IT PRESENTATION ON• EVOLUTION,ORGANISATION & ARCHITECTURE, MEMORY OF A

COMPUTER

Presented BY:-

U LALIT KR. MOHANTA(4)

Contents:• A. What is computer ?• B. Features of computer• C. Evolution of computer• D. Organisation of Basic Computers( includes architecture & memory )• E. Conclusion• F. Reference

What is Computer ?• A computer is defined as a fast electronic device that processes the

input data according to the instructions given by the programmer/user and provides the desired information as output.

• Computers are the essential ingredients for success in today’s world. They are being used in almost every field now, & every day new areas of activities are being discovered.

Features Of Computer• The increasingly popularity of computer has proved that it is very

powerful & useful machine. It has following features:-• A). Speed• B). Accuracy• C). Diligence• D). Versatile• E). Storage• F). Automatic• G). Reliability

Evolution of Computer• Begins with invention of the abacus in 3000 BC.• Later it followed by the invention of mechanical calculators in the year

1617.• The years beyond 1642 are marked by the inventions of zeroth, first,

second & third generation computers.• The year beyond 1980 till today are marked by fourth generation

computers.• Fifth generation computers are still under R&D.

Zeroth Generation Computers (1642-1946)• Marked by the invention of mainly mechanical computers.• Pascaline was the first mechanical device, invented by Blaise Pascal.• In 1800, the punched card was invented by Jacquard.• In 1822, Charles Babbage designed a machine called Difference

Engine which he later modified to build a digital computer, called Analytical Engine. It has all the parts of modern computers; therefore he known as the Father of Computers.

• The era of mechanical computers ended in 1946, when vacuum tubes were invented.

First Generation Computers(1945-54)• The computers were marked by the use of vacuum tubes or valves as

their basic electronic component.• These computers were faster than earlier mechanical devices.• Eg. ENIAC( Electronic Integrator & Calculator), the first electronic

computer using vacuum tubes.• Advantages over Zeroth Generation ComputersComparatively smaller in size.Consumed less power & generate less heat.Machine were reliable & do not broke down frequently.Required less maintenance.

Second Generation Computers(1953-64)• The computers were marked by the use of transistors in place of

vacuum tubes.• Eg. IBM 701, IBM’s first electronic large computer.• Advantages over First Generation ComputersComparatively smaller in size.Consumed less power & generate less heat.Machine were reliable.

Third Generation Computers(1964-78)• The computers were marked by the use of ICs in place of transistors.• As hundreds of transistors could be put on a single small circuit, so ICs

were more compact than transistors.• Eg. IBM 360, developed by IBM in 1964.• Advantages over Second Generation ComputersComparatively smaller in size.Consumed smaller amount of power & generate very less heat.Machine were faster & more reliable.

Fourth Generation Computers(1978-Present)• The computers were marked by the use of LSI in place of ICs.• VLSI is the latest technology that led to the development of the

popular personal computers, e.g. microcomputers.• Advantages over Third Generation Computers: Are very powerful in operations.Having huge memory & a fast processing speed.

Fifth Generation Computers• The computers are still under Research & Development.• Scientists are trying to implement USLI in place of VLSI i.e. they will

use an intelligent software.• These computers will have artificial intelligence & also have user

interface in the form of speech of natural languages.

Organisation of Basic Computers• A complete computer installation including CPU, the peripherals such

as hard disk drives, floppy disk drives, monitor, printer, mouse & Operating System which are designed to work & interact with each other and with the user is called a Computer System.

• Organisation includes the architecture of a computer system.• A computer system has the following main physical components:Input/output Unit.Central Processing Unit(CPU).Memory Unit.

Architecture of a Computer System

Hardware and Software• Hardware• Hardware refers to the physical elements of a computer. This is

also sometime called the machinery or the equipment of the computer.

• Examples of hardware in a computer are the keyboard, the monitor, the mouse and the processing unit

• Software• Software, commonly known as programs, consists of all the electronic

instructions that tell the hardware how to perform a task.• Software is capable of performing many tasks, as opposed to hardware

which only perform mechanical tasks that they are designed for. Software is the electronic instructions that tells the computer to perform a task.

Input/output Unit• Input Unit• An input device is any device that provides data to a computer.

Since the job of a computer is primarily to process input, computers are pretty useless without input devices. Just imagine how much fun you would have using your computer without a keyboard or mouse. Not very much. Therefore, input devices are a vital part of every computer system.

• Output Unit• Data generated by a computer is referred to as output. This includes data

produced at a software level, such as the result of a calculation, or at a physical level, such as a printed document. Devices that produce physical output from the computer are creatively called output devices. The most commonly used output device is the computer's monitor, which displays data on a screen.

Central Processing Unit• CPU is the main component or ‘brain’ of a computer, which performs all the

processing of input data. Its function is to fetch, examine, & then execute the instructions stored in the main memory of the computer.

• In microcomputers, the CPU is built on a single chip or integrated chip(IC) & is called a microprocessor.

• The CPU consists of the following distinct parts:Arithmetic and logic unit.Control unit.Registers.Buses.

Memory• Memory unit is that component of a computer system, which is used to store

the data, instructions and information before, during and after the processing by ALU.

• It is of following seven types:-o Read only memory (ROM).o Random access memory (RAM).oComplementary metal oxide semiconductor memory (CMOS).oFlash memory.oCache memory.oVirtual memory.oRAM disk.

• Storage Unit:• The storage unit of the computer consists of different storage devices

such as hard disk drive, floppy disk drive, pen drive, compact disk drive, etc.

• The storage unit is also called the secondary memory unit.• Motherboard:• Motherboard is also called systems board is the most important

hardware component of a microcomputer.• A motherboard contains the CPU chip, memory chip ( ROM & RAM

chips), I/O interface, expansion slots and many other logic circuits; as all the other boards of the computers are connected to this board; hence, it is like the mother of all other boards.

• Cards, Ports and Cords• Cards are the printed circuit boards used to hold the chips. Cards like video card,

sound card, I/O card, controller card & memory card.• The computer has several components, which are used as pathways for flow of

data. The rear of a PC has many empty holes or external sockets called ports or connectors. Ports like serial port, parallel port, game port, video port & USB port.

• Cords are cables used to plug into the ports. Cords like keyboard cords, monitor cords, power cords and printer cords.

• Power Supply• Power supply is considered the ‘heart’ of a PC.• A computer requires a clean & steady power source for working properly.• It is an important hardware, which provides the power source to a computer.• An uninterrupted power supply(UPS) keeps the computer running for few

minutes even when the electricity supply goes off.

Conclusion:-

• While preparing the presentation, we come to know about the computer, features and its basic components. We obtain a brief knowledge about computer organisation including it’s architecture which includes the main physical component.

References:-• A. Computer Fundamentals and Applications by Ashok Arora.• B. Google.

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THANK : YOU