEN LET V = V -Q150 IF INKEY$ = "8" THEN LET C = C+0160 IF INKEY$-= "7" THEN LET V = VA -C1170 IF N = 3 THEN GOTO 230180 IF 2 C AND V = X THEN GOTO 210190 CLS200 GOTO 100210 LET B = 8+8220 GOTO 60230 PRINT AT 1,1,"YOU HAVE SCORED";

B;" IN "3:;" SECONDS "240 STOP

bers the computer will calculate and dis-play the average fuel consumption in mpgand the total cost of petrol used betweenthese two entry numbers. Alternatively,entering 500 saves the program so that itwill run automatically when it is reloaded.Lines 40-70 search the array I for the first

unused element.Lines 90-300 allow entry of all data.Lines 320-510 contain the routines to produce

the list of dates or mileages and its manipu-lation.

Lines 560-740 cOmpute and display the mpgand petrol cost.

In lines 320, 330, 440 and 450 " " correspondto shift "Q".

If the program needs to be restarted, useGoto 40. The program will store up to 100entries, but this may be changed by alteringline 30.

Fuel

10)02.0

405070

9010011012013014015016017018019000210

230

250240

260270='90

300102033033534034535035536031;5

370II

390

economy.REM "RUNNING - COSTS - 1981REM DATA INPUT - RUN 30GOTO 40DIM I (100,4)LET R=0LET R=F:+1IF NOT I(R,1)=0 THEN GOTO 50PRINT "CURRENT ENTRY NO.="jRPRINT "HOW MANY ENTRIES DO YOU WISH TO MAKE?'INPUT ENFOP 0=R TO R+EN-1PRINT "ENTRY",0PRINT "ENTER DATE:",INPUT DPRINT D.PRINT "ENTER MILEAGE:",INPUT MPRINT MPRINT "ENTER PRICE/GAL:",INPUT PPGPRINT "(POUND SIGN)";PPGPRINT "ENTER TOTAL COST:"INPUT. TCOSTLET I<0, 1)=DLET I(0,2)=MLET I(0,3)=PPGLET 1(0,4).TCOSTCLSNEXT 0REM LIST MENUPRINT "FOR LIST OF DATE PRESS ""1"""PRINT "FOR LIST OF MILEAGES PRESS ""2"""PAUSE 4000POKE 16437,255LETD$=1NKEY$IF D$="1" THEN LET M$"=""IF D$="1" THEN LET DM=1IF.D$="2" THEN LET M$="ML."IF D$="2" THEN LET DM=2IF D$<"1" OR D$>"2" THEN GOTO 335CLSLET 0=1

400 FOR S=0 TO 8+6410 PRINT S,":"j1(S,DM)jM$420 NEXT S420 PRINT "ENTER NO. TO SCROLL"440 PRINT "ENTER ""400"" FOR MPG/COST"450 PRINT "ENTER""500""TO SAVE"460 INPUT SCROLL470 IF SCROLL = 400 THEN GOTO 550480 IF SCROLL = 500 THEN GOTO 780490 LET 0=0+SCROLL500 CLS510 GOTO 400550 REM CALCULATE MPG AND COST560 PRINT "ENTER START AND FINISH NO.S"5713 INPUT FE58(1 INPUT LE590 CLS600 LET MILDIF=I(LE,2)-I(FE,2)610 LET P0=0620 FOR X=FE+1 TO LE630 LET PO=P0+(I(X,4)/(X,3))640 NEXT X650 LET MPG..MILDIF/P0660 LET PC=0670 FOR X=FE+1TO LE630 LET PC=PC+I(X,4)690 NEXT X700 PRINT "FROM "A(FE.1W-"A(FE,2)"ML. TO710 PRINT I(LE,1),"-"A(LE,2);"ML."720 PRINT "A DISTANCE OF ";MILDIF,"ML."730 PRINT "M.P.0.="jMPG740 PRINT "COST OF PETROL=(POUND SIGN)"jPC750 PRINT "DO YOU WISH TO SAVE?"760 INPUT C$770 IF NOT C$="YES" THEN GOTO 310780 CLS790 PRINT "PRESS N/L WHEN READY"800 INPUT 2$810 IF $=" 'THEN SAVE "RUNNING -COSTS -1981"820 CLS3:::0 GOT° 40

PRACTICAL COMPUTING May 1982 147

Open file: Tandy

Star signsIT IS NOT only the lovelorn and super-stitious who are into astrology these days,writes Gordon Millington of Guildford,Surrey. Scientists too have found somevery interesting correlations between themovements of heavenly bodies and moremundane events.

The theory is that the position of theplanets at the time a child is born influ-ences its fortune for the rest of its life.Among the most important features ofthe natal chart - a symbolic representa-tion of planetary positions at the hour ofbirth - are the angles made by each ofthe nine planets with every other.

The program is written in TRS-80Level II Basic and makes rio use ofmachine code or hardware -specificroutines. The astrologer really needs hardcopy to pore over, so there is no attemptto present the results' on the VDUalthough this can be done easily enoughby omitting the L of LPrint and insertingGet or Inkey to stop scrolling as required.The printer is on-line throughout, and theonly other commands specific to it are thecodes in line 5. Those given are for theTandy Line Printer VII and may bevaried for other machines or omitted ifoutput is to VDU.

After printing the heading in double -size characters, the program presentseach of the planets in turn. It asks first forthe position of the planet in degrees andthen presents a menu in which the 12astrological signs of the zodiac are pre-sented and numbered in the conventional

Star signs printout.F.S-r-FRouroaI CPL FiSF.ECTS

R 194 12 15 111 48 45 37 SUN ASPECTS

202 4 23 119 56 53 45 MOON RSPECTS

206 179 83 146 149 157 URANUS RSPECTS

27 123 60 57 49 NEPTUNE ASPECTS

96 33 30 22 MERCURY ASPECTS

63 66 74 MARS ASPECTS

3 II JUPITER ASPECTS

VENUS TO SATURN ASPECT

Aspects in same order as Planets

Star signs program.

2 CLS5 LPRINT CHR$(31);"ASTROLOGICAL RSPECTS".PRINT.LPRINT CHRS(30)7 REM BY GORDON MILLINGTON, GUILDFORD, GU2 60P.9 DIM A(9).DIM D(80)10 FOR J.1 TO 920 READ P$,PRINT P$23 DATA SUN,MOON,URANUS24 DATA "NEPTUNE","MERCURY",,'MARS"25 DATA "JUPITER","VENUS","SRTURN"30 INPUT"HOW MANY DEGREES OF ITS SIGN"JA<J)40 cosue 600. CLS50 ON S GOSUB 500,505,510,515,520,525,530,535,540,545,550,55560 NEXT J70 CLS75 N.080 FOR X=1 TO 9.FOR Y=1 TO 990 K.A<X).2.A<Y>,D(N).ABS(K-2)95 N.N+1110 NEXT Y.NEXT X120 FOR N.1708.LPRINT 0(4);,NEXT.LPRINT"125 LPRINT130 FOR N=11T017.LPRINTD(N);.NEXT.LPRINT"/35 LPRINT140 FOR N.21T026.LPRINTD(N)J.NEXT.LPRINT"145 LPRINT150 FOR N=.31T035.LPRINTD(N),.NEXT.LPRINT"155 LPRINT160 FOR N.41T044.LPRINTD(N)).NEXT.LPRINT"165 LPRINT170 FOR N=51T053.LPRINTD(N)).NEXT.LPRINT"175 LPRINT180 FOR N.61T062.LPRINTD(N)I.NEXT.LPR/NT"185 LPRINT190 LPRINT D(71).LPRINT"VENUS TO SATURN200 LPRINT.LPRINT"AsOects in same order500 RETURN505 R<J).R<J5+30:RETURN510 R(J)=R<J)+GO.RETURN515 R(J>=R(J)+RORETURN520 A(J)=R(J)+120'RETURN525 PCJ)..P(J)+150'RETURN530 At1)..0(J)+180,RETURN535 A(J).A(J)+210.RETURN

AtJ)=A(J)+240.RETURN545 A(J)=A(J)+270.RETURN550 R(J)...R(J)+300;RETURN555 A(J)=A(J)+330.RETURN600 PRINT"1.ARIES 2.TAURUS605 PRINT"3.tEMINI 4.CRNCER610 PR/NT"5.LE0 6.VIRGO"615 PRINT"7.LIBRA 8.SCORPIO620 PRINT"9.SAGITTPRIUS 10.CAPRICORN625 PRINT"11.AQUARIUS 12.PISCES"630 PRINT.PRINT635 INPUT"IN WHAT NUMBER OF SIGN IS THE640 RETURN

SUN ASPECTS"

MOON ASPECTS"

URANUS ASPECTS"

NEPTUNE ASPECTS"

MERCURY ASPECTS"

MARS ASPECTS"

JUPITER ASPECTS"

ASPECT"as Planits".END

PLANET LOCRTED"JS

order, asking next for the number corres-ponding to the sign in which the planet islocated to be input. This is repeated inlines 10 to 60 for each of the nine planets.

The computed aspects are presented asa half -matrix with the redundant repeti-tions being computed but suppressed inthe printing. The first line of the printoutgives the eight angles the Sun makes withthe Moon, Uranus, Neptune, Mercury,Mars, Jupiter, Venus and Saturn. Thesecond line gives the Moon's aspects,beginning with Uranus and is one datumshorter than the first since the Sun -Moonaspect is given in the previous line. Eachsuccessive line is thus shortened until all36 aspects have been printed; the pro-gram ends with the Venus -Saturn aspect.

The aspect of 120 degrees, the trine,and its subdivisions 60 and 30 are gener-ally held to be fortunate in diminishingdegrees, whereas the 180 degrees angleor opposition is thought to be corres-pondingly unfortunate; 90 and 45dpgrees are also unfortunate but less so.There is some controversy over how far

on each side of the precise aspect itsinfluence extends, and it varies with casesanyway. The conjunction, 0 degrees, is ofvarying significance.

Astronomical data are required to setup an original map from which the birthdata are derived, but the matrix illus-trated can provide a check on the accu-racy of your keyed -in program. It isderived from the following data, whichyou can input when you run the programfor the first time:1 Sun 28 Leo2 Moon 20 Leo3 Uranus 12 Pisces4 Neptune 16 Leo5 Mercury 13 Virgo6 Mars 19 Sagittarius7 Jupiter 16 Libra8 Venus 13 Libra9 Saturn 5 Libra

Life and bounceFOR THE LAST few months Tandy Forumhas had too many hex to decimal conver-sion programs, complains Andrew

(continued on page 150)

148 PRACTICAL COMPUTING May 1982

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COMPRfTE LTD..Thonte House.Laisterdyke.BradfordTel. 0274-663471

GNOMIC LTD.,46. Middle Street.Blackhall,Hartlepool.Tel -0783-863871BRIERS COMPUTERSERVICES, 1 KingEdward Square.Middlesbrough.Cleveland.Tel 0642-2420173 LINE COMPUTING36. Clough Road. HullTel- 0482-445496

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PRACTICAL COMPUTING May 1982 149

Open file: Tandy

Cylindrical life.1 DEFINTA-Z;0070202 FORX=KTOK1:IFFEEK(X)=42THEN4

2223

INPUT " MAXIMUM BEFORE DEATH "(MINPUT "NUMBER AT WHICH REPRODUCTION

3 NEXT;IFPEEK(14400)=OTHEN2ELSE30 CAN START"9194 IFPEEK(X-65).42THEND=D+1ELSEC=-65 24 K=15425:K1=16319:CLS:SP=K:POKE SPt1435 IFPEEK(X+1)=42THEND=D+1ELSEC=1 30 At=INKEYt:IFAi=""THEN306 IFFEEK(X-64)=42THEND=D+1ELSEC=-64 40 POKESPF327 IFPEEK(X+63)=42THEND=D+1ELSEC=63 50 IFAd="E"THENOOTO28 IFPEEK(X+65)=42THEND=D+1ELSEC=65 60 IFAt="W"THENSP=SP-64:00T01009 IFFEEK(X+64)=42THEND=D+1ELSEC=64 70 IFAi="X"THENSP=SP+64:007010010 IFPEEK(X-63)=42THEND=D+1ELSEC=-63 80 IFA="A"THENSP=SP-1:00T010011 IFPEEK(X-1)=42THEND=D+1ELSEC=-1 90 IFAt="D"THENSP=SP+1:GOT010012 IFD>MORD<STHENPOKEX,32ELSEIFD>PTHENPOKEX+C,42 95 IFA="S"THENPOKESP)42:SP=SP+113 D=0:C=0:G0T03 100 IFSP<15360THENSP=SP+102420 CLS:PRINT:PRINT" ENTER ( 0-8 ) ":PRINT:PRINT 110 IFSP16383THENSP=SP-102421 INPUT" LEAST NUMBER OF SUROUNDING CELLS NEEDED 120 POKE SPt143:00T030

FOR CELL TO SURVIVE"15

continued from page 148)Tunnicliffe of Tilton -on -the -Hill, Leices-ter, who has provided two programs toadd a little life and bounce. CylindricalLife is very simple: the keys W, X, A andD will move the cursor, while S fires ashot on to the screen.

When you have finished putting yourcells on to the screen, press the Esckey, t , to start the program. The screenis continually scanned to make it appearthat one cell depends on the next at thetime of scanning only, i.e., if one cell diesthe death is recorded immediately. Foreach cell there are eight possible neigh-bours, given by lines 4 to 11. D is thetotal number of neighbours and C is the

Screen print.10 Fi$="20 K=VARPTR(AS) POKE K. 64 POKE K::+1. 0 F'OKE K+2, 60

:30 FOR J = 1 TO 16: LPRINT A$40 IF PEEK (K+1)<192 THEN POKEK+1 K+1 +64 : ELSE POKEK+1,00 : POKE K+2, PEEK K+2 ) +150 NEXT

position - if any - of a space so that ifreproduction occurs time is not wastedlooking for an empty space again.

Speed is of the utmost importance, andyou don't have to sit waiting for the next"scan" to see what is happening. TheCPU is sent in a buzz between lines 3 and13 until Esc is pressed. It is noticeablethat the = operation is faster than usinglogical And. The top and bottom row arenot used. This speeds up the program andprevents the Poking of system -crashingmemory locations.

Breakout is more complicated. Themoving character is controlled by thePeek (14400). After a breakout, morebricks are placed in both walls, and eachbrick is worth more. A bonus and extraball are provided after every sheetbeyond 1,000 points.

Screen printA SHORT BASIC ROUTINE for printing thecontents of the screen comes from Gor-don Grant of Crumpsall, Manchester.Only printable characters are acceptable,

but otherwise it is very fast and con-venient to use. It is best used by a Gosubfollowing an Inkey$, otherwise theprompt will be printed as well.

A string -variable name entry is createdat line 10. The length of this string is thenforced to be 64, and its start address isforced to the start of screen RAM at line20: The string is LPrinted 16 times, itsstart address being incremented by 64each time.

FireworksFIREWORKS is a one -line program' forTandy and Video Genie users from ChrisHarrison of New Ash Green, Kent:10 CLS: FOR J = 1 to 5: N = RND(70) + 5: G= N + 121: FOR A = 16383 TO 15360 STEP- N: POKE A,G: NEXT A: FOR B = 16383 TO15423 STEP - N: POKE N,G: NEXT B: NEXTJ: GOTO 10

Users of other machines will need toknow that 15360 is the top -left corner ofthe screen; 15423, top -right corner;16319, bottom -left corner; 16383,bottom -right corner.

Breakout.

!REM H '1 ) 1BREAKOUT(( BY A.J.TLINNICLIFFE ***

2 CLEAR2001DEFINTA-1:SC=0:SL=1:NM=4:G0T0300

3 CLS:BKitHRE(191):SSt=STRINGt(63t149)

7 PRINT110,STRINGt(N11,136),"SCORE °;SMPRINTB33,'HIGH SCORE'M8 PRINTI646Si;

9 FORR1:2T014:FORRH=OTOBLIPRINTBRI*64+04)+30tBKt;IN1-D:PRINTIR1*64+RH+521BKi;:PEXTIPEXTIPRINT1960ISSi;10 A):X=24:Y= 8:H=-1:V=0:K=15360*512+KIBA=140:BT=170:SPt=' 11:PCKEIbBT:Ef4i3+KIBS=191+K:FCRWW=0T02000:PEXT:00T060

20 G-1EEK(14400):IF6-THEN45

21 IFG=16THENIFB<BHTHENPOKEB,32:B=B+64:PCKEBIBT:GOT045

22 IFG=8THENIFB>BSTHENPOKEB,32:EOB -64:POKEBIBT

45 IFX=ITHEN59ELSEIFX>60THEK250

47 SP=X+H+(Y+V)*64+K:A=PEEK(SP)

50 IF A=32THENPOKE X+Y*64+K,32:X=X+H:Y=Y+V:POKESP1140 :001020

55 IFA=149THENPOKEX+Y*64+1632:Y=-V:Y=Y+V:GOT020

56 IFA=191THENPOKESP,32:H=-H:SC=SC+SL*10:PRINTt22,SCWFSCCHSTHEN60ELSEHS=SC:PRINT1431HSGOTO60

59 I=PEEK(Y*64+K):POKEY*64+K+1t32:X=2:IFZ=170THENH=1ELSE200

60 V=RND(3)-2:POKEX+Y*64132:00T020

200 POKEB,32:NM=N1-1:IFNM<ITHEN230ELSEPRINT@I0," '9:PRINT#10,STRINGi(KM,136);:FORDD=OT02000:NEXT:OOT010

230 CLS:SC=0:NM=4:FL=0:SL=1:PRINT:INPUT° DO YOU WANT TO PLAY AGAIN "Mt:IFQt="YITHEN3OCELSE END

250 CLS:FORGO=0T07:PRINT@524,CHRt(23)9' BREAKOUT " ":FORDD=OT0300:NEXT:PRINT15246TRINGi(20,32)9:FCADD=OT0300:NEXT:NEXT

251 CLS:IF SL>6 THEN 320 ELSE SL=SL+1

255 CLS:PRINT:PRINT:BP=BL*50:8C4C+BP:PRINT:PRINTCHRt(23):PRINTISTRINOt(BLI175):' X 50 '

260 PRINT:PRINT" BONUS POINTS AWARDED ":PRINT:PRINTICHRt(191)9'="*L*10:FORTT=0T02000:NEXTIO0T0320

300 CLS:PRINT:PRINT:PRINT" BREAKOUT ...BY A.J.TLWICLIFFE ':PRINT:PRINT' UP= (ESC) DOWN = (CTRLL)

HIT 'NEW LINE' TO PLAY "

305 PRINT:PRINT:PRINT:PRINT,CHRi(191);" = 1 0'

310 SKte":SKi=INKEYt:IFSKte" THEN 310

320 IF SC>1000 THEN IF FL4 THEN NM=NM+1

330 BL=2*SL:GOTO3

150 PRACTICAL COMPUTING May 1982

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Circle No. 197

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Circle No. 199151PRACTICAL COMPUTING May 1982

Hard -copy graphics

HERE Is a routine from Keith Bremer ofManchester to produce graphics hardcopy from a Nascom using the IOSLgraphics board. The output is specificallydesigned for a Nascom Imp with theImprint option, but could be modifiedeasily for other printers with graphicscapability.

The IOSL graphics board uses amemory -mapped display, where eachbit represents a single pixel on thescreen, and is 0 for black or 1 for white.Each byte in the display area holds eightbits on a horizontal line of the display.

0010 ,K***********************************0020 1* NASCOM GRAPHICS HARD -COPY OUTPUT *0Z30 ;* (IOSL screen graphics to NASCOM *

0040 ;* IMP printer with IMPrint ROM) *

0050 :***********************4************0060 ;

0070 ;Mav he entered from DAGIC or other0080 ;languages give a hard col,' of the0090 ;current graphics memory to the IMP.0100 ;No :input parameters are re=uired -- the0110 ;necessary values being taken from the0120 ;graphics driver's workspace.01300140 ;

01500160 ;LABELS USED:0170 ;

30E0 0C91 0180 DSPSZE EQU0198 ;0200 ;

3000 0C92 0210 DSPSTT EQU0220 ;0230

30E0 001F 0240 GMODE EQU0250

30E0 006F 0260 SRLX EQU0270 ;0280 ;

0290 ;STORAGE USED:0300 ;

OFC0 0310OFC0 BD00 0320 HINC

0330 ;OFC2 F000 0340 HREM

83580360 ;

0370 ;ROUTINE:0380 ;

0000 ORG 0

0000 210000 HCOPY LD HL,0 ;initial Y coord

;The following loops down the;outputting 7 screen lines at

0083 3E1F HC10085 DF6F0807 010000 '

000A AF0008 57

000C E50000 85000E FS080F C50010 3E070012 Al0013 CB380015 CB190017 CB390019 CB39081B 47001C 04001D AF001E 37001F 170020 10FD0022 110700

0390040004100420043084400450046004700480049005000518052005300540055005600570058005900600061006200638064006500660067806800698 HC2A070007100720

£C91 ;the address of a byte;containing the display;size as no. of lines.

£C92 ;the address of a word;holding the display start;pointer to RAM

ElF ;IMPrint graphic mode;initialisation

E6F ;NAS SYS serial output

ORG EFC8DEFW E00BD ;ie 0.74 as a binary mixed

;number nn.ff in hexDEFW 240 ;remaining bytes to fill

;the IMP buffer to 760

screen,a time

LD AeGMODE ;IMP graphics modeSCAL SRLX ;write A to printerLD BC,8 ;initial X coordXOR A ;previous bvte output (initially 0)LD D,A ;fractional Part of X coord = 0

;The following loops along a 7 line band;of the screen, outputting bytes to the;printer in graphic form

HC2 PUSH:HL ;save YPUSH DE ;save X fractionPUSH AF ;save Prev bytePUSH BC ;save X coordLD Ae7 ;mask for bit within byteAND C ;get hit no (0..7)SRL B ;divide X by 8 to get byte in lineRRSRLSRLLDINCXORSCFRLA ;shift A left toDJNZ HC2ALD DE,00007 ;D=current

C

CC

B,A ;bit no into BB ;adjust bit no.A

get bit mask

byte/ERaine count

(listing continued on next page)

For a complete line of video output, 48bytes are strung together in a row to give384 pixels in the x direction. Successivelines of 48 bytes each are used to provideup to 224 lines on the screen, 10-5K. Seefigure 1.

With the Imprint facility on the Nas-corn Imp, graphics output is possible,giving a horizontal resolution of 760points with a slightly lower density verti-cal resolution. Output is achieved bysending a control character, 1F hex, fol-lowed by exactly 760 bytes to be printedin graphics mode. These bytes hold sevenbits of data corresponding to the sevenpins in the print head, leaving one bitwhich is ignored. The bit -to -pin relation-ship is shown in Figure 2.

At the end of printing a graphics linethe Imp performs only a partial line -feedso that there is no gap between successivebands of graphics output. An image isformed by adding further bands ofgraphic output as far as necessary, asshown in figure 3.

This routine involves conversion fromthe horizontally -oriented bytes of thememory -mapped display to the verticallyorientated bytes required by the printer.

Unfortunately the Imp does not givethe same number of dots per inch verti-cally as it does horizontally. The ratio isabout 74:100 or 0.74, so if pixels aretransferred directly from the display,where the ratio should be about 1:1, thenthe printed image appears to be too tall.One method of avoiding this distortion isto adjust the output so that the printedimage has the same proportions as thedisplayed picture. This routine does thisby stepping along in the 'x' direction by0.74 at a time instead of 1.0. This gives amuch closer degree of geometric accuracythan direct output of pixels but meansthat some pixels are sampled twice duringthe output process.

The second problem is that the Impprint head cannot be driven so that one

Figure 1.Display

Memory''byte

48 bytes per lineup to 224 lines

1/ I I

Figure 2.

bit(ignored)

_...____...

bite

Figure 3.

top

Print head

bottom

I I

760 bytes per 'band'

each byte has 7 bits of graphicalinformation

IIIIIIIIIIIIIII

as many'bengs' as you need.

mebm

152 PRACTICAL COMPUTING May 1982

Open file: Z-80

111111111111111111!"

MEW" NU11111111EM AMEN11111111/F MEEMEW 1111r ANNS

II AMINO' AIMIEr 4111111111t AIMIEMIMI MOM=MEM AIME

1211111111

Figure 4.

Videodisplay

Printer

output

pin will print two adjacent pixels. Thisproblem only arises in graphics output,and is in any case taken care of by theImprint routines inside the printer. How-ever, if the program tries to print adja-cent pixels, then Imprint lights the errorlamp. To avoid this, the hard copyroutine adjusts the output appropriatelybefore sending the data to the Imp, bysuppressing a bit, if the previous byte alsohad that bit set.

Considering these problems, it is poss-ible to show how the routine builds up itsoutput on the printer. This is shown infigure 4, which represents part of thescreen display and the correspondingprinter image. The screen display is over-laid with the corresponding printer dis-play pixel positions in dotted lines. Thepixels shaded but marked X would be set,but are suppressed by the routine.

The subroutine comprises three majorloops, nested within each other, to outputa single vertical byte, within a loop tooutput the 760 bytes needed for a singleband, within a loop to output the totalnumber of bands needed for the image.Two data words are used, to define thehorizontal increment of 0.74 which maythus be changed by the user for otherconfigurations and a count to define thenumber of bytes to fill out to 760 on aline. This is calculated as

HREM := 760 - INT(384/HINC)where in this case HINC = 0.74 givingHREM approximately 240.

The filling -in bytes are all zeros, andsince the Imp in normal mode ignoresnulls, then the value of HREM need notbe exact so long as the total number ofbytes output is 760 or just over.

The code SCAL is a specific NasSysmonitor code which generates a call to asubroutine, in this case the serial outputroutine, SRLX. This code may bereplaced for other machines by anappropriate Call. The routine is relocat-able, the assembly listing being given foran origin of 0000. It is also possible tohold the routine in the same RAM blockas the graphics memory map.

(listing continued from previous page)

0730074007500760

;The following loops down 7 lines at the;current X coordinate to obtain a 7 hit;value to print;

0025 F5 0770 HC3 PUSH AF ;save bit mask0026 C5 0780 PUSH BC ;save position0027 E5 0790 PUSH HL ;save Y0028 ED4B910C 0800 LD BC,(DSPSZE) ;no. of lines in display

002C 37 0810 SCF002D ED42 0820 SBC HL,BC ;compare with current Y002F El 0830 POP HL

0030 Cl 0840 POP BC

0031 3017 0850 JR NCrHC4 ;jUMP if Y = max Y0033 E5 0860 PUSH HL ;save Y0034 C5 0870 PUSH BC ;multiply HL by 48

0035 ES 0880 PUSH HL0036 29 0890 ADD HL,HL ;4(2

0037 Cl 0900 POP BC

0038 09 0910 ADD HL,BC ;*30039 29 0920 ADD HL,HL ;*6003A 29 0930 ADD HL,HL ;*12003B 29 0940 ADD HL,HL ;*24003C 29 0950 ADD HL,HL ;*48003D ED4B920C 0960 LD BCr(DSPSTT) ;start of display0041 09 0970 ADD HLOSIC ;HL = addr of start of line0042 Cl 0980 POP BC iX displacement within line0043 09 0990 ADD 1-11_,BC = addr of byte in line0044 A6 1000 AND (HL) ;test b&t in byte0045 El 1010 POP HL ;restore Y0046 23 1020 INC HL ;step Y down to next line

Ern47 2001 1030 JR Z,HC4 ;skip carry if zero0049 37 1040 SCF ;set carry to shift into D004A CB12 1050 HC4 FL D ;shift D for next hit004C ID 1060 DEC ne count004D 2805 1070 JR Z,HCS ;end : .:., zerc

004F Fl 1080 POP AF ;restore bit mask0050 1803 1090 JR HC3

11001110 ;end of loop to find 7 bit pattern1120

0052 16AF 1130 HCHALF JR HC1 ;half way JUMP for outer1140 ;loop relocatability1150

0054 Fl 1160 HC5 POP AF ;lose hit mask0055 Cl 1170 POP BC ;restore X coord0056 Fl 1180 POP AF ;prey byte0057 2F 1190 CPL ;invert prey byte0058 A2 1200 AND D ;adjust current byte for IMP

1210 ;(see note on IMPrint graphics pin1220 ;driving limitations!)

0059 D1 1230 POP DE ;restore fraction of X005A F5 1240 PUSH AF ;save current as prey005B C5 1250 PUSH DC ;save X005C DF6F 1260 SCAL SRLX ;write byte 'Lo wrinter005E Cl 1270 POP BC005F 78 1280 LD Art ;shift X 8 bits into A,B,C0060 41 1290 LD B.00061 4A 1300 LD Ca ;fraction0062 2AC00F 1310 LD HL,(HINC) ;X increment as nn.ff0065 09 1320 ADD HL.BC ;add lower 2 bytes0066 CE00 1330 ADC Ar0 ;carry into top byte0048 55 1340 LD D,L ;store fraction in B0069 4C 1350 LD C,H ;whole part in BC006A 47 1360 LD B.A006B 218001 1370 LD HL,384 ;max X value006E 37 1380 SCF006F ED42 1390 SBC HL,BC ;compare X with max X0071 El 1400 POP HL ;restore prey byte into H0072 7C 1410 LD OrH ;then A

0073 El 1420 POP HL ;restore Y0074 3096 1430 JR NC,HC2 ;loop back for next X

14401450 ;end of loop to output a band 7 lines wide1460 ;

0076 ED4BC20F 1470 LD ' BC,(HREM) ibvtes to fill IMP buffer007A 04 1480 INC B ;adjust in case zero0078 0C 1490 INC C

007C AF 1500 XOR A iset output to zero0070 DF6F 1510 HC6 SCAL SRLX ;write A to printer007F OD 1520 DEC C

0080 20FB 1530 JR NZ,HC60082 10F9 1540 DJNZ HC6 ;write nulls until BC = 00084 010700 1550 LD BC,7 ;increment for Y0087 09 1560 ADD HL,BC ;Step to next hand0088 ED4B910C 1570 LD BCr(DSPSZE) ;display size008C E5 1580 PUSH HL008D 37 1590 SCF008E ED42 1600 SBC HLrBC ;compare Y with max Y0090 El 1610 POP HL0091 388E 1620 JR C,HCHALF ;loop if not vet >= max Y0093 C9 1630 RET

16401650 ;end of routine1660

PRACTICAL COMPUTING May 1982 153

THEVIC

NEEDSVIC

REVEALED

THE DEFINITIVE REFERENCEBOOK ON THE VIC SYSTEM

FROM NICK HAMPSHIRE

Now available. Price £10.00 from Commodore dealersand bookshops. Nick Hampshire Publications, P.O. Box13, Lysander Road, Yeovil, Somerset.

Circle No. 200

PRACTICAL COMPUTING May 1982154

Open file: Disc

DISCDIALOGUE

QERA changesTHE QERA ROUTINE by David Meeks,Disc Dialogue, January 1982, is mostuseful, writes A P Hill of Exeter, Devon,but there appears to be one major errorand two minor errors in the listing. The'algorithm to calculate the position of theunambiguous file name, UFN, in thedirectory buffer is false. It always returnsthe wrong location when the UFN islocated at the start of the buffer, 0080Hreturning the value 0000H.

As only the lowest two bits of the valuereturned by the BDOS in register A areof interest to us, a better algorithm is tosimply check the value of these bits,giving four possible values - 0, 1, 2 and3. These values show exactly where theUFN is located in the buffer.

Listing 1.BUFPOS MVI B, 1

RRCJNC NOLSBINR B

NOLSB RRCJNC NONSBINR BINR B

NONSB LXI H, 60HLXI D, 20H

FCBLP DAD DDCR BDNZ FCBLP

counter =1lowest bit set?jump if not setinc count if setnext lowest bit set?jump is not setinc count by 2 asthis bit = 220H below buffer start

add 20H to value inH until count = 0

0 = first UFN 0080H1 = second UFN 00AOH2 = third UFN 0000H3 = fourth UFN OOEOH

The code in listing 1 will achieve therequired result. The H register now con-tains start location of UFN in buffer, andthis piece of code should be substitutedfor the lines after

NEXT: dcr Aup to, and including the line

mov L, AThe return from this routine to CP/M is

liable to produce errors. A better methodis to store the value of the stack -pointeron entry to the routine - say, in OLDSP- and restore this value on exit from theroutine. Further, the return to CP/Mshould be via a jump to the main entrypoint at 0000H, and not via a return.Thus

START LXI, H, OHDAD SPSHLD OLDSPLXI H, STACK + 32SPHL

andBOOT LHLD OLDSPSPHLJMP 0000H

The section of code to print the drivenumber, within Print: is incorrect. As thedrive number will be 0, 1, 2, etc., addingthe value 40H will produce the ASCIIcodes A, B, etc. Thus 41H and not 40Hshould be added in the seventh line of thissection.

File sizesTHIS CP/M PROGRAM from JonathanPalfrey of Warwick, written for theMicrosoft assembler, counts the numberof lines in a file. It operates by countingcharacters and end -of -file markers whichare not preceded by CR or LF.

The program returns to the CCP whenfinished. This improves its speed, butmeans that it cannot be included in Subfiles. If you find this feature inconvenient,change the last two occurrences of "ret"to "jp 0".

Listing 2.

L100,102

161D161E161F

INRMOVINR

LM,AL

0100 JMP 1600 1620 MOV M,A0103 1621 INR L

L1600,1631 1622 MOV M,1600 LDA 0080 1623 INR L1603 CPI 00 1624 MOV M,A1605 J Z 1615 1625 INR L1608 CPI 03 1626 MOV M,A160A JNZ 0433 1627 INR L160D LDA 0083 1628 MOV M,A1610 CPI 3A 1629 INR L1612 JNZ 0433 162A MOV M,A1615 LXI H, 005D 162B INR L1618 NV! A, 3F 162C MOV M,A161A MOV M,A 162D INR L161B INR L 162E MOV M,A161C MOV M,A 162F JMP 0433

Continually typing STAT . canbecome tedious and a small patch willenable you to type STAT, STAT B:, orindeed STAT D: - if you have four discdrives - and get the full listing of all filenames and sizes. Any superfluous blanksin the command line will result in theoriginal one -line message being dis-played.

The first instruction in STAT.COM isan unconditional jump to 0433H. Mypatch substitutes a jump past the end ofthe program, and then jumps to 0433H.This can be done using DDT, and theresult appears as in listing 2.

Notice that you can still get the one -linedisplay of remaining space, if you reallywant it, by typing "STAT " - with aspace before the closing quotation marks.Also, the original "STAT *.*" commandstill works, as do all the other STAToptions.

The new version of STAT.COM maybe saved on disc by giving the command

SAVE 22 STAT.COMImmediately after getting out of DDT.

The resulting version of STAT is ofcourse non-standard, but I think thechange is a significant convenience if youwant the full listing and only a very minorinconvenience if you want the one -linedisplay.

File sizes.asegorg 100h

Id de,92Id c,15call 5cp 255JP z,noflle

Id b,10Id h1,0

rreci push bepush hlId de.92Id c,20cell 5

Pon hlpop be

0

jp ni,nevit

nextc

notcr, s

i serif,

Id de,128Idcp 26

cOseof

cp 13

JP notcrinc hl

Id b,aInc doId a,dcp 0

JP x.nextcJo rrMC

Id a,bcep 10

JP a,nexitcp 13

JP z,nesitInc hl

default fcb

I open file

; 'last character" LFI set line count to 0

I PUSh last characteri push line count; default fcb

; read iron file; pop line count1 pop last character; successful read?

I start of default buffer-, get next char from buffer; if end of file

; Juan out of rrec loop

I if CR then

; increment line countI remember last character

I increment pointer to buffer

I if still within buffergo to next characterelse read new record

I look .t last character

I increment line count If not LF or CR

nexus Id bc,lc$Id iy,plOtab

loopOs IdId e,liy,Id 1)

loopl, or asbc hl,de

c,juepiinc

JP loop]

jumpli addIdincincincIdcep

JP

Idnextlis Id

cpJrinc

Jo

lifini Idcallrot

nofilei IdIdcallret

olOtabi clefs

lc,, deft,

deft,

hl,de(bc,,abeiyiya,1

ni,loop0

de, Icea,(cle1

a,lafineenextli

c,95

de,n4$c,95

; FL holds line count to be put Into 195power -of -ten table

I set digit count - 0

I load de with poorer of tenclear carrysubtract power of ten

1 go If done; increment digit count

restore to positivestore digit countincrement buffer pointer

point to next poser of ten

if power -of -ten . I

repeat outer loop

get address of line count stringgo past leading zeroes

display line count string

and return to CCP

return to CCP

10000,1000,100,10,1lines 130 jun 1981 Jpr PelfreW

'no such file,

'PRACTICAL COMPUTING May 1982 155

APPLEPIE

Musical momentsPROGRAMS on Apple II Plus which arerepetitive in nature can be livened upconsiderably by including short tunes,writes Michael Findlay of Belfast. Thesecan easily be added to any Basic programand are particularly useful in acting as areward for a correct response.

There are two methods of adding atune to a program. The Apple II'sspeaker can be addressed by means of a

Listing 1.

$02E2L

02E2-

02E5-

02E6-

02E8-

02ED-

02ED-

02EE-

02F0-

02F3-

02F6-

AD 30 CO LDA $C030

Be DEY

DO 05 BNE $02ED

CE El 02 DEC $02E1

FO 09 BEB $02F6

CA DEX

DO F5 DNE $02E5

AE EO 02 LDX $02E0

4C E2 02 MP $02E2

60 RTS

Table 1.

(2) (1I) (1) (1)

J. J er

255 192 128 64

(14)

I32

machine -code routine which will have tobe BLoaded at the start of the program.Alternatively the routine can be enteredas Poke statements directly from theprogram, perhaps as a subroutine.

The ITT 2020 manual gives one par-ticular machine -code routine for playinga tune, but this is unsuitable for theApple II, as it would occupy a portion ofits zero -page memory already in use. Thismachine code has therefore beenamended slightly so that it occupies avacant part of the Apple II memory nearthe top of page two, starting at address$02E2-738 decimal in listing 1.

It is a very short program and is easilyentered from the keyboard in the usualmanner:CALL - 1510E2 : AD3 0 CO 88 DO 05

etc. ReturnAfter entering, check the listing by

02E2 Land the listing should appear on thescreen. It may now be saved on disc bythe command

BSAVE TUNE,A$ 02E2, L21Alternatively, instead of using this

method, the equivalent information maybe Poked into the same memory locationsusing a Gosub like the routine shown inlisting 2. The disadvantage of this methodis that this subroutine has to be typed intoeach program which requires a tune,whereas two instructions inserted some-where near the startsuch as:

40 D$ = CHR$ (4) : REM Control D50 PRINT D$; "BLOAD TUNE, A$ 02E2"

will add the same information to thememory from disc with less trouble.

The frequency and the length of a noteare determined by the speed at whichloops are executed in the machine -coderoutine. The routine searches for thepitch value - between zero and 255 - inlocation $02E0 - 736 decimal - and thelength value in location $02E1 - 737decimal. The appropriate values must bePoked into these locations from the Basicprogram.

The pitch values are given in table2. For notes one octave higher, simplyhalve the values given. The length of thenotes are shown in table 1.

To play a single note, you have only toinsert the following instructions:

Listing 2.

rifY;UP, 300007inialan FL Version Tune7inci1ci DATA 173,4RACI2?17.1120EU5,206:225,2J2401J9?Jacici DATA 202,208,245,174,224,2,76,22,2,q6

FUR I = 7:3:3 Ti 75R::::An4A READ R PUKE I , R

7-n7050 NEXT: RETURN

Table 2.G G* A Bb B C C# D Eb E F Fit

255 242 228 216 205 195 185 175 164 152 145 135

Sample program.

100 REM HI BLUE DANUBE tit

110 REM PITCH & LENGTH OF NOTES

120 REM WRITTEN AS CONSECUTIVE

NUMBERS

130 REM IN FOLLOWING DATA

STATEMENTS

140 DATA 128,128,128,128,102,12

8,87,128,87,255,87,128,87,25

5,102,128,102,255

150 DATA 128,128,128,128,102,12

8,87,128,87,255,87,128,87,25

5,97,128,97,255

160 DATA 135,128,135,128,114,12

8,76,128,76,255,76,128,76,25

5,97,128,97,255

170 DATA 135,128035,128,114,1

28,76,128,76,255,76,128,76,2

55,102,128,102,255

180 DI = CHR$ (4)

190 PRINT D$;'BLOAD TUNE,A$02E2'

200 REM SPECIFY NO.(X) OF NOTES

210 X = 36

220 M = 1

230 F = 736:LN = 737:T = 738

240 FOR I = 1 TO X

250 READ P,L

260 L = INT (L $ M): IF L 255 THEN

L = 255

270 POKE F,P: POKE LN,L: CALL T

280 NEXT

100 POKE 736, 195:S....mmnmmro.,,,!.,

Pitch

CALL 738

Monitor routineTo play a tune with a sequence of

notes, it is easier to add the pitch andlength values of the various notes as Datastatements and Read the pitch P andlength L as illustrated in the sample pro-gram.

In line 260, the length of all the notesin a tune may be changed by altering thevalue of M in line 220, subject to L <

255. If M > 1 then the tune is sloweddown, and if M < 1 the tune is speededup. Various interesting effects may alsobe obtained by letting M vary and playjust one note.

Letter ShuffleTHE OBJECT of the Letter Shuffle game bySA Reedy of Portsmouth, Hampshireis to shuffle the lines and columns in thesquare until the result shown in figure 1 isobtained.

The rows and columns may be shiftedsimply by pressing the key labelled forthat row or column. In the bottom right -

POKE 737, 128:

Length

156 PRACTICAL COMPUTING May 1982

Open file: Apple---

A!A B C!R B'

B!D E F!DEC'G H I' G-+D!R B C! R-+E!D E F!D E F! D-+F!G H I!G H I! G

! 1 ! 2 ! 3 ! 4 ! 5 ! 6 ! 7 ! 8 ! 9 !

C!A C!

F!D E F:

C ! A El !

H

-+G'R B C'A B C' A-+H'D E F'D E F' D-+1'0 H I 'G H I' G-+Letter Shuffle - figure 1.

C

H I

F

C F

H I

hand side of the screen there is a sectionwhich says whether your columns movefrom top to bottom, or bottom to top.Likewise it will tell you whether yourrows move right to left, or left to right.This can be reversed simply by pressingthe space bar.

Lines 60 to 200 print instructions,while lines 210 to 320 print square grid,column and row labels. Lines 330 to 450randomly places data into two-dimensional array and lines 460 to 940 inthe main program accept your move, shiftappropriate columns and rows within thearray and update the displayed grid andscore.

The program displays a direct map of anine -by -nine two-dimensional array. Allmovements within the array use a sub-routine as shown in lines 570 to 640.

Screen dumpIF YOU BOUGHT an 80 -column Epsonprinter for your trusty 40 -column AppleII Shaun Hope of Milton Malsor, North-amptonshire has a program which willsolve your printout problems. Unless youhave an 80 -column card your first print-out will come out like a typographer'snightmare with random spacing andcolumns of higgledy-piggledy figures.

Inserting the appropriate printer for-mat commands in all your programs andadding subroutines to switch the printeroff and on at the right times would takehours. This simple subroutine is easy toincorporate into your existing programsand will enable the printer to reproducethe Apple 40 -column format exactly as itappears on the screen. Admittedly youwill be wasting half of each sheet of paperon the printout, but the extra space isvery useful for adding comments. Thegeneral principles of this subroutine canbe adapted for other machines providedthat the screen display is memorymapped, that is, screen location is storedsomewhere in accessible memory.

The Apple primary text screen consistsof 40 columns and 24 rows, giving 960possible positions for each screen charac-ter. Each character displayed on thescreen is the content of one memorylocation. The actual memory used beginsat decimal location 1024 and ends at2047 and is thus 1,024 bytes long. The

(continued on next page)

Letter Shuffle.1 REM ***********************2 REM *'3 REM * LETTER SHUFFLE GAME *4 REM * CONCIEVED S. WRITTEN *5 REM * BY S.A. REEDY 6/5/81 *6 REM *7 REM ***********************10 D = 020 HT = 3:HI = 23:SC = 0: DIM D$(8),P (8,8)30 HOME40 VTAB 1: HIM HI50 PRINT "LETTER SHUFFLE"60 HTAB HI: PRINT70 HTAB HI: PRINT "YOU MAY MOUE ANY"80 HTAB HI: PRINT "ROW OR COLUMN BY"90 HTAB HI: PRINT "PRESSING:-": PRINT100 HTAB HI: PRINT "ROW <A -Ii"110 HTAB HI: PRINT "COLUMN (1-9)"120 PRINT130 HTAB HI: PRINT "PRESSING THE "

140 HTAB HI: PRINT "SPACE BAR WILL "150 HTAB HI: PRINT "CHANGE DIECTION"160 HTAB HI: PRINT "OF MOVEMENT": PRINT170 HTAB HI: PRINT "PRESENT DIRECTION"330 -HTRB-fir: -PRINT "LEFT TO:RIGNT-"190 HTAB HI: PRINT "TOP TO BOTTOM"200 PRINT : HTAB HI: PRINT "MOUE # "I210 VTAB 1220 HTAB 1: PRINT " 1 2 3 4 5 6 7 8 9"230 FOR X = 1 TO 9240 VTAB (2 * Xi250 HTAB HT - 2: PRINT260 UTAB (2 * Xi + 1

270 HTAB HT 2: PRINT CHR$ (X + 192)280 NEXT290 FOR 22 =2 TO 20: HIRE: HT -- 1: UTAB 22300 IF 22 = 8 OR 22 = 14 OR 22 = 2 OR 22 = 20 THEN PRINT "+

+": NEXT310 IF 22 = > 20 THEN 330320 PRINT ". !": NEXT330 DATA "A". "B".. "C" ,"8":"B""C", "A": "B", "C"340 DATA "D","E","F"."D","E","F","D","E","F"350 DATA "G","H","I""G":"H","I","G":"H":"I"360 FOR H = 0 TO 0: FOR V = 0 TO 8370 P$(H2Oi = ".": NEXT : NEXT380 FOR R1 = 1 TO 3: FOR R2 = 1 TO 27390 H = INT ( RND (1) * 9):V = ItTY ( RND (1) * 9)400 IF 1.4(H,V) < > "." THEN 390410 READ P$(H,U)420 HTAB (2 * H) + HT: VTAB 2 * 3: PRINT P$(1.1..))430 NEXT440 RESTORE450 NEXT460 FOR H = 0 TO 8: FOR V = 0 TO 8470 HMS (2 * H) + HT: VTAB (2 4, C') + 3: PRINT P$(1,0)480490500510520530540550

560570580590600610620630640650660670680690700710720730740750760770780790800810320

NEXT : NEXTH = 0:V = 0: HTAB HI + 7: UTAB 19: PRINT SCVTAB 19: HTAB 40: GET K$IF ASC (K$) = 32 AND D = 1 THEN D = 0: GOSUB 890: GOTO 500IF ASC (K$) = 32 AND D = 0 THEN D = 1: GOSUB 920: 0070 500IF ASC (K$) < 65 OR ASC (K$) > 73 THEN 550

U = ASC (K$) - 65: GOTO 710IF VAL (Kr) > 0 AND VAL (KS) ( 10 THEN H = ( VAL (Kr) - 1): GOTO 570GOTO 490FOR V = 0 TO 8

A$(1,1> = P$(H,U)NEXTIF D = 1 THEN 5351FOR X = 0 TO 8:Y = X - 1: IF V < 0 THEN Y = 8GOTO 640FOR X = 0 TO 3:Y = X + 1: IF Y > 8. THEN Y =

= A$(Y): NEXTFOR V = 0 TO SHTAB (2 * Hi + HTVTAB (2 * Vi +3PRINT P$(H,U)NEXT

SC = SC + 1: GOTO 490FOR H = 0 TO 8

A$(H) = P$(H,U)NEXTIF D = 1 THEN 820FOR X = 0 TO 8:Y = X 4: IF Y < 0 THEN Y .

P$(X,U) = AS(Y): NEXTFOR. H = 0 TO 8HTAB (2 * H) + HT: VIM (2 * U) + 3PRINT PS(H.V)NEXT

SC = SC + I: GOTO 490MuR X iu = + 1: IF Y > 8 THEN Y = 0

838 PCX,V):= R$(Y): NEXT840 FOR H = 0 TO 8850 HTAB (2 * H) + HT: VTAB (V * 2) + 3860 PRINT P$(H,U)870 NEXT880 SC = SC +. 1: GOTO 490890 HTAB HI: VTAB 16: PRINT "LEFT TO RIGHT"900 HTAB HI: VTAB 17: PRINT "TOP TO BOTTOM"910 RETURN920 HTAB HI: VTAB 16: PRINT "RIGHT TO LEFT"930 HTAB HI: VTAB 17: PRINT "BOTTOM TO TOP"940 RETURN

PRACTICAL COMPUTING May 1982 157

Open file: Apple

Screen dump.

9 REM >> -TEXT SCREPT-DOMP <<

19 REM A SIMPLE METHOD OFDUMPING AN APPLE ][ TEXT

SCREEN ONTO AN EPSONPRINTER 1: DEVISED

BY SHAUN HOPE) COPYRIGHT 1981

29 REM WRITTEN ON A 48K DOS 3.3SYSTEM WITH AN MX -82

PRINTER/INTERFACE TYPE 2

Part 1.99 REM DOS & PRINTER CONTROL

CODES TO BE INITIALISEDIN MAIN PROGRAM

100 RS = CHRS (13):D$ = R$ CHR$(4)

109 REM PRINTER IN SLOT 1

110 SLOT = 1

169 REM REFER TO P.15 OF THEAPPLE IC REFERENCE MANUALFOR SCREEN CODES

179 REM AS CONTAINS THE ASCIISCREEN CODE 0 (THE S SYMBOL)

189 REM L$ CONTAINS THE ASCIISCREEN CODES EXCEPT 0 INCORRECT ORDER

199 REM LS & Ai SHOULD ALSO BEDEFINED IN THE MAIN PROGRAM

200 A$ = "8"210 L$ = "ABCDEFGHIJKLMNOPORSTUVW

XYZ" + CHRS (91) + CHRS (92) + "r" + CHRS (95) + .

" + CHR$ (34) + "MVO**,-./0123456789:;<=>?"

220 LS = L$ + AS + LS + AS + L$ +AS + LS

230 GOTO 2000: REM A DEMO

Part 2.

989 REM THIS IS THE MAINROUTINE FOR TEXT DUMP.INSERT IT IN YOUR MAINPROGRAM AS A SBR, THENPROVIDE AN OPTION TO USEIT IN YOUR SCREEN DISPLAY.

999 REM SWITCH ON PRINTER ANDOUTPUT TO PRINTER ONLY

1000 PRINT DS"PRE"SLOTOS: POKE1656 + SLOT,72

1005 PRINT CHRS (27) CHRS (65) CHR$(8);

1009 REM I,J,K LOOPS CHECK WHATIS ON THE TEXT SCREEN (REF.MANUAL P.16)

1010 FOR I = 1024 TO 1104 STEP 40

1020 FOR J = I TO I + 896 STEP 128

1030 FOR K = 0 TO 381039 REM CHECK WHAT IS ON THE

SCREEN1040 X = PEEK (J + le)

1049 REM PRINT THE RELEVANTSYMBOL

1050 IF X = 0 THEN PRINT A$;: GOTO1070

1060 PRINT RIDS (L$,X.1);1070 NEXT K

1079 REM PRINT THE LAST COLUMN(OMIT SEMICOLON THIS TIMESO THAT WE ARE READY FORNEXT LINE).

1080 X = PEEK (J + 39)1090 IF X = 0 THEN PRINT AS: GOTO

1110

1100 PRINT MIDI (L$,X,1)1110 NEXT J,I1115 PRINT CHR$ (27) CHR$ (65) CHRS

(12)

1119 REM RESTORE SCREEN OUTPUT1120 POKE 11657 + SLOT,401129 REM SWITCH PRINTER OFF1130 PRINT DS"PREO"1140 RETURN : REM ROUTINE ENDS

Part 3.1989 REM THIS IS AN EXAMPLE OF

HOW TO USE THE DUMP ROUTINE1999 REM FIRST WRITE A TEXT

SCREEN PAGE2000 TEXT : HOME2010 PRINT ">>> DEMONSTRATION OF

TEXT DUMP TO AN <<<>>>" SPC(10)"EPSON PRINTER" SPC( 10)"<<<>>> BY S.HOPE COPYRIGHT 1981 <<<"

2020 FOR N = 5 TO 23: VTAB N: HTABN: PRINT "LINE "N: NEXT

2029 REM PROTECT ALL BUT THEBOTTOM LINE FROM SCROLLING.

2030 POKE 34,232040 HOME : PRINT "KEY: <P>RINT

OUT ,E>ND ";: GET I

2050 IF IS = "P" THEN GOSUB 1000: GOTO 2040

2060 IF IS = "E" THEN 20802070 GOTO 20402080 POKE 34,0: HOME : END

(continued from previous page)64 -byte difference between 960 bytesand 1024 bytes is not used by the screendisplay but for peripheral devices.

A map of the text screen on page 16 ofthe Apple II reference manual shows thatthe locations are not in normal arithmeti-cal progression, though there is somelogical order to them - this is why threeloops are necessary.

The screen -dump program first looksat each of the screen locations in turnfrom top left to bottom right of thescreen. Then it decides which screencharacter is stores at that location. Next itdetermines a suitable printer character touse, and finally it prints that out. Theprogram takes the precaution of protect-ing the display while this is taking place.

Part one of the program consists ofvariables which need to be initialised inthe main part of your program. Lines 100and 110 initialise necessary DOS andprinter controls and set the printer inter-face to slot one. Lines 200, 210 and 220initialise two string variables A$ and L$.

The 256 possible screen characters,including inverse and flashing charactersare defined on page 15 of the Apple IIreference manual. The first screencharacter is placed in A$; the remaining255 are placed in L$. Two string variablesare required because a string variable canhold no more than 255 characters.

The use of these string variables isnecessary in the first place because thereare considerable differences between thenormal ASCII character codes and theApple ASCII screen codes. For example,ASCII code 13 is a Control-M-Return- but Apple screen code 13 is anInverse -M. String variables allow you todecide what to print in place of charactersdisplayed on the screen in inverse orflashing mode. This program will printthese characters as normal upper case.

In part two, line 1000 switches on theprinter. Note the vital R$ which is ASCII13, Return. The Poke kills any output tothe screen to avoid disturbing the screendisplay while printing it out. Line 1005 isan optional extra, reducing the spacing

Cash Display.

10 REM MAKE VARIABLE TO BE PRINTED = Z.

20 REM THEN GDSUB 5

30 REM USE 'PRINT ZZ$' TO PRINT VARIABLE CORRECTLY FORMATTED I ROUNDED TO NEAREST PENNY.

40 REM USE 'TAB( 0 - LEN(ZZ$))' TO TAB ZZ$ AND BRING DECIMAL POINTS INTO VERTICAL LINE.

50 REM 'CASH FORMAT SUBROUTINE' MODIFIED L.NELSONHJONES FEB 1982 TO ALLOW FOR -VE NUMBERS (CREDITS)

50000 ZZ = 1: IF Z ( 8 THEN ZZ -= 1

5 10 Z = ABS (Z):Z = INT (2 * 100 + 1.5) /100

50020 2X$ = ".00": IF Z = INT (Z) THEN ZY$ = STR$ (Z)

50030 IF Z ( ) INT (Z) Trei GOTO 50060

50040 ZZ$ = ZY$ + 1)($: IF ZZ = 1 THEN ZZ$ = + ZZ$

50150 RETURN

50060 Z$ = STR$ (Z - INT (Z) + 0.00001):YY$ = LEFT$ (Z$,3):Z$ = SIRS ( VAL (YY$)):ZY$ =

STR$ ( INT (Z)): IF LEN (Z$) = 2 THEN

ZZ$ = ZY$ + YY$: GOTO 50100

50070 IF Z ( 1 AND Z ) 0 THEN YY$ "0":

50280 ZZ$ = SIRS (Z): GOTO 50100

50090 ZY$ = STR$ (2):22$ = YY$ + ZY$

501Y, IF ZZ = 1 THEN ZZ$ "-' + ZZ$

50110 RETURN

'4

GOTO 50090

between lines on the printer to give hardcopy which is in better proportion to thescreen display.

Lines 1010, 1020 and 1030 loop tofollow a correct sequence round the textpage, location by location. The excep-tions are the locations in the last column.Line 1040 determines the screen code ofthe character at the location.

At line 1050, if the screen code is zerothen a normal @ symbol is printed on theprinter. In line 1060, if the screen codedoes not equal zero, then the appropriatecharacter is selected from L$ and printedon the printer.

Lines 1070 to 1100 are similar to lines1040 to 1060 but this time no semicolonis included in the Print statements inorder to end a line. Line 1115 is optional;it should be included if line 1005 wasincluded to restore line spacing to nor-mal.

Lines 1120 and 1130 restore output tothe screen and switch off the printer. R$is not necessary this time - unlike line1000 where the printer is switched on.

The third part demonstrates how theroutine may be used from a program.Lines 2000 to 2020 creates a demonstra-tion display. Line 2030 protects thescreen display, except for the bottom line.In line 2040, the bottom line of thedisplay is used for prompting. Keying Pdumps the display on the printer but doesnothing else to the display.

Cash displayL NELSON -JONES from Bournemouth,found that Gerard Noel's subroutine forformatting cash figures, Apple Pie, Sep-tember 1981, became rather tangled ifnegative numbers such as refunds orcredits were introduced. This revisionmakes this very useful subroutine work inall cases.

158 PRACTICAL COMPUTING May 1982

THE MORE YOU TAKETHE MORE YOU GAIN FROM COMPUTING

MILESTONE: £190Manual alone: £20. -"Critical path" network analysis program for schedulingmanpower, dollars and time to maximise productivity.NEW IMPROVED. Interactive project management pro-gram that runs under CP/M. MILESTONE can be used totrack paper flow, build a computer, check a department'sperformance, or build a bridge. MILESTONE can be usedby executives, engineers, managers, and smallbusinessmen.

-- Produce PERT chart in minutes.- Find critical tasks that can't be delayed.- Investigate tradeoffs between manpower, dollars

and time.- Give plans to others using a printed project

schedule.- Change details and immediately see the results

on screen.- Balance time, manpower and costs.

Requires 56K RAM and CP/M. Specify Z80 or 8080. Alsoavailable for Apple Pascal, UCSD Pascal or CP/M-86operating systems. (Milestone -86 version 290 1) For-mats: 8, NS, MP, SB, TRS2, OB-1, XX, IPC, IDW:ACCESS/80A report generator and cross -tabulator. Virtually anyreport that can be described on paper can be generatedby using your existing ASCII data files. Produces reportsin minutes that would take hours to program in BASIC.- Level I - Report Generator and Cross -Tabulator -£210.- Manual alone £40Read ASCII files and create sorted reports with subtotal-ling capability. Provides multi/dimensional cross tabula-tion and computation. Includes operating syStemcommands.- Level II - Output and Logic Processor - E354. -Manual alone £45Everything in Level I plus, write out new files in any sortedorder (including subtotalling). Load arrays from files. Per-forms binary search on sorted arrays in memory. Includescontrol language extensions for complex applications.'Requires CP /M and 48K RAM. Formats: 8, NS, MP,CDOS, SB, TRS2, APPL.

DATEBOOK II: £190Manual alone £18.-

- Schedules appointments for up to 27 differentdoctors, lawyers, rooms, etc.

- File structure allovis for appointments up to oneyear in advance.Searches for openings that fit time of day, day ofweek and/or day of year constraints.

- Appointments made, modified or cancelledeasily.

- Copies of day's appointments can be printedquickly.

Requires 56K RAM and CP/M. Specify Z80 or 8080. Alsoavailable for Apple Pascal, UCSD Pascal or CP/M-86operating systems.Formats: 8, NS, MP, SB, APPL, TRS2, OB-1, XX, 1-5,IPC, IDW.

QUEST II: L685Manual alone £350QUEST I! is i'database management system for cus-tomer lists, inventory lists, employee lists or any kind ofinternal reporting. It may perform several operations onmany datafiles simultaneously.

- Up to 55 datatields within a record.- - inserting new datatields in an existing file.- Definition of datastructures in the way of Pascal.- 9 datafield types including: Date, Longmath

(double precision integer and reels), Table (oneor two dimensional)

- Definition of screen and printing masks.- Access on any desired keyfield using up to 15

criteri as.- Sorting in ascending or descending order on up

to 15 keyfields.- Default or user defined printing mask.

Aserenverartxltungsund Betriebsberaostngs GmbH

- Advanced report generator: writing on screen,printer or disk of all or a subject of records, of auser defined subset of datafields.

-. Error messages for fast eliminating of badentries.

- Two special utilities for error check.Menu selection with one -key -commands. Full data inde-pendence from QUEST -using programs. Full data shareability for minimum accesstime. Highest access flexibility.Possibility to use QUEST together with your LOGICALCor other programs by loading the also available interfaceprogram LOGIQUEST (for complex financial modellingapplications like statistics or "what -if?" questions).Format: APPL

PLAN 80: £190 - Manual alone £20A financial modelling system that's easy to use andpowerful enough to replace your timesharing applica-tions. Lets you calculate IRR and depreciation as well astrig functions effortlessly. You write a PLAN 80 model justthe way you would write a letter using any editor or wordprocessing program.Plan 80 results can be incorporated into any report thatrequires a financial model. It also tackles any numericproblem that can be defined on a worksheet. You'llremember how you created the model because calcula-tions are defined using real English - not matrix coordi-nates. What if function.Requires 56k RAM and CP/M. Also available forCP/M-86. Specify Z 80, 8080, or 8086. Formats: 8, NS,MP, SB, OB-1, XX, 1-5.

PERSONAL DATEBOOK -110. Manual alone20Time management and appointment scheduling calendarfor an -individual or small office with up to nine staffmembers. Displays one appointment schedule on screenat a time. Cancellations can be put into hold file for easyrescheduling at your convenience. Menu driven com-mands do not require referral to manual.Requires CP/M 2.x and 56k RAM. Specify Z80 or 8080.Also available for Apple Pascal, UCSD Pascal or CP/M-86 operating systems. Formats: 8, NS, MP, SB, APPL,TRS2, XX, PC, IDW.

WHATSIT?A' data base/querry/retrieval system that communicatescontroversationally, accepting questions and updates insimple sentences. Store, index and retrieve informationabout one or more aspects of related or unrelated sub-jects. Information is stored under your designated "sub-ject" and "tag" headings, which can be added to, changedor deleted at any time. 116 page manual assumes noprogramming knowledge. RequiresCBASIC2AND 24k RAM. Formats: 8, NS, MP, SB, APPL, OB-1,XX.

THE FIELD COMPANION £210. -Manual alone £20. -Created for the needs of the travelling Salesman orProfessional. Allows you to track the time spent with yourclients, each client having up to four user -defined sub -fields. Expense accounting is provided and is itemised ina detailed journal for budgeting and tax reporting pur-poses. Maintains appointments and current customer listincluding shipping and billing addresses, year-to-datesales and person to contact for follow-up. Invoicing fea-tures retrieves required data from both customer andproduct lists. Special instructions and discounts are sup-ported. Invoice copies may be output to a printer or sent tothe home office via modem, permitting electronic transferof the content of any report. Requires 56k RAM and CP/Mor CP/M-86 and 128k RAM. Formats: 8, NS, MP, APPL,SB, XX, IPC, IDW.

FOOTNOTE £125. -Automatically numbers and formats footnote calls, foot-notes and text, placing footnotes on the bottom of thecorrect page. At the user's option, the footnotes can alsobe removed from the text file to a separate note file.Footnotes can be entered singly or in groups, in themiddle or at the end of paragraphs. After running FOOT-NOTE the user can re-edit the text, add or delete notes,and run FOOTNOTE again to re -number and re -format.Price includes PAIR, a companion program that checksthat underline and BOLDFACE commands are properlyterminated. Requires CP/M, WordStar, 48k RAM. For-mats: 8, NS, MP, SB, APPL, OB-1, XX.

SPELLBINDER: £260 Manual alone £35.Full feature word processing system with OfficeManagement capabilities. Its special features includeease -of -use by office personnel, flexible print formatting &output, and powerful macro capability which allows fea-tures to be added for the unique requirements of eachuser. Mail list macro is included for mail merge with formletters.Requires CP/M & 32K RAM. Formats: 8, NS, MP, CDOS,SB, APPL, XX.

PASCAL/M: £280.- Manual alone £15.-CP/M compatible language for 8080/280 CPUs, sup-ports full Jensen & Wirth plus 45 extensions to StandardPascal including Random access files 40 segment pro-cedures & 16 bit BCD real type. Also includes symbolicdebugger which features trapping on stores, examiningand changing variables and tracing of program execution.Requires CP/M 2.2 & 56K RAM. Formats: 8, NS, APPL,TRS2.

PASCAL/M for 8086/88: £350. -Manual alone £15. -All the features of PASCAL/M for the 8086 and 8088processors running under CP/M-86.Requires CP/M-86 and K RAM. Formats: 8, 1-5.

PASCAL: Sort - £140. -Manual alone £14. -Fully commented source code into which the user simplyplaces the particular file description and sequencerequirements to obtain the desired sort. Can run stand-alone or as a overlayed segment of larger program. Usesindirect Shell -Metzner in RAM, interleaved polyphase(Fibonacci) merge on disk, full sector buffering and shor-test seek logic. Can match machine language sorts evenunder Pcode interpretation. Requires CP/M 2.x and 56kRAM and CP/M-86 and 128k RAM. Pascal?M,UCSDPascal or Pascal /MT. Formats: 8, NS, APPL, XX, MP,TRS2, IPC IDW.

SUPERCALC: £190Allows a layman to manipulate business data in a varietyof forecasting and accounting applications. Combines theinteractive nature of ad electronic spreadsheet with thepower and convenience of a simple simulation language.Video display can be scrolled over entire worksheet usingcursor controls. Symbolic vector reverrences eliminate'repetitive low level data manipulation commands. Easy touse menu driven "Help" commands. Requires CP/M and48K RAM. Formats: 8, NS, MP, SB, APPL, TRS2.Call for terminal formats.

SUPERDOS: £100. -Upgrade of CP/M2.2 for Superbrain. Includes ADM/31Hazeltine, or Superbrain Terminal emulation mode. Othernew features include 132 character keyboard buffer,repeat on all keys, key click, user programmable numerickeypad, 30% disk read/write improvement, real timeclock, baud rates to 19,2K on RS232 ports, printer hand-_,shake modes, 4 new utilities, and 4 fixes RequiresSuperbrain 3.0. Format SB.

COPYRIGHT:Access/80 Friends Software; Pearl Relational Systems; Pascal/M, ACT, Trans 86, Supercalc Sorcim, CBASIC 2,CBASIC/86 Compiler Systems; Datebook II, Milestone, Textwriter III Organic Software; Spellguard ISA; CP/M, CP/M-86 Digital Research; Superbrain Inteftec Data Systems; S -Basic Topaz Programming; Spellbinder Lexisoft; Selector IV;Selector/86, Glector Micro Ap.Prices quoted do not include dealer installation and training. Prices and availability subject to change without notice.

AustriaZollergasse 15A-1070 ViennaTel 01043-222-934331

ORDERS must specify disk type and format. Add 15% VAT to orders. Add£1 per item for postage and packing. All orders must be prepaid by cheque ormoney order to HITEC company, Acct. Nr. 12172508 at Barclays Bank Interna-tional, 16(18 Brompton Road, London SW1X 7QN. COD will also be accepted.Manual costs are deductible from subsequent software purchase. Prices do notinclude installation and training. Dealers enquiries welcome.

PRACTICAL COMPUTING May 1982

Circle No. 201159

For Price Performance the Best Microcomputer AvailableMulti -purpose low-cost micro -computing for the professional - the British Genius - the sophisticated business system for those

who require the full range of advanced computing facilities without the associated expense.

Z80 Microprocessor and CP/M * 64K Ram Detachable QWERTY keyboard, numeric and cursor

control pads 61 programmable function keys RS232 Serial and Centronics Interfaces Reverse Video and Graphics GPIB Option

24 x 80 Green Display Twin 5" Floppy Drives - capacity 320K or 700K Twin 8" Floppy Drives giving 1.2M or 2.4 M Single 8" Floppy and one integral Winchester hard disk

- 4.8M Single 8" Floppy and one integral Winchester hard disk

- 9.0M* CP/M is a trademark of Digital Equipment Corporation

The British Genius caters for a wide variety of applications including Order Processing, Invoicing, Stock Control, LedgerAccounting. Micro Solution offer a comprehensive range of well tried ready to run Software packages. Using the 61 function keysand the proven WORDSTAR software the British Genius is second to none as a word -processor. Furthermore the British Genius

will talk (asychronously) to almost any other computer and transfer files to and from that computer using well known andrecognised TTY software.

Maintenance & SupportMicro Solution offer an unparalleled support service. Our own team of maintenance engineers are available on 24 hour

response and telephone or on -site assistance is available for software queries.

To discover more about the fantastic British Genius contactBill Whaley or Bede Dunlop.

1(00

The Micro Solution LimitedPark Farm HouseHeythropChipping NortonOxfordshire OX7 5TVVTel: Chipping Norton (0608) 3256

Circle No. 202

Micromouse

HEAVY METALBill Bennett rounds upthe latest news of thefront -runningcompetitors in thisyear's race of therattling rodents.THE BRITISH HEAT of the Micromousecompetition is being held at the Compu-ter Fair, in Earls Court on April 23-25.The competition is all the hotter this yearas successful entrants will be contestingfor the chance to go to the Israeli port ofHaifa for the finals of Euromouse '82. Aplace in the sun is not the only incentive,nor is the usual glittering array of prizes:the real prize is the satisfaction of know-ing that your mouse is at the forefront ofits species, a cybernetic rodent.

More competitorsThis year the competition will featurean extra competition for school entries,with a separate prize. Micromouse organ-iser John Billingsley of PortsmouthPolytechnic will once again be in com-mand and he expects a larger number ofentrants than the 20 who showed atWembley last year. Provision has beenmade for last-minute entries, though theymay have to pay for their procrastinationby a penalty.

Current Micromouse champion,Thumper, and his human "minder" DaveWoodfield are currently favourites totake the laurel crown once more. How-ever they could be in for some stiff com-petition. Dave Woodfield's mouse fairlyflew around the maze last time out andmanaged a best time of only 45 seconds.The next best was a leisurely 1 minute

Champion 1981: Dave Woodfield withThumper

MICKEYS

15 seconds. In his haste Thumper cer-tainly lived up to his name, banging hishead against the wall faster than you cansay "heavy metal". This caused someconsternation among rival competitors,but the sheer margin of his victory left theresult beyond dispute.

Secrets revealedThe main challenger to Thumper isNick Smith with good old Sterling Mouse.Nick is the man who once ruled supremein Micromouse circles until he toldeveryone all his secrets in Practical Com-puting. Rumour has it that Sterling is nowrunning on 24V. The new high-poweredSterling will be whizzing about in a cloudof sparks, providing the audience withsomeone to cheer on.

The other two fancied runners areQuaestor, now in training at the AndrewBuckly stables, and the notoriousThezeus team. Thezeus was the firstmouse to appear based on the ZX-80microcomputer. With the touch -sensitivekeyboard sawn off, Thezeus is a strikingmouse; together with the Son of Thezeusit featured for a while in these pages.Alan Dibley, owner of the Thezeus Mic-romouse empire, has come up with athird model known by some asYetanotherzeus or T3.

Also expected to be turning up areGloria, Marvin, Dreamy Mouse,Ramouse 2, and Major Tom thequaintly -named cybernetic pet of AdrianDickens, representing Cambridge.

Smuggling their mice through customsto avoid quarantine regulations will be anumber of Continental contestants. PeterWatson, one of our men in Brussels andKlaus Gerber of Munich represent theEuropean nature of the competition.

Micromice will be on show throughoutthe three days of the Computer Fair, thefirst two days being taken up with variouseliminations. On Saturday afternoon it islikely that a separate final for the schoolentries will be staged and the grand finalwill take place on the Sunday in front ofthe distinguished judges.

Contender 1982: Nick Smith with SterlingMouse.

PRACTICAL COMPUTING May 1982 161

for onlyBE A SHARP BUSINESSMAN £278 +VAT

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ENGINEERING APPLICATIONSTechnical calculations in fields suchas mathematics, statistics, measurementsand mechanics are done superbly andeasily. The calculator more than meetsthe requirements of engineers andscientists.

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MANAGEMENT APPLICATIONSBalance sheets, so crucial to management analysis, and profitcalculations by break-even point analysis are instantly yours withthe PC -1500. By using the integral clock, calendar and alarmfunctions, this computer can also be used as a schedule reminder.

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SHARP PC -1500'Basic' PocketComputer£147.78 + VAT;Total £169.95

BASIC LANGUAGEThe most simple computer language is used for programming ease.Additional BASIC terms provide variables including two-dimensionalarrays, variable strings and many other advanced features.LARGE MEMORY16K bytes of ROM and 3.5K bytes of RAM, with 2.6K bytes in theuser area. Adding the optional CE -151, 4K byte memory module,expands the RAM to 7.5K bytes. An 8K byte memory module willbe available soon. The PC -1500 is battery powered and program anddata memories are fully protected, even when switched off.MINI -GRAPHIC DISPLAYThe 7 x 156 dot matrix allows almost any display, including gamesymbols. Line width is 26 characters and/or numbers.HIGH SPEED DATA PROCESSINGThe C-MOS 8 -bit CPU enables swift data processing. Complicatedtechnical or business calculations require far less time.QWERTY TYPEWRITER KEYBOARDThe first in a pocket computer. Lower case letters are available. Withthe optional CE -150 colour graphic printer, the PC -1500 can serve asa small personal typewriter. Word Processor software will be availablesoon.SIX SOFTWARE KEYSThese can`cerve as reservable keys, or as definable keys to defineprograms.CE -150 4 -COLOUR GRAPHIC PRINTER/CASSETTE INTERFACEAutomatic program, data and calculation printing. It printsvirtually any drawing in either red, black, green, or blue. Charactersare printed in nine different sizes and in lines ranging from 4 to 36digits in length. You can control the printer completely and directthe printing either up, down, left, or right. As a cassette interface itwill connect up to two cassette recorders, one for data and programstorage, the other for their recall. The CE -150 has a built-in recharge-able battery and is supplied with a mains adaptor, type EA -150.AVAILABLE SOON RS -232C interface. Software board to serve as input keys ingraphics, or pictures, previously drawn on a template. ROM (MASKROM) module also applicable. A wide range of business software.DIMENSIONSPC -1500: 195VVx25.5Hx86Dmm 17-11/16x1x3-3/8") Wt 375g 10.831b)CE -150: 330VVx50Hx115Dmm (13x2x4 inches). Wt 900g (1.98ibs).Full 12 MONTHS guarantee, with EQUIPMENT LOAN SERVICEduring downtime.°SAME DAY DESPATCH of orders - Systems by SECURICOR 24hour service, Ito attended premises only) or by first class registeredpost. AT NO EXTRA COST'SEND FOR FULL DETAILS to TEMPUS, the Hand -Held ComputerSpecialists.

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162

Circle No. 203PRACTICAL COMPUTING May

Book reviews

Computers inFarming, Milestoneor Millstone?By T Rehman and R J Esslem-ont. Published by the FarmManagement Unit, Universityof Reading, Earley Gate,Whiteknights Park, Reading,Berkshire. 70 pages, f2.50.

THIS BOOKLET is a seriousattempt to give farmers someidea of what computing mightdo for their business, and whatthe costs and difficulties arelikely to be. The authors coverthe ground quite thoroughlyand sensibly. The pros andcons are debated of bureauxservices versus a personalmicro - and if the latter ischosen, of home -written soft-ware over packaged products.

The field' is confused, withno simple answers either inhardware or software, andinevitably the material reflectsthese difficulties. The authorsdo the best they can, but onewonders how accessible even aslim work like this will be tobusy, pragmatic farmers. Still,it is hard to think of betteradvice that could be given onpaper to someone who prob-ably has never seen a compu-ter. If farmers still find thingsdifficult, they are no worse offthan the rest of us.

Peter Laurie

Simple PascalBy James J McGregor andAlan H Watt. Published byPitman 182 pages.

ALTHOUGH PASCAL is an easylanguage to teach to novices itcan present problems to pro-grammers converting fromBasic or Cobol, for example.Having to unlearn old habitsseems to be more difficult thanstarting from scratch. Thisbook offers an approach toPascal which could be usefulsince it concentrates exclu-sively on the most elementaryparts of the language.

The book starts from anexample program, and thenthroughout continues to useexamples more liberally thanany other Pascal text I haveencountered. This alone wouldmake it a useful adjunct to themore standard texts which aretoo often deficient in thisrespect. Among a number ofparticularly welcome featuresis the use of an If statement to

guard against the selector in aCase statement not referringto one of the labels. The moregeneral problem of data vali-dation is mentioned. Later inthe text stepwise refinement isbriefly presented.

The reservations I haveabout this book centre on thefact that it misses out all thedata -structuring featureswhich are most central to thelanguage. The novice learningfrom this book therefore failsto develop competence inthose aspects of the languagewhich give it its greatestadvantage over other lan-guages - Basic in particular.Comprehensiveness has beensacrificed for simplicity.

As a supplementary text thisbook will be useful to novices.'As a main text for learning thelanguage it is inappropriate tonovices, but could providesome support for Basic pro-grammers having difficultieswith Pascal syntax.

J Cookson

The Joy of Minis andMicrosBy P G Stein. Published byHayden. 200 pages. f8.55.ISBN 0 8104 515 65ADVICE to both those about toembark on computerisationfor the first time and the exist-ing user who has run into diffi-culties, is the aim of this book.Unfortunately if such a readerattempted to read it fromcover to cover he wouldbecome even more confused.

The Contents page suggeststhat the book is completelyconventional, listing as it doesa series of chapters on theoptions, how to make the rightchoice and how to use a smallcomputer. All very normaluntil you start to read, and itrapidly becomes apparent thatthis book is no more than asmall amount of new text tolink, very loosely, a collectionof old magazine articles. Theresult has only the barest sug-gestion of a structure and istherefore both confusing and avery uncomfortable read.

As the book is so unstruc-tured and general, it is almostimpossible to describe its con-tents briefly. However, it doesprovide sections on the dif-ferences between mini andmainframe computers andhow they might be utilised, andthere are articles on computer

languages and how to link toother devices. Games andapplications from microbio-logy to image enhancementare discussed, as are the work-ings of hardware and software.

Each chapter has an intro-duction followed by a streamof unrelated articles separatedonly by their titles, but only afew of them have any indica-tion of when they were firstpublished. There is nothing torecommend the verse whichoccasionally attempts tolighten the going, althoughthere is some wit in the rest ofthe writing.

It is a shame that more effortwas not put into this book asmuch of the advice is veryvaluable. Most of the articlesrefer to minicomputers, andwhere microcomputers arementioned they are regardedas being rather limited inscope. It then becomes clearthat the articles are severalyears old - they are allapparently from before early1978, which is a very long timeago in terms of the develop-ment of the small computer.

Conclusions This book contains soundadvice which is masked by thelack of structure and the datedfacts. While aimed at theunsophisticated reader it is sosuperficial in many areas that itwill not untangle confusion butadd to it. It cannot be recommendedas it is now nearly four yearsout of date, despite its 1981copyright date.

Martin Wilson

A Primer on PascalSecond edition, by RichardConway, David Gries and ECarl Zimmerman. Publishedby Winthrop. 430 pages.£9.70.

PASCAL HAS usually been usedas a second, more developed,

language for professionalsand, more recently and infewer numbers, private users.It is a compact language,modular in concept andmachine -efficient.

So why do non-professionalusers tend to flinch at the men-tion of its name and profession-als think of reasons to usesomething else? Its inherentcomplexity tends to be unfor-giving, which means that

greater effort is required toanalyse what is to be donebefore beginning to program.With the inclusion of a Pascaloption on most popularmachines, including Apple, away of acquiring Pascal com-petence has to be found.

Conway, Gries* and Zim-merman set themselves twotasks: to explain the elementsof programming in general andto teach Pascal as a first langu-age. The book is intended to beused by people without muchknowledge of systems analysisand problem definition. Hencethe authors assume that theirreaders need to be led gentlyover this ground without beingfrightened.

The primer does not claim tocover all the nuances and allthe possibilities of the langu-age. An introductory chapterconcentrates on problem an-alysis, but the complete begin-ner in such matters may needfurther help before becomingan instant systems analyst.

Chapter 4 is devoted toproblem -solving and designconsiderations relating to prog-rams. Few of us, on buying amachine possessing an instruc-tion manual, acutually read thething until we get stuck, so itmay well be that this order ismore useful than the conven-tional one of dealing tho-roughly with each subject inturn.

The book is remarkably easyto read. It begins with a seriesof small programs aimed atthose who always intend toread the instructions beforeopening the carton. It showswhat the result of using Pascallooks like, and leads progres-sively and persuasively intoPascal rules, the conventionsof which are well presented.

Conclusions The systematic use of Pascalroutines provides a clear, step-wise introduction to the sub-ject. This book, in conjunctionwith a computer's ownmanual, should enable deter-mined students to find theirway round the language. Theprogram -validation and fault-finding sections are to the pointand realistic. The presentation of thebook, via word processor, issimple, neat and agreeable tohandle and to use.

David Wilshere

PRACTICAL COMPUTING May 1982 163

Puzzle

'ON THE one -arm bandit at the KnottyAsh Cybernauts Social Club thereare three reels. Until last week it wasreturning a handsome profit, as wellas keeping the inmates happy withtheir winnings - especially as thebells give a prize of 4 yen even if theyare only adjacent to the win line.However, last week the Knotty Ash

by Tony Roberts

Thingwall imposed a 14 percent levyon all stakes, which was more thanthe average profit on the machine.

The problem was solved by one ofthe barmaids who noticed that bychanging just one symbol themachine began to make a profitagain, though only one-third of theold profit. Curiously, the new aver-age profit is exactly the same as theaverage loss it had begun to incur.

What was the change?

Solution to March puzzleAT THE ALTERNATIVE Technology (Com-puting) Fair the Audromeda was solarpowered and the Epsilon produced itsoutput through a VDU.

Beating thebetting levy

0

27 ways to win

Winnings:3 plums = 103 lemons = 53 cherries = 32 cherries = 21 cherry = 1A Bell anywhere oneach reel = 4

The three reels are:

WINLINE

WIN

Pressto spinreels

LINE

1

r 2 1

cherrycherry

2

plumcherry

3

bellcherryg g 3 plum

bellplumcherry

plumcherry

C5'

L.7-.) 5

X10lemonbelllemoncherry

lemonbelllemonplum

plumcherrylemoncherry

4 Yen cherrycherry

lemonbell

lemoncherry

DISKDRIVEDEALSFrom KRAM electronics, Victoria House,17 Highcross Street, Leicester LEI 4PFTelephone (0533) 27556

T,RELECTRONICSORDERINGYou may post your order with acheque payable to KRAMelectronics, or you may telephoneyour order day or night, any day,giving your ACCESS card number,a full description of the item andyour name and address.VATAll the above prices exclude VAT.Please add VAT at the current rate.CARRIAGEOrder over £100 ADD £6.Orders over £10 ADD £3.Orders under £10 ADD .50pPost to: KRAM Electronics, FREEPOST,Leicester or Tel: (0533) 27556

164

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Circle No. 204

PRACTICAL COMPUTING May 1982

SUPERBRAINISPECIALOFFERS:

£1,695 DUAL DENSITYMODEL(Lease for £10per week)

£2,095 QUAD DENSITYMODEL(Lease for£12per weeek)

PACKAGEDEALS:

WORD PROCESSING(§y§pifylveel : £2,795Duel Density SUPERBRAIN together with the Olympia ESW100 RO Daisywheel printer and a Serial to Parallel converterplus all plugs and cabling and the WORDSTAR WordProcessing Package with special function keys.

WORD PROCESSINGSYSTEM 2: £2,995(Lease for approx. £18 per week)

Dual density SUPERBRAIN together with the dual purposeOlivetti 121 Daisywheel printer/typewriter (can be used as aseparate electronic typewriter) and the WORDSTAR WordProcessing Package with special function keys.

Package Software supplied. Tailored software developed.

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Prices exclude VAT and are subject to fluctuation.

PRACTICAL COMPUTING May 1982

Circie No. 205165

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166 Circle No. 206

PRACTICAL COMPUTING May 1982

Machine code

Norman Kirkby starts at rock bottom with an explanation of howthe central processor in your micro builds simple numerical codesinto complex arithmetic operations. Using the built-in assemblerprogram of the Acorn Atom, he takes you step by step throughthe principles of assembler mnemonics, which put the power andspeed of machine -code programs at your fingertips.

More basicthan BasicHEXADECIMAL NUMBERING is merely amethod of expressing a number in a dif-ferent form from the familiar decimalmethod. The value of the number is notchanged. Hexadecimal, commonlyabbreviated as "hex", uses the symbols 0,1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, Fand is based on multiples and powers of16 rather than the 10 of the decimalsystem.

Hex OF is equivalent to decimal 15;hex 10 is equivalent to decimal 16; andhex FF to decimal 255, etc. Hex is usedbecause it is often more convenient thandecimal when expressing machine codeand, in the Acorn Atom, when referringto memory addresses. Because a set ofnumerals could be taken for either hex ordecimal numbers, a symbol is used toidentify numbers in hex. On manymachines it is a "$", but on the Atom it isa "*", and that will be used here.

Experts will quarrel over precise defin-itions of a machine -code program but theone suited to this article runs as follows:"A machine -code program is a list ofnumbers, called codes, some of theminstructions, some items of data, andsome memory addresses".

The micro takes each code in turn andobeys it if it is an instruction, processes itif it is data, or visits it if it is a memoryaddress. Note that the program is simplya list of numbers, as in programs 1 and 2.

The full name for each number is"operation code", often shortened to "opcode". Each number is stored in a mem-ory location with the next number in theimmediately following location. Ineight -bit computers each code must besmaller than 255 (*FF) since that is the

Program 1 Program 2

*A9 *A9*07 *07*18 *18*65 *6D*90 *00*85 *82*91 *8D*60 *01

*82*60

Machine -code programs 1 and 2

argest number which can be stored aseight bits. Nevertheless, 255 is ample toprovide a powerful instruction set.

There are differences between differ-ent microprocessors. What is describedhere refers to the 6502 microprocessorwhich is used in the Atom, Pet, UK 101,Apple and the basic BBC Micro amongothers, but not the ZX-80 or ZX-81, northe TRS-80 series.

The main work is done in theaccumulator which is an eight -bit regis-ter. A register is like a memory location- it has eight -bits - which it is located inthe microprocessor chip. Unlike otherregisters, the accumulator has a carry bitand various other friends in a status regis-ter. There is also an X register and a Yregister.

The Accumulator, and the X and Yregisters, can be loaded with an eight -bitnumber. With a little help from its friendsthe accumulator can transfer a number toor from a memory location or to or fromthe X or Y registers; it can add a numberin a specified memory location to its own

(continued on next page)

Table 1. Operation code and mnemonics for single -byte addresses.

MeaningLoad the accumulator with the next codeLoad the accumulator with the contents of the

location whose address is the next codeAdd to the contents of the accumulator the

contents of the memory location whose addressis the next code

Store the contents of the accumulator in thememory location whose address is the next code

Clear the carryReturn

Machinecode (hex)

A9

Mnemonic(Atom)

LDA @

A5 LDA

65 ADC

85 STA18 CLC60 RTS

Mnemonic(others)LDA#

LDA

ADC

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(continued from previous page)contents; it can compare its own contentswith those of a specified, memory loca-tion; and it can do other clever things too.Some of the simpler instructions areshown in table 1.

These instructions can be used to forma simple machine -code program, forexample to add 7 to a number that isstored in memory location *90, and thenstore the result in location *91. Non -Atom users can choose their own loca-tions but the addresses should be lessthan *FF for the moment. The followingare the steps to be carried out: Load the Accumulator with the number 7, Clear the carry. Add the contents of memory location *90

to the accumulator's contents. Store the result in location *91.

It is sufficient for our purposes to statethat you have to clear the carry beforeadding.

Program 1 is the machine -code pro-gram, built up by referring to table 1.Having decided on the program, it mustbe entered into memory so that the com-puter can get to work on it. This can bedone by entering the following program- program 3 - in the normal way:

10 REM ENTCODE ATOM20 PRINT "ENTER EACH CODE AFTER

EACH"30 PRINT "QUERY. IF CODE IN HEX

ENTER * FIRST"40 1=050 DO60 INPUT C70 I?*80=C30 1=1+190 UNTIL C=999

100 ENDIf you have another 6502 machine you

could try program 4, replacing S by amemory location at the beginning of 11locations which will not corrupt the textof the listing or the operating system.

Run the program, and answer eachprompt by entering the codes in program1 in order. That is, type *A9, or usewhatever is the symbol for hex on yourmachine, or enter the decimal equivalentfor *A9. Then press Return, type *7,press Return, and so on. When you reachthe end at *60 followed by Return, type999 and the program will end. If youdiscover a mistake after pressing Return,type 999 and the program will abort andyou can start again from the beginning.Note that 999 is not a machine code,merely a signal for the Basic program toend.

The machine -code program is now inmemory, in order, starting at memorylocation * 80 because line 70 of program3 said so. The contents of memory loca-tion *90 must be set to a number to beadded to 7. So choose 10, and set thecontents of location *91 to a knownvalue; say 0. On an Atom, execute:

?*90=10; ?*91=0Other users will use Poke, and their

own locations, and will replace the ";" bya ":.

10 REM ENTCODE OTHER20 PRINT "ENTER EACH CODE AFTER

EACH QUERY. IF CODE IN HEX.ENTER $ FIRST'

30 FOR 1=0 TO 1040 INPUT C50 IF C=999 THEN 1=10 GOT07060 POKE (S+I), C70 NEXT I

100 END

Program 4.Now you must execute the machine -

code program. The command for this onthe Atom is Link followed by the address-* 80 in this case - of the memorylocation holding the first code. On othermachines use the appropriate code, e.g.,the appropriate address for S. So execute:

LINK *80which tells the computer: "stop thinkingin Basic; start thinking in machine code;note the number after the Link commandand treat it as an address; fetch the codeat that location; treat it as an instructionand obey it; fetch the code in the nextlocation; obey it if it is to be treated as aninstruction, or process it if it is to betreated as data, or visit its location if it isto be treated as a memory address; and soon until you come to a memory locationcontaining a code equal to *60 andwhich is to be treated as an instruction;return to your Basic program at the pointwhere you left it and carry on with thenext Basic instruction". At this pointnothing appears on the screen to indicatethat anything has happened, so look atmemory location *91 by executing:

PRINT ?*91i.e., Peek it, and you will find it nowcontains 17 - the answer to the sum7+10. The machine -code program hasworked.

A crucial question may have crossedyour mind. How does the micro knowwhether a code is to be treated as aninstruction, as data, or as a memoryaddress? The answer lies in the precedingcode. The micro follows the rule: "Unlessinstructed otherwise, treat each code asan instruction. If the preceding code indi-cates otherwise, treat the code you areconsidering as an item of data, or as amemory address, accordingly".

The first code is always treated as aninstruction because there is never anyprevious code to say otherwise. The firstcode in program 1, *A9, when treated asan instruction, means "load theaccumulator with the next code". Clearly,therefore, the next code, *7, is to betreated as an item of data, so *7 is loadedinto the Accumulator. When it considersThe next, third code, *18, it is treated asan instruction and means "clear thecarry".

The fourth code, *65, is also treated asan instruction and means "add to thecontents of the accumulator the contentsof the memory location whose address isthe next code". Consequently the nextcode is treated as an address, *90, andthe instruction *65 is obeyed accord -

168 PRACTICAL COMPUTING May 1982

ingly. The sixth code, *85, is treated asan instruction and means "store the con-tents of the accumulator in a memorylocation whose address is the next code".The seventh code, *91, is therefore tre-ated as a memory address and the con-tents of the accumulator are stored inlocation *91. The last code, *60, istreated as an instruction - since theprevious code did not say otherwise -and means "return to Basic".

Most people would agree that makingup and entering a machine -code programis deadly boring, and debugging it isalmost impossible.' When computers wereyoung, code was in binary and even moreindigestible so, not surprisingly, someonethought of making the computer do theroutine job of converting instructions intocode.

They wrote a program called assemblerto take instructions that were closer toEnglish and which would generate andassemble the machine code. Clearly, theassembler instructions must use short-hand because the instructions themselvesare too long, so human memory -joggerscalled mnemonics are used instead - seetable 1. Note that the difference betweenthe meanings of LDA@ and LDA lies inthe way they treat the next code. Thefollowing program - program 5 - givesthe assembler mnemonics for program 1.

10 REM LIST 1 IN ASSEMBLER20 ?*90 =10; ?*91=025 PRINT "?*91="?*91'30 DIM P(-1)40 [50 LDA @#760 CLC70 ADC *9080 STA *9190 RTS

100110 LINK TOP120 PRINT "LOCATION *91 IS NOW

"?*91'130 END

However, it is not enough simply toenter the mnemonics - remember, it isonly machine code that the microproces-sor understands. The mnemonics must beoperated on to generate the code andassemble it somewhere in memory. Inlisting 5, line 40 says "what you are aboutto receive is in assembler, not Basic"; line100 says "Amen" to assembler andreturns to Basic.

Line 30 looks odd: it does not Dim astring of -1 elements, but means "assem-ble the machine code resulting from thefollowing mnemonics starting at the first

Machine code

free memory location after the end of thisBasic program text". For a program likeprogram 5 - i.e., one without any Dimstatements other than the Dim P(-1) -that location is the third one after the lastvisible character, which is "D" in thiscase.

In the Atom, the address of that loca-tion is given a special name "Top" forconvenience. Top is treated as anaddress, so to execute your machine -codeprogram resulting from listing 5 you needline 110.

Line 20 Pokes the initial values foryour sum into your two memory loca-tions. Lines 25 and 120 demonstrate thatthe machine code has worked. Nowexecute New, and enter and run program5, and you should see the contents oflocation change from 0 to 17.

When you ran program 3 or 4 earlier,and entered the machine code directlyfrom the keyboard, it was executeddirectly from the keyboard by enteringLink followed by the address of the loca-tion holding the first code. You can dothe same with program 5, but first youshould set the contents of location *91back to zero by executing:

?*91=0Now execute:

LINK TOPPRINT ?*91

and you will see that the contents haveagain been changed to 17. When you ranprogram 3 or 4, the Link command wasfollowed by the address of the first codeexpressed in the form of a number. Youcan do the same with program 5 byexecuting:

PRINT & TOPand you will get the hex address of Top,i.e., the actual address of the locationholding the first code. It is in hex, notdecimal, because & instructs the Atom toprint in hex. It is a two -byte number towhom we have not yet been introduced,but forget that for the moment.

Repeat the above procedure of zeroinglocation *91, Linking - but this timeusing the hex number for Top - andprinting the new contents of location*91. Write down the address of Top.

You should by now appreciate that theassembler mnemonics are merely astepping -stone to higher things, namelythe generation and assembling ofmachine code. Once they have done that

(continued on next page)

Table 2. Operation code and mnemonics for two -byte addresses.

MachineMeaning code (hex)

Load the accumulator with the contents of thelocation whose address is the next two codes AD

Add to the contents of the accumulator thecontents of the memory location whose addressis the next two codes 6D

Store the contents of the accumulator in thememory location whose address is the next twocodes 8D

Mnemonic Mnemonic(Atom) (others)

LDA LDA

ADC ADC

STA STA

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PRACTICAL COMPUTING May 1982 169

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Machine code

(continued from previous page)they are redundant. Prove this to yourselfby running program 5, and Listing it.Then corrupt some of the mnemonics byreplacing them with garbage of yourchoice. To prevent the beginning of themachine code being overwritten by anylengthening of the text of program 5, youshould delete line 70 and not lengthenany of the other lines.

List it again to see what a fine mess itis, but do not run program 5 in this state.Now demonstrate the execution of themachine code by executing the threestatements:

?*91=0; LINK *XXXX; PRINT ?*91as before, where XXXX is the number ofTop you wrote down. It still works, with-out the mnemonics.

Up to now we have been consideringhex numbers no bigger than *FF ordecimal 255, and which need only onebyte to hold them. But of course hexnumbers can be as big as you like, andyou need hex numbers greater than *FFif they are to express memory addresses.A limit of *FF locations would not pro-vide much more memory than a cal-culator. Because any hex number greaterthan *FF needs more than one byte, andbecause two bytes can hold numbers upto *FFFF, or decimal 65,535, andbecause that is ample for the RAM andROM of a home computer, memoryaddresses are usually two bytes long.

Table 1 column 1 refers to ". . thecontents of the memory location whoseaddress is the next code", which suggeststhat assembler and code cannot cope withtwo -byte addresses. In fact they can cope,and if you look at table 2, column 1 youwill find all the instructions from table 1that refer to addresses, except that theyrefer to two -byte addresses, and thecodes are different. Study the followinglisting which produces exactly the sameresult as program 5, despite the fact thattwo -byte addresses and different codesare used. The assembly listing - theprintout you get when an assembler pro-gram is run - demonstrates the change ofcodes. Program 6 is:20 ?*8200=10; ?*8201=025 PRINT"?*8201="?*8201'70 ADC *820080 STA *8201

120 PRINT "LOCATION *8201IS NOW"?*8201'

Since the mnemonics are identical, howdoes the micro know how to choose dif-ferent codes for, say, STA followed by aone -byte address as in program 5, andSTA followed by a two -byte address as inprogram 6? The answer lies in the line inthe assembler part of the program text.The rule the machine follows is, in effect"when you come to a mnemonic thatinvolves an address, look at the programtext between the mnemonic and the nextstatement terminator - that is, the endof a line, or a semicolon in a multi -statement line in the Atom or a colon onother machines. If in that area you find a

0 82 20 45 4E 44 D FFA9 7 18 65 90 85 91 60

Figure 1. Machine -code display.

single -byte number, treat that as thewhole address and choose the corres-ponding code for the mnemonic, follow-ing it by that single -byte number as thenext code. But if there is a two -bytenumber in that area, treat it as a double -byte address and choose the correspond-ing code, followed by the two -bytenumber as the next two codes, low bytefirst".

Program 1 is the code produced byprogram 5, and program 2 is that pro-duced by program 6.

To examine the machine code after ithas been assembled, run program 5 andexecute:@ =4; FOR I =TOP- 8 TO TOP+7; PRINT

&?1; NEXTIt sets the number of spaces for each

printed number to 4 -@ has a differentmeaning in this context. The Print state-ment is a Peek, and it prints in hex thecontents of memory locations from 8before Top to 7 after Top. You shouldsee the display shown in figure 1.

The contents of Top -8 are at the top,left-hand corner, and the contents of Topare at the beginning of the second line. Ifthe third to the sixth numbers in the firstline, 20 to 44, are treated as ASCII codesthey spell:

space ENDwhich is the end of the text of program 5.The D and FF are hex numbers which theAtom always uses to signify the end ofthe text of a Basic program. The first two0 and 82, are the line number in hex -decimal 130. This demonstrates that themachine code is assembled starting at thefirst free byte after the program text, aswas mentioned earlier.

If the program contains Dim state-ments other than the Dim P(- 1) for theassembler, the space for the string and/orarray elements is reserved beginning atTop, with the first machine code beingassembled in the location immediatelyafter the last byte of the last string orarray element.

You need not assemble the machinecode after the program text if you do notwant to. To assemble it starting atanother address of your choice, replacelines of program 5 with:

30 P = *8300110 LINK *8300

or with:30 P = *2A00110 LINK *2A00

Run the program and check that itperforms as before. You could also carryout a memory dump using location*8300 or *2A00 to confirm that thecode has been assembled there. This pro-cedure is useful if you want to put themnemonics temporarily in another partof memory.

170 PRACTICAL COMPUTING May 1982

HUYERYGUIDESOFTWARESoftware packages are listed by application, in alphabeticalorder, with the systems on which each package will run alsolisted alphabetically. The guide is not exclusively for businessapplications: if your company is the source or dealer for apackage with a more unusual application, send us the detailsand we will create a new category.

The usual criteria have been applied. The minimum con-figuration is 32K of RAM, a disc and a printer; the price of thepackage must lie between £50 and £1,000; the companieslisted are the source of the software or the main dealers inthe U.K., and the capacity quoted is per disc or drive.

Machine type by applicationCombined Ledger/Stock/InvoicingMachine type Supplier name Price CapacityApple II Vlasak Electronics Ltd £855 1,500 a/c 5,000 transApple II Dataforce (U.K.) Ltd £855Apple II Microsense Computers Ltd £340Apple II Southern Computer Systems £1,000 variesApple II/ITT Informex London Ltd £298 500 a/cApple II Star Systems Ltd £750 2,000 a/c 6,000 transCommodore 3032 Compfer Ltd £400 variesCommodore 3032 Analog Electronics £550Commodore 3032 Logma Systems Design £600 1-6 shopsCommodore 3032 Grama (Winter) Ltd £475 variesCommodore 3032 Bristol Software Factory £300 1,000 a/c 6,000 transCommodore 3032 Compfer Ltd £600 500 a/c 1,000 itemsCommodore 3032 HB Computers £695 500 a/c 2,500 transCP/M D T Systems £750 variesCP/M Wisbech Computer Services £900 variesCP/M Graffcom Systems Ltd £400 varies ,

CP/M Benchmark CS Ltd £950 variesCP/M Computastore Ltd £1,000CP/M Interface Computer Services £350CP/M Minicomputer CS Ltd £1,250 variesCP/M Salmon Microcomputing £750 1,600 items 1,000 transCP/M Selven Ltd £1,500 3K a/c 7K transCP/M Map Computer Systems £1,000 variesCP/M North Star Instar Business Systems £999 600-2,900CP/M North Star Criterion Business SystemsNorth Star DOS Inteligent Artefacts £510 1,500 a/c 5K transOhio Scientific Microcomputer BM £656Ohio Scientific Stratheden LtdTandy Model 2 Chess Consultancies £1,200Tandy Model 2 Chess Consultancies £995 5,000 items 1,500 a/cTandy TRS-80 Microcomputer Applications £90Tecs Jar Software Systems £650 500 a/c 300 nom. a/c

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PET from 8K: VIC 20 from 3.5KBoth books cover WHOLE 6502Instruction set, AND CONTAIN

FULL 6502 ASSEMBLERPRICES: 2/3/4000 PET & VIC BOOK £10ALL PET & VIC: book -' ASSEMBLER -

ON TAPE £15: ON DISK £17.

VIC BOOKM/C LANG MONITOR

CONTAINS

SAE details from:

State Machine.

DR P HOLMES (P)21 Colin DriveLONDON NW9 6ES

Circle No. 313

PRACTICAL COMPUTING May 1982 171

Western Computers Limited

comartNorth Star Horizon

CromemcoPLEASE CONTACT US FOR DETAILS

Blackpool Airport,Blackpool, Lancs.Phone Blackpool 404676/42660

Circle No. 314

5 DAY MICROCOMPUTERPROGRAMMING COURSESSTART EVERY MONDAYINCLUSIVE COST £170Part-time courses

seven days a weekMICROTEACH160 Edmund Street,

BirminghamTel: 021-236 4322

AT LAsT1 Circle No. 315

CLUSIVEpRICES IN- v 2642ALL osi-2IELEPHu

VICSOFTWARE

VICMENA full -feature version of the popular "Puckman" arcade.game for the UNEXPANDED VIC. Written entirely inmachine -code for fast action.SUPPLIED ON CASSETTE at £7

VICGAMMONStandard Backgammon game for the VIC with 3Kexpansion. Rapid computer responses. Instructions onhow to play are included.SUPPLIED ON CASSETTE at £7

More VIC software will be available by the time you readthis. Phone 051-227 2642 for details. GenerousDEALER DISCOUNTS available - phone Dave on051-227 2299 for details.

BUO -98-100 THE ALBANY, OLD HALL STREET,

LIVERPOOL L3 9EP

Circle No. 316

Database ManagersMachine type Supplier nameApple II ACT Microsoft LtdApple II Courtman Micro SystemsApple II Keen ComputersApple II/ITT Systematics International LtdApple II/ITT Diskdean LtdApple II/ITT Systematics International LtdApple II/ITT Informex London LtdApple II/ITT The Software HouseCommodore 3000/8 Stage One ComputersCommodore 3000/8 Commodore BM (U.K.) Ltd

Commodore 3032Commodore 3032/8CornpucorpCP/MCP/MCP/MCP/MCP/MCP/MCP/MCP/MCP/M SWTPCMetrotech SystemOhio ChallengerOhio ScientificSuperbrainSWTPCTandy TRS-80Tandy TRS-80Z-80/8080Z-80/Cromemco

CPS (Data Systems) LtdCompsoft LtdVerwood SystemsCompsoft LtdGreat Northern CS Ltd

Price Capacity£75£1.06 100K characters£425 up to 70Mbytes£72£120 varies£125 1,000 references£198 500-1,200 records£140 900 records£45-£250 650-2,400 records£150-£300 650-1,400-64,000

records£200 varies£190 600-5,000 records£375£400 30,000 records£110-£210 and varies

Microtek Computer Services £250-£500Cleno Computing Services £90-£325Interface Ltd £200Median-Tec Ltd £500Microbits £145Southdata Ltd £650Verwood SystemsMetrotechU-Microcomputerq LtdMicrocomputer BMAlan Pearman LtdSWTPCCleartone ADPACT Microsoft LtdStructured Systems GroupXitan Systems Ltd

Engineering Design SystemsMachine type Supplier nameApple II Haden Young Ltd

Apple II

Apple IIApple II/ITTCommodore

Commodore 3032

Commodore 3032

CommodoreCommodoreCommodoreCommodoreCommodoreCP/MCP/MCP/MEquinox

30323032/83032/83032/83032/8

Hewlett-Packard

Tandy TRS-80Tecs

James C Steadman

James C SteadmanAerco-GemsoftIsmail CAD

Micro Computation

The Alphabet Co

Comac SystemsComac SystemsComac SystemsComac SystemsComac SystemsMedian-TecMedian-TecMedian-TecEquinox

CSC (Northern) Ltd

Chess ConsultanciesJar Software

Estate Agents' SystemsMachine type Supplier nameApple II AtlantaApple II MicrosenseApple II/ITT Cyderpress

variesvaries

variesup to 8Mbytes

£200-£1,000£175£175£295 varies£100£75 varies£75£135 varies£850 4,000 records/disc

Price NotesFrom £50 Provide a comprehen-

sive series of soft-ware for .building/engineering

£200 Erect concretecolumns

£250 Multibay frames£175 Pipeline engineeringvaries Provide a range of

software for build-ing/engineering.

£300 Building -conversionspecification

£75 Time study andanalysis

£400 Asset register£400 Maintenance plan£400 Work orders£400 Plant history£400 Manpower analysis£500 Plastic portal frames£500 Slope -stability analysis£500 Retaining wall design£500 Civil/structural

engineering designfrom £200 Engineering design

systems.£450 Production planning£600 Production analysis

Price Notes£750£500£650

172 PRACTICAL COMPUTING May 1982

Buyers' Guide

Apple II/ITT'Commodore 3032CompucorpCompucorpCP/M

SystematicStage One ComputersVerwood systemsVerwood systemsSelven Ltd

£850£250£700£1,200

Estate salesEstate managementEstate agents' sales

and selectionSharp MZ-80K Wisbech Computer Services £195

Financial SystemsMachine type Supplier name Price NotesApple II Microdigital £200 Sales analysisApple II Microdigital £130 Credit controlApple II Microsense £194 Cashier retail/

wholesaleApple II PK Microsystems Solicitors' accountsApple II Dataforce £80 Cashflow projectionApple II Informex £98 VAT systemApple II Southern Computer Systems £750 Financial controllerApple II/ITT Microsense £125 VisiCalcApple II/ITT Systematics £295 Financial planningApple II/ITT Systematics £1,000 Financial controllerApple II/ITT Microsense £75 Modelling

desktop planCommodore 3000 Stage One Computers £250 Financial acounts

packageCommodore 3000/8 ACT Microsoft £125 Financial modellingCommodore 3032 Stage One Computers £100 Quote processingCommodore 3032 CPS £575 Invoice -costing/

jewellersCommodore 3032 L & J Computers £90 Cash bookCommodore 3032 ACT (Petsoft) £150 Financial planningCommodore 3032 Stage One Computers £100 Bank a/c reconcileCommodore 3032 Logma Systems £600 Sales/analysisCP/M Bytesoft £95 Financial modellingCP/M Micromedia £1,000 Invoice disc factoringCP/M Graffcom System £ 400 Hire-purchase systemCP/M MAP Computers £550 Financing system

sCP/M Microtek £ 500 Accounting.CP/M Microtek £750 Budget controlCP/M Median-Tec £500 Financial analysis

Graffcom Systems £450 Purchasing systemCP/M Business Solutions £395 MarsCP/M Vector Taylor Microsystems £390 Cashflow forecastingDurango F-85 Kesho Systems £1 , 000 Time recording/

ledgerSuperbrain Alan Pearman Ltd £315 Financial planningTandy TRS-80 Chess Consultancies £800 Sales statisticsTandy TRS-80 A J Harding £125 Financial balancingZ-80/8080 Intereurope £500 Financial modellingZ-80/8080 Graham Dorian £325 Sales analysis retail

General LedgerMachine type Supplier name Price CapacityApple II Computech Systems £295 500 a/c 1,700 transApple II Dataforce (U.K.) Ltd £225 200 a/c 1,000 transApple Style Systems Ltd £250 1,000 a/c, 2,000

postingsApple II Southern Computer Systems £750 1,000 a/c 12 branchesApple II/ITT Systematics International LtdApple II/ITT Guestel Ltd £300 200 a/cCommodore 3032 Bristol Software Factory £300 1,000 a/c 6,000 transCommodore 3032 Analog Electronics £450Commodore 8000 Commodore BM (U.K.) Ltd £300 600 a/c 3,000 transCompucorp Verwood Systems £250CP/M Wisbech Computer Services £300CP/M Business Solutions Ltd £390 variesCP/M Bytesoft £690 variesCP/M PR Daly & Co Ltd £500CP/M Haywood Associates Ltd £500CP/M Median-Tec Ltd £500 500 a/c 5,000 transCP/M Ludhouse Ltd £500 200 a/c 5,000 trans

COLOURAND

SOUND!

'SIMPLY FILE' RECORDS SYSTEM(DBMS).Select by any key. Print alphabetic lists,mailing labels. Calculate, total, average col-umns. Fast, easy, robust and VERY ver-satile. DISK ONLY: £65

'SIMPLY WRITE' FAST WORKPROCESSORSome E300-£400 programs have no morefacilities. Tape or disk, any printer, 40-80column PET. Needs 16K. TAPE £40, DISK£45

GOTTA PET? ADDA VIC!High resolution graphics, programmablecharacters, colour and sound on your PET?All this PLUS a complete extra computerusing your PET's drives, printer etc? Underf200 including VIC and our super PET-VICLINK! (Available separately).

PRICES PLUS VAT BUT INCLUDING P&P. SENDFOR DETAILS, MORE UNUSUAL ITEMS. GET OURFREE 'MICROMAIL' PET NEWSLETTERS.

SIMPLE SOFTWARE LTD.,15 Havelock Road,Brighton, Sussex BN1 6GL10273) 504879

Circle No. 317

SEARCHING FOR`BEST PRICE' .. .

FOUND 'BEST PRICE' .. GOTOPET RRP PRICE4016 16K £550 £4674032 32K £695 £5908032 32K £895 £7608096 £935DISK DRIVES2031 170K £395 £3354040 343K £695 £5908050 1M £895 £760PRINTERS4022 8000L £395 £3358023 136COL £895 ETho8026 DAISY £995 £845

VAT to be added @15%Carriage - £5 per item

If you know what you want why wait?These are the prices you need

ORCHARDCOMPUTER SERVICESOrchard House, 21 St. Martins St..Wallingford, Oxon.Tel. Wallingford (0491) 35529Open 6 days per week,

Circle No. 318

I" JOYSTICKTAMARISK JOYSTICK

£22.50 inclusive

GAME EXTENSION SOCKET

£6.50 inclusive.from TAMARISK DESIGN SERVICES290 Brooklands Rd, Manchester M23

061-969 8729

Circle No. 319

PRACTICAL COMPUTING May 1982 173

BUDGET COMPUTER SALES

in

WEST YORKSHIRE

TRS80 Model Illwith built in drives 1384.00

Twin TEAC drives 390.00Single TEAC drives 236.00Teac Scripta KSR £798Epson MX100 550.00

Diskettes from 1.55

12 Month WarrantyPrices Exclude VAT

AMBASSADORBUSINESS COMPUTERS

For Sales, Service, Help

ASHLEY LANE WORKS, SHIPLEY,

8017 7SL. Tel: (0274) 595941

Circle No. 320

V. GENIE UPGRADES* PRICES INCLUDE VAT *

Memory upgrade to 32K RAM 44.95 (kit).Lowcase cony. 28.00; TAB/CLR keys 3.45: New ROMwith keyboard debounce and personalised power upmessage (15 chars max) 7.95: Eprom card takiaS 16K of2716 Eproms, connects to expansion port 29.95.AY3-8910 sound generator on PCB with demo tape49.95, boxed 56.95; Eight channel A/D converter to addon to sound generator board 23.00: Eproms, 2716 3.47,2532 4.99 (All single rail): Eprom blowing service; frommaster ROM (2516/2716/2532/2732), 3.50 + 50p/PROM; from HEX listing 3.50 + 50p/32 bytes program-med (all plus cost of Eprom, our supply): Erasing 50p/chip: C15 cassettes 65p each. Printer examples:V. Genie. printer interface with cable 39.95Microline 80 315.00 Microline 82A 465.00Epson MX8OFT 425.00 Epson MX82T 420.00V. Genie DiSk drives 5.25 inch boxed with PSU and allcables, examples:Twin 40 track 506.00 Twin 80 track 654.95Any kit fitted for 7.50 plus carriage (12.00).Repair service for Genie, TRS80, Superboard & VIC 20ALL PRICES INCLUDE VAT, AND P&P ON ORDERSOVER 10.00OTHERWISE ADD 75p. CATALOGUE 50p.Ring your order thru' on Barclaycard for imm. despatch.ARC Electronics.54, Heron Dr, Sandal, Wakefield, W. Yorks.Telephone Wakefield (0924) 253145.

io Circle No. 321

MICROCASE"turns a board into a real computer"For NASCOM 2

COMPUKITSUPERBOARD

ALSO UNCUT FOR NASCOM 1ZX81 EXPANSIONS ETC.Direct from us or from your dealer -

but make sure you see aGENUINE MICROCASE

SIMPLE SOFTWARE LTD15 HAVELOCK ROADBRIGHTON, SUSSEX BN1 6GL ,,,dm,®(0273) 504879

Circle No. 322

CP/M

CP/MCP/MCP/M

Computastore Ltd £500

Great Northern CS £345Selven Ltd £400Interface Computer Services £350

999 a/c 99 centresnine computers

250 a/c1,000 a/c 3,000 transvaries

CP/M Microbits Ltd £500 variesCP/M Map Computer Systems £300 250 a/c 3,500 + transCP/M North Star Benchmark CS Ltd £250 150 a/c 500 transHorizon Claisse-Allen Computing £500 999 a/c 99 entries,

nine computersNorth Star DOS Intelligent Artefacts Ltd £295 1,500 a/c 5,000 transOhio Scientific Stratheden Ltd £500 variesTandy Model 2 Chess Consultancies Ltd £400 1,000 a/cTandy TRS-80 Tridata Micros Ltd £225 500 a/c 1,800 transZ-80 Liveport LtdZ80/8080 Solitaire £500 Upao 26 by 400 a/cZilog MCZ range Microbits £500 100 a/c 5,000 trans

Hotel and Travel PackagesMachine type Supplier name Price NotesApple II Dataforce £525 Hotel managementApple II Informex Logic £298 Travel agents' systemApple II Informex Logic £298 Hotel administration

systemApple II/ITT Guestel Ltd £500 Hotel billingApple II Diskwise Ltd £695 Hotel reservation and

guest billingCommodore 3000 Landsler Software £350 Hotel guest billing

Incomplete RecordsMachine type Supplier name Price CapacityApple II/ITT Padmede Computer Services £450 900 a/c 2,000 trans/discApple II Keen Computers £580 up to '70MbytesApple II Southern Computer Systems £750 500 a/c 2,000 transCommodore 3032 Stage One Computers £750 500 centres 2,300 a/cCommodore 3032 Micro Computation £555 120 a/c 5,000 transCP/M Wisbech Computer Services £750CP/M CPL Ltd 250 headings,

2,000 transper 5.25 disc

CP/M Benchmark Ltd £975CP/M Bytesoft £250 3,000 transCP/M Criterion Business Systems £375 2,500 entriesCP/M Ludhouse Ltd £1,000 variableCP/M Salmon Microcomputing £950 5,000 entriesCP/M Map Computer Systems £550Durango F-85 Kesho Systems £1,000Exidy Sorcerer Basic Computing £350 See also MicroputeTandy Model 1 A J Harding (Molimerx) £150 1,200Tandy Model 1 Quickmet £785 300 a/c 2,000 transTandy Model II IBIS Business Info Systems 9,000 a/c codes

Job Costing/BillingMachine type Supplier name Price CapacityApple II Informex London £498 1,000 emp-pro-exp

codesApple II Deltic Computing Ltd £250Apple II Southern Computer Systems £750Apple II/ITT Padmede Computer Services £300 999 clients 99 ratesApple II/ITT TABS Ltd £99 100 jobs 3,000 transCommodore 3032 CSM Ltd £600 1,000 jobs 100 peopleCommodore 3032 Stage One Computers £100 300 appointmentsCP/M Business Solutions Ltd 190 variesCP/M Map Computer Systems Ltd £ 550 400-96,000 jobsCP/M Graffcom Systems Ltd 400 variesCP/M Ludhouse Ltd 1,000 1,000 jobs 35 codesCP/M Microtek Computer Services £ 1,000CP/M Great Northern CS Ltd 455 300 clientsCP/M Salmon Microcomputing £300 225 codesCP/M CPL Ltd £300CP/M Goldcrest £200CP/M North Star Intelligent Artefacts £275

174 PRACTICAL COMPUTING May 1982

Buyers' Guide

Mailing SystemsMachine type Supplier nameApple II Keen Computers LtdApple II SBD Consultants LtdApple IIApple IIApple II

Apple IIApple II/ITTApple II/ITT

Apple II/ITTCommodore 3000/8Commodore 3032Commodore 3032Commodore 3032/8CompucorpCP/MCP/MCP/MCP/MCP/MCP/MCP/MCP/M HorizonCP/M North StarCP/M North StarCP/M VectorNorth StarNorth Star HorizonTandy TRS-80Tandy TRS-80Z-80/8080Z-80/8080

Microsense Computers LtdInformex London LtdAtlanta

Price£300£55£70£198£55

Keen Computers £495Systematics International Ltd £300The Software House £57

Personal Computers LtdAmplicon MS LtdMMS Computer SystemsStage One ComputersCompsoft LtdVerwood SystemsGoldcrestCompsoft LtdStructured Systems Group £50Graffcom Systems Ltd £250Median-Tec Ltd . £500Microbits £230Interface Computer Services £200Microtek Computer Services £250

£250£195£375£250

Intelligent ArtifactsMicromedia SystemsTaylor MicrosystemsIntelligent ArtifactsWisbech Computer Services £195A J Harding (Molimenc) £55Comput-A-Crop £78Intereurope SD Ltd £200Micro Focus . £90

£50£145£250£100£190£250£200£400

Order Entry/InvoicingMachine typeApple IIApple IICommodore 3032CompucorpCP/MCP/MCP-MCP/MCP/MCP/MCP/MTandy TRS-80Z-80/MCZ

PayrollMS -chine typeApple IIApple II/ITTApple II/ITTApple II/ITTApple II/ITTApple II/ITTAppleApple II/ITTCommodore 3000/8Commodore 3000/8Commodore 3032Commodore 3032Commodore 3032Commodore 3032Commodore 3032CP/M

CP/M

Supplier nameInformexSouthern Computer SystemsMMS ComputersVerwood SystemsWisbech Computer ServicesGraham -DorianGoldcrestPR Daly & CoGraffcom SystemsInterface LtdMedian-TecTridata MicrosSoftware Architects

Supplier nameDataforce (U.K.) LtdTW Computers LtdInformex London LtdAlgobel ComputersVlasak Electronics LtdComputech SystemsStyle Systems LtdTabs LtdCommodore BM (U.K.) LtdLandsler SoftwareAnalog ElectronicsL & J ComputersIntex Datalog LtdComputastore LtdACT (Petsoft) LtdBenchmark CS Ltd

Haywood Associates Ltd

Capacity500 addresses

1,000 names andaddresses

32,767 records500 addresses750 names and

addresses'400 entries1,50Q-4,000 records3,000 records325 records13,000

27,000varies800-5,000 records

variesvariesvaries

1 200 per disc60Q-3,750 recordsvaries30,000 entriesvaries

Price Notes£198 Invoicing system£750 Invoicing£250 Order control£250 each£600£500 200 invoices 1,500£300 Invoicing£200 Invoicing£350 Order entry/invoicing£250 Invoicing

Invoicing£75 Invoicing£600 Order entry/invoicing

Price£375£145£298£295£375£379£350£99£150£150£90£220£195£75£195£350

£350

Capacity

500 employees200 employees300 employees450 employees50 weekly 100 monthly200-600 employees200-500 employees

200 employees483 employees600 employees300 employees,

50 departments

113S80 Models1+111and VIDEO GENIE

Turnyour

Into oneof these

Announcing ACCEL3 - the practicalBASIC compiler for home, education,or business.

Are you troubled by gradual graphics,languid loops, tedious table searches, orcapricious keyboard response? ACCEL3is the cure. Highly compatible withinterpreted BASIC - correct programscompile without modification.On Tape or Disk £49.95

PO Box 39. Eastlelgha Hants, 505 5WQ

sou emsoftware

Circle No. 323

TRAP THEINVADER! !theARTIFICIALINTELLIGENCEgamefor yourAPPLE I I (32k dos3.2)

NOW £16Send cheque to LCS and receive diskcontaining visible BASIC programsand 12 -page tutorial book.Or,circle number on card for moreinformation.

-6,1;s1.;1;ss1:14;:

37 St Andrew's Drive, Seaford

MOater SVSteMS Sussex 5N25 2SB

Circle No. 324VINYL

MINI,TH

FLOPPY FILESW INDEX CARDS .

25p EACHMINIMUM ORDER 10ADD P&P + VAT £1.25

10 FILES IN RING BINDER£6 including P&P + VAT

DATA BASE169 HIGH ST., CHEVELEY,

NEWMARKET, SUFFOLK CB8 9DG.

Circle No. 325

PRACTICAL COMPUTING May 1982 175

The NEWOLYMPIA103 KSR

rff'lwir)Available from

Trade distributors

Telephone (0386) 3591Dealer enquiries invited

Circle No. 326

MANUFACTURERS . . .

MICRO -CADTHE RACE IS ON . . .

* We supply NEC, Temcy & other computersand watanabe plotters

* Our software turns them into workingdraughting systems

* Complex schematics, layouts and detaildrawings handled

* Top quality hard copy output

* Compatible with existing CP/M systems.

* Price range £5,000-E25,000

* Commercial software packages also sup-plied.

DON'T GET LEFT BEHIND . .

CONTACT: JENTECH SERVICES LTD.,NORWAY, BRIDGNORTH.SHROPSHIRE WV16 4SU.

OR RING 1074 62) 5287 NOW.

Circle No. 327

THE POWER BANKPlug your micro computer video unit and Printer intothe POWER BANK and forget about a disabling break inthe electricity supply. This unit will continue to runyour system for up to one hour in the event of a mainsfailure . WITH NO INTERUPTION TO YOUR WORK!

Batteriesincluded

Vital when running business systems. This unit will ofcourse suppress MAINS SPIKES and SURGES.

SIGNWAVE OUTPUT

Retail price £320 + VATWeight 13Kgms Size 43cms x 20cms 9cms

POWER TESTING LTD1 St Mary's Lane, Upmlnster

Tel: UprnInster 26938

Circle No. 328

Apple II/ITTApple II/ITT

AppleApple II/ITTCommodore 3000/8

CP/MCP/MCP/MCP/M

CP/MCP/MCP/MCP/MCP/MCP/MCP/MCP/MCP/M North StarCP/M North StarCP/M VectorDurango F-85HorizonOhio ScientificSharp MZ-80Tandy TRS-80Tandy TRS-80Tandy TRS-80Tandy Model 2Tandy TRS-80Tandy TRS-80TecsZ-80/8080Z-80/8080Zilog MCZ range

Median-TecSalmon-MicrocomputingMap Computer SystemsDaman Computer Services

Selven LtdPR Daly & Co LtdGraffcom Systems LtdHorizon Software LtdPCL Software LtdLudhouse LtdComput-A-CropMicrobitsMicromedia SystemsIntelligent ArtefactsTaylor Micro SystemsKesho SystemsClaisse-Allen ComputingStratheden LtdTridata Micros LtdA J Harding (Molimerx)Chess ConsultanciesFIBSP J NorrisTridata Micros Ltd3 -line ComputingJar Software SystemsLiveport LtdSolitaireMicrobits

Personnel and AdministrationMachine type Supplier nameApple II Informex LogicApple II Informex LogicApple II/ITT Informex Logic

Apple II/ITTApple II/ITTCommodore 3000CompucorpCP/M

CP/M North StarCP/M Vector

Informex LogicInformex LogicIntex Datalog LtdVerwood SystemsMedian-Tec Ltd

MicromediaTaylor Microsystems

Z-80/8080 Intereurope

Property ManagementMachine type Supplier nameApple II/ITT Cyderpress LtdApple II/ITTApple II/ITTApple II/ITTCommodore 3032/8CP/MCP/MCP/MZ-80/8080

Informex London LtdCyderpress LtdAlgobel Computers LtdCompsoft LtdCompsoft LtdAlgobel Computers LtdSalmon MicrocomputingGraham Dorian Software

Purchase LedgerMachine type Supplier nameApple II Dataforce (U.K.) LtdApple II Logic Box LtdApple II Deltic Computing LtdApple II Computech SystemsApple II Southern Computer Systems

Systematics International LtdPadmede Computer Services£300

£500£300£350£900

£500£350£500£500£495£450£495£500£495£52£490£500£500£750£250£120£400£429£500£218£140£250£250£500£500

Price£198£298£298

£198£198£100£250£1,500

£595£390£500

Price£650£298£650£650£190£400£650£900£325

Style Systems LtdGuestel LtdCSM Ltd

Price£315£490£250£295£750

£250£300£550

1,000 employees500 employees300-96,000 employees1,000 employees/

Mbyte400 employees

500 employees

1,200 employees300 employees175 employeesvaries350 employees100 employees

250 employeesvaries400 employees

400 employees

1,000 per disk400 employees

300 employees500 employees200 employees300 employees

ApplicationPersonnel recordsStaff selection testsEmployment agency

systemMedical recordsHospital administrationHospital administration

Employment agencysystem

Personnel recordsPiece workPersonnel records

Capacity

300 entries500 properties400 properties13,00027,0002,000 trans

varies

Capacity200 a/c 1,000 trans400 a/c 1,000 trans1,000 trans500 a/c 1,600 transvariable

900 a/c 4,500 trans/disc

650 a/c 1,750 trans200 a/c1,000-2,000 a/c

6,000-10,000 trans

176 PRACTICAL COMPUTING May 1982

Buyers' Guide

Commodore 3000/8

Commodore 3032Commodore 3032

Commodore 8000CompucorpCP/MCP/MCP/MCP/MCP/MGPMCP/MCP/MCP/MCP/M

CP/M

CP/MCP/MCP/MCP/MCP/MCP/MCP/M

CP/M North StarDurango F-85Exidy SorcererHorizonOhio ScientificTandy Models 1 &Tandy TRS-80

Tandy TRS-80Zilog MCZ range

Z-80Z80/8080

Sales LedgerMachine typeApple IIApple IIApple IrApple IIApple II/ITT

Anagram Systems £399

ACT (Petsoft) LtdCompfer Ltd

£120£300

Commodore BM Ltd £300Verwood Systems £250CPL Ltd £300Goldcrest £300Wisbech Computer Services £300Bytesoft £400Business Solutions Ltd £390Median-Tec Ltd £500Ludhouse Ltd £500Great Northern CS Ltd £315Structured Systems Ltd £460Selven Ltd £600

Salmon Microcomputing £350

Map Computer Systems LtdMicrobitsPR Daly & Co LtdComputastore LtdHaywood AssociatesInterface Computer ServicesSelven Systems

£300£500£350£400£350£350£600

Benchmark CS Ltd £250Kesho Systems £500Basic Computing £125Claisse Allen Computing £500Stratheden Ltd £500

2 Chess Consultancies Ltd £250FIBS £750

Apple II/ITTApple II/ITTApple IIAppleCommodore 3000/8

Tridata Micros LtdMicrobits Ltd

Liveport LtdSolitaire

Supplier nameComputech SystemsDataforce (U.K.) LtdLogic Box LtdDeltic Computing LtdPadmede Computer Services£300

£225£500

£500

Price£295£315£490£250

Guestel Ltd £300Systematics International LtdSouthern Computer Systems £750Style Systems Ltd £250Anagram Systems £299

200-2,000 a/c800-16,000 trans

200 a/c 700 trans1,000 trans

7,000 entries600 a/c 4,500 trans

variesvaries500 a/c 5,000 trans500 a/c 5,000 trans500 a/cvaries1,000 a/c

2,000 trans1,000 a/c

24,000 trans400-96,000 a/cvaries

500 a/c 3,100 trans

varies500 suppliers 5,000

trans100 a/c 300 trans

See also Micropute800 a/c 2,000 transvaries300-500 a/cpart of integrated

system125 a/c 1,000 trans400 suppliers

1,000 trans

200 by 26 a/c

Capacity500 a/c 1,600 trans200 a/c 1,000 trans300 a/c 1,300 trans1,000 a/c900 a/c 4,500 trans/

disc200 a/c

650 a/c 2,500 trans250-2,000 a/c

500-10,000 transCommodore 3000/8 CSM Ltd £550 and 1,000-2,000 a/c

£650 6,000-10:000 transCommodore 3032 ACT (Petsoft) Ltd £120 200 a/c 700 transCommodore 8000 Commodore BM (U.K.) Ltd £300 600 a/c 4,500 transCompucorp Verwood Systems £250CP/M Wisbech Computer Services £300CP/M Goldcrest £300CP/M CPL Ltd £300 with invoicesCP/M Business Solutions £425CP/M Bytesoft £400 variesCP/M PCL Software Ltd £475 950 a/cCP/M Great Northern CS Ltd £415 500 a/cCP/M Haywood Associates Ltd £350CP/M Median-Tec Ltd £500 500 a/c 5,000 transCP/M Ludhouse Ltd £500 2,000 a/c

8,000 trans

RAM BARGAINS4116-20Ons

4116-25Ons

2114-30Ons

2114-45Ons

80p each100+68p each

70p each100+55p each

85p each100+75p each

75p each100+65p each

2716-5V-450ns £2.10 each2532-450ns £4.10 each4146-15Ons £6.95 eachOther IC's available.Add 50p P&P 4- VAT at 15%.

ATHANA FLOPPIESMinis with free plastic library case + Hub ringsS/S-S/D £17.95 for 10

£19.95 for 10£23.50 for 10£26.50 for 10£15.50 for 10£24.50 for 10£25.50 for 10

S/S-D/DD/S-D/DS/S-Quad D8" discs. S/S-S/D

S/S D/DD/S-D/D

All other disks available.Add 85p P&P + VAT at 15%.

24 -HOUR TELEPHONE SERVICEFOR CREDIT CARD USERS

QUANTITY DISCOUNTS AVAILABLE -OFFICIAL ORDERS WELCOME

OPUS SUPPLIES10 BECKENHAM GROVE,

SHORTLANDS, KENT. VISA11111111111Mt

Circle No. 329

GO FORTHComplete DIY FORTH kit1) Installation manual £10How to do it + definitions + editor

2) Source code listing for one processor .... £106502, 6800, 6809, 8080, 8086/8088, 9900, 1802

Manual + one listing £19

Dual 8" disc drives £525 + VAT2 x 8" single -sided double -density Shugart drives+ box + PSU + intelligent controller.

MicroProcessor Engineering Ltd21 Hanley Road ShirleySouthampton SO1 5APTel. Southampton 775482

Circle No. 330

1111111111111111111111111111111111111111111111111111111111111111111111111111

ZX81 MONOPOLYare you still playing with yourself?

Occasionally during the life of a Micro a program is writtenthat can go on to become a standard. ZX81 MONOPOLY is onesuch program. Most computer simulations are solitary affairsusing a program that caters only for one or two players. ZX81MONOPOLY allows 6 players to compete with the machinedoing all the boring bits, acting as board rule -book, umpire,dice -thrower and accountant. No cheating is allowed andwhen required a list of a players' properties and the develop-ment situation for each can be listed. No need to worry aboutmissing the rent either your ZX81 is also trained as a rentcollector. The program is well driven by a clear MENU at thestart of each player's turn and after the dice has been thrown.ZX81 MONOPOLY also allows the game to be SAVED with aWINNER so far report. The program requires 16k RAM andcomes complete with instructions. Let all your friends andfamily appreciate the ability of your ZX81 NOW ZX81 MONO-POLY for 16K at £8.00 inc VAT and postage. Cash with orderfrom the publishers Dept 50.

DEPT ZM WORK FORCE140 WILSDEN AVE

LUTON BEDS LU1 5HR

III1111111111111111111111111111111111111111111111111111111111111111111111111

Circle No. 331

PRACTICAL COMPUTING May 1982 177

SPRINGCLEARANCE

DIABLO DAISY WHEEL PRINTER1 ONLY £575

CALCOMP 8" SINGLE SIDEDDRIVES. 1 ONLY £500

WANCO S.W.T.P.C. MINI FLOPPYDRIVES. 1 ONLY £250

UNIFLEX + BASIC ANDPRECOMPILER £300

DATA BASE169 HIGH STREET, CHEVELEY,

NEWMARKET, SUFFOLK CB8 9DG.

Circle No. 332

Is there anyone interested in sel-ling Micro Computer BusinessSystems to the retail jewelleryindustry?

We have this to offer:1) High quality showroom space inHatton Garden itself.2) Sales contracts with 5000 plusretail jewellers all over the U.K.3) Long experience in supplying toretail jewellery industry.

Please write to Box No. 451

WANT TO LEARNPROGRAMMING?

TRIAL COURSE4 hours for £10

For this or other assistance onmicrocomputers ring Jack or Irison 928 8989 ext 2468 or write to:

Microcomputer Advisory Centre,Polytechnic of the South Bank,Borough Rd., London SE1 ORA.

Circle No. 334

LOW PROFILE KEYBOARDS16 switch (4x4). PhosiBronze gold-platedcontacts.Keytop legends 0-9 plus 6 plain.G.F.P.C. Board with edge connections.Overall switch height from board 12.5mm.Switch pad area 65mm sq. approx.PRICE £7.00 plus postage & VAT.Cheques for £9.20 payable to:

AVONSWITCH PRODUCTS LTD.River Street, Pewsey, Wiltshire SN9 5DH.Delivery within 14 days.

Circle No. 335

CP/MCP/MCP/M

Graffcom Systems LtdComputerstore LtdSalmon Microcomputing

£450£400£350

540-7,000500 a/c 3,500 trans1,000 a/C

24,000 transCP/M Selven Systems £600 500 a/c 5,000 transCP/M Map Computer Systems Ltd £300 400-96,000 a/cCP/M Daman Computer Services £900 1,500 a/c 500 transCP/M PR Daly & Co Ltd £350CP/M Interface Computer £350 varies

ServicesCP/M North Star Benchmark CS Ltd £250 200 a/c 500 transDurango F-85 Kesho Systems £500Exidy Sorcerer Basic Computing £125 See also MicroputeHorizon Claisse-Allen Computing £500 800 a/c 2,000 transTandy Models I & 2 Chess Consultancies Ltd £250 300 a/cTandy TRS-80 Tridata Micros Ltd £225 175 a/c 1,350 transTecs Jar Software Systems £550 500 a/cZ-80 Liveport Ltd

Stock SystemsMachine type Supplier name Price CapacityApple II Logic Box Ltd £490 1,200 itemsApple II Vlasak Electronics Ltd £150 7,000 itemsApple II Dataforce (U.K.) Ltd '£200 850 itemsApple II U -Microcomputers Ltd £199Apple II Microsense Computers Ltd £100Apple II Informex London Ltd £198Apple II Southern Computer Systems £1,000Apple Style Systems Ltd £250 900-80,000 itemsApple II/ITT Microdigital Ltd £225 625 itemsApple II/ITT Vlasak Electronics Ltd £285 500 itemsApple II/ITT Systematics International Ltd £500 200-2,500 itemsApple II/ITT Guestel Ltd £300Apple II/ITT Padmede Computer Services £300 2,000 postingsApple II/ITT The Software House £80 800 itemsCommodore 3000 Intex Datalog Ltd £195 2,400-3,700 itemsCommodore 3000/8 Commodore BM (U.K.) Ltd 600-2,000 itemsCommodore 3000/8 Rockliff Brothers Ltd £275 3,400-10,000 recordsCommodore 3032 Logma Systems Design £600 1-6 shopsCommodore 3032 ACT (Petsoft) Ltd £75 2,400 items 1,000 a/cCommodore 3032 ACT Microsoft Ltd £75 1,200-5,900 itemsCommodore 3032 Anagram System £320 500-600 items 255 a/cCommodore 3032 L & J Computers £60 500 itemsCommodore 3032 Bristol Software Factory £300 2,300 itemsCommodore 3032 Stage One Computers £100 and 600-650 items

Commodore 3032 SMG Microcomputers £395-£495 2,450-7,000 itemsCommodore 3032 Compfer Ltd £350 200 lines 20 barsCommodore 3032/8 Compsoft Ltd £190 13,000Compucorp Verwood Systems £250CP/M CPL Ltd £300CP/M Goldcrest £300CP/M Wisbech £300CP/M Bytesoft £700 2,000-8,000 linesCP/M Compsoft Ltd £400 27,000CP/M Microtek Computer Services £750CP/M PR Daly & Co Ltd £350CP/M Great Northern CS Ltd £375 1,500CP/M Haywood Associates Ltd £350CP/M Median-Tec Ltd £500-£800 1,000 itemsCP/M Microbits £500 variesCP/M Graffcom Systems Ltd £350 350 records/discCP/M Salmon Microcomputing £400 5,000 itemsCP/M Map Computer Systems Ltd £250CP/M Ludhouse Ltd £1,000 12,000 partsCP/M Interface Computer Services £350 variesCP/M Selven Systems £600CP/M Cromenco Micromedia Systems £1,000CP/M Horizon Microtek Computer Services £500- varies

£ 1 , 000

CP/M North Star Benchmark CS Ltd £450 350 items 275 transCP/M Vector Taylor Micro Systems £995 4,000 items/Mbyte

178 PRACTICAL COMPUTING May 1982

Buyers' Guide

North Star DOSExidy SorcererTandy TRS-80Tandy TRS-80Tandy TRS-80Tandy TRS-80Tandy TRS-80Tandy TRS-80Tandy TRS-80Tandy TRS-80Tecs

TecsZilog MCZ rangeZ-80/8080Z-80/8080Z-80 MCZ

Intelligent Artifacts LtdBasic ComputingChess ConsultanciesA J Harding (Molimerx)Cleartone ADPChess ConsultanciesFIBSMicro GemsTridata Micros LtdMicrogems SoftwareJar Software Services

Jar Software ServicesMicrobitsGraham Dorian SoftwareRogis Systems LtdSoftware Architects Ltd

Z-80 Liveport Ltd

Word ProcessingMachine type Supplier nameApple II Dataforce (U.K.) LtdApple II SBD Consultants LtdApple II Keen ComputersApple II/ITT Systematics International Ltd £75Apple II/ITT Algobel Computers Ltd £75 800 linesApple II/ITT Personal Computers Ltd £225-£300 200,000 charactersCommodore 3000 Stage One Computers Ltd £125

£195£125£995£150 1,000 items£325 4,000 items£750 500 items six sites£750£150 1,000 items£200-£375 630 items/disc£150 1,000-2,000 items£800 10,000 items 5,000

orders£850 1,000 items 300 a/c£500 2,300 items£325 varies£500 900-3,500 items£600 varies

Commodore 3032Commodore 3032CompucorpCP/MCP/MCP/MCP/M North StarNorth Star ('c')Z-80 Superbrain

Price Capacity£190£60£275 up to 70Mbyte

Dataview Ltd £159ACT (Petsoft) Ltd £325Verwood Systems £500Wisbech Computer Services £245Interface Computer Services £200Microbits £230Intelligent Artifacts £250Intelligent Artifacts £250Alan Pearman Ltd £225

MiscellaneousMachine type Supplier nameApple II Vlasak ElectronicsApple II Humac LtdApple II Humac Ltd

Apple IIApple IIApple IIApple

Apple II/ITTApple II/ITT

Apple II/ITT Diskwise

Humac LtdKeen ComputersKeen ComputersStyle Systems Ltd

Informex LogicInformex Logic

Apple II/ITT CyderpressApple II/ITT CPR Systems Ltd

Apple II/ITTApple II/ITTApple II/ITT

Commodore 3000Commodore 3000Commodore 3000Commodore 3032Commodore 3032

Commodore 3032Commodore 3032Commodore 3032Commodore 3032

Personal ComputersPersonal ComputersPadmede Computers

Anagram SystemsAnagram SystemsThe Alphabet ComMicrolandStage One Computers

Stage One ComputersCommodore BM (U K )CSM LtdS A Systems

12,000

varies varies

Price Capacity£30 Petrol pump losses£1,000 Auctioneer's package£600 Invoicing sales -

timberMicrofiche records

£499 Inhouse teletext£499 Graphics£750 Retail warehouse

management£198 Insurance records£198 Time records -

solicitors£198 TV rental management

system£650 Auction system£960 Insurance brokers

system£195 Operational research£100 Time series analysis£500 Insurance brokers

system£850 Media control system£800 Slot machine monitor£250 Newsagent suite£175 Printers quote system£100 Insurance brokers

system£200 Printers job control£50 Appointments planner£500 Window replacement£550 Farming - office

systems

MAILSAFEDISKETTE MAILERSLOW PRICE HIGH QUALITY

Protect your valuable Software & DataIf you mail floppy disks

Make sure they arrive safein a MAILSAFE

Available in 51" and 8" sizes

For free sample & details

BASIC BUSINESS SUPPLIES50 Edinburgh Drive, Ickenham,Uxbridge, Middx. UB10 81:1Y.

Tel: Ruislip (08956) 76012

Circle No. 336

ZX80/81 INTERFACEAt last -a well designed interface that allows you touse the ZX80 or ZX81 as a controller.It provides: 24 programmable I/O lines. Units can be daisy chained up to 96 I/O Can be used in Basic or machine code. Screw terminals and ribbon cable header pro-

vided. Design eliminates mechanical linkage problems. Provision for external power supply. Does not -interfere with Sinclair expansion units. Detailed notes and software provided.

£45.00 PLUS V.A.T.Cheque with order please to:

BYTRONIC ASSOCIATES

88 RUSSELL BANK ROADSUTTON COLDFIELD, WEST MIDLANDS 874 4RJTel: 0675 81448Bytronic Associates also provide a wide range of equip-ment for learning how to use micros as controllers, e.g.steppers, DC motors, ADC, DAC, pneumatic units etc.

Brochure available on request

Circle No. 337

INVESTORS WITH MICROSTo aid your analysis of share price move-ments we now offer:1. Bound copy of weekly closing prices of the FT index,All -Share Index, and the 30 shares comprising the FTIndustrial Index, from January 1977 to the present time, onemonth of numbers per page. Included are 5 -year logarithmicand linear mini -charts of each history. This is a mine ofinvaluable research information at a fraction of the cost ofaccumulating it yourself. Price: t35 incl. p.p.

2. "Stocks and Shares Simplified" by Dr Brian J. Millard.This book includes listings of programs for moving averagecalculations, and is a well proven approach to maximisingstock market profit. Price: f7.80 incl. P&P.

Lombardy Computers Limited,121 High Street, Berkhamsted,Herts HP4 2DJ.Tel: (04427) 4247.

Circle No. 338

PRACTICAL COMPUTING May 1982 179

BASICEvening & Day Courses

LOGOS COMPUTERS

30 Church Road,Barnes, SW13

Tel.: (01) 748 5813

Circle No. 339

ZX MICROFAIRNEW CENTURY HALL(next to the CIS building)

Corporation StreetMANCHESTER

SAT. 29 MAY 1982 (10.00-6.00)SUN. 30 MAY 1982 (10.00-5.00)

EVERYTHING FOR YOUR SINCLAIR MICROA choice of the wide selection of programs and add-ons nowavailable for the 240/81, from leading suppliers.* HARDWARE * SOFTWARE * BOOKS/MAGS * USERGROUPS *Admission (door) Adults 50p. Children 30p.

(Advance tickets) Adults El. Children 50p.Advance tickets (cheques to 'ZX MICROFAIR') and exhibitiondetails from: Organiser: Mike Johnson, 71 Park Lane,Tottenham, London N17 OAG.P.S. DON'T FORGET THE LONDON SHOW: 3rd ZX MICROFAIR30 April/lst May 1982, Central Hall, Westminster, SW1. Lots ofnew products (Doors open 12.30 Friday 29 April).

Circle No. 340

80 x 24 VDUAll the electronics for a 24 lines by BO characters visualdisplay unit on one assembled and tested printed circuitboard measuring 8.75 inch x 6.50 inch.You provide: power supply plus 5 v at 1.2 amps, plus 12v/-12 vat 25 mA, ASCII encoded keyboard, video monitor.The VDU -I will talk to the R.S. 232 serial port on yourcomputer, at up to 9,600 baud. Many features are includedeg: cursor addressing.

VDU -1 Assembled and tested p.c.b. E135PSU-1 VDU -1 power supply E32

All prices subject to C2 registered delivery, plus VAT.

SS -50 BOARDSVMB - I SS -50 8k (2114 RAM) + 8k (2716 EPROM) may bedisabled on A 1k byte basis bare board plus documentationE30; PHOTO - 1 SS -50 prototyping board wire wrap/soldered wire lines E16; PHOTO -2 SS -30 prototyping boardwire wrap type E9: PROTO - 3 SS -50 prototyping boardmedium density wire wrap type E12; 1 SS -50 real time clockboard (hours, min, sec, day, month, year) plus auto leap yearand battery back up. Printer spooling under flex 2.0. Assem-bled and tested E45; SS/1 SS-30/SS-50 board subject to Elpost & packing, plus VAT.

SIRIUS CYBERNETICS LTD7 EUSTON PLACE, LEAMINGTON SPA

WARWICKSHIRETEL: (0926) 316110

Circle No. 341

uNAELE-CRYSTALREDUCES GLARE

k a 91INCREASE OPERATOR EFFICIENCY

* Specially formulated for VDU and TV Screens* Reduces Screen Static* Increases operator efficiency by reducing

eye strain* Wit not harm screen surface* Recommended installed price

E18 for up to 26"screensDEALER & O.E.M. ENQUIRIES WELCOME

STATIFLECT -GUARD, 55 FAIRBURN DRIVE, GARFORTH,,LEEDS 1.525 2AR. TEL: (0532)864981 (24hrs)

See us on

Stand 520Computer Fair

Circle No. 342

Commodore 3032 L & J Computers £420 Machine hireCommodore 3032 Mandata Ltd £1,000 Insurance brokersCommodore 8000 Peach Data Services £350 Library retrieval

systemCommodore 8000 Peach Data Services £550 Footware industry

sales reportingCommodore 8000 Peach Data Services £995 Clients home

accountingCommodore 8000 Stage One £800 General accounting

packageCommodore 8000 Stage One £330 Petaid/VVordcra-ft/

VisiCalc link.CP/M Benchmark Ltd £350 Time recordingCP/M Bytesoft £850 Work in progressCP/M Bytesoft £150 Perpetual inventoryCP/M Bytesoft £850 Bill of materialsCP/M Bytesoft £200 Kit controlCP/M Microtek £500 Garage systemCP/M PR Daly & Co £450 Time recordingCP/M Horizon Software £1,000 Integrated business

systemCP/M Horizon Software £400 Costing systemsCP/M Research Resources £240 Statistical analysisCP/M Sail £1,000 Jewellers integrated

systerriCP/M Salmon Microcomputer £150 Appointments plannerCP/M Selven Systems £400 Nominal ledgerCP/M Map Computer Systems £450 Time recordingCP/M Map Computer Systems £750 Calor systemCP/M Map Computer Systems £425 Newsboy/newsagents

systemCP/M Haywood £500 Time recordingCP/M Comput-a-Crop £1,000 Farm managementCP/M Microtek £1,000 Plant hireCP/M Goldcrest £300 Nominal ledgerCP/M North Star Micromedia £195 Vehicle maintenanceCP/M Vector Taylor Microsystems £495 Bill of materialsOhio Scientific Stratheden Ltd £300 Statistics packageOhio Scientific Stratheden Ltd Insurance brokers

systemOhio Scientific Stratheden Ltd Hospital packageNorth Star DOS Intelligent Artifacts £52 Parts list management

and orderingNorth Star Horizon Wisbech Computer Services £750 Double -glazing

manufacturerNorth Star Horizon Wisbech Computer Services £750 Double -glazing

costsNorth Star Horizon Wisbech Computer Services £450 Time recordingSuperBrain Alan Pearman Ltd £190 Statistics packageSuperBrain Alan Pearman Ltd £105 APL utility functionsSuperBrain Alan Pearman Ltd £225 APL Text editor/

processorSuperBrain Alan Pearman Ltd £125 Micro -mainframe

communicationsSuperBrain Alan Pearman Ltd £490 Modelling/simulationSuperBrain Alan Pearman Ltd £325 Actuarial calculationsSuperBrain Alan Pearman Ltd £75 Password security

systemSuperBrain Alan Pearman Ltd £225 Report formattingSuperBrain Alan Pearman Ltd £195 CP/M networksSuperBrain Alan Pearman Ltd £380 Hard graphics copyTandy TRS-80 Chess Consultancies £995 Haulage

administrationTandy TRS-80 Cleartone ADP £300 WIP and invoicing

systemTandy TRS-80 Cleartone ADP £500 Patient and drugs

recordsTandy TRS-80 P J Norris £1,000 Comprehensive sales

and purchaseTandy TRS-80 Quickmet £785 Integrated accounts

package

180 PRACTICAL COMPUTING May 1982

Buyers' Guide

Zilog MCZ range Microbits

Zilog MCZ range MicrobitsZilog MCZ range MicrobitsZ-80/8080 Intereurope

£1,000 Insurance brokerssystem

£1,000 Production control£1,000 Bill of materials£500 Conference organiser

Alphabetical list of suppliers

Supplier3 -Line Computing

0482-445496ACT Microsoft Ltd

021-455-8585

Aerco-Gemsoft04862-22881

A J Harding (Molimerx)0424-22039

Algobel Computers Ltd021-233-2407

Amplicon M S Ltd0273-608331

Anagram Systems0403-50854

Analog Electronics0203-417761

Alan Pearman Ltd0244-46024/21084

Atlanta Data Systems Ltd01-739-5889

Basic Computing0535-65094

Benchmark CS Ltd0726-61000

Bristol Software Factory0272-277135

Business Solutions Ltd01-554-5985/0582

Bytesoft Systems Limited0533-531441

Chess Consultancies Ltd061-832-6792

Cleartone ADP0495-244555

Clenlo Computing Services01-653-6028

Commodore BM (U.K.) LtdSlough 74111

Compfer Ltd0772-57684

CPS (Data Systems) Ltd021-707-3866

CPL(Cwmni Peirianneg Llyn Ltd)

(0758) 3035Compsoft Ltd

0483-39665/505918Comput-A-Crop

01-771-0867CPR Systems Ltd

04492-5488Computech Systems

01-794-0202

Address36 Clough Road

Hull HU5 1QLRadclyffe House

66-68 Hagley RoadBirmingham B16 8PF

27 Chobham RoadWoking Surrey

28 Collington AvenueBexhill -on -Sea, East Sussex

33 Cornwall BuildingsNewhall StreetBirmingham B3 3QR

Richmond RoadBrighton, Sussex BN 1 6JA

60a Queens StreetHorsham, West Sussex RH13 5AD

47 Ridgeway AvenueCoventry

Maple House, Mortlake CrescentChester CH3 5UR

350/356 Old StreetLondon EC1V 9DT

Oakworth RoadKeighley, West YorkshireBD22 7LA

7r8 Aylmer SquareSt Austell, CornwallPL25 5LL

Kingsons House, Grove AvenueQueen Square, Bristol BSI 4QY

1 Park Avenue, IlfordEssex IG1 4LU

16 New StreetLeicester LE1 5NR

Progress House31-33 Mount Street, SalfordManchester M3

Prince of Wales Industrial EstateAbercarn, Gwent NP 1 5RJ

15 South View CourtThe Woodlands, Beulah HillLondon. SE19

818 Leigh RoadSlough Industrial EstateSlough Berkshire

Preston Computer Centre6 Victoria Buildings, FishergatePreston Lancashire

Arden House, 1102 Warwick RoadAcocks GreenBirmingham B27 6BH

Liverpool House, PwllheliGwynedd LL53 5DE

Great Tangley, Manor FarmWonersh, Guildford, Surrey

32 Whitworth RoadLondon SE25 6XH

37-39 Ipswich StreetStowmarket, Suffolk

168 Finchley RoadLondon NW3

Sales contactTim Hill

MatthewWauchope

John Harding

Amanda Anders

Peter Wood

Frank Laughton

Mike Collier

John Fisher

W J Kyle -Price

S Page

David Biggins

D G West

C J Holbrook

A Gould

L Roberts

Jenny Wilson

Roger Taylor

Laurence Payne

EXIDY SORCEROR, 16K, as new with leads,manuals, Sorceror club newsletters, withBASIC upgrade kit not fitted. £350 ono. Mr. M.Yaacob, 9 Clare Garden, Riverside, Cardiff,Wales.

ACORN ATOM 12K + 12K, VIA, PSU, soft-ware, leads. £260. Tel: 01-531 1033.

PET 32K, new ROM, extl. cassette deck,software/books. £400 ono. Tel: 0827 873840.

ACORN ATDM 12K + 12K PSU, manualgames. £230 ono. Tel: Rickmansworth 76143.

HP41C + Barcode Reader + Maths module+ Solution Books. Cost £299 new. Sell £210ono. Tel Swansea 290241.

TRS-80 48K two disc drives VDU cassetteprinter, 50 discs, 100 programs, books£1,050. 0752-661364 (Plymouth).

ZX81 16K. Basic line re -numbering and multi -line erasure. M/C code, cassette £3.95. M. J.Franklin, 69 The Heights, Northolt, Middx.

MZ-80K MUSIC and SOUND EFFECTS(20K), five programs, cassette, "Chipsongs"- lively jigs and reels, "Birdsongs" - millionsof variations! "Engines" - quite remarkable,"Chipsong Generator" - actually composes,spontaneously! "Weird music" - demon-strates POKE and USR. All for £9. G. B.James, 21 Lamond Place, Aberdeen AB23UT.

HIGH RESOLUTION PACKAGE (£7.50),Music package (£6.50) for UNEXPANDEDVIC. 0634 814118 for details.

KSR 33 TELETYPE with stand, excellent con-dition, 20mA I/O plugs straight into your Nas-com etc £85. Chester 382292.

ZX81-16K GRAPHIC GAMES CASSETTES"Maze", "Defender", etc. £2. Tel: (0533)897268.

CASIO FX702 user group £6.50/year for 6issues of Newsletter. R. Cooper, 11 BraintreeRoad, Dunmow, Essex.

MZ-8OK SALES program, cassette basedincludes invoicing, statements and VAT. SendSAE for full details to: D. M. Bellwood, 6Barlow Rd., Sheffield, S6 5HR.

16K ZX81 for sale. Has D. K. Tronics graphicROM. With software, it is worth £250. Bargainat £199. Phone Southend (0702) 714764.

VIDEO GENIE, 16K LII, sound, joysticks, b/wmonitor, 2nd cassette. Books, manuals, soft-ware, v.g.c., £350 ono. Tel: 0234-741169

MZ-80K 48K Basic and monitor listings, SharpASM/Edit, £390, Deeside 810245.

PET 32K, new ROM, external large keyboard.Also QUME Sprint 55, interface, word proces-sor software(fixed/proportional spacing). PET& QUME manuals, £1,300 ono. Tel: Chip-penham 75222.

32K PET 2001 series. Integral cassette, smallkeyboard, old ROMs, programs, variousbooks, sound box, etc. Little used, £425.01-778 9932.

TANDY QUICK PRINTER II, £90, includingcable, interface. David Kampfner, 4 GreshamGardens, London NW11. 01-458 8240.

TRS-80 16K L2, screen, recorder, manualsetc. £275. Milton Keynes 670615.

PRACTICAL COMPUTING May 1982 181

PERIPHERAL SALE: Dolphin BD80 printer120CPS £189, also BD8OP with Pet interface£210. Data Dynamics 390 RS232 printer £80.IBM 735 Selectric Terminal Printer £196. Tel:0435-830680.

32K 380Z research machines computer. Asnew condition in original blue case. Buyersupplies their own ASCII keyboard. Completewith Basic software, utilities and documenta-tion, £700. Reading (0734) 594365.

APPLE II + 48K with disk drive and controller,colour card, Alf MC16 music synthesiser withsoftware and manual, various software,£1,200 ono. Tel: (0329) 232698.

APPLE II PLUS 48K, colour card, over £60software, cassette player, 5 manuals, allleads, modulator, paddles, only six monthsold, PERFECT CONDITION, still under war-ranty only £695. Phone Uxbridge (0895)35129.

ZX81, 16 xK RAM, 30 Programs + M/C Lang.Books, Motherboard kit. Real lost £145, willaccept £125 ono. (still under guarantee) Tel:01-898 4863.

APPLE. Educational Software for PrimarySchools. Interesting game settings. Excellentgraphics, presentation, documentation. Discsor cassettes (£5-£8 each). Details/Cataloguefrom Kingfisher Software. Tel: 02756 68152.

10 1K ZX81 GAMES-M/C = Canyon!, Shuttle,Asteroids. BASIC = Galaxians, Simon, SpaceInvasion, Connection, Destroyer, Hangman,Gunfight. Cassette £2.50 Listings £3.00 c.w.o.Ian Morrison, 17 Winton Circus, Saltcoats,Ayrshire KA21 5DA.

DO YOU WRITE MACHINE CODE on thebacks of envelopes? Pad of 80 coding sheets£2.40 inc. p&p. Toseland, 30 Torrs Road,Harrogate HG1 4TB.

ZX81 FAST ACTION top quality 4K machinecode programs. Scramble, Galaxy Invaders,Space Invaders, Gunfight, Asteroids. £3.95per program on tape. J. Steadman, 6 CarronClose, Leighton Buzzard, Beds., LU7 7XB.

TANDY LINE PRINTER VII, only a fewmonths old, still guaranteed. Will accept £179.Tel: 021-358 5312.

SHARP MZ8OK Education Software,calorimetry £5. Galvonometers £5. Gas Laws£5, German Vocabulary Test (2 volumes)£7.50 per volume Send for full details toQUALITY SOFTWARE, 21 Dunes Drive,Formby, Merseyside L37 1PE.

NASCOM 2. 64K in cased rack. RamA +RamB, 4MHz no -watts, Programmable graph-ics, Sound, ROM Basic, ROM Toolkit, Pascal,Pilot, Forth, Assembler, Games etc. Basic &Toolkit may be paged out to give 62K unse-able RAM. Phone Nigel Edwards0202-8753210.

SHARP MZ8OK 48K, 18 months old, resetswitch, MX8OFT Interface, user notes, and£200 worth software. Includes Calc II, Data-base, Supercopy, Printer Basic, ExtendedBasic, Star Trek, Word Processor, SpaceInvaders, Disassembler, Sound Effects, M/CCode and Chess. Deliver 30 miles Luton.Nearest £420. Drek (0582) 418577 (evenings)666678 (days).

COMPUTER GAMES - five home -producedgames available (strictly non -arcade type) for16K TRS-80. S.A.E. for details to: 57 RowleyStreet, Walsall WS1 2AZ.

CSC (Northern Ltd)(0274) 391076

CSM Ltd021-382-4171

Cyderpress Ltd0491-37769

Daman Computer Services061-793-7015

P R Daly09274-29815

Deltic Computing LtdBasingstoke 59715

Diskdean Ltd01-242-7394

Diskwise Ltd05793-3780

D T Systems(0603) 27833

Equinox Computer Systems01-739-2387/9

Fully IntegratedBusiness Systems Ltd021-328-7920

"Ash Court", 2 Ash GroveGreat Horton Road,Bradford BD7 1BN

Refuge Assurance HouseSutton New Road, Birmingham

2 Church LaneWallingford, Oxfordshire

Kennedy House, Rutland StreetSwinton, Manchester M27 2AU

Oaklands Gate, NorthwoodMiddlesex HA6 3AA

2nd Floor, May Place HouseMay Place, Basingstoke,Hampshire

23 Bedford RowLondon WC1R 4EB

25 Fore StreetCallington, Cornwall

32 Surrey Street,Norwich NR1 3NY

Kleeman House, 16 Anning StreetNew Inn Yard, London EC2

18 Hanover DriveGravelly Industrial ParkTyburn Road, BirminghamB24 8TE .

Goldcrest Computer Services67 Union Street, Newport Pagnell C HartnettNewport Pagnell Buckinghamshire613188/611988

G W Computers Ltd 89 Bedford Court Mansions01-636-8210 Bedford Avenue, London WC I

Graffcom Systems Ltd 52 Shaftesbury AvenueLondon

c/o Lifeboat Associates32 Neal Street, LondonWC2H 9PS

Refuge House2-4 Henry Street,Bath

PO Box 117, 141 Euston RoadLondon NW1 2AY

11 Station ApproachNorthwood, Middlesex

22 Newland StreetKettering, Northamptonshire

Regent House, 16 West WalkLeicester LEI 7NG

168-186 South StreetRomford, Essex RM I 1TR

Pargate House, Cross Road,Chorlton- cum -Hardy, ManchesterM21 1DH

8-12 Lee High RoadLondon SE13 5LQ

61 High StreetCroydon, Surrey

Cambridge RoadOrwell, Hertfordshire

19-21 Denmark StreetWokingham, BerkshireRG11 2QX

First Floor, 17 Guithavon StreetWitham, Essex

Graham Dorian Software01-379-7931

Guestel Ltd0225-65379

Hayden Young Ltd01-387-4377

Haywood Associates Ltd01-428-9831

HB Computers Ltd0536-520910

Horizon Software Ltd0533-556550

Humac LtdRomford 752005

IBIS Business InformationSystems Ltd.061-881 0585

Informex London Ltd01-318-4213/7

Instar Business Systems01-680-5330

Intelligent Artefacts-0223-207689

Intereurope SD Ltd0734-789183

Interface ComputerServices Ltd

0376-518112Ismail CAD

James C Steedman0903-814923

Keen Computers0602-583254

Kesho Systems041-226-4236

47a St Johns Road, Tottenham,London N15

18 Manor Road, Upper BeedingSteyning, Sussex

5b The PoultryNottingham

72 Waterloo StreetGlasgow G2

Stewart Smith

Peter Mart

C Murphy

L J Watson

Peter Daly

R Cornforth

M Kusmirak

John Metcalf

BarbaraCastedine

Allan Timpany

Johnny Johnson

John Oatham

F Brown

0 Ismail

Bob Ellis

Angus Nial

182 PRACTICAL COMPUTING May 1982

Buyers' Guide

L & J Computers01-204-7525

Landsler Software01-399-2476/7

LiVeport Ltd0736-798157

Logma Systems DesignBolton 389854

Ludhouse Ltd01-679-4321

Map Computer Systems Ltd01-633-3084/5

Median-Tec0734-664969Metrotech

0895-58111Micro Computation

01-882-5104Micro Focus

Microact Ltd021-455-8585

Microbits0734-792021

Microcomputer Applications0734-470425

Microcomputer BM01-981-3993

Microdigital Ltd051-227-2535

Microgems Software0602-275559

Microland0723-70715

Micromedia SystemsNewport 59276/7

Micropute0625-612818

Microsense0442-41191/48151

Microtek0689-26803

Minicomputer CS Ltd0494-448686

MMS Computer Systems0234-40601

P J Norris ComputerApplications053-183-428

Padmede Computer Services025-671-2434

PCL Software Ltd021-552-6126

Peach Data Services Ltd0283-44968

Personal Computers Ltd01-626-8121/2/3

PK Microsystems Ltd01-839-3143

3 Crundale AvenueKingsbury, London NW9 9PJ

29a Tolworth Park RoadSurbiton, Surrey KT6 7RL

The Ivory WorksSt Ives, Cornwall

2-10 BradshawgateBolton, Lancashire

2-6 Marian RoadLondon SW16 5HR

Belgrave Industrial EstateHoneywell Lane, OldhamOL8 2LY

120 Oxford RoadReading, Berkshire

Waterloo RoadUxbridge, Middlesex UB8 2YW

8 Station ParadeSouthgate, London N14

c/o Lifeboat Associates32 Neal Street, London WC2

Radclyffe House66-68 Hagley Road, EdgbastonBirmingham

Barford House, Shute EndWokinghamBerkshire RG11 1BJ

11 Riverside CourtCaverSham, ReadingBerkshire

4 Morgan StreetLondon E3 5AB

25 Brunswick StreetLiverpool L2 OBJ

32 Buckingham AvenueHucknall, Nottinghamshire

17 Victoria RoadScarborough, North Yorkshire

Seymour House14-16 Chepstow RoadNewport, Gwent

Communique Place9 Prestbury PlaceMacclesfield, Cheshire

Finway RoadHemel HempsteadHertfordshire

50 Chislehurst RoadOrpington, Kent

Pilot Trading Estate163 West Wycombe RoadHigh WycombeBuckinghamshire

26 Mill StreetBedford

Rochester House, Canon FromeLedbury, HerefordshireHR8 2TG

112/116 High StreetOdiham, BasingstokeHampshire

146-150 Birchfield LaneOldbury, WarleyWest Midlands B69 2AY

5 Horinglow StreetBurton on Trent DE14 1NJ

194-200 BishopsgateLondon EC4M 4NR

46-47 Pall MallLondon SW1Y 5JG

Jack Goodman

E Landsler

M Ward

Denis Thomson

Graham Jones

P J Norris

John Packwood

P Hemmings

Brian Homewood

Mike Hardwick

APPLE GRAPHICS TABLAT complete,unused not needed on project. £380. Tel:0225 310916.

SINCLAIR ZX81 16K RAM PACK - almostnew - £42 o.n.o. Bedford (0234) 857105.

ZX81 DATA: provides read, data and restorestatements (integral data values only). Cas-sette £2.50. ACCOUNTS - budget yourdomestic or business spending. Savesdatafiles separately from program. Cassette(16K) £3.45. A. N. Wilson, The Vicarage,Whitworth Square, Rochdale, Lancs., OL128PY.

ZX81 16K STOCK ANALYSIS PROGRAM:Menu driven, user -definable, gives results ofstock used, gross profit compares stock hold-ings and gives graphic display of results. Idealfor restaurant, small shop, pub, small hotel,etc. Only £3.75 on cassette. J. Lavelle, WindyHill, Far Westhouse, Ingleton, Yorkshire LA63NR.

ZX81 1K THE ULTIMATE GAMES TAPE: 20IK games for only £3.75 on cassette. Includes:reaction, pontoon, shoot out, bomber, andmany more. J. Lavelle, Windy Hill, Far West-hoUse, Ingleton, Yorkshire LA6 3NR.

6800-1-2-3-8 ASSEMBLER. Runs on CBMPET. Fast 2 pass macro assembler. Interfaceto Davidson -Richards Eprom programmer.SAE further details. CWO. Manual £2. Disc£28. M. Tyler, 2 Park View Drive, CashesGreen, Stroud, Glos. GL5 4NQ.

COMMODORE PET 8050 complete withaccounting system and data base - less than6 months old f 2,250.00COMMODORE PET 8050 complete withaccounting system only 18 months old£1,500.00. Tel: 0963 62797 for further details.

TELEVIDEO TS801 64K IMB floppy CP/Mcomputer 6 months old very good condition.£1,950. Diablo 630 daisy wheel 9 months old,fully maintained, £1,100. Sanders Technology12/7 printer with sheet feeder and 5 fonts, 9months old, £2,300. Tel: 0273 722240 any-time.

Z80A, 5MHZ, 64K, twin 5" DS -DD drives &controller, Serial/Parallel I/O, S100 bus &power, with 24 x 80 VDU board, 180 c.p.s.Matrix printer, and system case. Runningdemo but needs building into its box. Allsoftware, discs, listings, manuals, circuits etc.Total cost £2,500 + £200 worth of goodtechnical stuff thrown in free. Only needs £100video monitor & keyboard to complete. Bar-gain £1,500 lot. St. Albans 64077 evenings/weekends.

OSI C2 -4P, 8K RAM, 300/4.8K Baud cassette,32 x 64/32 x 32 display. Expansion bus,sound, d/a port, good graphics. £199. Ashby-de-la-Zouch (Leics.) 411146.

TRS-80 ... 16K, L2, monitor, cassette, man-uals. All as new, only 8 months old. (Buyinghouse) hence only £290. Tel: Burton -on -Trent65779.

PAPER TIGER IDS 560 letter quality Matrixprinter virtually unused £800. Tel: 01-2860071.

t YOUR TRS-80NIDEO GENIE program listingprinted, 50p per sheet (63 lines) on highquality fanfold paper or 50p per 100 lines onunperforated roll paper. Minimum order £1.00,your tapes/discs returned post free. Cheque/PO to Dave Ingledew, 20, Embsay Rd., LowerSwanwick, Southampton.

PRACTICAL COMPUTING May 1982 183

8K SYM working TELETYPE, residentassembler editor, fast Basic, super monitor.Excellent keyboard QWERTY and Hex £2.50.Tel: 0386 3148.

NASCOM 2, 32K RAM, NAS/Graphics ROM,8K BASIC, 3 Amp PSU. Complete with man-ual, portable TV and cassette recorder -£350 ono. Tel: 06286 5505.

MZ8OK USERS. 'COPY PROGRAM', copiesany software from monitor £6. 'SPACEATTACK' (knight's forth) fast graphics £4, orboth programs £8. P. Massey, 61 GreenAvenue, Astley, Manchester M29 7FF.

SHARP MZ-80K "Championship Tables" -motivational game devised by Maths Special-ist encourages speed and accuracy. Satisfac-tion assured. Cassette £4.00 (6K BASIC). P.Downes, 11 Melbury Grove, Birmingham B146BN.

ZX81, 16K MOVING GRAPHIC GAMES 10challenging, flicker -free games with instruc-tions. CASSETTE 1: Golf (with fairways,greens and scoreboard), Lunar landing,Fighter Pilot, Meteor, Alien Invaders. CAS-SETTE 2: Galaxy Guardian, Gridfire, CosmicFighter, Superlander, Shootout. One cassette:£4.99. Both cassettes £7.99. From I. Beynon,33 The Chase, ROMFORD, RM1 4BE.

APPLE II OWNERS - Protect your softwarewith this 16 sector DOS compatible system.Operates like a normal disk until a secret wordis typed in - then secret programs can bestored and recalled! ONLY £10. Mr. D. Fen-ton, 62 Chester Rd, Huntington, Chester, CH36BT.

16K ZX81, with printer and cassette recorder£150. Write Booth, 72 Sleaford House, Black-thorn St., London E3.

HITACHI 9" MONITOR, £75. Philips N2234cassette recorder with counter £30. Tel: (06473) 3456.

APPLE 48K DISC 3.3, parallel interface, RFmod, word processor, utilities, games anddiscs, £950. Woking (04862) 70890.

VIC-20, BASIC SYSTEM, computer and cas-sette. As new, only £169. Genuine reason forsale. Ask for Simon; Maidstone (0622)812385.

VIC: TWO CASSETTES AVAILABLE, 1 for £5or both for £8. Each has 6 programs. SAE, G.Quaglia, 232 Shoebury Road, Thorpe Bay,Essex.

PET 2001 8K: £350. Only used occasionallyand then mainly for computer games. Buyercollects. Tel: (evenings) Middlesbrough591656.

TAPE OF VIC SOFTWARE with cataloguelisting games and DS VIC BASIC. Adds over40 commands! Send £1 to DS Software, 19Reddings, Welwyn Garden City, Herts.

ZX80/81 16K "WORDMASTER". Over 20004 -letter words. Absorbing and educational.Tape £2.25. State 4K/8K ROM. F. Manders,24 Horton St., Lincoln LN2 5NG.

ANYONE HAVE AN ATARI 400 or 800 toswap for Hi-Fi system (with possible cashadjustment). Hi-Fi consists of Aiwa front load-ing cassette, AD6300 Dolby/Metal/CRO2 JVCamp JAS11 30 watts RMS per channel.Philips deck, Solavox speakers, Akai reel toreel 2 speed with Dolby.

P R Daly & Co Ltd01-868-7284

Quickmet SoftwareDevelopment0202-888217

Research Resources Ltd07073-26633

Rockliff Brothers Ltd051-521-5830

SA SystemsNewbury 45813

Salmon Microcomputing0325-721368

SBD Consultahts Ltd01-940-5194

Selven Ltd0376-40900

Sheffield MIS Ltd0742-20224

SMG MicrocomputersGravesend 55813

Software Aids InternationalLtd01-204-9396

Software Architects Ltd01-734-9402

Solitaire Ltd04252-71448

Southdata Ltd01-994-6477

Southern Computer SystemsTorquay 212957/8

Stage One Computers Ltd0202-23570

Stratheden Ltd0624-26668/25639

Style Systems Ltd0254-71638

SWTPC Ltd01-491-7507

Systematics International Ltd0268-284601

T & V Johnson Ltd0276-62506

T W Computers Ltd061-456-8187

Taylor Micro Systems021-358-2436

The Alphabet Company03046-7209

Tridata Micros Ltd021-622-6085

U -Microcomputers LtdWarrington 54117

Verwood Systems0788-87629

Vlasak Electronics Ltd0494-448633

Wisbech Computer Services(0945) 64146

Xitan Systems Ltd0703-38740

Butts Mead, High Road, EastcotePinner Middlesex HA5 2EY

57 Leigh Road, WimborneDorset BH21 1AE

40 StonehillsWelwyn Garden CityHertfordshire

2 Rumford StreetLiverpool L2 8SZ

Allington Lodge, Round EndNewbury, Berkshire RG14 6PL

PO Box 26 Croft -on -TeesDarlington DL2 2TN

15 Jocellyn RoadRichmond, Surrey TW9 2TJ

West House Chambers3 Sandpit RoadBraintree, Essex CM7 7LY

77 Hallam Grange RiseSheffield SIO 4BE

39 Windmill StreetGravesend, Kent

14 Chapman Crescent KentonHarrow, Middlesex

34/35 Dean StreetLondon W1V 5AP

Highcliff House 411-413Lymington Road

Highcliff, Dorset BH23 5EN10 Barley Mow Passage

London W47 Park Hill Road, Torquay,

Devon

6 Criterion Arcade N HewittOld Christchurch RoadBournemouth

Exchange House, 54 Athol Street P BridsonDouglas, Isle of Man

28a Railway Road R HormanDarwen, Lancashire BB3 2RG

38 Dover StreetLondon WI

Essex House, Cherrydown R YoungBasildon, Essex

165 London Road T JohnsonCamberley, Surrey GU15 3JS

293 London RoadHazel Grove, StockportGreater Manchester

Hamstead Industrial Estate C A TaylorOld Walsall Road, Great BarrBirmingham

2 Whitefriars Way, Sandwich A L MinterKent CT13 9AD

Smithfield House, DigbethBirmingham B5 6BS

Winstanly Industrial EstateLong Lane, WarringtonCheshire

Verwood House, High Street N HowardWest Haddon, Northamptonshire

Vlasak House, Stuart Road Paul VlasakHigh Wycombe, BuckinghamshireHP13 6AG

10 Market Street, Wisbech Ian DuffyCambridgeshire PE13 1EX

23 Cumberland PlaceSouthampton

I Metcalf

M Taylor

S A Trinder

S J A Still

Susan Ben -David

R Crowther

R A Coates

David Bull

Richard White

A Plackowski

184 PRACTICAL COMPUTING May 1982

FREELIBRARY BOX with every TEN -PACK

**PLUS**NEW DISK DIRECTORY & DISKWRITER

when ordering two packs or more

**PLUS**BRUSHED CHROME PAPERMATE PEN

when ordering 5 -9 TEN -PACKS

**OR**GOLD PLATED PAPERMATE PENwhen ordering 10-1 TEN -PACKS.

DISKINGFOR THE FINESTMINIDISKS & ACCESSORIESAll disks are factory fresh and individuallycertified 100% error -free.

DISKING INTERNATIONAL PLEPOS1 LIPHOOK HANTS (;1J.:30 /131 EL(O428)722563

5 1/4 If MINI DISKS

VERBATIM The World's favourite media 'Datalife' are alldouble density with hub ring reinforcement.

EXC VATMD525 S/Sided 40 track £18.95MD550 D/Sided 40 track £24.95MD577 S/Sided 77 track £26.95MD557 D/Sided 77 track £34.9510 & 16 Hard Sector at same prices

MEMOREX The Ultimate in Memory Excellence based onmany years of experience with recording media.

EXC VAT£18.45

MEMX 1D S/S D/Density £21.45MEMX 2D D/S D/Density £23 9510 & 16 Hard Sector at same prices

MEMX 1S/S S/Density

BASF FlexyDiske

BASF cross -linked Oxide coating for long media life andspecial lubricants minimise head wear.

EXC VA9T

BASF 1D S/S D/Density £21.45BASF 20 D/S D/Density

E251..4955

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DISKING SUPERLUXE DISK LIBRARY

Manufacturedexclusively for usto our own design.the SDL keepsyour valuabledisks flat & dustfree. while at thesame time allow-

ing you instant visual selection of any single disk. Thestandard SDL holds 20 disks, while the SDLX holds 28disks. The SDL may be uprated to an SDLX retrospec-tively.

SDL only £8.65SDLX only £10.39

DISKING DISKMAILERSThis product also exclusively ours. is a strong plasticenvelope for mailing one. two or three disks. in safety andcomes complete with warning labels & address labels.DM only 50n

DISK DRIVE HEAD CLEANING KITS

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Prevent head cra-shes and ensureefficient error -freeoperation.Enough for 26 bi-monthly cleans &a lot cheaper thana service call!

SUPERBRAIN SOFTWAREDATAKING corning soon will mathematically massageany Datastar or Wordstar data file, and columnate withreport writer Instant Sales. Nominal or Purchase ledgeror Comprehensive Sales/Purchase Reporting for Data -star users.DATAKING only ..£49.00DATAKING User Manual £2 50

PLASTIC LIBRARY BOXESThe genuine Egly Box that stores and protects your disksin tens - Unbeatable - (FREE with every ten disksordered)LB only £1.90

£16 50pATTENTION THE TRADEPlease write to us on your letter headed paper. and ask forour special trade prices and ottersGive your software the ultimate in presentation We canmake the SOL & SDLX in your colour PVC with your logo.Sample plastics swatch available tree by request

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We accept Armed Forces and allMinistry of Defence Establishmentsorders over £50.00 in value. All othercustomers cheques with orderplease payable to DISKING. If youare a large establishment, andcannot raise cheques without aninvoice, please post or telephone usyour order, and we will send a pro -forma invoice by return, for youraccounts department to pay against.

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We accept Barclaycard and Accesscard. You may write your cicard No.on your order or telephone the order,day or night, 365 days a year. Youmay speak for as long as you like,and don't forget to give full details ofwhat you wish to purchase, yourcredit card number, credit card hol-der's name & address, and deliveryor invoice address if different.

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PRACTICAL COMPUTING May 1982 185

WHY BUY FROM CAMDEN? WE SUPPLY : THE HARDWARE WE SUPPLY : THE SOFTWARE

* WE SUPPLY : THE BACK-UP

* WE SUPPLY : THE EXPERIENCE

WE SUPPLY : THE KNOWLEDGE

Superbrain64K QD MODELPLUS EPSON MX8OFTPLUS FULLY INTEGRATEDACCOUNTS PACKAGE

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MAIN DISTRIBUTORS FOR ALL THE LEADING MAKES OFMICROCOMPUTERS AND PERIPHERALS.

OFF THE SHELF PROGRAMS TO SUIT MOST APPLICATIONSFROM THE LEADING SOFTWARE HOUSES - WITH PROVENRELIABILITY.

FROM OUR OWN ENGINEERING WORKSHOPS WITH FULLYQUALIFIED TECHNICIANS OR ON -SITE SERVICE - YOURCHOICE.

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OUR FULLY TRAINED STAFF WILL ADVISE ON YOURREQUIREMENTS TO SUIT YOUR NEEDS AND IMPROVE YOURBUSINESS.

Apple III128K MODELINCLUDES MONITORVISICALC III - SOSMAIL LIST MANAGERAND APPLE BUSINESS BASICPLUS SILENTYPE PRINTERPLUS ADDITIONAL DISK DRIVELoi PER WEEK LEASE

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AMCOMPUTER CENTRE LTD

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ACCESSORIESZ-80 SoftcardMonitorsGraphics Tablet

186

Circle No. 208

PRACTICAL COMPUTING May 1982

End of file

STARFIGHTERTHE GAME of Starfighter is written inmachine code, with sound, for theTRS-80 Level 2, 16K, Models 1 or 3.With the tapes containing the programyou receive a 32 -page instruction manualentitled SC -78503 Starfighter - NewPilot Induction Manual. You will notice itis produced by "SGA PeriodicalsOffice/Landbase Central - Printing:5E". The manual is issued to all newStarfighter pilots and not only gives com-plete specifications for the SC -78503 andthe operation of the "TRS-type controlconsole" but also brings the trainee up todate in the political environment, condi-tions of service, handling of servicerecords - saving games on tape, to you- and gives details of enemy and friendlycraft likely to be encountered. There isalso a section on combat tactics.

You will either love or hate the man-ual. If you have read much science fictionyou will be able to skim over the pseudo -science to reach the information, and inthe process begin to feel like a rookieStarfighter pilot. If you merely want a setof rules, you will find them all in themanual but will have to hunt throughmountains of verbiage: "As an aid totarget identification, the SC -78503incorporates a target outline display fortargets directly in front of the craft. Theoperation of craft display is a compara-tive process which produces an arbitraryscreen display". I have to admit that Ifound it good fun, and as much a part ofthe game as the program itself.

Two tapes are supplied. The first is atraining program called a "combatsimulator", with which you can fly mis-sions against any and all types of craft youare likely to meet. It will notify you ofpilot errors. You can also request a list ofall available controls or stop the action.The complexity of piloting an SC -78503

Conclusions Starfighter is a state -of -the art game forthe 16K TRS-80. The game has some arcade features butthe opponents behave in a varied andIntelligent manner. It should appeal even Ifyou do not usually enjoy solo games. There are no apparent bugs in theprogram and it loaded easily. It is simple to save a game In progress,which is necessary if you ever work yourway up the ranks to the status of Starlord. The graphics are excellent, consideringthe TRS-80's limitations, and the soundadds greatly to the fun and feeling ofexcitement. Ratings:

Physical qualityPerceived complexitySubject complexityRealismPlay balanceOverall

Very goodFairly highFairly highVery goodDemandingExcellent

Mercenaries - the Solar Galactic Authority needs you. BobColtman reviews this buccaneering space game from The WarMachine.makes the pilot trainer extremely useful.

Starfighter pilots are hired as mer-cenaries by the Solar Galactic Authority,a company locked in war with the PetroResource Conglomerate. Pilots areassigned to patrol particular sectors ofspace, with difficulty based on rank, andare to investigate all sightings. This wouldnot be all that difficult if it were not forthe fact that many of the encounters arewith friendly star merchants, other Star -fighters, beacons, debris, etc.

Shooting at your friends is penalised,and rightly so, and trying to tell friendfrom foe can be very nerve-racking.Unfortunately, some merchants are actu-ally pirates and some Starfighters are

I fired until I heardhis hyperchargefield collapsing.

actually rogues in business for them-selves. The SC -87503 has an identifica-tion device, but this only works at veryclose range and can be jammed. Inves-tigating a sighting too aggressively cancause even friendlies to open fire.

As a mercenary, the Starfighter pilot isexpected to collect enough bounty onlegal kills to pay for the manoeuvringfuel, the hypercharge which is used forlong jumps, weapons and screens, andtow tickets which you need if you are leftstranded in space due to damage or lackof hypercharge. To gain promotion youcan only claim kills that have not beendeclared for bounty - an interestingproblem.

After launch from Landbase Central Ifound myself in an empty sector with onlystars showing on the viewscreen. I usedthe Long -Distance Target Scan to find apossible sighting, played it sneaky byshutting off my identity beacon, and hitdrive. Hyperdrive booted me intoanother sector, and I quickly switched tocombat mode and flicked on targetingwhich allowed me to line up my screenwith whatever was in the sector.

The display panel showed the rangeand axis of the target; this one was22,000 distance units away - the scale ofdistance units is classified - and the axiswas constantly changing since the targetwas taking evading action. At this dis-tance it was merely a large dot. No mes-

sages were incoming, and range was con-stant so I triggered a request for identifi-cation. The target did not respond and Idecided to close the range in order tomake a positive ID and use the man-oeuvring jets.

As I closed in I decided that if combatoccurred it would probably be at longrange, so I switched on the beam weapon- range 3,500 - rather than the waveweapon which has a range 500 but doesmore damage.

As I closed in, the target began toevade violently and signalled me that itwas a SC -87503 Starfighter. Not knowingwhose side he was on I left my signalbeacon off and continued to close range,hoping to use my identification devicewhich checks the target's tactics, brand offuel, etc., and identifies a target as friendor foe.

The target turned towards me and thedistance closed rapidly. He was continu-ing to signal, which jammed my equip-ment and we flashed past each other. Inoted he had begun to turn on to my tailand I was going too fast to turn with him.Even though I cut my speed I was stillunable to get him on to the viewscreenand my identification device finally sig-nalled

'IDENTIFIED . . . MARAUDERAttack!

Too damned late! Wham! He had openedfire and I could not get him into targetlock.

I hit maximum acceleration, hoping toopen the range. Wham! I could not takemuch more of this and opened fire wildlyto distract his attention. He let up as Imoved out of range, but I was still unableto turn inside him. I cut my speed com-pletely, turned as quickly as possible andmanaged to catch him in target lock as heflashed by.

I upped my speed, and as the rangeclosed, I held down the target lock so thatmy SC -87503 followed him automati-cally. I opened fire and held down thefiring button until I heard the lovelysound of his hypercharge field collapsing.After the debris cleared my panel warnedme that my hypercharge field was run-ning low.

One combat and I already need arecharge; but then I am lucky to be hereat all. If I had not begun the mission witha full charge, I'd be in trouble now.

I would tell you more, but I'm due forlaunch in 10 minutes.

The War Machine is published monthly by Emjay, 17 LangbankAve, Rise Park, Nottingham, NG5 SBU. £1.25 an issue, £13for an annual subscription, postage and packing included.

PRACTICAL COMPUTING May 1982 187

MICROTEK

where SOFTWAREmeets HARDWARE

SHARP 3201 COMPUTERFull Systems available, Choice of Printers - Accounts, Payroll,Stock Control, Invoicing - Custom Programming to order. From£2,995 + VAT

For further details write to:

MICROTEK 15 Lower Brook St.Ipswich, Suffolk

tel. (0473) 50152

Circle No. 209

AIM Research Cambridge

Good software needn't cost the Earth!

CP/M SOLUTIONSWe sell programs we use ourselves.Can your present dealer say that?

Forth The small computer language of the eighties!

Xforth is our highly praised implementation of theForth -79 International Standard, with full CP/M compati-bility and enhancements that make it one of the mostpowerful Forth syktems around. From £45

Word processing The Amethyst group of programs, byMark of the Unicorn. Mainframe quality for micros.Screen editor Mince £110 Paginator Scribble £110 Bothtogether £210 Mince demo disc & manual £20 (£12refundable against order).

Spelling checker The Word best by far, yet cheapest. SeeByte Review. £48Spreadsheet T/Maker II It does a number on Viscalc!

£150Database d Base H 30 -day no risk trial. £370

Prices are subject to availability and are for North Star DD discs.Superbrairi and 8 inch formats: add £5 each to xForth, Scribble, Mince,Mince dent°, Other formats: please write.Add £3 p&p to all orders. We may have had to register for VAT by thetime you read this, but we will absorb VAT on prepaid orders receivedbefore 31 May 1982, except T/Maker and dBase.

Dealer enquiries welcomed.

20 Montague Road, Cambridge CB4 IBX.Tel: (0223) 353985

BEER RUN

PEGASUS II

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COUNTYFAIR

SABOTAGE

:::::

SOD SOFTWARE

15 Jocelyn Road, Richmond TW9 2TJ

Telephone 01.948 0461

Telex 22861

Disk

£19.95

Disk

Disk

1111£18.00

pisk

£16.95

Disk

111111£12.95

Please telephone for a full catalogue, or use the coupon provided.Dealer enquiriei are welcome. All prices are plus VAT, postage & packing free.

Name

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Address

Circle No. 210 Circle No. 211

188 PRACTICAL COMPUTING May 1982

New-fangled hardwareold-fashioned value at NSC

Computer Shops!!!PRINTERS

SEIKOSHA GP80ACheapest dot matrixprinter. Recommendedby Acorn andCommodore. £199.00

SEIKOSHA GP100AWider version of GP80A

£230.00SEIKOSHA 8510

New friction/tractor printerwith graphics £475.00

OKI MICROLINE 80 Low cost. 80 column, upperlowercase with pin and friction feed. £275.00

OKI MICROLINE 82 Bi-directional printing,programmable form length, serial and parallel. £399.00

OKI MICROLINE 83120 cps bi-directional on 15 inch paper. £759.00

SERIAL INTERFACERS -232 interface for M 80 £105.00

HI -SPEED INTERFACEHigh Speed RS -232 interface for M 80/82 £185.00

TRACTOR Tractor for M 80/82 £55.00TYMAC INTERFACE

Apple interface and cable for M 80 series £89.00EPSON MX 80 80 column tractor fed printer £358.00EPSON MX 80FT

As MX 80 but with friction and tractor £399.00EPSON MX 80FT II

As MX 80FT but with hi-res dot graphics £449.00EPSON MX 82 Friction and tractor feed £399.00EPSON MX 82FT

Graphics, friction and tractor feed £449.00EPSON MX 100

As MX 80FT but with full 15 inch platen £575.00APPLE INTERFACE

Apple interface and cable for MX series £89.00SERIAL INTERFACE

Serial interface and RS -232 cable for MX £59.00BUFFERED INT. As above with 2K buffer £79.00RIBBONS Ribbons MX 80/82 £9.00RIBBONS Ribbons MX 100 £13.00CENTRONICS 737-2

Letter quality printing - parallel version £425.00CENTRONICS 737-4 Serial version £475.00CENTRONICS 737P Pet version £485.00CENTRONICS 739-2

As 737-2 but with high res graphics £495.00CENTRONICS 739-4 Serial version £544.00CENTRONICS 150-2

150 cps, bi-directional, logic seeking £499.00CENTRONICS 150-4 Serial version £544.00CENTRONICS 779

Due to a bulk purchase, NSC are able to offer you thisDP quality, upper case only printer with infinitelyvariable print size (10 to 16.5 cpi) and full logicseeking head at less than half the normal trade price £295.00

INTEGREX CX80Full colour printer for Apple, VIC etc. £895.00

COLOUR INTERFACEApple colour dump card for above £125.00

RIBBONS Tricolour ribbons for above £5.00QUANTEX 6000 150 cps matrix printer £875.00ANADEX DP 9500L

150 cps, 15 inch platen, serial and parallel £895.00ANADEX DP9501

As DP9500 with graphics and other features £1045.00RIBBONS Ribbons for Anadex DP9000 series £14.00TEXAS 820 RO

High quality for 150 cps programmable printer £1300.00OLYMPIA EK100KSR A typewriter and letter quality

printer all in one package at the amazing price of £995.00DIABLO 630 RO High quality daisy wheel printer

capable of using metal or plastic daisy wheels P.O.A.B.D.T Cut sheet feeder for Diablo and other daisywheel printers from £650.00

FUJITSU 5P83080 cps daisy wheel - the fastest around! E1995.00

On all printers please add £6.00 for carriage.All other items please add 50p for p&p.

Circle No. 212PRACTICAL COMPUTING May 1982

COMPUTERSACORN ATOM

Available ex stock in any configuration - 8K+ 2K kitor assembled in any size up to 12K+ 12K. New ROMenables compatibility with BBC machine.

PRICES INCLUDING VAT & P&P8K+ 2K Kit £140.00 8K+ 2K Assembled £174.50Colour Atom inc PSU £204.0012K+ 12K Assembled £289.50 Power Supply £10.20

VIC 20Fast becoming the most popular home computer.Price including VAT £189.95 (p&p E3.00 extra).

PETBritain's best known micro computer. Our prices startfrom E375.00

APPLE IIOur best selling medium priced computer. Start withthe basic unit and build up your system with diskdrives, Pascal system, graphics tablet, voicerecognition card, Visicalc. etc. Phone for our latestprices on all these items.

APPLE III128K computer + Monitor III and Apple III Softwarecomprising Business BASIC, Sophisticated OperatingSystem (SOS) and Apple II emulation. £2545.00.

COMART COMMUNICATOR4MHz, 280A , S100 Computer with choice of twin170K, 390K or 720K floppy disk drives or one floppyand one 5Mb Winchester hard disk. Also available20Mb hard disk which can be added to any of theabove. This computer has been designed withcommunications in mind and we can offer an interfaceto Prestel as well as the usual accounting packages.Prices start at £1750.00.

We've just as a

RAN000PI ITHCFISED DEALER

The new Xerox 820,as seen onTV. is now availableon display with prices starting from £1750.00

NORTH STARCome and see the Advantage, a major new systemfrom a well established manufacturer. £2195.00.We can also supply the Evergreen Horizon.

RAIR (THE ICL PERSONAL COMPUTER)The D.P Manager's favourite micro. The 3/20 machinehas twin 250K floppy disk drives and the 3/30 has onefloppy and one 5Mb Winchester hard disk.Also available is a 10Mb hard disk drive which can beadded at the time of purchase or at a later date.M/PM for multi user environments. Programminglanguages available include basic Fortran, Pascal,Cobol and Assembler. Prices start from £2,750 andrental terms are available.

CROMEMCOIf you're looking for a 'Unix' like operating system,look no further. Cromemco's Cromix offers you up to63K memory space per user with the ability to runC/PM programmes if required. Choose from Systemzero, one, two, three or Z -2H.

If you are looking for a VDU to complementyour system, NSC can supply any one from avariety of manufacturers at prices ranging from£400-£2,500.LEAR SIEGLER, TELEVIDEO. VOLKER CRAIG,BEEHIVE, DEC. IBM.

FLOPPY DISCSWe stock Dysan at the following prices: S/SidedS/Density suitable for Apple etc. £25.00 per 10 (plus50p p&p). D/Sided D/Density suitable for Rair,Cromemco, Comart, North Star E40.00 per 10(plus 50p p&p).

BOOKS+FANFOLD PAPERReadily available in avariety of widths.C12 Cassettes, PrinterRibbons and mostcomputer accessories

12""MONITORS

Low resolution£99.95(plus E6.00 carriage)

High resolution,green screen

£134.95(plus E6.00 carriage)

NSC are a BBC Micro Computerdealer, come in, see andbuy your computer peripherals.

ORDER BY POST WITH CONFIDENCEInstead of calling personally at NSC Computer Shops youcan send cash with order. Please complete the order formbelow.All prices are exclusive of VAT except where otherwisestated. Prices correct at time of going to press.

N C COMPUTER

SHOPSNSC Computer Shops, 29 Hanging Ditch,Manchester M4 3ES. Tel: 061-832 2269

'Please send the following order:

NAME

ADDRESS

POSTCODE

P&P

I

I

PRICE I

I

I

I

I

TOTAL ._ _ _ IMost of our prices are heavily discounted and therefore payment Imust accompany the order. Credit card payments will be accepted.Please quote credit card number and type of card. Cheques payableto NSC Computer Shops.

I wish to pay by Access./Barclaycard./Diners Card ('delete asapplicable).CARD NO. 8®lC)I

C11110111=111111111MMIll I

SIGNATURE

NSC Computer Shops, 29 Hanging Ditch, Manchester 914 3E5Tel: 061-832 2269

PRC1582

DATE

NSC 34 A (RB)189

NOW THEY ARE TALKINGAll you need to get your computer talking highlylegible speech is a RS232. Unbelievable? Call usthe unit will cost £250 complete.

THE S-100 BUSNew and old is here to stay. Its flexibility and cheapness faroutweigh any possible defects. We offer a range of boards,systems and software that are unrivalled in price and per-formance. Examples:Z-80 CPU +RS232 port +Monitor £125Disk controller with DMA and CPM £16564K fully static low power RAM 8 Mhz £425256K RAM 8/16 bit transfers £65026 Mbyte Hard Disk Subsystem £2,495

YES...we have the 68000/808628000 on the S-100 either as boardsor as systems under Unix/Forth/CPM86 with Pascal, Fortranand Basic.

SPECIAL OFFERComplete 64K system Z80 based with CPM2.2, VDU, printerand 2.4 Mbyte floppy disk store. £2,995So if you need A/D converters, real time clocks, tektronixemulators, or any other S-100 board, please call us.

BRISTOL SYSTEMS LTD.,13 Ravenswood Road, 0272 730578Redland, 0272 741053Bristol BS6 6BN. 0275 892495

Circle No. 213

BEEBUG FOR THE

BBC MICROINDEPENDENT NATIONAL USERGROUP FOR THE BBC MICRO

IF YOU'VE GOT A BBC MACHINE, OR HAVEORDERED ONE, OR ARE JUST THINKINGABOUT GETTING ONE, THEN WE HOPEBEEBUG HAS SOMETHING TO OFFER YOU.BEEBUG provides a central information pointfor users of the BBC Micro, and is a registeredreferral centre for the BBC project.We run a regular newsletter (10 issues peryear) devoted exclusively to the BBCmachine.New program listings in each issue (3-0 Noughts andCrosses, and full colour Moon Lander in the April issue).Hardware hints and tips. How to decide between the Aand B options. How to upgrade the A option. Reviews ofthe latest software. A series of articles on getting themost out of your machine. How to add joysticks andgames paddles to both the A and B options. Softwarecompetition. A beginner's guide to BBC BASIC starting inthe April issue. Discount software and hardware. Regularadvice clinic to answer your queries. Other projects andactivities in the pipeline, plus a host of ideas contributedby members.

Dr D. E. GrahamSheridan Williams

Membership:Introductory offer

6 months £4.501 year £8.50

BEEBUGPO BOX 50

St AlbansHarts

Make cheques payable to BEEBUG or SAE for further details

Circle No. 214

SIMPLICALCFOR EVEN 8K PETS FROM CRONITEI

THE LOW-COST ALTERNATIVESimpliCalc is a small, powerful work sheet program. It runs on any CBM PET, except "old ROM",even cassette -based. The sheet is viewed on the screen.

SimpliCalc makes the "what if" exercise available on all sizes of CBM. On a 32k it provides amuch larger useable matrix than any similar program: on an 8k it provides enough space toanalyse a capital purchase or personal tax computation.

SimpliCalc is freeform. Its uses are many. For instance, it's been calculating chemical weights,projecting profits by product group, and costing out salary reviews. Be inventive.

SimpliCalc is simple to use, with 8 single -key commands. Print your sheet out, and save it oncassette or disc depending on version. A comprehensive manual is provided.

To order your copy of this versatile numeric tool, send cheque with details of your system,specifying whether your CBM is *2001/3000/early 4000 (PEEK (144) = 46) *late 4000 *8032 andwhether you want cassette £29.90 incl. VAT or disc £36.80 incl. VAT (specify drive type).Security copies available (no backup possible) at £4.00 cassette and £6.00 disk incl. VAT.

CRONITE COMPUTER SYSTEMS LTD., Montgomery Street, Birmingham B111DT.

Further details from Mark Turner on 021-773 8281 - telex 338247 VisiCalc is a trade markof Personal Software Inc.

Circle No. 215190 PRACTICAL COMPUTING May 1982

LONDON COMPUTER CENTRENEW! from Tele Videothe TS802 £2,250* Expandable to multi-user system and hard disks.* Superbrain compatibility.* CPM operating systems 64K Ram.* Detachable keyboard with 22 function keys (Wordstar option).* Expandable up to 6 users, multi -tasking system with Emperor 20 (10m byte hard disk) 64K

processor, back-up floppy disk £4,500.* Plus each user terminal with 64K Ram, only £1,050.* Green screen - true decenders.* Built in 1 Mbyte dual disk drives.* OPTIONS. 1.6m byte dual discs £500.* 10m Hard disk £1,995.* Expandable up to 6 users, multi -tasking sys-

tem with TS806 (10m byte hard disk) 64Kprocessor, back-up floppy disk £4,500.

* Plus each user terminal with 64K Ram, only£1,050.

= ACT £2,395

w -11...&-rsinus 1SIRIUS 1

16 bits for the price of 8 bits

128K RAM1.2M disk storage

The SPECIAL LCCAPPLE SYSTEM

48K Apple Two Disk Drives & 12" GreenScreen Monitor £1,39580 Column card with Decenders £135CPM Softcard £9516K (Integer) Card £65Centronics Parallel Card £75Serial Printer/Communications Card £75

AUTO SHEETFEEDER £580

New! 12"wideAutomaticSheet Feederfits allbelow

EPSONMX -80 FTMX -80 FT2MX -100

MILINEMS WOW

SUPERBRAINWITH NEW EXTRA FEATURES

FROM £1,795

11111111111111111111111111111111111111111r

AUTHORISED TANDYDEALERModel I48K System2 Disk DrivesGreen ScreenComplete £995

Model IIwith TRSDOS andno extra chargefrom £1,995

Model III16K £55048K £57548K with diskdrives £1,350

PET! APPLE! TRS80! HORIZON! OWNERS!Let LCC - the BIG COMPUTER CENTRE -

put you a cable's length away fromLETTER QUALITY PRINTING with 7 Star Printers.Olivetti ET21. 20 CPS. Doubles as typewriter £795TEC 40. 40 CPS. JAPANESE DIABLO 630 uses Diablo Daisy Wheel &Ribbons £1,235Daisy Wheel II 60 CPS. RICOH 1600 Daisywheel £995Qume SPRINT 5. 45 CPS. £1,350FLOWRITER RP 1600 60 CPS.The most intelligent daisy. Proportional spacing with right justifica-tion on Wordstar, Wordpro, Apple Writer, Scripsit as from Basic.

£1.500£1.650£1,695

NEC. 55 CPS.FUJITSU 80 CPS. Plastic/Metal wheelsDEMONSTRATIONS ON ALL MODELS

ALL PRICES ARE EXCLUSIVE OF VAT AND DELIVERYDEALER' ENQUIRIES INVITED ON ALL PRODUCTS

43 GRAFTON WAY, LONDON W1P 5LA (Opposite Maples )

OPENING HOURS: 11-7 MON-FRI 12-4 SAI Tel: 388 6991/224 hour answer phone: 01-388 5721

PRACTICAL COMPUTING May 1982

Circle No. 216191

SYSTEMS FORBUSINESS...

As business system specialists we're able to offer a fullrange of software adapted to low cost hardware, so eventhe smallest business can benefit from computerisation ata comparable cost - and as you grow so can yourcomputer system.

Apple II from £1895Apple III from £2900

Sharp PC3201 from £2895Commodore 4000 from £1875Commodore 8000 from £2995

Systime 500 from £7000Choose from our comprehensive software packagesincluding the widely acclaimed FMS Accounting System,financial modelling, payroll, filing systems and assetregister; or take advantage of our software expertise witha package tailor-made for your requirements. Full leasingfacilities available including software.

...COMPUTERSFOR PEOPLE

The same expertise we offer to businesses is also availableto our home computer customers. You can select from ourrange of hardware, accessories, games, hooks andeducational programs - and we'll demonstrate anysystem before you purchase.

* VIC 20 COLOUR COMPUTER31/2K user memory24 colour variations

3 x 3 octave sound voices4 programmable function keys

PLUS - games cartridges; extra RAM packs: 3K, 8K,16K; light pen; games paddles; printer; disk drive

* SHARP MZ8OK COMPUTER48K memory

3 octave sound rangeMultiple graphic character set

INCLUDES - keyboard, screen with 40 characters &24 lines, and cassette unit with tape counter.PLUS - printers, disk drives, interface cards and choiceof BASIC, FORTH, PASCAL, ASSEMBLER orMACHINE CODE.

2 year guarantee on most productsRing for current prices!

COD SERVICE AVAILABLE -ring for details

OPEN MONDAY - SATURDAY9.00 am to 5.30 pm

/OUTERCE&

15-17 North Parade BRADFORD BD1Tel (0274) 391166

192

5MB WINCHESTERFOR APPLE I I

LOWEST COST/MBYTE FROM ANY SUPPLIER

SINGLE APPLE CONTROLLER

PASCAL COMPATIBLE "DROP IN" BIOS

LICENSABLE "PROTECTED SOFTWARE" OPERATING SYSTEM(only available to bona -fide software suppliers)

DEDICATED APPLE II

FAST DELIVERY

SUBSYSTEM DOES NOT INCLUDE APPLE DRIVE

1,\NSOXIXtiNvit*

SYMBFILE

LOWEST UK PRICES

R.R.P. £1450TO PLACE YOUR ORDER, OR TO MAKE

FURTHER ENQUIRIES, CONTACT: -

symbioticcomputer systems

85/87 STATION ROAD, WEST CROYDON,

SURREY CR0 2RD

01-6808606Circle No. 217

PRACTICAL COMPUTING May 1982

TELEVIDEO SYSTEMSTHE solution to stand alone and multi-user microcomputer systems.

The most advanced microcomputer architecture available on themarket today.

Multi-user SystemsTS806 - 64K RAM 370K floppy Supports 6 users

7.4MB Winchester £4104

TS816 - 128K RAM 18MB Winchester Supports 16 users14MB tape drive £7388

TS800 - 64K RAM work station £1026

Standard Features* CP/M 2.2* MmmOST multi-user, multi -tasking, executive* Internal networking at 800Kbd using SDLC protocols* External communications at up to 38Kbd* Shared or dedicated disk resources* Shared or dedicated printers* Built in tape drive for Winchester back up* Serial and parallel printer ports* No cost penalty for upgrading from stand alone to

multi-user* Data security with system passwords* Low cost maintenance because of quality engineering

and built in diagnostics* Nationwide maintenance and support

Stand alone SystemsTS802 - 64K RAM 736 floppy £2175TS802H - 64K RAM 370K floppy 7.4MB Winchester £3990

* Selectric style detached keyboard.* Green phosphor screen (25x80) with status line.* Twin disc drives.* Built in expansion - Networking port for communication

to multi-user system.

OPTIONAL FEATURES* Wordstar and Spellbinder word processing* Integrated accounts (written and supported in the UK)* Compilers

Digital Research - Pascal MT +- PL/1- CIS COBOL- DBASE II

Microfocus* Database* Supercalc* Choice of printers

- Fujitsu SP830 80 cps daisy wheel- NEC spinwriter- Sanders Technology S700 (to 450 cps)- Oki and Epson matrix

Prices quoted are based on an exchange rate of £1 = $2

Purchase rent or lease from the market leaders in multi-user microcomputer systems

THE ELECTRONIC OFFICE

PHOENIX BUILDINGS 32 WEST ST. BRIGHTONTel: BRIGHTON (0273) 722248/9

Circle No. 218

PRACTICAL COMPUTING May 1982 193

KNIGHTS ANNOUNCE THE M1 -80ADEAL Al The new MZ-80A with BASIC, PASCAL, and

MACHINE CODE languages and 100 programsto get you off to a flying start £477

DEAL A2 Everything as per deal Al but we allow you £50for any Sinclair computer.

DEAL K1 MZ-80K with BASIC, PASCAL, FORTH,MACHINE CODE and 100 programs £425

DEAL P1 PC1500 hand held micro, 16K ROM + 3.5KRAM £134

DEAL P2 CE150 four colour printer for the PC1500 £109

DEAL P3 CE151 4K memory expansion module £36

DEAL B2 SHARP MZ-80B with standard Sharp Basic,machine code, Knights easy Assembler, disas-sembler, 70 programs and Sharp Double preci-sion Basic. £999

DEAL B3 MZ-80P6 printer, interface card and all cables£453

Dear Microfans,I have just returned from spending a month in Japan using the new MZ-80A

and PC1500 computers. The MZ-80A follows the styling of the MZ-80K but has50K of RAM and 6K of ROM memory. It has a green screen and a properQWERTY keyboard with a numeric keypad -a total of 72 keys. The volume,brightness and reset controls are mounted externally on the new model and cantherefore be adjusted at any time. The MZ-80A has a most interesting videosection which allows graphics to be entered in standard or reverse mode but thereally unusual feature is what I can only describe as 'ROLLER COASTERVIDEO'. This allows the programmer to scroll the screen up and down within adouble size video ram. A listing disappearing off the top of the screen is retainedin the extra video memory and can be recalled by pressing a key. This scrollingeffect can be used to great effect in business and games programs and some ofthe 100 programs we supply with the MZ-BOA make use of the roller coastervideo to great effect. The Basic includes AUTO, PAGE and COPY and wesupply each MZ-80A with three programming languages - BASIC, PASCALand Machine code. The comprehensive manual lists all the Basic commands,details the monitor routines, and also includes the full circuit diagram. Themanual has 90 programs to assist you in learning Basic and in addition to thesewe supply a further 100 programs on tape. We shall be releasing furtherlanguages for the MZ-80A in the coming weeks.

The PC1500 is the big brother of the highly successful PC1211 hand heldcomputer. It features an 8 bit processor, 16K ROM and 3.5K of RAM (which isexpandable to 11.5K). The printer is like a miniature X -Y plotter printing graphsetc. in red, blue, green and black.

Sharp in Japan were very pleased with the way we have been running theSharp International User Group. We now have more than 2000 members in 42countries. Membership is free when you buy your Sharp from Knights - it costs£3 to join if you bought elsewhere. The newsletter keeps you up to date with all

DEAL B4 MZ-80FD dual floppies, interface, cables, man-ual and master disc £696

DEAL B5 As deal B4 but with the addition of our KNIGHTCOMMANDER which adds commands likeRENUMBER, TRACE, DUMP VARIABLES,BLOCK DELETE etc to SHARP MZ-80B diskbasic. £725

DEAL B6 MZ-80EU expansion unit £47DEAL B7 COMPLETE MZ-80B system of micro, P6

printer, floppies, expansion unit, all cables,cards, manuals, etc. £2095

DEAL B8 Complete system as B7 with the addition of diskprograms for stock control of 2000 items, dataprocessing word processing, invoicing, 1500name/address mailing list, Knight Commander.

£2195DEAL B9 Everything in deal B8 plus KNIGHTS FORTH

LANGUAGE, ASSEMBLER, disassembler and70 programs £2295

DEAL B10 CP/M for the MZ-80B £60

the latest Sharp developments on a world wide basis and is full of usefulprograms and information about Sharp which is otherwise unobtainable.

Sharp in Japan were also very impressed with our new Forth language disk forthe MZ-80B and with our Knight Commander for the MZ-80B. While in Japan Icompleted many software agreements and we will shortly be releasing a wholenew range of programs to add to the hundreds we already have available forSharp. New programs for the MZ-80K include Defender, and Greedy Gremlinswhile for the MZ-80B we release 2001 a space odyssey and 747 flight simulator.

Sharp Japan confirmed to us that Knights are the largest dealer outsideJapan. They were especially pleased to hear that atter trading with them foreight years we have still never charged anyone at any time to repair a Sharpproduct - who needs one or two year guarantees?

For further details of any Sharp products ring, write or telex and we will do ourvery best to help you now and in years to come. Our newsletters will continue toassist you and we are always only a telephone call away. We use Sharp microsevery day in our own business and each enquiry receives the personal attentionof Alec or Graham Knight.

As we sell more Sharp products than any other dealer we guarantee our offersare unbeatable - if anyone else equals our deals we will beat that price on thespot.

Happy computing,

Graham Knight.P.S. At present we handle all export enquiries from Aberdeen but shortly we willbe opening in Germany, Denmark and Holland.P.P.S. Japanese readers can contact us direct at KNIGHT TECHNO SOFT,Sasebo Computer Centre, Nagasaki Prefecture.

ALL PRICES EXCLUDE V.A.T.108 Rosemount Place, Aberdeen AB2 4YW

Telephone: 0224 630526Telex: 739169 "KNIGHTS TV"

Knights T.0COY_Pkgr

Circle No. 219

194 PRACTICAL COMPUTING May 1982

DYNABYTE 5000.THE SYSTEM THATGROWS WITH YOU

The Dynabyte 5000 from Metrotech is one of the most flexible and comprehensiveMicro's available. It's smoothly upgradeable from a basic system with

630 thousand bytes storage to a powerful multi -processing, multi-user networkwith 99 million bytes.

The Dynabyte's Level 4 operating system, asuperset of MP/M, enables you to attach up to

eight terminals to your system. It can run severaljobs from one terminal simultaneously (up toeight at one time). You can connect up to 16

printers, share the processor, share the printers,add one terminal, one printer, or a block of

memory.

A full range of Software is available includingword processing, communications, database,

integrated business systems, all standardlanguages and viewdata.

011111711111rE15000

The Dynabyte system is distributed in the UK solelyby Metrotech, Waterloo Road, Uxbridge, MiddlesexUB8 2YW. Tel: 0895-58111 Ext. 265, 287, 247 & 269.

Metrotech is a member of the Grand Metropolitan Group.

aaaa ackfuacanTERMINALS PRINTERSanaa aaaaaaaa

O. 11.11.11.11.11

UP TO 400K MEMORY

COMMUNICATIONS

MATRIX. LINE OR LETTER QUALITY

DYNABYTE5000

7MB

CARTRIDGE TAPE

........./......'.51/9 in. WINCHESTERFIXED DISK

ION -LINE STORAGE]

6MB10M816MB

11MB23MB45MB

8 in. W NCHESTERFIXED DISK

2MBI, 31:62Mm13131MB

OPERATING SYSTEMS 5114 in DISKETTE 8 in. DISKETTECPIM MP M CPINEI

All Dynabyte 5000 models include standard features ofan S-100 bus architecture, 64K of RAM, a 4 MHz Z80A,

one parallel and two serial ports. All systems run onCP/M, MP/M and CP/NET.

Circle No. 220 19 8.

We'd love to manufacture the game you've invented.If we can tear ourselves away from it.

If your programme is compelling enough toglue us to our television sets, then it's just what we'relooking for. And if we can leave it alone for longenough to produce it, we'll glue millions of otherpeople to their sets as well.

THORN EMI is looking for video games and other

general interest programmes, which have beenproduced for home computers from the following:

Apple, Atari, B.B.C., Commodore, Sinclair orTexas Instruments.

196

Whether you're a professional programmer orcompetent amateur, if you have produced a pro-gramme that you think we may be interested in, we'dlove to hear from you.

Please don't send the programme direct. Writeto Home Computer Software Department,THORN EMI Video Programmes, Upper.St. Martins Lane, London W.C.2. and wewill send you an application form.Leaders in home video entertainment.

Circle No. 221PRACTICAL COMPUTING May 1982

Practical Computing and Your Computer present..

put rPersonal:

computingc

mputers

systemsSmallbusiness

April 23-25,1982Earls Court,LondonFriday & Saturday: 10am - 6pmSunday: 10am - 5pm

Admission £2.00 adults£1.00 children under 16.

At The Computer Fair you can see and compare an enormousrange of personal and home computers. Find out what they can doand which one would suit you best. Talk to the experts and discover

for yourself how much or how little - you need to spend. Choosefrom an amazing abundance of software programs and packages,

cassette units, VDU terminals and scores of computer games.

Swap your views and know-how with hundreds of other homecomputer enthusiasts - and find out a whole lot more from

computer professionals.

Plus-The Micro MouseContest.

Come and watch theincredible ingenuity of

computer controlled`mice" and how they find

their way (or not!) to thecentre of a maze. The

knockout heats and theEuromicro British Final

can all be seen at TheComputer Fair!

4.4 Bring the whole family -don't miss this

opportunity of bringingcomputers into your

everyday life.

Bringing computersto everyday life

PRACTICAL COMPUTING May 1982 197

04,Oillniirapion'eweptieople forAtarIN

3 Consoles available:Atari 400 with 16K RAM(AF36P) £345Atari 400 with 32K RAM(AF37S)£395Atari 800 with 16K RAM (AFO2C) £645Lots of other hardware: 16K RAM Module (AFO8J) £64.00Cassette Recorder (AF28F) £50.00 32K RAM Module (AF44X) £125.35Disk Drive (AFO6G) £345.00 32K Upgrade for 400 (AF45Y) £75.00Thermal Printer (AF04E) £265.00 Floppy Disk (YX87U) £2.75Printer Interface for 400 (AF41U) £49.95 Le Stick (AC45Y) £24.95Printer Interface for 800 (AF42V) £49.95 Joystick Controllers (AC37S) £13.95Interface Module (AF29G) £135.00 For full details ask for our hardware leafletVersawriter (AF43W) £169.00 (XH54J) SAE appreciated

NOW YOU CAN JOIN THE U.K. ATARI COMPUTER OWNER's CLUB. An independent user's group.Four issues of the club magazine for only £1.60! Address your subscription to Graham.

THE CHOICEST GEMS OF ATARI SOFTWARE FROM MAPLINAdventure GamesStar WarmRescue At Rigelinvasion OrionDatestonesol RynGalactic EmpireHi -Res Adventure// 2Analog AdventureAdventure LandPirates AdventureMission ImpossibleVoodoo CastleThe CountStrange OdysseyMystery Fun HousePyramid of DoomGhost TownSavage Island ISavage Island IIGolden VoyageEnergy CzarKingdom

C 32K (80248) £28.95 C 32K (8021X) £22.45-C 32K (B023A) £18.95C 32K (8022Y) £14.95

C 24K(B0140) D - 48K ( 8025C) £24.95

D- 32K ( 8033L ) £24.95 C 24K (13000A) £14.95 C 24K( 80018) £14.95 C 24K (B002C) £14.95 C 24K (80030) £14.95-C 24K -(B004E) £14.95C - 24K (8005F) £14.95

C 24K (B006G) £14.95C- 24K (B007H) £14.95

-C -24K (B008J) £14.95- C 24K (B009K) £14.95

C 24K (111010L) £14.95C-24K(8011M) £14.95-C 16K -(YG53H) £8.95

C 8K (YG55K) £8.95

Teach -Yourself ProgramsConversational French 5C 16K (YG44X) £32.50Conversational German 5C 16K (YG45Y) £32.50Conversational Spanish 5C - 16K - (YG46A) £32.50Conversational Italian 5C 16K (Y6478) £32.50Touch Typing -2C- 16K (YG49D) £14.95States 8 Capitals C 24K (YG56L) £8.95European Countries 8

Capitals C 16K (YG57M) £8.95

Learn Programminginvitation to Programming C 8K (YG43W) £11,95Basics of Animation C 32K (B057M) £9.95Basics of Animation D 32K (8058N) £10.95Player Missile Graphics C 16K (8059P) £18.95Player Missile Graphics 0 24K ( B0600) £19.95Display Lists C 16K (13051F) £9.95Display Lists 0 -24K (8052G) £10.95Horiz/ Venice I Scroll C 16K (8053H) £9.95Honz / Vertical Scroll D 24K (13054J) £10.95

Page Flipping C 16K (B055K) £9.95Page Flipping D 24K - (8056L) £10.95Master Memory Map Wallchart (X H57M) £4.00

ermines, ProgramsVisicalcWord ProcessorCalculatorGraphStatisticsArcade GamesStar RaidersAsteroidsSpace InvadersMissile CommandSuper BreakoutTan TrekTan TrekStar Trek 3.5Race In SpaceShooting GalleryMountain ShootJawbreakerBasketballTank TrapTank Trap

0 32K (YL39N)f 119.95 D- 32K (Y642V) £85.00 D- 24K (Y650E) £16.95-C16K(IG51F) £11.95 C 16K (YG52G) £11.95

E 8K (YG66W) E 8K (YG600) E 8K (YG7OM )-E 8K (YG64U)-E- 8K - (YG67X)

C 24K (YL36P) D 32K (YL37S) C 32K (8015R)-C - 16K (80350) C - 16K (8036P) C 16K (8012N)-D- 48K (80260) E- 8K(Y661R)

C 16K (YL34M)D -32K (YL350)

£29.95£29.95£24 50£29.95£29.95

£8.95C11.95£14.95£14.95£14.95£10.95£22.95£29.95

£8.95£11.95

£12.95£22.45

Thunder Island -C- 16K (80375) £1015Rotating Tilt C 16K (B048C) £14.95Lunar Lander C 16K (8016S) £10.95JumboJet Lander C 16K ( 8046A) £29.95Submarine Commander C 16K - (8047B) £24.50Sunday Golf C 166 (8013P) £10.95DartsTournament PoolSnooker & BilliardsChess

Horne Oame ProgramsScram C 16/24K (YG58N)Cypher Bowl C -32K (8020W)

C 16K ( 8042V) £19.95 C 16K (8045Y) £19.95 C 16K (8044X) £19.95 E 8K (YG63T) £29.95

Microchess C 16K (YL40T) £15.95Checker King C 16K (YL41U) £15.95Cribbage & Dominoes C 166 (8043W) £14.95

Send sae now for our new software leaflet with details of all the above programs. Order As XH52GLots of exciting new software titles available soon. Keep in touch with Maplin!Subscribe now to America's leading Atarionly magazine - Analog -6 issues per year for just £9.

Poker Solitaire C16K(8017T) £10.95Blackjack C 8K -(YG62S) £6.95Fast Gammon C 8K (YL33L) £9.95Revers] (Othello -type) . - C - 16K (8019V) £14.95Gomoko C 16K (8018U) £14.95Hangman C 8K (YG54J) £8.95Humpty Dumpty &Jack &Jill -C - 16K - (8038R) £19.95Hickory Dickory Dock C- 16K (8039N) £19.95British Heritage

JigSaw Puzzles C 16K -(8040T) £19.95European Scene

Jig -Saw Puzzles -C-16K(8041U) £19.95Atari Safari (25 Programs) C - 16K - (B0490) £18.95Atari Satan (25 Programs) D 16K (B050E) £24.95Mind Bogglers (3 Programs) C - 16K (YL3811) £8 95Music ProgramsMusic Composer E - 86 IYG48C) £32 50Movie Themes (use with

Music Composer) - C 16K(B034M ) £995

Computer La gggggg Basic A+ D- 48K (8031J) £52.50Operating System A + - D 48K ( 8030H) £52.50Basic A+

Operating System A + D 48K (B032K) £99.50OS Forth 0 24K (YL29G) £44.90Pilot E82C - 8K (YG69A) £49.50

Utilities3D -Super Graphics D 48K (8028F) £29.953D -Super Graphics -C- 48K -(8029G) £29.95Atari World (Graphics) 48K (8027E) £43.95Assembler Editor E 8K (YG68Y) £34.50Assembler C 16K (YL32K) £14.956502 Disassembler C 8K - (YL3OH) £8.956502 Disassembler DEIK(Y1.31J) £11.95CharacterGenerator C.16KCYL27£1 £9.97CharacterGenerator 016K(YL28F) £12.50Telelink E 8K (YG59P) £1495

Key: C =Cassette, 0 -Disk, E -Cartridge.2C -2 Cassettes etc. 81( 16K etc. showsminimum memory requirement.

- Issue 2.

00. Order as GG24B.

rimixon Maplin Electronic Supplies LtdP.O. Box 3, Rayleigh, Essex.Tel: Southend (0702)5529111554155.

Note: Order codes shown in brackets. Prices firm until 15th May, 1982 and include VAT and Postage and Packing

(Errors excluded).

DemonstrationsM our

shopsNO V4

See the amazingAtari's in

action at

159161 KingS., Hammersmith

VA

Tell 01.7480926

or at 284 LondonRoad,

Viestclitl-on-Sea,Essex.

Tel: (0702)554000

Circle No. 223198 PRACTICAL COMPUTING May 1982

I

-SYSTEM 4000EPROM EMULATOR/PROGRAMMERS

P4000 PRODUCTION EPROMPROGRAMMERThis unit provides 'simple, reliable'programming of up to 8 EPROMs. Ithas been designed for ease ofoperator use - a single 'program'key starts the blank check - pro-gram - verify sequence. Indepen-dent blank check and verify controlsare provided along with mode, pass/fail indicators for each copy socketand a sounder to signal a correct keycommand and the end of a program-ming run. Any of the 2704/2708/2716 (3 rail) and 2508 / 2758 / 2516/ 2716 / 2532 / 2732 EPROMs maybe selected without hardware or per-sonality card changes.2 year warranty. Price £545 + VAT:+ £12.00 DELIVERYVM10 VIDEO MONITORThis compact, lightweight VideoMonitor gives a clean crisp pictureon its 10" screen. Suitable for usewith the EP4000, SOFTY and othersystems. 12 month warranty. Price£88 + VAT, carriage paid.

MODEL 14 EPROMERASERS

MODEL UV140 EPROMERASERSimilar to model UV141 but with outtimer. Low price at £61.50 + VAT,postage paid.

EP4000 EPROM EMULATOR/PROGRAMMERThe microprocessor based EP4000has been designed as a flexible, lowcost, high quality unit for emulatingand programming all the popularNMOS EPROMs without the needfor personality cards, modules orhardware changes. Its softwareintensive design permits selection ofthe 2704 / 2708 / 2716 triple railEPROMs and the 2508 / 2758 /2516 / 2716 / 2532 / 2732 single railEPROMs for both the programmingand emulating modes.The video output (T.V. or monitor) formemory map display in addition tothe built-in Hex LED display, forstand alone use, is unique in thistype of system. This, with the doublefunction 28 key keypad, powerfulediting features, powered down pro-gramming socket, buffered tri-statesimulator cable and 4k x 8 data RAMgives you the most comprehensive,flexible and compact systems avail-able today.2 year warranty. Price £545 + VAT:+ £12 DELIVERY

MODEL UV141 EPROM t<4ERASER 14 EPROM capacity Fast erase time -r-

Built-in 5-50 minute timer Safety interlocked to prevent eye

and skin damage Convenient slide -tray loading of

devices Available Ex -Stock at £78 + VAT

Postage Paid

DISTRIBUTORS REQUIRED - EXPORT ENQUIRIES WELCOME.

GP INDUSTRIAL ELECTRONICS LTD,UNIT E, HUXLEY CLOSE, NEWNHAM INDUSTRIAL ESTATE,PLYMOUTH, DEVON PL7 4JNTELEPHONE: PLYMOUTH (0752) 332961 (Sales) / 332962 (Technical Service).

SOFTY 44:0

SYSTEMS et

SOFTY 2LOW COST 2716EMULATOR/PROGRAMMER Direct output to T.V. High speedcassette interface On cardEPROM Programmer. Multifunc-tion ' )uch keypad 2K Monitor in2716 2K RAM 128 bytescratchpad RAM 2K EPROMEmulation Can program 2732/2532 in two halves Editingfacilities including - Data entry/deletion, Block shift, Block store,Match byte, Displacement calcula-tion Supplied with ZIF socket,Simulator cable, comprehensivemanual, Antistatic lined EPROM trayand PSU. SOFTY 2 £169 + VAT(includes p&p)

SOFTY 1LOW COST 2704/2708EMULATOR/PROGRAM MER Direct output to T.V. High speedcassette interface - On cardEPROM Programmer Multifunc-tion keypad 1K Monitor in 2708 1K RAM 128 byte scratchpadRAM 1K EPROM Emulation Comprehensive editing facilities Supplied with ZIF socket, Simula-tor cable and comprehensivemanual.SOFTY 1 (Built and tested)£120 + VATSOFTY 1 Power Supply £20 + VAT

SOFTY 1CONVERSION CARDEnables SOFTY to program thesingle rail EPROMs, 2508 / 2758 /2516 / 2532. Selection of devicetype and 1K block are by pcb slideswitches. ZIF Programming socket.Supplied built and tested. £40 +VAT.EX -STOCK EPROMS

1-24 25-99 100 up2732 6:50 5:75 4:952716 2:80 2:60 2:402708 2:80 2:60 2:40

ADD VAT AT 15% - POSTAGE PAID

WRITE OR TELEPHONE FOR DETAILSON ANY OF OUR PRODUCTS

PRACTICAL COMPUTING May 1982CIrcle No. 224

199

CUNARD HOTEL, LONDON MAY 5-;1982

Opening Times: 10.00 hrs -18.00 hrs

closing 17.00 hrs on the last day)

Specially designed forbusinessmen who are

aware of the needto make their

company more efficient!This three day event, running parallel with the majorconference, is designed to show the hardware andsoftware equipment and expertise available in thisarea of Information Technology.

All aspects relating to the practical issues of purchasingand installing, operating and applying VideotexSystems will be covered.

Exhibits wIl I range from large "Turnkey" packages to thesmaller, but equally Important peripheral devices -terminals, printers, subscribers and telecommunicationsInterfaces.

This Is the 5th In the highly successful series of viewdataand videotex exhibitions sponsored by IPC BusinessPress, the world's largest business publishers. In the pastthese exhibitions have been successfully used Inlaunching the latest adaptors and complete systems.These systems are the modern tools of the new era inInformation Technology.

Don't miss out on this opportunity

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Fill out and return the form below.

Run in parallel with

VIDEOTEX SYSTEMS '82 CONFERENCE

Cunard International Hotel, May S-7

VIDEOTEX'SMoose send . tickets for Videotex Systems '82 ExhIbttlon fo

I IName

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I IAddress

I I

I I

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M.r

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We will assist YOU in your DECISIONfor Planning, Modelling,

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We will support YOU in achievingthe most from your Microcomputer

now, and as your business growsVISICALC MICROMODELLER MICROFINESSE

SALES, PURCHASE AND GENERAL LEDGERCOSTING AND STOCK CONTROL

WORD PROCESSING AND MAILING

For the best professional service contact:JOHN CHANG, MSc, ACMA

Komputation Automation Information Ltd203A Belsize Road, London NW6

01-328 7038 & 01-328 3968

ikippea computarAND OTHER GOOD MICROS

Circle No. 225

PHOTO ACOUSTICS LTDTHE ONE STOP COMPUTER SHOP-

VIC 20 computer £189.95Expansion box £97.953K RAM packs £29.958K RAM pack £44.9516K RAM pack £74.95Joysticks £10.00C2N cassette deck £44.95

CBM 8032 £875.00.CBM 8050 £875.00CBM 8026 £1,006.00CBM 4032 £690.00CBM 4040 £690.00CBM 4022 £399.00

These prices are Cash andCarry. Ring Dick at Watford forquote.** Software Available **

Apple II computer £784.00Disc drive 4- cont. £384.00Disc drive without £301.00Eurocolor card £70.009" Hi-res B/W monitor £99.009" Hi-res green monitor

£110.0012" B/W monitor £79.0012" green monitor £87.00

Genie I computer(Ring for quote)

EG3014 Expansion £228.00EG3013 Expansion £234.00EG3013/WExpansion£264.00EG400 disk drive £243.0012" B/W monitor £79.0012" green monitor £87.00

** Games software avail. ** * * Software avail. * *

58, High Street 255a St. Albans Road.Newport Pagnell Watford, Herts.Bucks. (entrance in Judge Street)Tel: 0908 610625 Tel: 0923 32006

ALL PRICES INCLUDE VAT .111,CREDIT CHARGE MAIL ORDER

Circle No. 226

200 PRACTICAL COMPUTING May 1982

Main DealersBirmingham

Byteshop Computerland9496 Hurst StreetTel 021 622 7149

DublinLendac Data Systems

8 Dawson StreetTel 0001 372052

GlasgowByteshop Computerland

Magnet House61 Waterloo StreetTel 041 221 7409

LeedsHoldene

Manchester Unity House11 12 Rampart Road

Tel 0532 459459

LondonByteshop Computerland324 Euston Road NW1

Tel 01 387 0505

DigitusLading House

10 14 Bedford StreetCovent Garden WC2

Tel 01 379 6968

Jarogate197 213 Lyham Road

Brixton SW2Tel 01 671 6321

ManchesterByteshop Computerland

11 Gateway HousePiccadilly Station Approach

Tel 061 236 4737

NottinghamByteshop Computerland

92a Upper Parliament StreetTel 0602 40576

SouthamptonXitan Systems

23 Cumberland PlaceTel 0703 38740

Dealers

BristolSenton

27 St Nicholas StreetTel 0272 276132

CambridgeCambridge Computer Store

1 Emmanuel StreetTel 0223 65334

CheshireHoldene

82a Water LaneWilmslow

Tel 0625 529486

EdinburghHoldene Microsystems

48 Great King StreetTel 031 557 4060

LutonRemdex Bradley Systems

31/33 Wellington StreetTel 0582 23682

ManchesterNSC Computers

29 Hanging DitchTel 061 832 2269

NorwichAnglia Computer Centre88 St Benedict's Street

Tel 0603 29652

SheffieldHallam Computer Systems

1 Berkeley Precinct451 Ecclesall Road

Tel 0742 663125

WatfordLux Computer Services

108 The ParadeHigh Street

Tel 0923 29513

Comart LimitedSt Neots Cambs PE19 3JG

Tel (0480) 215005Telex 32514 Comart G

into a major benefit.TPA

ADVANTAGE is the exciting new, packaged highperformance desk top computer with integral videoscreen. It brings the proven reliability, so longthe hallmark of Nortbsitri(products, into newand broader fields of application.

Add the established Comarttechnical, software, and servicesupport and the ADVANTAGEbecomes a major benefit to userslooking for a low cost, yet versatile,dedicated system. NOW! maim

Just look at the benefits.ADVANTAGE is economical:

A complete integrated accountingsystem and word processing systemwill cost around £4500 dependingon the printer and software used.

ADVANTAGE is versatile:You have the benefit of applicationsoftware that is already availableand proven on NORTH STARSystems.

ADVANTAGE is new:It's Business Graphics canconvert data into bar charts,pie charts, graphs, and 3Drepresentations instantly. And,what you can see on the screenyou can print.

TM Advantage is a trade mar* of North Star Computers IncZOCA ,s a trade mark of Dog IncSelectricts a trade mark of IBMCP M is a nage mark of Dgnal Research Inc

For the technically minded, ADVANTAGE is a4MHz, Z80e based microcomputer with 64Kdynamic RAM, a 20K Byte display dedicated RAM,plus 2K Boot PROM.

An auxiliary 8035 processor provideskeyboard and disk control. It has a12" green screen, and integrated

twin quad capacity 5" disk drivesproviding 720K Bytes of datastorage. It has an 87 key Selectric''style keyboard with 9 control keys,14 key numeric/cursor control pad,15 programmable function keys,

and 49 conventional character keys.ADVANTAGE comes complete

with Business Graphics, selfdiagnostic software and graphicsdemo software. Its G-Basic/G-DOS,and Graphics CP/M-are supersetsof the industry standards. They

enhance ADVANTAGE'S Graphicand Character Mode capabilities,and provide a consistent operating

comartSPECIALISTS IN MICROCOMPUTERS

A member of the Comarl Group of Companies

environment for development andapplication programs written in anyother CP/M compatible language.

To see more of the benefitsof the ADVANTAGE ask yourComart Dealer, or send nowfor further information.

Circle No. 228PRACTICAL COMPUTING May 1982 201

To: Dept 346UIICS Intertext HouseLondon SW8 41.1J cr

ITer. 01-622 9911(all hours)

Cossors fast test and

rep service is

available toall users of

411:11

Ilie AMPEXQU you's

NASHUACOPYINGMACHINES

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SORENSENPOWER SUPPLIES

These arejust so me of the companies- _

who have nowappointed us as UK service

agents and whose customerscan take

advantageof our unrivalled

test and

ide reputationfor high

repair service.Our vvorlducts means that all our repair

quality prodwork is done to the highest standard

(MOD Defence Standard0521 in fact).

Additionally,we have insurance

cover

for the time your equipmentis in our

hands. So,this is a service that you can trust.

nt, our service is fast-Just as important, air single

in emergencieswe can rep

boardswithin 48 hours.

If you own any of these products,

or indeed have any electronicsservice

problemsto discuss, j

Henry Lassman

ust telephoneon Harlow (0279) 26862.

We know we can h elp

Cossor ElectronicsLimited

The PIDDaClesElizabeth Way

Harlow Essex CM19 5B6.

cossorelectronicsThInkIng fior tomorrow

.:WE CAN ASSIST

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If you are a supplier of

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IN YOUR OWNHOME,IN YOUR OWNTIME,AT YOUR OWNPACE.

Learn computer programming quickly andeasily through the renowned ICS "OpenCollege" system.

Use the famous ICS study texts,backed up by your own expert tutor,and learn computer programming, theproven way, with ICS home study.

Introductory Course, BASIC, COBOL& IBM 360 Programming allcovered.... PLUS examination coursefor ASSOCIATEMEMBERSHIPOF THEBRITISHCOMPUTERSOCIETY.

ALL DETAILS FREE-SIMPLY RETURN THE COUPON BELOWPlease send me your prospectus on Computer PrOgrammtng

Name

Address

IIN MIII MN NMI MN IIMI NM NMI IM ON MI 1E1 MI OM Ell INII IIINI I Circle No. 230

Circle No. 229S.B.D. Software is proud to announce their distribution agreement withthe most up to date APPLE -only magazine in America

CALL A.P.P.L.E.MAGAZINE

In today's fast changing world of the APPLE you just can't afford to staybehind, so don't settle for anything less than the best APPLE-onlymagazine in America.

Now you can purchase this outstanding magazine for the low price of1.75 per issue.

Your subscription for 12 or 24 magazines may start from any month in1981.

Single back Issues are available at £2.25 per issue including postage andpacking.

A bound volume of the issues in 1980, 1979, 1978 are available for£20.00, 15.00 and £10.00 respectively, including postage and packaging.(Please note that in 1980 & 1981 there were only 9 issues published but in 1982 therewill he 12 issues.)

E 12 issues @ £21.00 E 24 issues @ £40.00Europe Air Mail postage, add £6 per I2 issues

NAME

ADDRESS

TOWN

Please start my subscription

POSTCODE

Month Year

Barclaycard/Access Number

Please make cheques payable to CALL APPLE (UK)

Send to:- CALL APPLE (UK), c/o SBD Software,FREEPOST, RICHMOND, SURREY TW9 1BR(No postage stamp required)Telephone 01-940 5194

Expiry Date

The Famous Book

"ALL ABOUT APPLESOFT"Now available @ £9.50 incl. P. & P.

202 Circle No. 231PRACTICAL COMPUTING May 1982

nosSsomMEM unionsnascom

MEAM PERPORMAIKENascom have come a long waysince their acquisition by Lucas.With the knowledge of over30,000 units already in the fieldyou can buy with confidencefrom NASCOM.PRODUCTS:We have kits, built and testedboards, and our fully assembled andtested NASCOM 3system with a fullchoice of configura-tion either cassette ordisc based. Alternativeoperating systemsinclude NAS DOS andCP/M.

Nascomannounce

theirEducational

computerIt/hero-Ed£399

4. VATand

a 1.21 -green

enmonitor

ina/cmcasef120+VAT

SOFTWARE:We have a team of programmers whoare writing software and coursewareespecially for UK educational busin-ess and domestic users.FREE ADVICE:We have appointed experts to adviseon the specialist use of micro

computers inU.K. schools,homes orbusinesses.

Learn more aboutNASCOM now.Complete thecoupon for furtherinformation and afull list of dealers.

no/corn micro P

BACK-UP:We have a nationwide dealer net-work giving full sales back-up andafter sales service. From our headoffice we have a service line to sortout any problems.SYSTEM EXPANSION:NASCOM machines are designed togrow with users. Easily and simplyNASCOM systems can beexpanded by adding extra modulesto the basic system.

LUCAS LOGIC LIMITEDNASCOM MICROCOMPUTERS DIVISION,Welton Road, Wedgnock Industrial Estate,Warwick CV34 5PZ, England.

0'3 MIX SielTilL 1115 >),91 213 Pt ?I 11113 2E94E3 sr out 33 Calk ,r?

eau%. 111 Of 72,143 1E, XL %2 RAMO 72Lose

14 X11.0 9 staIS tis ram

v4 104est 6 Sla

P9, reil 111 Lova 4

ant{416 141 F99. szt

Ira- MAR,settK Ix

'78EreDealerEnquiriesWelcome

moo mom

To Lucas Logic Ltd., Nascom Microcomputers Division, Welton Road,I Wedgnock Industrial Estate, Warwick CV34 5PZ, England

all Please send:I Literature 0 Dealer List 0 Prog. Book Form 0

Name

Position

Establishment

Address

Tel. NoPC2

Lucas Logic Ar_J

Circle No. 232PRACTICAL COMPUTING May 1982 203

PET (32K)SYSTEM A: £595SYSTEM B: £1600SYSTEM C: £1995140 Column + 80 ColumnsEquipment available°Special Otter CBM 8024 Fast DotMatrix Printer - 1895)

SUPERBRAIN (64K)SYSTEM B: £2380SYSTEM C: £2830SYSTEM D: £4380

RAIR (64K)0SYSTEM B: £3190SYSTEM C: £3575SYSTEM D: £4699SYSTEM E: £6164(Two Users)

SYSTEM E: £7029(Three Users)

SYSTEM E: £7644(Four Users)

SYSTEM E: £8109(Five Users) Hard Disk Expansion 30MB+

APPLE II (48K)SYSTEM A: £939SYSTEM B: £1843SYSTEM C: £2580

APPLE III (128K)SYSTEM B: £3152SYSTEM C: £3900SYSTEM D: £5335

Awide selectionof Computers

plusa service facilitythat's second to

none.SYSTEM A: Basic Computer including display screen and keyboardSYSTEM B: Computer including display screen, keyboard, dual disk

drive(s) and matrix printer for Business Users(e.g. Accounts, Database, etc)

SYSTEM C: Computer including display, keyboard, dual diskdrive(s) and daisy -wheel correspondence qualityprinter for Word Processing.

SYSTEM D: Computer including display, keyboard, floppy diskdrive, plus hard disk drive for 5 MB+ on-line andmatrix printer.

SYSTEM E: Multi -User Computer - AS SYSTEM D - plusAdditional VDU Terminals for up to 5 Users

Johnson ,c -R4microcomputers ),Lis.v

Johnson House 75-79 Park Street Camberley Surrey Telephone 0276 20446Robophone Answering 24 hrs. Prestel page No 200632 Mad Box No 027620448

48 Gloucester Road Bristol Telephone 0272 422061148 Cowley Road Oxford Telephone 0865 721461

Circle No. 233

ICRO-8 I UK Subscription Dept.24 Woodhill Park Pembury Tunbridge Wells Kent TN2 4NWGET THIS free software offer when you subscribe to MICRO -80 - The specialist magazine forTRS-80 and VIDEO GENIE.LOOK AT the programs you get FREE when you subscribe . . .

* Level I in Level II - Convert your Level II TRS-80 to operate as a Level I machine. Opens a wholenew library of software for your use.* Copier - Copies Level II System tapes, irrespective of where they load in memory. Copes withmultiple ORG programs.* Z80 MON -A low memory, machine language monitor which enables you to insert OP codes,edit memory, punch system tapes etc.* Improved Household Accounts - Powerful enough to be used by a small business.* 80 Composer A music generating program which enables you to play music via your cassettecord.* Plus Two Games - Poker and Cube (a version of the Rubiks cube for Disk users)and don't forget MICRO -80 is now available in monthly cassette edition as well - all the publishedprograms each month ready to load on cassette.

Please enrol me for an annual subscription and send me my FREE cassette program. I enclose£16.00 E (magazine only) or £43.60 El (magazine and cassette edition).(enclose your cheque/P.O. made payable to MICRO -80 and send to the above address)Software offer, and cassette edition prices applies to U.K. residents only. Overseas subscription rateson application.

NameBLOCK CAPITALS PLEASE

Address

PC 5/82

204

Circle No. 234PRACTICAL COMPUTING May 1982

WITH

MICRO NETWORKS

IT'S NOT JUST

AN ACT

When you buy an ACT Sirius 1 from Micro Networks, ofPall Mall, you get more than just a new machine. Thestaff are computer professionals recruited from themainframe world who really understand how to apply acomputer to solve business problems; they know aboutthe pitfalls and will guide you round them. If there is not astandard set of software packages that exactly matchyour requirements, then they will carry out the necessarytailoring or will commission a consultant on your behalf iftotally new programs are needed.

The ACT Sirius 1 is a welcome arrival on the smallcomputer scene with its 16 -bit CPU, 128K bytes of

PRACTICAL COMPUTING May 1982

memory and 1.2 megabytes of disc storage. The greenscreen, separate keyboard, Microsoft BASIC and CP/M86 are all included in the price - which is a modest£2,395.00. The Micro Networks service, advice andsupport are thrown in for free.

We also have Piiceon, Superbrain and Compustar instock at very attractive prices, together with a lull rangeof supporting peripherals and software.

MICRO NETWORKS60 PALL MALL LONDON 01-839 3701

Circle No. 235205

OZWilefor dapPle

Apple 11 Apple ///Full systems, expansion cards, printers, software,disks, books

Good service - low pricesFull systems

Computer professionals to analyse your require-ments, demonstrate your system, deliver installand train your staff at no extra cost.

MI Add-ons at discount pricesJust leekRamex 16K RAM card only £69.Videx videoterm 80 -col card only £179Z80 softcard only £189Cash with order only - please add 15% VAT.

Write or 'phone for full details

(m)ozwise computer/28 CROFTS ROAD, HARROW, MIDDX. HAI 2PH.

01-863 2309 24 hour service

Circle No. 227

CIDER CARDS FOR THE APPLENEW EPROM PROGRAMMERNIA BOARD - 2 in 1

Save your important BASIC and MACHINE CODE programs on EPROMS.Programs any pin compatible 2716/2532 eproms. Easy to use - just followVDU instructions.. It is also a powerful VIA interface card - see VIA BOARDbelow. ZIF sockets. Just plug into any Apple slot and go. To store BASICprograms must use CIDERSOFT-BASIC MANAGER and 32K MEMORYBOARD. "Please specify diskette (3 300, 2 11 or cassettes for programs.

£58.00NEW 32K MEMORY BOARD - can R/W to RAMS too!

Reads EPROMS/ROMS/RAMS in any combination. 8 socket to store up to 32Kbytes of BASIC and MACHINE CODE programs. Sockets are softwareselected by ONE instruction. Reads 2716/2532 pin compatible EPROM&ROMS/RAMS.

£38.00NEW VIA BOARD - Parallel/Serial/Timers all in 1

Single VIA 6522 has 2 x8 bit programmable 61 -directional ports, 4 controllines, 2 programmable timers and 8 bit shift register.

NEW DOUBLE VIA BOARDAs above but with 2 VIA chips giving TWICE the power.

WIRE WRAP PROTOTYPE BOARDPlugs into Apple sockets for prototype design.

£29.50

£45.00

£10.50CIDERSOFT - BASIC MANAGER ROM

Contains programs for the 32K MEMORY BOARD which LOAD,CATALOGUE/MANAGE Applesoft Basic programs from memory board.

£15.00We also program BASIC (Applesoft) or MACHINE CODE programs on 2K/4KEPROMS. Please send program(s) on diskette(s)/cassette(s).

PROGRAMMING 2K - £4 4K - £5I.C. and MEMORIES

2716 - £4.50; 2532 - £9.50; VIA 6522 - £9.50; 6176 LP - £10.50SPECIAL OFFER of 10% DISCOUNT for EDUCATIONAL INSTITUTIONS

All prices are inclusive of VAT and P&P. Cheques are payable to CIDER LTD.Please send SAE for details.

COMPUTER INTERFACE DESIGNELECTRONIC RETAIL LIMITED5 King Street, Margate, Kent. Tel: (0843) 23210

ARE YOU A ZX81 USER WHO'S NOTPLAYING GAMES?

£4150Including VAT.Complete

Each ECR81 comes complete with its own individualcertification tape, tested and serial numbered to prove yourmachine reliability.

Mains Operation only. Mains & DIN connector leads provided. Certification of tape head alignment - height and azimuth. Certified tape tension, torque and speed. Fast forward and rewind tape search controls.The ECR81 is also suitable for Sinclair ZX80

Please allow up to 28 days delivery. The ECR81 isbacked by our 14 day money -back option.

MONOLITHelectronic productsTelephone: Crewkerne 0460 74321 Telex: 46306

206

ECR 81 DATA RECORDER SAVES ANDLOADS YOUR PROGRAMS EVERY TIME!The ECR81 Enhanced Certified Recorder from MONOLITH is amajor advancement in cassette recorder technology which minimisesthe problems associated with standard audio recorders. The unit is ahigh reliability program store for ZX computers based on a modified,proven cassette mechanism. The two sections of data recordingcircuitry automatically ensure precise levels are written onto thetape and that optimised signals are received by the computer.

THE ECR81 IS NOT SUITABLE FOR AUDIO REPRODUCTIONNO MANUAL VOLUME OR TONE CONTROL ADJUSTMENT PROVIDED

To: MONOLITH ELECTRONICS CO. LTD., 5/7 CHURCH STREET, CREWKERNE, SOMERSET

Please supply me with: Price Total

__(Qty.) Monolith ECR 81 Enhanced Certified Recorderls)

to be used with my ZX81

£47.50(Each)

I also enclose postage & packing per recorder £2.50

_ Prices include VAT Eease print

Name:Mr/Mrs/Mi.[I I I I I I I I I111111Address 1111 111111111111111H11111111111 1111111111111111

Circle No. 236PRACTICAL COMPUTING May 1982

ComputerSuperniarketBig name hardware at cash-and-carry prices- and with service you'll find hard to matchSHARP, COMMODORE, TEXAS, RICOH, VIC1111 16K RAM Cartridge 60.00 69.00

ATARI and TANDATA EQUIPMENTFully tested before despatch, or collection

VIC 1112 IEEE IntVIC 1210 - 3K RAM CartridgeVIC 1211M 3K RAM (Hi -Res) Cart

44.0025.0028.00

50.6028.7532.20

complete with instruction manuals, tapes, and VIC 1212 Programmers Aid 28.00 32.20

fitted with 13 amp plugs. VIC 1213 Machine Code Mon 28.00 32.20VIC 1515 Matrix Printer 186.90 215.00

COMMODORE EQUIPMENT VIC 1540 Single Disk Drive 344.35 396.00Model User Ram exc VAT inc VAT VIC Joystick 6.52 7.504016 12" 40 Col. 16K Mem 445.00 511.75 VIC Paddle (Pair) 11.00 12.654032 12" 40 Col. 32K Mem 560.00 644.00 VIC Expansion Unit (Arlon) 78.00 89.708032 12" 80 Col. 32K Mem 699.00 863.85 Lid for above expansion unit (Aron) 6.95 7.998096 12" 80 Col. 96K Mem 1040.00 1196.00

SUPERPET Micromainframe 1300.00 1495.00

2031 121K Disk 350.00 402.504040 347K Disk 560.00 644.008050 1M Byte Disk 755.00 868254022 Printer 350.00 402.508023 High Speed Printer 785.00 902.75

SHARP EQUIPMENTModel ' User RamMZ8OR 64K RamMZ8OF I Floppy Disc I/O CardMZ8OMDB Master Diskette 8 ManualMZ80F15 CableMZ8OFD Disc Drive

exc VAT950.00100.0031.00

9.00589.00

inc VAT1092.50

115.0035.6510.35

677.35PET/IEEE Cable 18.00 20.70 MZ8OEU Expansion Unit 50.00 57.50IEEE/IEEE Cable 20.00 23.00 MZ80P5 Matrix Printer 415.00 477.25VIC 20 Personal Computer 173.90 199.99

VIC/C2N Cassette 36.00 41.40 RICOHVIC 1011A RS232 Int 28.50 32.78 RP1600 Letter Dual. Printer IEEE 1200.00 1380.00

VIC 1110 81( RAM Cartridge 36.00 41.40 RP1600S Letter Dual. Printer Cent. 1300.00 1495.00

F

To Computer Supermarket Ltd.,3rd Floor, Douglas House.Queens Square, Corby, Northamptonshire

Please send meModel No. Item Price Shipment Total Into only

I enclose my cheque for £Or debit my Access' BarclaycardDiners Card American Express No

(Cardholders may telephone orders to 05363 61587 81Signature

Name

Address

(BLOCK CAPITALS PLEASE,Your remdtance should be made payabie to Computer SupermarketReader s Account. and snail remain your money anti the gtaocls havebeen despatched to you at the address specifiedAli goods offered are subject to Computer Supermarket conditionsof sale copies evadable on request Reg ,n Eand No 2646589Prestel subscribers may order through the Prestel service.Directory No 400400. PC

PRACTICAL COMPUTING May 1982

. S

...

r --

TEXAS EQUIPMENTTI -99/4A 16K RAMFull range of peripherals available

ATARI EQUIPMENTAtari 400 16K RAM ComputerAtari 800 16K RAM ComputerFull range of peripherals available

TANDATA EQUIPMENTMicro TantelAlpha Tantel

260.00 3 .10

260.83 299.95456.52 525.00

152.17 175.00182.61 210.()0

Full colour output. Connects to any TV. Full British Telecomapproval. Requires British Telecom 96A jack -plug. Givesaccess to massive home computer base information fromMortgages to Theatres, Stocks to Holidays.Telephone us for further information on ease of installation.

Prices are valid only for the cover datemonth of this magazineCredit Facilities Available Ring or write for full details

Special Price List Available for bonafideGovernment and Educationalestablishments.All orders will be acknowledged by return of post.

Insured shipment arranged anywhere in UK for an additional£14.37 (inc. VAT). VIC, Atari and Texas shipped by insured post F.O.C.Approved Distributor for Commodore, Sharp, Atari and Texas.All goods sold with full manufacturer's warranty and subject to conditions of sale (available on request)ALL MACHINES ARE FULL UK STANDARD.

it.. .. . .

0000 oo 0000

5.-

:6:

.0 6. 00000

00000

C

ob.S.

6 (0.COMPUTER SUPERMARKET LTD3rd Floor, Douglas House, Queens Square, Corby, Northamptonshire.Telephone 05363 61587/8 and 62571 Telex COMPSU 341543/4 Prestel No. 400400

Circle No. 237207

THE SPRINT 945 & 55 cps

UNIE

THE SPRINT 1035 cps

Test drive ourhot new daisywheelersIf you've always wanted letter -quality printing, but thecost has put you off, then the SPRINT 9 and SPRINT 10are for you. Now you can have the same high qualityprint - usually only available on word processingsystems- at prices that will let you forget all aboutdot-matrix terminals. With speeds of 35, 45 and 55 cps(average English text. not burst rate), the reliable highperformance of SPRINT terminals leaves the crowdbehind. Prove it to yourself with a test drive.

Call or write your Qume Distributor

Qume®Qume (UK) Limited

Bridgewater Close, Reading, Berks. RG31JTTel: (0734) 584646. Telex: 849706

A British Company of ITT

Switch selection of interfaceparameters and forms handlingallows simple OEM systemintegration.

Automatic proportional spacing,without decreasing systemthroughput, sets the newstandard for print quality.

To cut service costs and reduceadjustments, the exclusiveKevlar belt is stronger andlighter than steel, with virtually nostretch.

For the highest accuracy in thehistory of daisywheel printing.our Microdrive" carriage drivemechanism has no cables orpulleys.

QUIlle EUKAUTHORISED DISTRIBUTOR

ACCESS DATA COMMUNICATIONS LTD., Unit 17,Eskdale Road, Uxbridge Industrial Estate, Uxbridge,Middlesex UB8 2RT. Tel: (0895) 30831.

ALPHATECH COMPUTER SYSTEMS LIMITEDUnit 6d, Rose Industrial Estate, Cores End RoadBourne End, Bucks. SL8 5BA. Tel: (06285) 28237

BYTECH LIMITED, Suttons Industrial Park,London Road, Earley, Reading RG61AZ. Tel: (0734) 61031.

DAISY TERMINALS LIMITED, Bridge Road,Haywards Heath, West Sussex. Tel: (0444)457546.

ISG DATA SALES LIMITED, Unit 9, Fairacres Industrial Estate,Dedworth Road, Windsor, Berkshire.Tel: (07535) 57955.

ROHAN COMPUTING LIMITED, 52 Coventry Street,Southam, Warwickshire. Tel: (092681) 4045.

208

Circle No. 238PRACTICAL COMPUTING May 1982

Oh No - NOT ANOTHER Apple Database?!!!

Some Questions and Answers on ACCESS -A new data-base management system for Apple computers tromSPIDER SOFTWARE.

How many records can I have?This depends on the size of each record. The maximum record size is 1560characters. The maximum number of records per disk volume is 7936 but this isdependent on the record size. As an example, if your records are 200 characterslong, you may have a maximum of 671 records per volume. A maximum of 40fields per record is available.

How long will it take to find a record?A powerful advanced IRAM (Indexed Random Access Method) is utilised formajor record retrieval purposes giving an access speed of either instant recall orwithin 3 seconds. Any field (or combinations thereof) with multiple search criteriawill either give instant recall or will take a maximum of 23 seconds. On theSyMBfile hard disk everything is at least 7 times faster.

How long will it take to sort a disk full of information?All sorting is done on an index. If the sort is on the primary index it will take 0.2seconds regardless of the number of records. To sort out any field which is notindexed involves first creating an index for that field which is then sorted. Thetime taken depends on the record size (generally less than 3 minutes). Any indexcan be saved for later use or made into a primary index. Sorting a disk need nbtinvolve creating a sorted version of the database.

How many disk drives do I need?ACCESS will ideally run on 2 drives. However, it will support a single drivesystem and a version is available for the SyMBfile 5 megabyte hard drive.

How about report formats?Reports are user -configured and can contain report headings, column headings,column sub -totals, brought forward totals, grand totals, computed fields, pagenumbering etc. Reports can be on selected and/or sorted data.

What if the dog chews my program disk?We provide copy routines for backing -up of the program disk and the data disksas many times as you require. The ACCESS system is a combination of hardwareand software.

Is the program menu -driven?YES. ACCESS constantly displays prompts indicating the options availablewherever you may be in the program.

How is the data stored?ACCESS creates and uses its own data disks. However, facilities are provided toenable you to produce standard DOS 3.3 text files in either sequential or randomaccess format using any sorted or selected fields. Because of ACCESS's own datastorage techniques a very large database may require more than one disk to storethe text file(s) produced.

How easy is it to create records and edit them?ACCESS has a powerful word processor style screen editor enabling insertionand deletion of characters, etc., full cursor control across fields and pages of arecord. A maximum of 40 screen pages are available. Password protected fieldsare supported as are computed on -screen fields.

What if I delete a record by mistake?ACCESS only marks a record as deleted. Facilities are given to either "un-delete"deleted records or purge deleted records from the database.

My current database takes ages for me to add and saverecords because it needs to re -structure the entire file tokeep the "primary key" in alphabetical order. Will thishappen with ACCESS?No!!! ACCESS uses logic and technique to handle your data; there is no reason(should you have the stamina) why you should not fill an entire disk withinformation as fast as you can type and immediately retrieve all the informationin sorted order or order of entry, etc. All complex and time -critical functionsincluding disk input and output, indexing, sorting, searching, screen display andediting are performed by ACCESS using powerful machine -code routines.

What hardware do I need?48K Apple II Plus with DOS 3.3 and 1 or 2 disk drives. Most makes of printer aresupported.

Why should I buy ACCESS and how much is it?Most facilities in ACCESS are available in other comparably priced databasemanagers. However, ACCESS is more powerful and faster than its competitors ineach function. ACCESS has gone beyond the boundary of merely complexfacilities, it is powerful and "intelligent" enough to make itself extremely simpleto use. The retail price including VAT is £199.95.

A technical sheet is available on the ACCESS system from your localApple dealer who should be able to give you a demonstration of itsflexibility.We stock a large range of packaged software for the Apple. Pleasewrite or telephone for a copy of our comprehensive list.

Dealer inquiries invited. Personal callers by appointment only please.

SEE US ON STAND 29 AT APPLE '82

SPIDER SOFTWARE98 AVONDALE ROAD,.SOUTH CROYDON,

SURREY.Tel: 01-680 0267 (24 hours a day -7 days a week)

BARCLAYCARD

LUM111

Circle No. 239

The biggest Apple eventever held in Britain!

likaPPie0 1st National Apple User Convention

, .

Whether you're an active Apple user, or just fascinatedby the rapid development of microcomputing generally,you won't want to miss the action -packed weekend thatwill make up Apple '82.

From Friday, June 4, to Sunday, June 6, the whole ofthe ultra -modern Fulcrum Centre in Slough will becompletely devoted to the onward march of the micro,when some of Britain's top computing experts will berevealing their secrets.FRIDAYis education day - the staging of the first National AppleEducation Forum and a chance for teachers and lecturersto exchange ideas, evaluate software and Listen to aseries of lectures covering every aspect of computer -assisted learning. Some 25 Apples will be on show,demonstrating a wide range of applications in the schoolenvironment.SATURDAY and SUNDAYwill be for users generally - the first National Apple UsersConvention. So many leading fLgures in microcomputingwant to take part that presentations will be givensimultaneously in two adjoining theatres throughout theweekend.

The full timetable of events covers database systems,graphics, music and speech synthesis, Pascal, Cobol andother languages, commercial and industrial applications,hardware and software troubleshooting and micros inmedicine.

A central feature of the convention will be acommunications workshop, to explore latestdevelopments in linking Apple to Apple, Apple tomainframe, remote information retrieval systems andbulletin boards. It will give a unique insight into a subjectthat is rapidly becoming one of the most exciting aspectsof computing today.

And for light relief, there will also be the national finalsof the nail-biting Apple Olympics.

Mail the coupon below for full details of plans forApple '82 - and about the first-class accommodation thatcan be reserved for you at some of the best hotels in thearea for a modest £17 a night - far below their normalrates.

This major event in the Apple world is attracting usersfrom all parts of the British Isles and overseas. But ticketsare limited, so early booking is advisable.

Send for free Apple '82 fact pack now!

Please send full details of Apple'82 to:

Name

Address

PC/5

POST TO: Apple '82, Europa House, 68Chester Road, Hazel Grove, Stockport SK7

L- - - - - - - - - - - - - Circle No. 240

PRACTICAL COMPUTING May 1982 209