1. The fiest Electronic computer was designed and built at the university of pennsylvania
based on vacuum tube technology. Vacuum tubes were used to perform logical operation
and to store data.generations of computers has been divided into five accordingto the
development of technologies used to processors,memories and input output units.
1st
Generation computer: 1942-55
2nd
Generation computer: 1955-64
3rd
Generation computer 1964-75
4th
Generation computer 1975-present
5th
Generation computer present and beyound

2. 1ST
GENERATION COMPUTER
The first
generation computer used
vacuum tubes.it is the first
beginning of commerical
computer age is from
UNIVAC ( universal
automatic computer ). It was
developed by two scientists
MAUCHLY and ECHERT
.the friest generation
computers were used during
1942-1955.
Example :- ENIVAC , UNIVAC-I etc
Advantages :
vacuum tubes were the only electronic component available during those
days.
These computers could calculate data in millisecond.
Disadvantages :
these computers were very large in size.
They consumed a large amount of energy.
They wrer not very reliable.

3. Air conditionning was required.
Very slow speed
used machine language only ,punch cards for input and less data store.
SECOND GENERATION COMPUTER :The second generation conputer used
transistors.the scientists of Bell Laboratories developed transistorsin 1947.these
scientists include John bardeen’,William Brattain and William Shockley.the size of
computer decreased by replacing vacuum tubes with transistors.
The era of miniaturization begins. Transistors are much smaller than vacuum tubes, draw
less power, and generate less heat.
Example :-
IBM11400, CDV 164 etc.
Advantages:-
smaller in size. Used less energy.
More reliable.better speed.
Used assembly language insead of machine language.
Disadvantages:-
Air conditioning was required.
Only used special purpose.

4. It is costly and used punch cards were used for input.
THIRD GENERATION COMPUTERS :-
the third generation computers used the integrated circuits.
JACK KILBY developed the concept of integrated circuit in 1958.A single IC chip
contain thousands of transistors.these computer became samller in size,faster
and more reliable and less expensive.
EXAMPLE :- IBM, UNIVAC etc.
Advantages :-
smaller in size and more reliable.
Use less energy.better speed and could calculate data in nanosecond.
Good storage.
Used mouse an keyboard for input.
Produced less heat.and used high level language.

5. DISADVANTAGES :-
Air conditioning was required.
FOURTH GENARATION COMPUTER :-
the fourth generation computers started with the invention of
microprocessor.the microprocessor contains thousands of ICs.TED HOFF
produced the first microprocessor in 1971 for intel.the size of modern
microprocessors is usually one square inch.it contain milllions of electronic
circuits.
EXAMPLE :- Apple Macintosh ,IBM PC.
ADvantages:-
more powerful and reliable.
Very small in size,lesspower consumsed and less heat generation.
No air condition are required.
All types of high level language is used in 4
th
generation.
5
th
GENERATION COMPUTERS :-
Scientists are now working on the 5
th
generation computers using recent
enginnering advances. It is based on the technique of ARTIFICIAL
INTELLIGENCE.computers can understand spoken words and imitate human
reasoning.
Scientista are working to increase the speed of computer. They are trying to
create a computer with real IQ with the help of advanced programming and
technologies. The advanced and modern technologies will revolutionize the
computer in future.