Computer Generations

Computer Generations

Computer's hardware gradually change from time to time ,
The  journey of computer from beginning to present is displayed in the form of five generations:-

Following are the main five generations of computers
Genration & Description

1 First Generation
The period of first generation : 1946-1959. Vaccum tube based.

2 Second Generation
The period of second generation : 1959-1965. Transistor based.

3 Third Generation
The period of third generation : 1965-1971. Integrated Circuit based.

4 Fourth Generation
The period of fourth generation : 1971-1980. VLSI microprocessor based.

5 Fifth Generation
The period of fifth generation : 1980-onwards.ULSI microprocessor based




First Generation

The period of first generation was 1946-1959.

First generation of computer started with using vacuum tubes as the basic components for
memory and circuitry for CPU(Central Processing Unit). These tubes like electric bulbs
produced a lot of heat and were prone to frequent fusing of the installations, therefore,
were very expensive and could be afforded only by very large organisations.

In this generation mainly batch processing operating system were used. In this generation
Punched cards, Paper tape, Magnetic tape Input & Output device were used.

There were Machine code and electric wired board languages used.

The main features of First Generation are:

*Vacuum tube technology

*Unreliable

*Supported Machine language only

*Very costly

*Generate lot of heat

*Slow Input/Output device

*Huge size

*Need of A.C.

*Non portable

*Consumed lot of electricity

Some computer of this generation were:

*ENIAC

*EDVAC

*UNIVAC

*IBM-701

*IBM-650

Second Generation

The period of second generation was 1959-1965.

This generation using the transistor were cheaper, consumed less power, more compact in
size, more reliable and faster than the first generation machines made of vaccum tubes.In
this generation, magnetic cores were used as primary memory and magnetic tape and
magnetic disks as secondary storage devices.

In this generation assembly language and high level programming language like FORTRAN,
COBOL were used.

There were Batch processing and Multiprogramming Operating system used.

The main features of Second Generation are:

Use of transistors

*Reliable as compared to First generation computers

*Smaller size as compared to First generation computers

*Generate 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

*A.C. needed

*Support machine and assmebly languages

Some computer of this generation were:

*IBM 1620

*IBM 7094

*CDC 1604

*CDC 3600

*UNIVAC 1108


Third Generation

The period of third generation was 1965-1971.

The third generation of computer is marked by the use of Integrated Circuits (IC's) in place
of transistors.A single I.C has many transistors, resistors and capacitors along with the
associated circuitry.The I.C was invented by Jack Kilby. This development made computers
smaller in size, reliable and efficient.

In this generation Remote processing, Time-sharing, Real-time, Multi-programming
Operating System were used.

High level language (FORTRAN-II TO IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68 etc.) were
used during this generation

The main features of Third Generation are:

• IC used
• More reliable
• Smaller size
• Generate less heat
• Faster
• Lesser maintenance
• Still costly
• A.C needed
• Consumed lesser electricity
• Support high level language

Some computer of this generation were

• IBM-360 series
• Honeywell-6000 series
• PDP(Personal Data Processor)

Fourth Generation

The period of Fourth Generation was 1971-1980.

The fourth generation of computers is marked by the use of Very Large Scale Integrated
(VLSI) circuits.VLSI circuits having about 5000 transistors and other circuit elements and
their associated circuits on a single chip made it possible to have microcomputers of
fourth generation. Fourth Generation computers became more powerful, compact, reliable,
and affordable. As a result, it gave rise to personal computer (PC) revolution.
In this generation Time sharing, Real time, Networks, Distributed Operating System were
used.

All the Higher level languages like C and C++, DBASE etc. were used in this generation.

The main features of Fourth Generation are:

• VLSI technology used
• Very cheap
• Portable and reliable
• Use of PC's
• Very small size
• Pipeline processing
• No A.C. needed
• Concept of internet was introduced
• Great developments in the fields of networks
• Computers became easily available

Some computer of this generation were:

• DEC 10
• STAR 1000
• PDP 11
• CRAY-1(Super Computer)
• CRAY-X-MP(Super Computer)

Fifth Generation

The period of Fifth Generation is 1980-till date.

In the fifth generation, the VLSI technology became ULSI (Ultra Large Scale Integration)

technology, resulting in the production of microprocessor chips having ten million

electronic components.

This generation is based on parallel processing hardware and AI (Artificial Intelligence)

software.

AI is an emerging branch in computer science, which interprets means and method of

making computers think like human beings.

All the Higher level languages like C and C++, Java, .Net etc. are used in this generation.

AI includes:

• Robotics
• Neural networks
• Game Playing
• Development of expert systems to make decisions in real life situations

The main features of Fifth Generation are:

• ULSI technology
• Development of true artificial intelligence
• 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