Basic of Computer


A computer is a electric machine that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming. Commonly consisting of digital circuitry, that accepts (inputs), stores, and generates (outputs) data as numbers, text, graphics, voice, video files, or electrical signals.

  • Father of the computer – Charles Babbage
  • Father of the modern computer – Alan Turing
  • Basic Architecture of Computer: John Von Neumann (1947-49)
  • First Programmer: Lady Ada Lovelae (1880)
  • First Electronic Computer: ENIAC (1946) – J.P. Eckert & J.W. Mauchly
  • First computer for the home user introduced – IBM in 1981

Generation of Computer

There are five generations of computers.


1946-1959 is the period of first generation computer.

J.P.Eckert and J.W.Mauchy invented the first successful electronic computer called ENIAC, ENIAC stands for “Electronic Numeric Integrated And Calculator”.


i)It made use of vacuum tubes which are the only electronic component available during those days.

ii) These computers could calculate in milliseconds.


i)These were very big in size, weight was about 30 tones.

ii) These computers were based on vacuum tubes.

iii) These computers were very costly.

iv) It could store only a small amount of information due to the presence of magnetic drums.

v) Large amount of energy consumption.


1959-1965 is the period of second-generation computer.

Second generation computers were based on Transistor instead of vacuum tubes.

 Example : Honeywell 400, IBM 7094, CDC 1604, CDC 3600, UNIVAC 1108


i)Due to the presence of transistors instead of vacuum tubes, the size of electron component decreased. This resulted in reducing the size of a computer as compared to first generation computers.

ii) Less energy and not produce as much heat as the first genration.

iii) Assembly language and punch cards were used for input.

iv) Low cost than first generation computers.

v) Better speed, calculate data in microseconds.


i)A cooling system was required.

ii) Constant maintenance was required.

iii) Only used for specific purposes.


1965-1971 is the period of third generation computer.

These computers were based on Integrated circuits.

IC was invented by Robert Noyce and Jack Kilby In 1958-1959. IC was a single component containing number of transistors.

Examples:  PDP-8 ,PDP-11, ICL 2900, IBM 360


i)These computers were cheaper as compared to second-generation computers.

ii) They were fast and reliable.

iii) Use of IC in the computer provides the small size of the computer.

iv) IC not only reduce the size of the computer but it also improves the performance of the computer as compared to previous computers.

v) This generation of computers has big storage capacity.


i)IC chips are difficult to maintain.

ii) The highly sophisticated technology required for the manufacturing of IC chips.


1971-1980 is the period of fourth generation computer.

This technology is based on Microprocessor.

A microprocessor is used in a computer for any logical and arithmetic function to be performed in any program.

Graphics User Interface (GUI) technology was exploited to offer more comfort to users.

Examples: IBM 4341


i)Fastest in computation and size get reduced as compared to the previous generation of computer.

ii) Heat generated is negligible.

iii) Small in size as compared to previous generation computers.


i)The Microprocessor design and fabrication are very complex.

ii) Air conditioning is required in many cases due to the presence of ICs.


The period of the fifth generation in 1980-onwards.

This generation is based on artificial intelligence.

The aim of the fifth generation is to make a device which could respond to natural language input and are capable of learning and self-organization.

This generation is based on ULSI(Ultra Large Scale Integration) technology resulting in the production of microprocessor chips having ten million electronic component.

Examples: Desktop, Laptop, Note-Book

Read More Computer Awareness Study Notes

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