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Experiment No.: 2

Title: Introduction to the Standard/ Normal (SPP) of the Parallel Port of a PC

Group Members:

BARRIENTOS, Rocelle Mae

COLYONG, Nikki Grace

DE LEON, Jeffrey

DUMO, Tatiana Amor Cuepo

MATIS, Amelyn

Submitted To:

Engineer Jefferson Walcien

Date:

August 23, 2011

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I. EXPERIMENT OBJECTIVES

1. To show how to configure the parallel port for standard/ normal SPP

operation.

2. To show how to use the data, status and control ports of the parallel port to

output or read-in data from an input application.

II. EQUIPMENT AND MATERIALS

Parallel Port Interface Testing Board

PC (with WIN2000 or lower OS)

Parallel Port data cable/ DB25 data cable

III.EXPERIMENT PROCEDURES

1. Do the following exercises using DOS debug:

A. Output any number in hex on your data port.

a. Open MS DOS prompt.

 b. Type debug then enter.

c. Type o 378 NN. Where NN is the number in hex you will output.

B. Read the status of the switches on your status port by executing the

command: i 379 (enter).

C. Interpret the number inputted. Change the status of the switches on your 

input generator module then read in again the input. Take note of the effect of 

the most significant bit (MSB) in your readings.

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D. Output any number in hex on your control port. Interpret the displayed

output. Take note also of the bits on the control port that are inverted.

2. Do the following:

A. On your data port, display/output binary counting for:

a. One run.

 b. Repeated run.

c. Ten times run.

B. Repeat (a). Instead, display the numbers in the Fibonacci Series.

C. Write a routine using DOS debug to turn ON Data 0 on the data port of the

  parallel port when any of the switches on the status port are activated

(reset/presses).

D. Write a routine using DOS debug to turn ON the LEDs on the data port

from the LSB LED to the MSB LED when the PBNO switch on Bit 4 on the

status port is momentarily pressed. When the PBNO switch on bit 3 is

momentarily pressed the LEDs will turn ON one at a time from the most

significant bits (MSB) to the least significant (LSB) bits.

E. Repeat 4a. (Binary Counting): Instead, use bit 6 on the status port to

increment the count. Use bit 5 to decrement and Bit 4 to reset the count

displayed on the data port.

IV.EXPERIMENT RESULTS

MS DOS:

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C:/Windows/debug

o 378 11

o 378 22

o 378 56

o 378 88

o 378 A3

-i 379 0III IIII

7F

-i 379 IIII IIII

FF

-i 379 I0II 0III

B7

-i 379 I0II IIII

BF

-i 379 00II 00II

33

LEGEND:

I – ON / LED LIGHTS

O – OFF / LED DIMINISHED

FOR PROCEDURE I = 1.C

1. O 378 11 LED DISPLAY : _000I 000I__ 

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2.

2.

2.

2. O 378 22 LED DISPLAY : __00I0 00I0__ 

 

3. O 378 56 LED DISPLAY : __0I0I 0II0__ 

4. O 378 88 LED DISPLAY : __I000 I000__ 

5.O 378 A3 LED DISPLAY : __I0I0 00II__ 

0 0 0 0 I 0

0 0 I 0 0

0 I 0 I 0 I

I 0 0 0 I

I 0 I 0 0

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FOR PROCEDURE I = 2

1. 0III IIII OUTPUT IN THE PC : __7F__  

2. IIII IIII OUTPUT IN THE PC : __FF__  

3. I0II 0III OUTPUT IN THE PC : __A7__  

4. I0II IIII OUTPUT IN THE PC : __AF__  

5. 00II 00II OUTPUT IN THE PC : __33__  

V. OBSERVATIONS

From the conduct of the experiment, the group observed the operation of the

 parallel port. This is when the module was connected to a windows 98 computer.

First, we observed that we use the notations o 378 to denote the desired outputs. Our 

instructor however assigned the output numbers so that all groups will have uniforms

data results. We have seen how the 2-bit hexadecimals when inputted as the output of 

the module, have altered how many and which of the LED’s will light. The LED’s

however are operating in two 4-bit binary numbers. For example, when we inputted o

378 14, the LED had an output of 0001100 showing the equivalent of the

hexadecimal in the binary system. Second, we reversed the procedure wherein we

inputted the data. We have done this by changing the status of the switches, taking

into consideration the most significant bit. The switches now indicate the two 4-bit

 binary number which is interpreted as a 2-bit hexadecimal number. This can be done

 by entering i 379, and pressing the enter key. The equivalent binary number will

appear simultaneously. We noticed that this part is just the reverse of the first

 procedure. The two procedures are maintaining the same principles.

VI.CONCLUSION

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From the data and results obtained from the performance of the experiment,

the following conclusions can be made. First, the need for the correct notations for 

input and output are very much needed in order to gather correct data. Second, we

only enter the output in the hexadecimal system accompanied by the o 378 notation.

After which the LED’s will respond, producing the equivalent binary number 

expressed in two 4-bit binary numbers. Third, we enter the input by changing the

status of the switches wherein the 8 switches corresponds now to the two 4-bit

number. We enter the notation i 379 and then the hexadecimal equivalent will appear 

simultaneously after pressing the enter key. The experiment is mainly about the

function of the module wherein we utilized the parallel port to output or read-in data

from the DOS debug application.

VII. RECOMMENDATIONS

The conduct of the experiment is a success, however the group believes that it

is better to make a research work before the performance of the experiment. This is to

limit and prevent the errors and difficulties in the gathering of the required data and

results. Despite of this, the group still wants to recommend this activity as a way of 

checking whether or not the whole module is working. The procedures for this

activity or experiment are easy to follow, thus it is student-friendly. In addition, the

 procedure is not only limited on the Instrumentations but the theories and facts

learned in Logic lecture are also reflected in this activity.

VIII. APPENDICES (RESEARCH WORK)

PARALLEL PORT

A parallel port is a type of interface found on computers ( personal and otherwise) for 

connecting various peripherals. In computing, a parallel port is a parallel 

communication physical interface. It is also known as a printer port or Centronics port. The IEEE 

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1284 standard defines the bi-directional version of the port, which allows the transmission and

reception of data bits at the same time.

a. HISTORY

The Centronics Model 101 printer was introduced in 1970 and included the first parallel

interface for printers. The interface was developed by Robert Howard and Prentice Robinson

at Centronics. The Centronics parallel interface quickly became a de facto industry standard;

manufacturers of the time tended to use various connectors on the system side, so a variety of 

cables were required. For example, early VAX systems used a DC-37 connector, NCR used the

36-pin micro ribbon connector, Texas Instruments used a 25-pin card edge connector and Data 

General used a 50-pin micro ribbon connector.

Dataproducts introduced a very different implementation of the parallel interface for their 

 printers. It used a DC-37 connector on the host side and a 50 pin connector on the printer side— 

either a DD-50 (sometimes incorrectly referred to as a "DB50") or the block shaped M-50

connector; the M-50 was also referred to as Winchester. Dataproducts parallel was available in a

short-line for connections up to 50 feet (15 m) and a long-line version for connections from 50

feet (15 m) to 500 feet (150 m). The Dataproducts interface was found on many mainframe

systems up through the 1990s, and many printer manufacturers offered the Dataproducts

interface as an option.

IBM released the IBM Personal Computer in 1981 and included a variant of the

Centronics interface— only IBM logo printers (rebranded fromEpson) could be used with the

IBM PC. IBM standardized the parallel cable with a DB25F connector on the PC side and the

Centronics connector on the printer side. Vendors soon released printers compatible with both

standard Centronics and the IBM implementation.

IBM implemented an early form of bidirectional interface in 1987. HP introduced their 

version of bidirectional, known as Bitronics, on theLaserJet 4 in 1992. The Bitronics and

Centronics interfaces were superseded by the IEEE 1284 standard in 1994.

 b. USES

Before the advent of USB, the parallel interface was adapted to access a number of 

  peripheral devices other than printers. Probably one of the earliest devices to use parallel

were dongles used as a hardware key form of software copy protection. Zip 

drives and scanners were early implementations followed by external modems, sound 

cards, webcams, gamepads, joysticks and external hard disk drives and CD-ROMdrives.

Adapters were available to run SCSI devices via parallel. Other devices such

as EPROM programmers and hardware controllers could be connected parallel.

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For consumers, the USB interface—and often Ethernet  —has effectively replaced the

 parallel printer port. Many manufacturers of personal computers and laptops consider parallel to

  be alegacy port and no longer include the parallel interface. The guidelines for 

Microsoft'sWindows Logo Program "strongly discourages" systems builders from including

 parallel ports.[5] USB-to-parallel adapters are available that can make parallel-only printers work 

with USB-only systems.

c. HARDWARE PROPERTIES

The D-Type 25 pin connector is the most common connector found on the Parallel Port

of the computer, while the Centronics Connector is commonly found on printers. The IEEE 1284

standard however specifies 3 different connectors for use with the Parallel Port. The first one,

1284 Type A is the D-Type 25 connector found on the back of most computers. The 2nd is the

1284 Type B which is the 36 pin Centronics Connector found on most printers. IEEE 1284 Type

C however, is a 36 conductor connector like the Centronics, but smaller. This connector is

claimed to have a better clip latch, better electrical properties and is easier to assemble. It alsocontains two more pins for signals which can be used to see whether the other device connected,

has power.

Pin No (DB25) Pin No (36 pin) Signal name Direction Register - bit Inverted

1 1 Strobe In/Out Control-0 Yes

2 2 Data0 Out Data-0 No

3 3 Data1 Out Data-1 No

4 4 Data2 Out Data-2 No

5 5 Data3 Out Data-3 No

6 6 Data4 Out Data-4 No

7 7 Data5 Out Data-5 No

8 8 Data6 Out Data-6 No

9 9 Data7 Out Data-7 No

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10 10 Ack In Status-6 No

11 11 Busy In Status-7 Yes

12 12 Paper-Out In Status-5 No

13 13 Select In Status-4 No

14 14 Linefeed In/Out Control-1 Yes

15 32 Error In Status-3 No

16 31 Reset In/Out Control-2 No

17 36 Select-Printer In/Out Control-3 Yes

18-25 19-30,33,17,16 Ground - - -

Table 1. Pin Assignments of the D-Type 25 pin Parallel Port Connector.

The above table uses "n" in front of the signal name to denote that the signal is active

low. e.g. nError. If the printer has occurred an error then this line is low. This line normally is

high, should the printer be functioning correctly. The "Hardware Inverted" means the signal is

inverted by the Parallel card's hardware. Such an example is the Busy line. If +5v (Logic 1) was

applied to this pin and the status register read, it would return back a 0 in Bit 7 of the Status

Register. The output of the Parallel Port is normally TTL logic levels. The voltage levels are the

easy part. The current you can sink and source varies from port to port. Most Parallel Ports

implemented in ASIC, can sink and source around 12mA. However these are just some of the

figures taken from Data sheets, Sink/Source 6mA, Source 12mA/Sink 20mA, Sink 16mA/Source

4mA, Sink/Source 12mA. As you can see they vary quite a bit. The best bet is to use a buffer, so

the least current is drawn from the Parallel Port.

d. STANDARD PARALLEL PORT

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Table 2. Data Port

 Note 1 : If the Port is bi-directional then Read and Write Operations can be performed on the

 Data Register.

The base address, usually called the Data Port or Data Register is simply used for outputting data on the Parallel Port’s data lines (Pins 2-9). This register is normally a write only

 port. If you read from the port, you should get the last byte sent. However if your port is bi-

directional, you can receive data on this address.

Table 3. Status Port

The Status Port (base address + 1) is a read only port. Any data written to this port will be

ignored. The Status Port is made up of 5 input lines (Pins 10,11,12,13 & 15), a IRQ status

register and two reserved bits. Please note that Bit 7 (Busy) is a active low input. E.g. If bit 7

happens to show a logic 0, this means that there is +5v at pin 11. Likewise with Bit 2. (nIRQ) If this bit shows a '1' then an interrupt has not occurred.

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Table 4. Control Port

The Control Port (base address + 2) was intended as a write only port. When a printer is

attached to the Parallel Port, four "controls" are used. These are Strobe, Auto Linefeed, Initialize

and Select Printer, all of which are inverted except Initialize.

The printer would not send a signal to initialize the computer, nor would it tell the

computer to use auto linefeed. However these four outputs can also be used for inputs. If the

computer has placed a pin high (e.g. +5v) and your device wanted to take it low, you would

effectively short out the port, causing a conflict on that pin. Therefore these lines are "open

collector" outputs (or open drain for CMOS devices). This means that it has two states. A low

state (0v) and a high impedance state (open circuit).

 Normally the Printer Card will have internal pull-up resistors, but as you would expect,

not all will. Some may just have open collector outputs, while others may even have normal

totem pole outputs. In order to make your device work correctly on as many Printer Ports as possible, you can use an external resistor as well. Should you already have an internal resistor,

then it will act in Parallel with it, or if you have Totem pole outputs, the resistor will act as a

load.

An external 4.7k resistor can be used to pull the pin high. I wouldn't use anything lower,

 just in case you do have an internal pull up resistor, as the external resistor would act in parallel

giving effectively, a lower value pull up resistor. When in high impedance state the pin on the

Parallel Port is high (+5v). When in this state, your external device can pull the pin low and have

the control port change read a different value. This way the 4 pins of the Control Port can be

used for bi-directional data transfer. However the Control Port must be set to xxxx0100 to beable to read data, that is all pins to be +5v at the port so that you can pull it down to GND (logic

0).

Bits 4 & 5 are internal controls. Bit four will enable the IRQ (See Using the Parallel 

 Ports IRQ) and Bit 5 will enable the bi-directional port meaning that you can input 8 bits using

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(DATA0-7). This mode is only possible if your card supports it. Bits 6 & 7 are reserved. Any

writes to these two bits will be ignored.

e. FIBONACCI SERIES

The Fibonacci Series is a sequence of numbers first created by Leonardo Fibonacci (fi-

 bo-na-chee) in 1202. It is a deceptively simple series, but its ramifications and applications are

nearly limitless. It has fascinated and perplexed mathematicians for over 700 years, and nearly

everyone who has worked with it has added a new piece to the Fibonacci puzzle, a new tidbit of 

information about the series and how it works. Fibonacci mathematics is a constantly expanding

 branch of number theory, with more and more people being drawn into the complex subtleties of 

Fibonacci's legacy.

In mathematics, the Fibonacci numbers are the numbers in the following integer  

sequence:

(sequence A000045 inOE

IS).

By definition, the first two Fibonacci numbers are 0 and 1, and each subsequent number is the

sum of the previous two.

In mathematical terms, the sequence F n of Fibonacci numbers is defined by

the recurrence relation

with seed values

The Fibonacci sequence is named after Leonardo of Pisa, who was known as Fibonacci.

Fibonacci's 1202 book   Liber Abaciintroduced the sequence to Western European

mathematics, although the sequence had been described earlier in Indian mathematics. (By

modern convention, the sequence begins with F 0 = 0. The  Liber Abacibegan the sequence

with F 1 = 1, omitting the initial 0, and the sequence is still written this way by some.)

Fibonacci numbers are closely related to Lucas numbers in that they are a complementary

  pair of Lucas sequences. They are intimately connected with the golden ratio, for example

the closest rational approximations to the ratio are 2/1, 3/2, 5/3, 8/5, ... . Applications include

computer algorithms such as the Fibonacci search technique and the Fibonacci heap data

structure, and graphs called Fibonacci cubes used for interconnecting parallel and distributed

systems. They also appear in biological settings, such as branching in trees, arrangement of  

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leaves on a stem, the fruit spouts of a pineapple, the flowering of artichoke, an uncurling fern and

the arrangement of a pine cone.

The first 21 Fibonacci numbers F n for n = 0, 1, 2, ..., 20 are:

 F 0 F 1  F 2  F 3  F 4  F 5  F 6  F 7  F 8  F 9  F 10  F 11  F 12  F 13  F 14  F 15  F 16  F 17  F 18  F 19  F 20

0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765

The sequence can also be extended to negative index n using the re-arranged recurrence

relation

which yields the sequence of "negafibonacci" numbers satisfying

Thus the complete sequence is

 F −8  F −7  F −6  F −5  F −4  F −3  F −2  F −1  F 0  F 1  F 2  F 3  F 4  F 5  F 6  F 7  F 8

−21 13 −8 5 −3 2 −1 1 0 1 1 2 3 5 8 13 21

 

IX.BIBLIOGRAPHY

http://en.wikipedia.org/wiki/Parallel_port

http://beyondlogic.org/spp/parallel.pdf 

http://library.thinkquest.org/27890/mainIndex.html

http://en.wikipedia.org/wiki/Fibonacci_number