3.generation of computers

7/30/2019 3.Generation of Computers

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Anitha Padmanaban ACET

GENERATIONS OF COMPUTERS




Introduction

The various computing devices invented to solve different

types of problems are classified into generations

The technological development in the field of computers

refers to the improvement in hardware and software

technology




Computer Generation

Vacuum tubes: 1940-1956

Transistors: 1956-1963

Integrated circuits: 1964-1975

Very large-scale integrated (VLSI) circuits: 1975-1989

Modern Digital Computer: 1989- present




First Generation

Used vacuum tube technology for calculation

Can be used as storage and control device

Vacuum tube is made up of glass and contains

filaments inside it

The filaments when heated generate electronics that

help in the amplification and de amplification of

electronic signals




First Generation

Also known as Vacuum tubes or thermo ionic valves

based machines

Language used: Machine Language (0’s and 1’s)

Input: Punched Cards

Output: Printout

Examples

ENIAC, EDVAC, EDSAC and UNIVAC




Vacuum Tube Technology




First Generation

Advantage

Fastest computing device

Able to execute complex mathematical problems

Disadvantage

All the functions depend on machine language (0’s & 1’s),

hence programming is not easy Designed as a special purpose computers, hence not

flexible in running different types of application




First Generation

Disadvantage

Very bulky and large

Not easy to install

Not easy to transfer from one place to another

Produce more heat, thus should be kept in a cool place

Executes only one program (Single tasking)

Not reliable and require proper maintenance




Second Generation

Uses transistors instead of vacuum tubes

Transistor was invented by Shockley, Brattain and

Barden in 1947

A transistor is a semiconductor device that is used to

increase the power of the incoming signals by preserving

the shape of the original signal

It has three connections,

Emitter (E), Base (B), Collector (C)




Second Generation

Base is the gate through which the signal needed to be

amplified is sent

The signal sent through the base is a small flow of electrons

Also act as the input gate for transistor

Collector is used to collect the amplified signal

Emitter acts as a output gate for emitting the amplified

signal to external environment

Example: PDP-8, IBM 1401, IBM 7090




Second Generation

Language: Assembly language

Assembly Language is a

low level language

Uses simple English words called mnemonics

Input: Punched Cards

Output: Printout




Transistors




Second Generation

Advantage of transistor over vacuum tubes

Improve the performance of computer

A superior technology

Smaller

Faster

Cheaper

Generate less heat More reliable

More productive




Second Generation

Advantage

Printers, secondary storage, operating system were

developed in this era

Could be transferred from one place to another

Requires less power

More reliable

Do not require more maintenance at regular intervals




Second Generation

Disadvantage

Input and output was not improved

Always requires AC

Costly

Executes only specific functions




Third Generation

Uses Integrated Circuits (ICs) technology

Also known as microelectronics technology

Developed by Jack Kilby and Robert Noyce in 1958

The various components of ICs are

Transistors

Capacitors

Resistors




Integrated Circuit




IC Chip




Third Generation

Advantage

Low cost

Very high performance

Requires very low power

Smaller

Faster More efficient

More reliable




Third Generation

Advantage

Easily transportable

Uses high level language

Programs written in one language can be executed in some

other computer

Executes any type of functions

Less maintenance




Third Generation

Disadvantage

Very small storage capacity

Cannot handle complex computations

Costly

Always to be placed in AC




Fourth Generation

Uses Large Scale Integration (LST) and Very Large Scale

Integration (VLSI) technology

Also uses IC technology to build basic circuits

LSI

Allows 1000s of transistors to be fitted in one silicon chip

VLSI

Allows 100s of 1000s of transistors to be fitted in one silicon chip




Fourth Generation

LSI and VLSI led to the development of microprocessor

Example: Intel P4004 developed in 1971

A microprocessor incorporates various components of acomputer like

CPU

Memory

Input

Output units on to a single chip




VLSI Design




Personal Computer

Can be used by an individual

Smaller in size

Less cost

Used for personal work

Uses static and dynamic RAM




Fourth Generation

Advantage

New operating system

Graphical User Interface (GUI)

LAN

Very powerful

Highly optimized and reliable User friendly

Requires less power to operate




Fourth Generation

Problems

Soldering of LSI and VLSI is complex

Works on instructions given by user




Fifth Generation

Modern digital computer

Based on Ultra Large Scale Integration (ULSI)

ULSI allows 10 million electronic components to befabricated on one small chip

Increased speed and power

Primary and secondary storage devices

Cheaper and more efficient




Fifth Generation

Invented portable computers like

Laptop, pocket computers, Personal Digital Assistant

(PDA), etc

Parallel processors

Centralized computer like servers

Optical disk technology

Internet and its different services




ULSI




Fifth Generation

Advantage

Faster and powerful computer

Can execute large number of applications at same time

Decreased in size

Very comfortable to use

Disadvantage

Works under user instructions

3.generation of computers

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