This document discusses the five generations of computers. The first generation used vacuum tubes and included the ENIAC. The second generation used transistors like the IBM 7094 series. The third generation was based on integrated circuits like the PDP-8. The fourth generation used microprocessors and introduced GUIs. The fifth generation applies artificial intelligence and ULSI technology in devices like desktops and laptops.

2. Generations of computer:
1) FIRST GENERATION.
2) SECOND GENERATION.
3) THIRD GENERATION.
4) FOURTH GENERATION.
5) FIFTH GENERATION.

3. FIRST GENERATION
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”.
Few Examples are:
ENIAC
EDVAC
UNIVAC
IBM-701
IBM-650

4. Second generation:
The used transistors. The scientists at Bell
laboratories developed transistor in 1947. These
scientists include John Barden, William Brattain
and William Shockley. The size of the computers
was decreased by replacing vacuum tubes with
transistors. The examples:
1) IBM 7094 series,
2) IBM 1400 series
3) CDC 164 etc.

5. THIRD GENERATION
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.
Few Examples are:
1) PDP-8
2) PDP-11
3) ICL 2900
4) IBM 360
5) IBM 370

6. FOURTH GENERATION
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.
Few Examples are:
1) IBM 4341
2) DEC 10
3) STAR 1000
4) PUP 11

7. FIFTH GENERATION
The period of the fifth generation in 1980-
onwards.
This generation is based on artificial intelligence.
This generation is based on ULSI(Ultra Large
Scale Integration) technology resulting in the
production of microprocessor chips having ten
million electronic component.
Few Examples are:
1) Desktop
2) Laptop
3) NoteBook
4) Ultra Book
5) Chrome book