Generation of computer 

   History of computers is a chain that runs from the ancient abacus and the  analytical engine if the nineteenth century, through the modran computers of present age. It is genrally divided into five generation. Each generation of computer is characterized by major technological developments of that time.

First Generation Computer (1940 - 1956)

Vaccum tube were used in the first generation computers. Vaccum tubes generated so much heat that they had to be cooled by air condition. Vaccum tubes burnt out very often and it was difficult to repaire and maintain the computers first generation. 

1) First  generation computers used vaccum tubes.

2) Speed was slow and memory was very small.

3) They were hugs in size taking up entire room.

4) First generation computers were very expensive and unreliable.

5) They consumed a lot of power and generated a lot of heat.

6) Input was based on purched.

7) Output was obtained on printouts  through electric  typewriter.

8) Machine language was used in these computer. 

Second Generation of Computer (1956 - 1963)

in 1947, three scientists, William Shockley, john Bareed and walter Brattain invented  transistor. Transistor function like a vaccum tube. It replaced the vaccum tubes in the second generation computer. Transistor was faster, more relable, smaller and much cheapter than tube.

1) Transistor were used instead of vaccum tube. 

2) Transistor reduce the size of computers and increase the speed and memory capacity.

3) Computer became more relabile and cheaper.

4) Second generation computers are punched card reader, magnetic tapes, magnetic disks and printer.

5) Assembly language was used in these computer.

6) High level programming languages, FORTRAN and COBOL were introduced in this generation of computer.

Third generation of computer (1963 - 1971)

Integrated Circut (ICs), also know as semiconductor chips were used in third generation of computers instead of transisters. IC chips were developed in early 1960. A single IC chips increased the power and decreasedthe cost of computers. Invention of IC chips was a great breakthrough in advancing computer technology. the following are the characteristic of third generation of computer. 

1) Third generation of compuuter used IC chips. 

2) IC chips improved the speed and memeory of computers .

3) Computer consumed less electricity, became smaller , cheaper nad more relable than second generation computer. 

4) Keyboard and  monitor were used with computer 

5) These computer could run different  ap[plication program at the same time .

Fourth Generation of Computer

      In this generation of computer LSI (Large Scale integration) and VLSL. (very large scale integration) chips having million of transisters were developed . Microprocesser  was also developed in fourth generation of computer. A microprocessor is a single chip that can handle all the processor of a computer 

 The following are the characteristic of fourth generation of computers.

1) Microprocessor was developed which resulted in the developed of microcomputer.