INTRODUCTION

What is computer

History of computer

Classification of computer

Function of computer (Input , output , storage , Processing)

Branches of computer (I/O device , storage device , )

Number system

Generation of computer

Operating system

Virus

Computer language

Point of Sale terminal

Computer Network

Email

Topology

Terminology

Internet

Distributed system

DOS ( Disk Operating System)

Flow chart

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COMPUTER

Computer is an electronic device in which data/information can be inputted for processing to desired output.

It is come from Greek word to “compute” means calculation.

History of computer

Two Types of computer :- Mechanical computer. Electronic computer.

Mechanical computerPascline: - Ist Mechanical computer maked by blasé pascal in 1642 . his machine is

cappble performing addition and substraction automatically .

Difference engine: - Charls babage discovered by a difference engine development to a mechanical computing machine name as difference engine is was cappble performing multitop calculation .

Analytical engine: - in 1930 analytical engine upgrade by Charles Babbage. It was more powerful mechanical computer. This machine is design for any type of mathematical calculation. This machine is similar to modern computer. He many respects as it has input uinit, processing unit, and output unit. It is also contains memory for stored 1000no. each no. 50 digits.

Electronic computer:-

ABC (Atanasoff Barry computer ):- This electronic machine was developed by dr. john attanasoff to solve certain mathematical equations . it was called the atanasof berry computer or ABC . its used 45 vaccume tubes and punched cards and also used as input output device.

ENIAC (Electronic Numeric Integrator and Calculator):- The first electronic machine was made 1946 by JP Eckert and JW mauchly it contained 18000 vacuume tubes , 70000 register 10000 capiciters and 60000 switches occupaid a true car garrige . it consume 150 kw of power and had to be water cooled it wated 27 tuns the ENIAC cast rate 50 lakh to be made.

EDVAC (Electronic Discreet Variable Automatic computer): - it is use to binary no. system and a much larger memory them that of ENIAC computer.

Invention of transistor: - ATs Bell labs. Transistor is a tiny electrical operatic switch. That can alternate between “on” and “off” many reasons of time/second transistor is a

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occupine less space. Consumed less energy need to walk time and les weight compare to vacuums tubs.

Abacus ( chaineez people) - Development abacus , abacus is noon as first manual calculating machine this device permit the user to represent number by the position of beads on a rack abacus was invented around 600 BCs simply addition substraction can be carried out repitly and efficiently still be used in chaina rasia and India .

CLASSIFICATION OF COMPUTER

COMPUTER

Analog computer Digital computer Hybrid

Micro computer Mini computer Mainframe Computer Super Computer

1) Micro computer: - They are desktop or portable computer that can run simple programs such as word processing or spread sheet.

a) Personal computer: - it is available in several sizes such as laptop, pocket computer, notebook computer.

b) Work stations:- A type of computer use for engineering application, desktop publishing, software development and other type of application. That required a moderate amount of computing power. And high quality graphics capability. Workstation is desktop computer but more powerful than P.C.

2) Mini computer: - Mini computer is also known as midrange computer. Its cost and computing power lies in the middle of micro computer and mainframe computer. Mini computer are used for multi user in universities, research, organization, bank and industries.

3) Mainframe computer: - Mainframe computers are more powerful and faster than mini computers. They are general purpose computer with a large area of application. Such machines are typically operated by professional, programmer and technicians also the maintenance of this computer is more expensive.

4) Super computer: - Super computer are high capacity machine that require special air condition rooms. They are fastest computing device Man has ever created. Super computer contains a number of CPUs which operate in parallel to make it faster. They are use for weather forecasting, weapons research and development,

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rocketing, and nuclear research. PARAM is the first super computer made in India.

Function of computer:-

Data / Input storing Pr ocessing OutputInstruction

INPUT – Data and instruction entered in to a computer for processing purpose.

Storage - Saving data and instruction to make them readily available for intial or additional processing as and when required.

Processing – Performing airthmatic operations or logical operation on data to convert them into usefull information.

Output- The process of producing usefull information or result for the user such as a printed report or visual display.

Branches of computer (components of computer)

1. Hardware 2. Software 3. Firmware 4. Live ware

HardwareThe Physical components of a Computer system whom we can touch and see are hardware. Such as – Moniter , keyboard , etc.

Types of hardware: - there are four types of hardware.

Input device Storage device Processor Output device Online Temporary Register Softcopy Input device Permanent ALU Hardcopy Offline Input device CU

Input deviceA device Used to ( by which we) entering data and instructions into the computer system Is called Input device.

Ex.:- Keyboard, Mouse Scanner, Joystick, Track ball, Light pen, digitizer, Game pad

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Types of Input device :-

Online Input device – “ A device or system directly connected to the CPU.” Online input device are used for a system of real time application. The data entered could be

processed immediately and the output is shown to user. However only one user could operate on them at a time.

Some online devices are: -

1. Dumb terminal: - These consist of a keyboard and a display unit. They can not stored any information. These terminal are connected to a main computer, generally called as a sever whatever information is required these terminals fetch it from the server show the output to the user.

2. Voice recognition device : - Use for recognition the human speech it consists of a microphone or telephone that converts the human speech into the electrical signals. Such signals patterns are transmitted to the computer where it is match with already stored pattern to identity that input. These prestored patterns are called the vocabulary of the system.

3. Touch tone terminals (TTT) :- Through TTT the user interacted with the system by touching the screen or monitor it self. The screen displays the various options for the user and he select the required options by touching those options. Ex. Of such terminals can be seen in ATM centers.

4. Mouse: - Mouse is a pointing device which can be used very effectively on graphical user interface (GUI) like windows. The mouse can perform operation like locating, copying or moving files. And any more things. Mouse may have a single button or double button or even three buttons. These buttons are used to select the required item on the screen by clicking it.

A mouse consists of the following components:- 1. A roller ball that translate movement to the system.``2. Two or three button for making selections.3. A housing which contained the above the and its moved around on the mouse pad.4. A cable and connecter for connecting the mouser to the system.

Off line Input device – “ A device or system not directly connected to the CPU.” In offline input device data can be recorded by using punch machine and them fade into the system to read as in case of punch card. These certainly save computer time and even provide facilities for more than one person to enter data simultaneously.

Punch card: - Data is punched on cards of predetermine size of using keys punch machine. A typical punch card has 12 rows and 80 columns. 12 and 11 rows are referred to as zone rows. One character is representing in each column and a 80 column card can hold 80 character. A collection of cards known as deck is pleased on the card reader. Position of had is sensed by photo electric cells and the signals are deciphered by the computer.

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Storage device The device in which we can saving data and information is called Storage device.

Ex.:- HDD, RAM, ROM, Floppy Disk, CDROM Drive, Memory.

Memory Memory is an essential component of digital computer. It function is to store information. It stores

data, program, features or any other kind of information.

STORAGE DEVICE

Temporary storage Permanent Storage Or Or Primary storage Secondary Storage Or Or Main memory Auxiliary Memory Or OrSemi-conductor memory Magnetic chore MemoryExample- RAM, ROM, PROM, EEPROM.

Permanent storage

Magnetic tapes Magnetic Disk Optical DiskEx. DAT (Digital Audio Tape). Floppy disk CD-ROM, DVDROM. Cassettes Hard disk Winchester disk

RAM: - This is a Random Access Memory and also known as internal or main memory. It is a read and writer memory of computer. The user can writes information into RAM and read information from it. RAM is volatile (erasable) memory. That means the information is stored in it is erased as soon as power is turn off.

ROM: - This is non volatile memory. Its contains are retained it the power supply goes of. It is also called read only memory. ROM is used for permanent storage of information. The stored information can only be read from ROM at the time of operations.

PROM: - This is programmable read only memory user can program it according to their needs. The disk advantage of PROM is that is can be program only one’s thus user can not change it contains after edit program once.

EPROM (Erasable Programmable Read Only Memory): - An EPROM is Erasable Programmable Read Only Memory. User can program its contents more than once. EPROM is used to store permanent data that may need up date in after sometimes. The contents of EPROM can be erased by the exposure to high intensity.

EEPROM: - This is a Electrically Erasable programmable Read Only Memory. It can be both program and erased with electrical stimuli. The complete data dang e erased in one operation if desired. EEPROM requires 21 volt pulsed for writing or erasing and 5 volt for read operation.

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Cache memory: - the cache memory placed in between the main memory and C.P.U. it is much faster than main memory. The access time of a cache memory is 15-25 neno seconds where as that of the main memory in 80 neno seconds. The cache memory is not accessible to users. The capacity cache memory in such less as compare to the main memory.

Magnetic tape: - Magnetic tape is secondary storage data at the low cast. Data recorded on the tape dang e erased and new data can be stored in its place. Magnetic tape are non volatile in nature and data is store permanently.A magnetic tape is a thin plastic tape coated with a magnetic material. Normally they are 0.5 inches wide take. A magnetic tape is divided into oriental cross called channels or tracks and vertical column called frames.

Floppy disk: - A floppy disk is a removable round piece of Mylar plastic that store data and programs as magnetic spots. Data is stored as electromagnetic charge on a metal oxide will that coats the Mylar plastic track and sector are logically created areas on the disk and the process of forming tracks and sector on the disk is known formatting are establishing.

Types of floppy: - 1st 5.25 inches and 2nd 3.5 inches.

(1) 5.25 inches: - it was the common size of floppies for PCs made before 1987. a 5.25 inches disk it covered in a protective cover of thin vinyl. This type of floppy is

normally capable of storing between 100kb and 1.2mb data.

(2) 3.5 inches: - A 3.5” disk is also known as micro copy and its protective cover are hard plastic. There storing capacity ranges from 400kb to 1.44mb of data. The most common size for PCs is 720kb and 1.44mb. a floppy disk may be single sided or double sided.

Write protect notch

Level

Drive spindle hole

Alignment hole

Alignment notch

5.25 inches floppy disk

Hard disk: - Hard disk is thin but raged metal platters covered with a substance that allows data to be head in the form of magnetized spots. Hard disk is one or more plotters sealed together

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within and enclosed. Hard disk drive located inside of the cabinet. Data may be recorded on both sides of the disk plotters. “The hard disk is around; metal platters in the hard derive of the computer. It stores large amount of information.” The hard disk has a magnetic coating it is sealed into the hard drive and often installed inside the computer where you can’t see it. Hard disk capacity is measured in bytes and speed is measured by transfer rate in the bytes/seconds.

STORAGE MEASURMENT

(1) Bit: - “0 and 1” no. is called bit.(2) Byte: - A combination of 8 bits is known as bytes.(3) Kilo byte: - A KB is abbreviated as k or KB and is equivalent to 1024 bytes.(4) Mega byte: - A mega byte is abbreviated as M or MB and is equivalent t 1024 KB.(5) Giga byte: - A giga byte is abbreviated as G or GB and is equivalent to 1024 MB.(6) Tera byte: - A tera byte is abbreviated as T or TB is represent the capacity of 1024 GB

(100, 9,511,627,776 byte).

Processor: - The device who perform arithmetic operation or logical operation on data in order to convert them into useful information.

Ex.:- Register, ALU, CU.

Output device“That device who gives us result after processing I known as output device.”A device used in a computer system to supply information and result of computationto the out side world

Ex.:- Monitor, Printer, Speakers, Laser printer, Plotter.

Types of output device :- Soft copy output device :- computer output which is displayed on the screen of a

terminal and provides no permanent copy . Ex. Monitor’s - CRT , LCD , TFT …….

CRT(Cathode Ray Tube):- A CRT displays screen is the most commonly form of the monitors. It displays the data and information received from the computer. A CRT is a vacuum bubs used as a display screen. This technology is also used in television sets.

FPD (Flat panel Display): - CRTs provide bright and clear images but they add addition weight and consumed more power. Due to this reason they are not suitable for portable computer. FPD are much thinner and light weighted as compare to CRTs. FPD are made up of two plats of glass with a substance between them.

LCD (Liquid Crystal Display):- In LCD the substance used between the plates is a Liquid Crystalline material. Out of two plates the front plates is kept transparent and back plates is reflective.

Hard Copy output device :-

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Printed or limited output form a computer device in human readiable form.Ex. Printers , plotters ,

Printer

Impact Printer Non Impact Printer

Serial Printer Line Printer Laser Printer Inkjet Printer Thermal Printer Dot Matrix Chain Printer Printer Band Printer Daisywheel Printer Drum Printer

Impect Printer :- A printer which prints character by causing hammers to strike against the paper on which information is to be printed.

Types of Impect Printer – 1. Serial Printer –

a. Dot Matrix Printer - Dot matrix Printer is a character printer which print one character at a time and all kinds of image as a patterns of dots.

b. Daisy Wheel Printer2. Line Printer –

a. Chain Printer b. Drum Printer c. Band Printer

Non Impact Printer : - In non impact printer character and images are form without making direct physical contact with paper.

Ex: 1. Laser Printer: - They are very similar to today photocopy machine. In laser printer use the

principal of dot matrix printer of creating image with dots. His images are created on a photo sensitive drum treated with magnetically charged ink like toner.

2. Inkjet Printer: - Inkjet Printer are non impact printer . they spray small electrically charged drop less of ink form four muzzles through holes in a matrix and high speed into printer.

3. Thermal Printer: - A typical thermal printer contains heating elements for each dot position on print line. They required special heat sensitive paper when a spot on a sensitive paper is heated him becomes dark. A printer had contains heating elements that are heated by the electrical current.

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Software“ A set of program procedure and associated releated to the effective operation of computer system is noon as software.”A set of instruction and program is called software.

software

Application software System software

User radimet Assembler loader compiler linker o/s

Application s/w :- Software which are designed for specific purpose such as pay calculation and inventory control etc. is noon as application s/w.

System s/w :- A set of one or more program designed to control the operation of computer system is called system s/w.

Types of s/w

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User

Application software

System software

Hard Ware

Assembler :- Assembler is a program which translate on assembly language program in to machine language is called assembler .

Loader – loader is a program that loads machine codes of a program in to the system mempory .

Compiler – compiler is a program which translate a high level language program in to machine language is called a compiler .

A compiler is more intelligent than assembler.

Linker – A linker is a program that links smaller program to form a single program.

Operating system – An integrated set of programs used ot manage various resourece and over all operation of a computer system is noon as operating system .

Interprater – An interpreter is a program which translate statement of a high level language program in to machine codes . it translate one state ment of the program at a time . A compiler is faster than interpreter 5 to 25 time.

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BLOCK DIAGRAM OF COMPUTER ORGAINZATION

Data

Information

Disk Operating System (DOS) Current directory

C: \> Command ending position/ prompt Current drive. Command Prompt.

There are two types of command: -Internal commands: - Internal commands are the commands stored in the file command.com which is

loaded into main memory at the time booting thus internal commands are also loaded in the main memory and remains in the main memory as long as computer is on. These commands can be executed at the any time as no extra file is required to run them.

Ex. Dir, cd, md, cls, copy, delete, rd, etc.

External commands: - external commands are stored in different files. Each external command as its own File. Thus they cannot be executed if there files is not loaded in the memory. Generally these files are stored on the secondary storage and loaded into the main memory whenever requested.

Ex. Format, Attrib, tree, disk copy.

File name should be only 11 characters, in which 8 character for main name and 3 characters for extinction name. We can use A to Z characters and 0 to 9 numbers and some special symbols like that $, @, ~, {,}, &.

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Input unit

Storage Unit

Output Unit

ALU

CU

Ex. Akhil.doc Extinction name. File name (main name) MD: - For make directory. CD: - For change directory. Del: - For Delete. Copy con: - For make file. Type: - for open file. Cls: - For clear screen. Cd.. : - For come out from any dir. b : for space. For enter.

--- File1 Ram Sita (Sub directory)

Net Game

File2 Dos

C:\>_ C:\>D:D:\>mdbwsD:\>cdbwsD:\>ws>copycon file1---------------------------------------------^zD:\>ws>md sitaD:\>ws>md ramD:\>ws>cd ramD:\>ws\ram>md netD:\>ws\ram>md gameD:\>ws\ram>cd netD:\>ws\ram\net>md dosD:\>ws\ram\net>copycon file2--------------------------------------^zD:\>ws>ram>net>cd\D:\>

Copy command- C:\> copy <source file name> new file name>Ex. C:\> copy ram shyamIf want to copy from C :\> to D:\> thenC:\> copy ram D:shyam

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WS

Wild card:- It have two special symbol “? and *”. When we misspell our file name or forgot file name then use “?” symbol. Ex. - ???n.com (arun.com)

* Symbol shows all file.Ex. – C :\> dir *.comThis will show all file which extinction is .com.C:\>dir b *.* This will show all file with any extinction.C:\> Account> b copy b a:*.*Thus will come from a: to account folder of c:. C:\> copy b a:*.*All document or copy of a: will be copy in c:C:\>account>copy a: ram.*Copy will be in account from a: ram file with any extinction.

Rename:-C:\>ren b<source file name>b <new file name>Ex. – ren b rakesh b Narendra

Shorting: - for alphabetical arrangement.Ex. – C:\>dir| sort> prgIf we delete any file by mistake then for finding them used undelete command.C:\>undelete

External commands: - Tree:- We know that DOS stores the files and directories in a tree structure. Tree commands in used to

display full tree structure of the files and sub dir within a directory.Syntax:- C:\>tree b <dir/drive name>Ex. – C:\>tree b ws b d:

Deltree commands:- The deltree commands is used to delete an unwanted directory. If we want to delete directory with its all subdirectory and file we used deltree command.

Syntax:- C:\>deltree b <directory name>

CHKDSK (check disk):- this command is used to determine the status of a hard disk and known as the status of the disk.

C:\>CHKDSK b <path name> b switch

Disk compare:- This command is used to compare to floppies. Syntax:- C:\>disk comp b <drive1>b <drive2> b switchC:\>disk comp b A: b B:C:\>disk comp b A: b B:/1This switch (/1) is used to compare only one side disk.C:\>disk comp b A: b B:/8This switch (/8) is used to compare to disk track by track.

Disk copy:- this command is used to make an abject copy of floppy disk it also copies the system files and other hidden files one disk to other disk.

Syntax: - disk copy b <source drive> b <target drive>

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Booting: - The term booting is used to describe the process of loading and operation system from the secondary memory into the computer main memory.

Initially the diagnostic routine test the main memory and other components of the system to insure that they are working properly. Then ROM- BIOS (Basic Input Output System) is copies to main memory and check the input output devices.

File Attributes: - Thus to insure the security of file, four attributes are there to indicate the type of file with to access authorization. These four attributes are as follows:-

(1) Read only file: - If a file attributes of a file set as read only then it can be deleted or modified.

(2) Hidden file:- This attributes is also used avoid the unauthorized access the file. If this attributes is set “on” then that file is not shown in the common listing of all file.

(3) System file:- If this attributes is set “on” then is work as a combination of read only and hidden attributes. It means such a file is set as read only and is not display in file listing.

(4) Archive file:- If an archive bit is set it means that the file is modified since last time it was accessed.

Number system

S. no. Name of no. system Digits Base/Radix Example

1 Binary 0,1 2 01110011

2 Decimal 0-9 10 89

3 Octal 0-7 8 176

4 Hexadecimal 0-15 16 7D

Decimal Hexadecimal Binary Octal

0 0 0000 0

1 1 0001 1

2 2 0010 2

3 3 0011 3

4 4 0100 4

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5 5 0101 5

6 6 0110 6

7 7 0111 7

8 8 1000 8

9 9 1001

10 A 1010

11 B 1011

12 C 1100

13 D 1101

14 E 1110

15 F 1111

Sign bit: - “0 means +” and “1 means -". An integer can be positive or negative. We do not have any other symbol in the binary symbol. If sing bit is 0 then value will be positive or bit is 1 then value will be negative.

0 0 1 1 0 1 0

Sign bit

Signed magnitude scheme: - Method: - Step 1- Convert the decimal no. into its binary equivalent. Step-2:- Represent the converted Binary no. in the no. of bits available for representation. If n bits are available for storing a decimal no. n-1 are used for the magnitude and 1 bits for sing bit.Ex. – (37)10 = (100101)2

n-1 n--------------------------->1 0 1 0 0 1 0 1

= - (37)10 372 18 ----12 9 ----02 4 ----02 2 ----12 1 ----0

One’s compliments:- One’s compliments is used to represent negative integer. Step Ist: convert the positive integer in the given no. of bits the sign bit will be 0 now. Step IInd: Flip all the bits that is convert “0s” into 1 and 1s into 0s.

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ASCII: - The ASCII code used 7 bits to represent any character set. Earlier every manufacturer used a different code to represent a character resulting in choose and utter confusion. Finally the computer industry has accepted the ASCII code. The full form of ASCII is American Standard code for Information Interchange.

EBCDIC: - It is an 8 bit code. Large computer system uses this EBCDID code. The full form of EBCDIC is Extended Binary Coded Decimal Interchange Code.

Positive and negative integer: - the set of whole number is called set of integer. Thus the number having no fractional part and hence no decimal point are called integer. The positive integer are written without a sign before them where as negative integer having a (-) sing before them.

Floating point number: - In modern computer a real number is stored in he standard floating point form. A real number is set to be in standard floating point form if it is expressed as m*bn where b is the base of number system and n is the meatisaw which satisfy the relation.

Ex. 0.111*2-13 are in standard floating point form.

Distributed system: - A distributed system comprises of independent sub system that are connected through various communications lines. These system can be divided into two types.

(1) Centralized distribution system (2) De centralized distribution system.

1. Centralized distribution system: - In this type of system there are a central computer called as the server that controls the network and provide central storage space for information in addition server also takes the responsibility of assigning and resources to various computer connected to it. These other computers are generally called clients or workstation.

2. De centralized distribution system: - In this types of system two or more computer are directly connected to each other and share resources. That is no central control over the network, one advantage of this kind of system over centralized distribution system is that it is non dependent on any one central system. If the server in centralized distributed system fails the entire network fails

Network of computer: - A network is an inter connection of two or more computers in order to unable transfer of data or information from one place to another place by making use of network could even share certain resources like printer hard disk modem etc.

The network classified into two types: -(1) Homogenous (2) Heterogeneous

Homogenous network: - In this network computer with singular architecture or connected together example of this types is LAN. Such network may be confined a building or campus where in different department needed to communicate with each other. These could be connected using point to point cables.

Heterogeneous: - To the name suggested this computer have different architecture at different set of rules to communicate among each other. An ex. Of this type is WAN which a network of worldwide is. These could be connected via cables, telephone line or even satellites.

Motherboard: - The mother board is the primary component of the entire system without the support of the circuitry and function that. This device provides even the CPUs unable to functions.

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GENERATION Generation of computer talk is step in technology it provide a

Farmwork for the growth of computer industry.First Generation :- Time duration :- 1942 to 1955 Technology :- Vaccume tubes used in first generation Computer comes in first generation :- IBM-650 , ENIAC , UNIAC Advantage and Disadvantage :- 1. Slow operating speed and restructed computing capability. 2. High power consumption and short life. 3. Large space requirement. 4. Limited computing capability. 5. AC required.Second Generation :- Time duration :- 1955 to 1964 Technology :- The transistor were used in second generation. Computer comes in second generation :- IBM-1401 , Honey well – 200 Advantage and Disadvantage :- 1. The transistor was smalled to Vaccume tubes. 2. Wider commercial use. 3. More Relaible. 4. Commercial production was difficult and costly. 5. AC required . 6. Less heat generated.

Third Generation :- Time duration :- 1964 to 1975 Technology :- The computer that were designed with use of ICs. Computer comes in Third Generation :- IBM-360 , CDC-1700 , ICL-2903 Advantage of disadvantage :-

1. IC was used in replace of Transistor.2. Portable.3. commercial Production was eaiser and cheeper.4. AC Required in many cases.5. Not working continue in hours.6. Use of operating system .7. less heat generated.

Fourth Generation :-

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Time duration :- 1975 to198 Technology :- VLSI A fourth generation computer has vlsi chips as its brain it is

the LSI technology which let to the development of very small but more power full.

Computer comes in fourth generation :- Intel 4004 , apple I II IBM Advantage and disadvantage :-

1. Totly general purpose.2. Very reliable.3. Not AC required in most cases.4. Much faster than previous generation.5. data storage capacity.

Fifth generation :- The fifth generation computer a promise but not at reality they aim to bring

as machine with genuine iq ability to reason logically it process the voice recognition and image processing jobs very fast this kind of information still under development.

Time duration :- 1984 to on world Technology :- ULSI used in fifth generation. Computer comes in fifth generation:- Intel – notebook ,laptop, Pentium pc sun workstation , param 10000 Advantage and disadvantage :-

1. Portable pcs are much more smaller then the pcs of 4th generation.2. several times more powerfull then the pcs of 4th generation.3. They consume much less power 4. many of the large scale system of generation have hot pluggable

features.5. They have faster and large primary and secondry storage as

compaired to 4th generation.

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Computer language A computer language is the means of communication used to communicates betbeen people and computer.

Machine language :- The set of instruction codes whether in a binary or in decimal notation

which can be directly under stood by the computer with out the help of a translator is called a machine language or machine code.

Advantage and disadvantage :- 1. program writeen in machine language are excute very fast by the

computer .2. machine dependent . 3. difficult to program .4. error prone ./5. difficult to modify.

Assembly language :- “ A program written in mnemonics is noon as assembly language.” A program can be eaisly written in alpha numeric symbols instead of 0 and 1

meaning full and eaisly remembrable symbols are selected for this purpose . Ex. ADD – Addition , SUB – Substraction Such symbols are noon as mnemonics . Advantage and disadvantage :-

1. An assembly language program runs faster to produde the desired result.2. programming is difficult time consuming.3. one computer to can not be used any other computer.

High level language :- A programming language who is structer is application oriented and is

independent of the structure of computer. Advantage and disadvantage :-

1. machine independent .2. easy to learn and use. 3. few errors . 4. lower efficiency .5. Lack of flexibility.

There or types of high level language – BASIC , FORTRAN , COBOL , pascal, ALGOL,

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Character stic of computerVolume :- volume for handling large amount of data .Accuracy :- they need for high degree of accuracy is satisfied by the computer Repetitiveness :- processing sycle that repeat them selves over and over agan ideally suited

to computer .Complicity :– to perform the most complax calculationSpeed – enable to respond very quickly to given switcation speed measured By

MIPS .Common data :- one item of data may be involve in several procedured by a varaity of users.Clock speed – the frequiency as which the puls are generated and process is equivalent to

133.10 per second the frequency of puls generated is noon as clock speed .

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Operating System

One of the primary job of operating system is to be provide and interface betbeen the user and hardware this enterface enable a user to use hardware resources ifficiently.The operating system perform following function :-

1. Processer management.2. memory management .3. Input Output management.4. File management.5. scheduling 6. time during .7. security management.8. Error Prone.

Classification of operating system :- All operating system can be classified tn to four general catagries.

(1) Single User Operating System :- Single user operating system which allows only one user to work on a

computer at a time is noon as single user operating system. Ex. DOS , Windows 9x etc.

(2) Multi User Operating system :- A multi user operating system allow a number of user to work to gether on a

single computer eache user will be provided a terminal connected to a single computer

Ex. Linux , Unix , Windows NT.k

(3) Single Tasking operating system : - Single tasking operating system which can excute only a single task at a

time is noon as single tasking operating system.

(4) Multitasking Operating system :- Multitasking operating system supports execution of more than one job at a

time on a computer . Ex – windows XP

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Virus

Virus is a program which have no address on disk A replecting code segment that attacks it self to a program or data file virus is also noon as a illegal program .because a virus have no address in disk so virus include with other program and disturb the path or make program useless.

Types of virus :-Bootsector virus :- A boot sector virus alerts on hide in the bootsector usally the first

sector of a bootable disk or hard drive boot sector virus were prevlent in the 1980.

File virus :- A file virus often written in the scripting language for Microsoft program such as word,excel,is sraid in Microsoft office by infecting documents and spraid sheet.

Email virus :- An email virus is a virus which uses email message as a made of transport .these virus often copy them selvs by automatically mailing copys to hundreds of people.

Name of virus – I love You , Fun love , Hello

Name of Antivirus – They have to protect our computer from viruses. Macro , Norton , Panda ,Avast,solo. POINT OF SALE TERMINAL – The point of sale terminal process tranzection that occur over and over again. Ex . The deposit of pechex or payment of monthly bills. The point of sale terminal may be any thing from an ordery telephone to a high

speed electronic cash registor many detail stores have these for pay role processing or account to reasiable.

OCR – Optical Character Reader with recognition reader examinies each character one by one what ever be the style hand written of printed the pattern detected by the OCR reader is method against a set of patterns store in the computer.

MICR – Magnetic Ink Character Recognation MICR character are printed with a magnetic Ink or toner magnetic printing is used so that the character can be reliable read in to a system even when they have been over printed with other marks such as conciliation stamps the character are read with a device similar in nature to the head of an audio tape recorder.and the read later forms bulsafe insure that each latter produce a unique web forms for the read head.

PC – Persnal Computer it was only 1981 that IBM came out with its IBM PC family of computer which were excepted by customers the IBM PC consist of a system .unit which contains the microprocessor chip noon as intel 8088 Ram of 256 kb it has one floppy drive and the working memory .

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PCXT- PCXT is the personal computer with xtended technology this contains a floppy drive and a hard disk drive it is also based an micro processer chip intel 8088 that were used operating system DOS and windows 95.

PC AT – it is the PC with Advance Technology .this has micro processer chip intel 80286 which is a faster chip as well as a true 16 bit computer as compaired to PC or PCXT 16/2 bit computer which these computer calld also support Unix operating system.

Laptop- A small protable personal computer that runs on either battries or AC laptop have flate LCD or plasma screen and small key board must can run the same software as there desktp counter parts laptop wait as little as 5 ponds .

Plamtop – A protabel personal computer whose size enable it to be held in one hand while it is operated with the othe hand a major difference betbeen palmtop computer and laptop computer is that plam top are usalyy powerd by of the self battries such as A cells palmtop computer do not have disk drive there program are stored in ROM and are loaded in to RAM .

Desktop – Desktop computer is a computer that’s fire conventirely on the surface o buisnuess desk most personal computer as well as sum workstation com be conecdet disk top computer .

Booting :- Every pc has built in ROM or BIOS which contains instructions to check the status of device the process of loading opoerating system from the disk in to the main memory of the PC is called Booting .

Booting sequence – Hard disk , floppy , CD-ROM , ………….DOS System Files – IO.SYS , COMMOND.COM , MS DOS .SYS are those system

files are used while booting . DOS.SYS – 1. To intract directly with application program and IO.SYS programs.

2. Read programs for display information storing and retirving of data printing etc.

IO.SYS – After booting reset the disk function and initializes attached device load commond .com file.

COMMOND.COM – Rad commond from the keyboard and excutable file perform error check and display error messages if it find an error give the DOS disk prompt.

Warm Booting – To skip the RAM test with the held of restart on CTRL+ALT+DEL key is noon as warm booting .

Cold booting – The process of switching of computer of testing checking the RAM and then booting is called cold booting .

FILE – A file is the place were we store data which is processed by the computer the size of any file name is of 11 character in which 8 character are primary name and three character are secondary name of extention.

Ex. Akhil.Doc . doc , .xls , .ppt

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Computer Network

Concept of Network – A group of computer and other device connected to gether is called network . and the concept of connected computer sharing resources is called networking .Computer connected over fa network can make that information exchange eaiser and faster .The information moves directly from computer to compiler.Types of Network -

1. LAN – A Local Area Network is an interconnection of computer system through one type of transmission media and is entirely contuened in a building it is relaitivily a small network typically personal to an organigation the maximum limit of this network is 10 km .

2. MAN – Metropoliten Area Network are the network spraid over a city and it cover an area of 100 km it links computer facilities in city through same and different transmisoon media .

3. WAN – A Wide Area Network is a group of computer connected in a Wide spraid Ared it many interconnected LANs spraid sheet in large distance it provides nation wide connectivity.

Advantage of networking – 1. Resources networking – The users can shair all programs data and peripheral

which are available to any one an introconnected computer.2. Relaibility – A file can have copys one two or more different machine .3. Cost Factor – the networking have better performance and prize other than

computer.

Disadvantage of Network – 1. Data security – As all the data resources are all pooled to gether it is possible for

unothrized personal to access classified information if network security is weak poorly implemented.

2. Privacy – a network may also been loss of privacy as any one specially your boos with the wright net privileges may be in position to read your private email.

TOPOLOGY

The term of topology in the contest of communication the geometric arrangement of any network is its topology the computer are work station in the network are linked to gether according to the physical arrangement of work station and nature of work is called topology .Few popular topologyes are –1. Star 2. Ring 3. Bus

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4. Tree 5. Graph (mass)

Star Topology – Each node is connected to single centrally located file server using its own dedicated segement of cable this topology has the advantage of minimum data trophic along the cables . thus providing optimum performance but because a single machine must coordinate all the data communication this topology required and extremily powerfull and expensive file server .

Ring – In the ring topology computer are arrange in a circil data trouble around the ring in one direction with each device on the ring actingas repeator ring network tyipically use a token passing protocol.

Bus – in bus topology all computer are connected by a single length of cabiling which a rerminator at each in the bus topology is the simplest and widly use network design.

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hub

Tree topology: – This is a network topology containing 0 or more nodes that are linked together in a herichickel fashion the top most node is called the root the root may have 0 or more child nodes connected by links.

Graph: – in this method of connection 0 or more nodes are linked together in an orbiter fashion any two nodes in a graph may be connected by a link

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HUB

HUB

Terminology :- Terminology used In Network

Nodes – The PCs and the server are noon as a network device are network nodes general a device or node is connected directly to the network cable or data path.

Media – The media and data fbus are colectivily used to refer to the data path media can be .

1. Bounded – such as cabler wire . 2. Unbounded – Free space .

Host – The term host refer to the micro computer attached to a network device it may

also refer to the native operating system on a work station thus MS DOS is a host operating system .

Work Station – A work station is a computer used as a node on a network primary use to run application program .

Email

“ Email is a method of sending messages voice , video and graphics over digital communication link such as the internet any where in the work at very cost effective rates technically email is a type of clint server application that provides a routed stored messages service betbeen any two email account .”

How Email works on the Internet – Email is the most havilly used featursf of the internet you can use it to send messages two any one who is connected to the internet or connected to a computer network . That has a connection to the internet such as online services email messages are sent in the same way as most internet data . The TCP Protocol break your messages in to packets the IP protocol diliver the packets to the proper location and then TCP resembles the messages on the reciving end so that it can be read .

Email protocol – You want to send a message to a user running a different messaging program some translation may be nessessary because of the complicity involve in having many different system send and recive message in many different formats email protocols have become nessesry .

Types of Email Protocols – Some of these protocols discussed in the following .1. X.400 2. SMTP 3. UUCP 4. IMAP.4 5. MIME

Structure fo email messaging –

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An email message is made up of binary data useally in the ASCII text format ASCII is standerd that enable any computer reguardless of its system or hard ware to read the text ASCII code describes the character you see on your computer screen .

There are five section of email messages – (1) Email address (2) Header (3) Body (4) Signature (5) attachment

Protocols – by the term protocol we mean the set of rules or standerd designed to enable computers to get conncted with one another and than exchange information with as little errors as possible the internet protocol are is a low level protocol that route packets off data across spraid network tied to gether by routes to form the internet or intranet . data troubles in packets called IP data grams .

TCPIP – TCPIP is a protocol stack designed to connect to a different network on which the internet is based TCPIP can work with any hardware or operating system TCPIP is just shair hand notation for a full protocol are set of protocol that have standerd ways of intrecting with each other.

MEMBER OF TCPIP –TCP ( Transmisson Control Protocol ) – Insure that connection are made and mentined betbeen computer .

IP ( Internet Protocol ) – Handle software computer address .

ART ( Address Resolution Protocol ) – Relates to IP address with hardware mac address .

OSPF ( Open Shortest Path First ) – That increase its speed and reliability .

RIP ( Routing Information Protocol ) – Finds the quickest rout betbeen two computer.

ICMP ( Internet Control Message Protocol ) – Internet control message protocol handle error And send error message .

BGP/EGP ( Border Gateway Protocol /Exterior Gateway Protocol ) – Handle how data is passed gateway betbeen network .

SNMP ( Simple Network Management Protocol ) – Simple network management protocol allow network administrator to connect and manage network device.

PPP ( Point to Point Protocol )- PPP provides for dialup networked connection to network ppp is commonly used by internet service provider to allow customers to connect to there services .

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SMTP ( Simple Mail Transfer Protocol )- SMTP how email si passed betbeen server on a TCPIP network . POP3/IMAP.4 (Post Office Protocol 3/Internet Message Addressing Protocol 4) – Both setup ways for client to connect to server and collect email .

Internet layer Protocol – Internet layer protocol is used for routingh and providing single network interface to the upper layer routing is a comlax and important and it is the job of the internet layer fto carry It out the various protocols at the internet clear all .IP – ARP – RARP – Result Address Resoulution Protocol .ICMP – Boot P - Boot Programs .

Network Architecture – network architecture refers to physical layout of the computer connection and the logical method of there communication the first parts is known as topology or physical connection the second part is protocol these are individually discussed . The network architecture can be one of the following –

1. Ethernet 2. FDDI –3. ATM – 4. Token Ring -

InternetSome Simply fied description of the internet are alarge computer network or network of networks an instantenios and globle messaging system.Characterstic of Internet :-

1. A complax network2. disorgranized3. decentralized 4. composed of billians of file5. widly used 6. international in escope7. dinemic changing

What the internet is not :-

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1. Organized no central2. centrally controlled 3. completely authentic4. static or predictable5. easy to navigate6. free of charge

Browsers :- A web browsers is a program you use to view pages on navigate the world wide

web browsers are some time reffered to us web clint or other fancy name currently the most popular browsers for the WWW , netscape , navigator,Internet explorer .

NCSA MOSAIC – MOSAIC was the first color full graphical browser and is the instruction mental in marking the web as popular as it today mosaic was development ncsa at the university of illinoise windows mosaic are in various operating system like maintash and UNIX .

LYNX – You are limited to using text only browsers such as LYNX it is use only UNIX.Microsoft Internet Explorar – Microsoft Internet Explorar called explorer is the largest use browsers in the

world explorer runs in windows 9x on the world .Netscape – Netscape navigater also known as netscape is available for windows macintosh

and for many different versons fo UNIX in running the x windows system .and the avility to handle plugin for more new and interesting features at to be developed.

Domen name – most organization use domen name that are easy to remember each domen name and with an identify that tell you that type of website it is current domen name identify .

. com - commercial business . edu - educational instruction . gov - government intities

Search engine – A search engine is a software that services through a data base of web pages for

specific information. Catagary of search engine – Yahoo , hotbot , webcrawler , exite , lycos , khoge , google , altavesta ,

FTP – One of the most popular uses of the internet is to download files . The is transfer file from a computer on the internet to your computer thousands of

files are download every day on the internet most of these files are download usilng the intenet FPT commenly reffered to as FTP this protocol can also be used to upload files from your computer to another computer on the internet .

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HTTP – Hyper Text Transport Protocol

HTTP protocol it used to managed the links betbeen one hyper text document and another HTTP is the machanish that open the relected the document twhen the select the hyper the text no mater where that document reside on the web.

Web page Web site – A web page is subset or a complete or a web site web site can congest only of all hundred of web page web is glover information system that ground of a internet 500 milions special formatted document noon as web page an inbisilble place analog to the web page .

Status Dyanamic -

status dyanamic

Hard copy document model.

No instruction with information .

No response from document .

Information can change .

Allow instruction with information .

A response instruction .

Dynamic Page – Document that use programming and data base to creat intrict contest is noon as dynamic page .

Status page – hard copy based document that provide no means of instruction betbeen information and reader is know as statics page .

XML – Extensible Markup Language each second web language links most device

phemano most of use get a with picture but all fuzzy XML is information because it is beb page made language with emblication be on the browser XML is specific data organized language.

HTML – Hyper Text Markup Language which runs on a computer that has as web browsers

instaline in it has colction all style that define the browse the component of www document.

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Wev server – A web server servers web pages to klindels occur the internet are internet The

web server host the page screpec program and multifile and subs them using HTTP A protocol designed send files to web browsers.

Clint server – To be a through client server development both clint of server must share in the

buisiness for example a data bus server process request from the client to look up data all up data it inks data bus in this is client server the search at its end to response to the qure recived from a client it is not acting at the removed disk driver it is fully part sefice in the trangection to illestrued this conset .

Mail server - A mail transper a jented all MTA mail server all mail exchanger in the contentst of the domen name system is the computer program are software agent that transfer e mail massage from one computer to another computer.

File Server – Stores Network users data file.Print Server – Manage the printer that are connected to the network and the printing of user

document on the network Printers .Communication server – Handles many common communication function for the network such as Email

fax or internet services .Application Server – Shares network enable versons of common application software and eliminates

the need for software to be installed on each work station .Database server – Manages a common data base for the network handling all data storage data base manage ment and request for data .

Proxy server – A proxy server that provides access to files from other servers by retriving than either from its local or the remote server proxy refer to a person or agency who has authority to act for another taken litrally does that mean a proxy server acts in place of another server proxy is a computer system or ruouter that brakes the connection betbeen sender an receiver . functioning as a relay betbeen client and server proxy servers are used to help prevent attacket from inbading the private network . proxy is are one of several tools used to build a fire ball.Feauters of proxy server –

1. address translation and checking application level and circuit level.

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2. filter request. 3. improve performance. 4. load distribution.

VRML – VRML a protocol for produce or creating navigable hyperlinked 3D shapes on the web in other words image or object you can spin around or a seen you can spin around the center point of view and some times you can zoom in and out .VRML produce a hyper space 3 dimensnal space that appears on your display screen and you can figrable move within this space that is as you press keys to term left right up down.

FLOW CHART Flow chart: - “A flow chart is a graphical representation of the sequence of operation for the solution of a problem.” Flow chart is basically the plane to be follow at when the program is written is acts like a road map for a primmer. And guides him how to go from the starting point to the find point while writing a computer program.

Symbols of flow chart: -

Terminal: - terminal symbol is used indicate the starting(begin), stopping(end),. It is the first symbol and also the last symbol in the program logic.

Input & output symbol: - Input, output symbol is used to indicate the operation of an input/output device in the program. It there is program instruction to input data from disk or any other of input device. Then that step will be indicates in the flow chart within an input/output symbol. Similarly all output instruction whether it is output on a printer, magnetic, tape, magnetic disk, terminal screen or any output device in the flow chart with the input/output symbols.

Processing: - Processing symbol is used in flow chart to represent arithmetic instruction and data movement instruction.

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Condition symbol: - If condition is satisfied then yes path to be. Otherwise no path to be taken.

Yes

Algorithm: - A sent of instruction which describes the steps to be follow it to carry out an activity is called an algorithm or procedures for solving a problem.

MEANING OF A FLOWCHART

A flowchart is a diagrammatic representation that illustrates the sequence of operations to be performed to get the solution of a problem. Flowcharts are generally drawn in the early stages of formulating computer solutions. Flowcharts facilitate communication between programmers and business people. These flowcharts play a vital role in the programming of a problem and are quite helpful in understanding the logic of complicated and lengthy problems. Once the flowchart is drawn, it becomes easy to write the program in any high level language. Often we see how flowcharts are helpful in explaining the program to others. Hence, it is correct to say that a flowchart is a must for the better documentation of a complex program.

GUIDELINES FOR DRAWING A FLOWCHART

Flowcharts are usually drawn using some standard symbols; however, some special symbols can also be developed when required. Some standard symbols, which are frequently required for flowcharting many computer programs are shown in Fig.1

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FULL FORMS

ABC – Attanasaff Berry Computer.ALGOL – ALGOrithmic Language.ALU – Airthmatic Logic Unit.ARP - Address Resolution Protocol.ASCII – American Stander Code for Information Interchange.ASP – Active Server Page.ATM – Automatic Tailer Machine / Asynchronos Transfer Mode.BASIC – Beginners Allpurpose Symbolic Instruction Code.BCC – Blind Carbon Copy.BCD – Binary Coded Decimal.BGP/EGP – Border Gateway Protocol / Exteriur Gateway Protocol.BS – Booting Sequence .CAD – Computer Aided Design.CAM – Computer Aided Manufacturing.CC – Carbon Copy.CD – Compact Disk .CGA – Cathod Graphics Adapter .COBOL – COmon Buisness Oriented Language.CPU – Central Processing Unit .CRT – Cathod Ray Tube.CU – Control Unit.DAT – Digital Audio Tape .DBMS – Data Base Management System.DIPS – Data Information Process System .DOS – Disk Operating System.DPI – Dot Per Inches .DVD – Digital Versatile Disk .EBCDIC – Extended Binary Coded Decimal Interchange Code.EDVAC – Electronic Discreat Variable Automatic Compueter.EEPROM- Electrically EPROM.EGA – Enhansed Graphics Adapter.ENIAC – Electronic Numaric Integrater Automatic Computer.EPROM – Erasable PROM.FAT – File Alocation Table.FDD – Floppy Disk Drive .FDDI – Fiber Distributed Data Interface.FEP – Font End Processer .FIFO – First In First Out.FMS – File Management System.FORTRAN – FORmula TRANslation.FPD – Flate Panel Display .

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FTP – File Transfer Protocol .GUI – Graphical User Interface.HDD – Hard Disk Drive.HTML – Hyper Text Markup Language .HTTP – Hyper Test Transfer Protocol.HW – HardWare.ICMP – Internet Control Message Protocol.IIS – Internet Information Server.IMAP 4 – Internet Message Advertising Protocol Four.IP - Internet Protocol.ISDN – Intigrated Services Digital Network.ISP – Internet Service Provider.KIPS – Knowladge Information Process System.LAN – Local Area Network .LCD – Liquied Cristal Display.LILO – Last In Last Out.LIPS – Logic Information Process System.MAN – Manipulating Area Network.MICR – Magnetic Ink Character Recogination.MIME – Multipurpose Internet Mail Extension .MIPS – Mega Instruction Per Second . OCR – Optical Character Reader.OMR – Optical Mark Reader.OOP – Object Oriented Programming .OSPF - Open Shortest Path First.PC – Persnal Computer .PD – Plasma Display .PL – Programming Language.POP3 - Post Office Protocol. ThreePPP- Point to Point Protocol.PRIMENET – PRIME Computer NETwork.PROM – Programable ROM.RAM – Random Access Memory .RIP - Routing Information Protocol.ROM – Read Only Memory .SMTP – Simple Mail Transfer Protocl.SNMP - Simple Network Management Protocol.SQL – Structerd Query Language .SVGA – Super Vedio Graphics Adapter.SW –SoftWare.TCP - Transmisson Control Protocol.TFT – Thin Film Transistor.TTT – Touch Ton Terminal.ULSI – Ultra Large Scale Integration.

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UPC – Universal Product Code.UPS – Ultra Powr Supply.UUCP – Unix to Unix Copy.VDU – Visual Display Unit.VGA – Vedio Graphics Adapter.VLSI – Vere Large Scale Integration . VLT – Vedio Lookup Table.VRML – Virtual Reality Moduling Language.VTR – Vedio Tape Recorder.WAN – Wide Area Network.WWW – World Wide Web . XGA – eXtended Graphics Adapter.XML- Xtensible Markup Language.

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