Generations of Computers  

5 Generation of Computer | 4th Generation of computer | 5th Generation of Computer

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Generations of Computers  

The computer has evolved from a large-sized simple calculating machine to a smaller but much more powerful machine. Computers are classified into five generations. Each generation used a different technology. Let us discuss the characteristics of each generation.

First-generation computers (1940-1958)

  • They used vacuum tubes.
  • They used punch cards for the input and output of data.
  • They calculated data in milliseconds.
  • They were very large in size but had a small storage capacity.
  • They were slow in speed.
  • They consumed a large amount of energy.

Examples: ENIAC and UNIVAC.


The ENIAC (Electronic Numerical Integrator and Calculator) was the first electronic computer developed by J. Eckert and J. Mauchly in 1946.


The UNIVAC (Universal Automatic Computer) was the first commercially available computer developed by J. Eckert and J. Mauchly in 1951.

Second-generation computers (1959-1963)

Second Generation(1959-1965) - Computer Education

  • They were smaller in size than the first-generation computers.
  • They used transistors instead of vacuum tubes.
  • They used punch cards and magnetic tapes for the input and output of data.
  • They were faster, cheaper, and more efficient than the first generation
  • They could calculate data in microseconds.
  • They were costly and could be used only for specific purposes.

Examples: IBM 1401, RCA 501, Honeywell 200.

Third generation computers (1964-1970)

  • They used Integrated Circuits (ICs) in place of transistors.
  • An IC is also called a chip and may contain thousands of transistors.
  • They used keyboard for input of data and monitor for its output.
  • They were smaller, faster, cheaper and more efficient than the early computers. Hence, they were made available to the general public.

Examples: IBM 360, Apple 1, ICL 1900.

Fourth-generation computers (1971-present)

  • They are more powerful and reliable than the previous generation computers.
  • They use microprocessors. Microprocessors are Very Large Scale Integrated (VLSI) circuits that contain many ICs on a single chip.
  • They use a keyboard, mouse, scanner, and so on of data; and monitor, printer, speakers, and so on for its output.
  • They have a high storage capacity.
  • They are much smaller, faster and the cheapest among all the generations.

Examples: IBM PC, Apple Macintosh, HP 9000.

Fifth-generation computers (present-future)

The fifth-generation computers are still under development. They are expected to have the following capabilities.

  • Use of super large-scale integrated chips
  • Artificial intelligence, a technology that enables a computer to think like humans and perform human-like tasks such as voice recognition, decision-making, and translation between languages
  • Ability to recognize image and voice
  • Ability to solve complex problems including decision making and logical reasoning