COMPUTER EDUCATION

(E-504)

UNIT I: MEANING, DEFINITION AND

HISTORICAL PERSPECTIVES OF COMPUTER

MEANING AND DEFINITION OF COMPUTER

Computer: A computer is an electronic device, operating under the control of instructions stored

in its own memory that can accept data (input), process the data according to specified rules,

produce information (output), and store the information for future use.1

It performs the following three operations in sequence.

1. It receives data & instructions from the input device.

2. Processes the data as per instructions.

3. Provides the result (output) in a desired form

The word compute is derived from the Latin word ‘computare’, was meaning “arithmetic,

accounting”.

The Computer meaning is the digital device that stores information in memory using input devices

and manipulate information to produce output according to given instructions.

The actual machinery, the physical parts of a computer system refer to as Computer hardware; the

instruction (a program) that tells the computer what to do or how to do, that is called Computer

software (often called just software).

HISTORICAL PERSPECTIVE

At most in 600 B.C. first real try for calculation was done in china. An accounting device called

Abacus was discovered. Abacus is a counting device, which become famous in whole world by

china through Japan & India.

a) Abacus is known as the first Model computes. This machine is used till now to teach counting

to the children.

11 Vermaat, Misty E. Microsoft Office 2013 Introductory. Cengage Learning, p.IT3. 2014

b) First mechanical calculating device was discovered by French nineteen year old young boy,

Blaze Pascal in year 1642. this device was named Pascaline.

c) British mathematician and inventor Charles Babbage, who was a professor in Cambridge

University, imagined a complete computer and to make this imagination come true. In the year

1822, he succeed to make a working model of a such machine

By which algebraic equation and arithmetic table could be solved and the result was true till the

third place of decimal. This machine was named as Difference Engine. Charles Babbage is called

father of modern digital computer. He developed binary number system.

d) In 1886 Hollerith established a company named Tabulating Machine Company for the business

of these machine.

e) In 1948 Howard A.Aikeb, a scientist of Harvard university, with IBM got success to develop

first electronic computer named Automatic sequence controlled calculator. This named MARC-1.

d) After it many large computer were made,which did work on binary method and that also had

facility of memory storage. There are some example of these- EDUAC, UNIVAC-1,EDSAC etc.

DEVELOPMENT OF COMPUTER

The progress of computer is regularly running after 1946 to till now. as electronic parts were

developed, a new step is added in development of computer. before we get more information about

development of computer.

VAN NEUMANN ARCHITECTURE OF COMPUTER

In1946, in governorship of famous mathematician of Cambridge university John Neumann in

discussion about the subject ‘Design of Electronic (Digital) computer’. computer specialist

recommended following computer related necessities.

1- In computer the storage of data should be in binary number system.

2- The architecture of computer should be such, that desired change in entered data and used

instructions can be done.

3-Computer should have the capacity to store data, as well as to represent the result by running

and store a program, by using stored data.

Its means the standard achltechrure for computer of future, which was named as ‘Van Neumann

Architecture’, was decided in this conference.

COMPUTER GENERATIONS AND ITS CLASSIFICATION.

GENERATIONS OF COMPUTER

On the basis of main electronic parts used in the computer, it is classified in following five

generations-

Generation Component used

First Generation

(1946-1956 )

Vacuum tubes

Punched cards for data input,

Punched cards and paper tape for output,

Supported machine language only.

Magnetic tapes and drums for external storage.

Very costly

Generated a lot of heat, Need of AC

Slow input and output devices

Huge size, Non-portable

Consumed a lot of electricity

Some computers of this generation were: ENIAC, EDVAC,

UNIVAC, IBM-701, IBM-650

Second Generation

(19556-1964)

Use of Transistors

Size of the computers started reducing,

Assembly language started being used in place of machine

language,

Concept of stored program emerged,

High level languages were invented.

Reliable in comparison to first generation computers

Smaller size as compared to first generation computers

Generated less heat as compared to first generation computers

Consumed less electricity as compared to first generation

computers

Faster than first generation computers

Still very costly

AC required

Supported machine and assembly languages

Some computers of this generation were: IBM 1620, IBM 7094,

CDC 1604, CDC 3600, UNIVAC 1108

Third Generation

(1964-19750 )

Integrated Circuits (IC)

Phenomenal increase in computation speed,

Substantial reduction in size and power consumption of the

machines,

Use of magnetic tapes and drums for external storage,

Design-of Operating systems and new higher level languages,

Commercial production of computers.

More reliable in comparison to previous two generations

Smaller size

Generated less heat

Faster

Lesser maintenance

Costly

AC required

Consumed lesser electricity

Some computers of this generation were: IBM-360 series,

Honeywell-6000 series, PDP (Personal Data Processor), IBM-

370/168, TDC-316

Fourth Generation

( 19760-1985)

Very Large Scale Integrated Circuits (VLSI)

Invention of microcomputers,

Introduction of Personal Computers,

Fourth Generation Languages.

Portable and reliable

Very small size

No AC required

Concept of internet was introduced

Great developments in the fields of networks

Computers became easily available

Some computers of this generation were: DEC 10 19, STAR

1000, PDP 11, CRAY-1(Super Computer), CRAY-X-

MP(Super Computer)

Fifth Generation

(1985 – till today)

Artificial Intelligence (At)

Ultra Scale Integrated Circuits (ULSI)

Micro Processor (SILICON CHIP)

Development of Natural language processing

Advancement in Parallel Processing

Advancement in Superconductor technology

More user-friendly interfaces with multimedia features

Availability of very powerful and compact computers at

cheaper rates

Some computer types of this generation are: Desktop, Laptop,

NoteBook, UltraBook

CLASSIFICATION OF COMPUTER

Computer can be classified in following groups- 1. On the bases of functionality, 2. On the bases

of Size

1. Type of computer on the bases of functionality

Analog computer-Analog means to establish similarity between two numbers. In

analog computer, by changing physical method in electronic signals with the help

of electronic circuits used regularly. In analog computers, data is recognized as a

continuous measurement of a physical property like voltage, speed, pressure etc.

Readings on a dial or graphs are obtained as the output, ex. Voltage, temperature;

pressure can be measured in this way.

Digital Computer- In digital method digit can transfer from their place. Its work

after changing all received information into binary digit. On the memory digital

computer a digit or alphabet is designed by switching of binary code 0 and 1 in

different blocks. Its does all calculation multiply, divide and even power also do

by adding. Its has following characteristics:-

o Execution of given information.

o Analysis in very short time.

o Cent-percent accurate and real result.

o Small size, light weight and low price.

Hybrid computer- By in corporate of good characteristics and specialty of analog

computer and digital computer, hybrid computer is invented. Its signal are

converted in digital form. For that work some special devices are used, which called

‘Modem’. It is the short from of modulator demodulator. Modem does the work to

convert analog signal in digital signal and to convert digital signal in analog signal.

Optical computer- Now in the development of computer of fifth generation,

optical fibre is used to connect one part to another part. Calculations part of this

computer are also making upon optical system. To do calculation it is more or less

than this time, optical fiber method is used to make a wireless computer, by this

computer will faster is comparison.

Atomic computer- In Carnagge Melon University, the work to make atomic

computer is on progress. The effort to make such computers having 10,000 times

more capacity and speed than today’s computer is on progess.

2. Type of computer on the bases of size

Super Computer - The fastest and most powerful type of computer

Supercomputers are very expensive and are employed for specialized applications

that require immense amounts of mathematical calculations. For example, weather

forecasting requires a supercomputer. Other uses of supercomputers include

animated graphics, fluid dynamic calculations, nuclear energy research, and

petroleum exploration.

Mainframe Computer-A very large and expensive computer capable of

supporting hundreds, or even thousands, of users simultaneously. In the hierarchy

that starts with a simple microprocessor (in watches, for example) at the bottom

and moves to supercomputers at the top, mainframes are just below

supercomputers. In some ways, mainframes are more powerful than

supercomputers because they support more simultaneous programs. But

supercomputers can execute a single program faster than a mainframe.

Mini Computer - A midsized computer. In size and power, minicomputers lie

between workstations and mainframes. In the past decade, the distinction between

large minicomputers and small mainframes has blurred, however, as has the

distinction between small minicomputers and workstations. But in general, a

minicomputer is a multiprocessing system capable of supporting from 4 to about

200 users simultaneously.

Micro Computer or Personal Computer – A microcomputer is a small, relatively

inexpensive computer with a microprocessor as its central processing unit (CPU).

It includes a microprocessor, memory, and minimal input/output (I/O) circuitry

mounted on a single printed circuit board(PCB).

Desktop Computer: a personal or micro-mini computer sufficient to fit on a

desk.

Laptop Computer: a portable computer complete with an integrated screen and

keyboard. It is generally smaller in size than a desktop computer and larger than

a notebook computer.

Palmtop Computer/Digital Diary /Notebook /PDAs: a hand-sized computer.

Palmtops have no keyboard but the screen serves both as an input and output

device.

Workstations-A terminal or desktop computer in a network. In this context,

workstation is just a generic term for a user's machine (client machine) in contrast

to a "server" or "mainframe."

BLOCK DIAGRAM OF A COMPUTER PERIPHERALS, AND WORKING OF A

COMPUTER.

The data is entered through input devices such as the keyboard, mouse, etc. This set of instruction

is processed by the CPU after getting the input by the user, and then the computer system produces

the output. The computer can show the output with the help of output devices to the user, such

as monitor, printer, etc.

Input Devices

Output Devices

CPU (Central Processing Unit)

o Storage Unit

o ALU (Arithmetic Logic Unit)

o Control Unit

Input Devices: The user provides the set of instruction or information to the computer system

with the help of input devices such as the keyboard, mouse, scanner, etc. The data representation

to the computer system is in the form of binary language after that the processor processes the

converted data. The input unit implements the data which is instructed by the user to the system.

We can enter the data from the outside world into the primary storage as the input through input

devices. The input devices are the medium of communication between the outside world and the

computer system.

There are some important features of input devices which are given below:

1. The input devices receive or accept the data or instruction from the user, who exist in the

outside world.

2. These devices convert the data or instruction into the machine-readable form for further

processing.

3. The input device performs like the connection between the outside world and our computer

system.

4. The keyboard and mouse are common examples of input devices.

5. When the whole procedure is finished, we get the desired output from the output devices

such as monitor, printer, etc.

Output Devices: The output devices produce or generate the desired result according to our

input, such as a printer, monitor, etc. These devices convert the data into a human-readable form

from binary code.

The computer system is linked or connected to the outside world with the help of output devices.

The primary examples of output devices are a printer, projector, etc.

These devices have various features which are given below:

1. These devices receive or accept the data in the binary form.

2. The output devices convert the binary code into the human-readable form.

3. These devices produce the converted result and show to the user.

Central Processing Unit (CPU)

The computer system is nothing without the Central processing Unit so, it is also known as the

brain or heat of computer. The CPU is an electronic hardware device which can perform different

types of operations such as arithmetic and logical operation.

The CPU contains two parts: the arithmetic logic unit and control unit. We have discussed briefly

the arithmetic unit, logical unit, and control unit which are given below:

Control Unit: The control unit (CU) controls all the activities or operations which are

performed inside the computer system. It receives instructions or information directly from

the main memory of the computer. When the control unit receives an instruction set or

information, it converts the instruction set to control signals then; these signals are sent to

the central processor for further processing. The control unit understands which operation

to execute, accurately, and in which order.

Arithmetic and Logical Unit: The arithmetic and logical unit is the combinational digital

electronic circuit that can perform arithmetic operations on integer binary numbers.It

presents the arithmetic and logical operation. The outputs of ALU will change

asynchronously in response to the input. The basic arithmetic and bitwise logic functions

are supported by ALU.

Storage Unit: The information or set of guidelines are stored in the storage unit of the

computer system. The storage unit provides the space to store the data or instruction of

processed data. The information or data is saved or hold in computer memory or storage

device. The data storage is the core function and fundamental of the computer

components.

Components of Computer System

The hardware and software exist on the computer. The information which is stored through the

device is known as computer software. The hardware components of the computer system are

related to electronic and mechanical parts, and the software component is related to data and

computer programs. Many elements are connected to the main circuit board of the computer

system called a “motherboard.”

COMPUTER HARDWARE:

Hardware refers to the physical components of a computer. Computer Hardware is any part of the

computer that we can touch these parts. These are the primary electronic devices used to build up

the computer. Examples of hardware in a computer are the Processor, Memory Devices, Monitor,

Printer, Keyboard, Mouse, and the Central Processing Unit.

COMPUTER SOFTWARE:

Software is a collection of instructions, procedures, documentation that performs different tasks

on a computer system. we can say also Computer Software is a programming code executed on a

computer processor. The code can be machine-level code or the code written for an operating

system. Examples of software are Ms Word, Excel, Power Point, Google Chrome, Photoshop,

MySQL etc.

A set of instructions that drives computer to do stipulated tasks is called a program. Software

instructions are programmed in a computer language, translated into machine language, and

executed by computer. Software can be categorized into two types −

System software

Programming Software

Application software

System Software

• System software is computer software designed to operate the computer hardware to

provide basic functionality and to provide a platform for running application software.

• Refers to the operating system and all utility programs that manage computer resources at

a low level.

The BIOS (basic input/output system) gets the computer system started after you turn it on

and manages the data flow between the operating system and attached devices such as the

hard disk, video adapter, keyboard, mouse, and printer.

• The boot program loads the operating system into the computer's main memory or random

access memory (RAM).

• System software also includes system utilities, such as the disk defragmenter and System

Restore.

Examples :- Operating Software, Basic Input/Output System (BIOS) Program, Disk Defragmenter,

Disk Cleanup

Programming Software

• Programming software include tools in the form of programs or applications that software

developers use to create, debug, maintain, or otherwise support other programs and applications.

• The term usually refers to relatively simple programs such as compilers, debuggers, interpreters,

linkers, and text editors,

Example of programming language: C , C++, C#, BASIC, JAVA, Visual Basic, Phyton, HTML,

PHP

Application Software

• A program or group of programs designed for end users

• Allows end users to accomplish one or more specific (non-computer related) tasks.

Examples of Computer Application Software: Word processor, Spreedsheet, Presentation

Software, Database Management System, Dekstop Publisher, Graphic Editor, Web Browser

Relationship between Hardware and Software

• Mutually dependent. Both of them must work together to make computer produce a useful

output.

• Software cannot be utilized without supporting hardware.

• Hardware without set of programs to operate upon cannot be utilized and is useless.

• To get a particular job done on the computer, relevant software should be loaded into the

hardware

• Hardware is a one time expense.

• software development is very expensive and is a continuing expense.

• Different software can be loaded on a hardware to run different jobs.

• A software acts as an interface between the user and the hardware.

• If hardware is the 'heart' of a computer system, then software is its 'soul'. Both are

complimentary to each other.

Differences between Software and Hardware

Sr.No. Software Hardware

1 It is a collection of programs to bring

computer hardware system into

operation.

It includes physical components of

computer system.

2 It includes numbers, alphabets,

alphanumeric symbols, identifiers,

keywords, etc.

It consists of electronic components like

ICs, diodes, registers, crystals, boards,

insulators, etc.

3 Software products evolve by adding

new features to existing programs to

support hardware.

Hardware design is based on architectural

decisions to make it work over a range of

environmental conditions and time.

4 It will vary as per computer and its

built-in functions and programming

language.

It is mostly constructed for all types of

computer systems.

5 It is designed and developed by

experienced programmers in high-

level language.

The hardware can understand only low-

level language or machine language.

6 It is represented in any high-level

language such as BASIC, COBOL, C,

C++, JAVA, etc.

The hardware works only on binary codes

1’s and 0’s.

7 The software is categorized as

operating system, utilities, language

processor, application software, etc.

The hardware consists of input devices,

output devices, memory, etc.