The document summarizes the five generations of computers from 1940 to present. The first generation used vacuum tubes and were large, unreliable, and produced a lot of heat. The second generation used transistors which made computers smaller, more reliable, and efficient. The third generation used integrated circuits which further increased processing speed and portability. The fourth generation used microprocessors and introduced personal computers. The fifth generation under development aims to be intelligent through artificial intelligence and parallel processing.

2. Introduction
 Each generation of computers is characterized by
major technological development that
fundamentally changed the way computers
operate, resulting in increasingly
smaller, cheaper, more powerful and more efficient
and reliable devices. Read about each generation
and the developments that led to the current
devices that we use today.

3. First Generation (1940-1956)
 The First Generation of Computer
was built using Vacuum Tube and
magnetic drums for memory as
major Component.

4. The main feature of first generation :
 Used Vacuum tubes.
 Very large size, unreliable and slower than
other generation.
 Most data were entered in the form of Punch
card.
 Produce a lot of Heat.
 They were difficulty of maintenance .

5. Second Generation (1956-1963)
 This Computer used
Transistor and Diodes instead
of vacuum tubes as Main
electronic Components.

6. The main feature of second generation :
 Use transistor and diodes.
 Smaller in Size than first generation.
 Produce less amount of Heat than first generation.
 Machine dependent High level Language.
 More Reliable, efficient , Higher accuracy than 1st
Generation computers.

7. Third Generation (1964-1971)
 The Computer which used IC
are called Third Generation
of Computer. An IC Contain
100 of Electronic Component
Eg: Transistor, Capacitor's
, register's etc.

8. The main feature of third generation :
 IC were Used.
 Processing Speed Increase to Nanosecond.
 Monitor, Keyboard were Introduce as data output and
Input Devices respectively.
 More reliable and better performance .
 Computer become Portable.
 Operating System were used.
 The size of Computer rapidly decrease Compare to
Second Generation Computer.

9. Fourth Generation (1971-till now)
 Fourth Generation Computer
used Large Scale Integrated
(LSI) and Very Large Scale
Integrated (VLSI).
Accommodate 1000's of
Component are in Single Chip.
The Microprocessor used in
these Computers.

10. The main feature of fourth generation :
 Computer's are highly reliable.
 The Operating Speed increase to Picoseconds and
MIPS (Million of Instruction Per Second).
 Micro Computer were Introduced.
 Magnetic Disk and Optical Instrument device Become
Common for a Mass.
 Hard and sophisticated programs are used.

11.  Word processing and e-mail system were introduced
 Multi-processing, Multi-media and multi-tasking is
Possible.
 Smallest Computer Called Desktop, Laptop and
Palmtop were introduced.
 Eg: IBM-PC, DEC 10, IBM 4341, IBM
System/370, BURROUGHS B7700, HP3000, Apple
2, Apple Macintosh, Cray X-MP.

12. Fifth Generation (Present, future)
 This Computer are set Under
Development. The Computer
Which will use AI (Artificial
Intelligence ) and use Bio-
Chip as memory device
Created by User are called
fifth generation .

13. The main feature of fifth generation :
 They will be Intelligent.
 They will be Capable of Parallel Processing.
 Because of use of Super Conductor Material like Bio-
Chip speed will be very high.
 Large Subset of Natural Language like
English, Japanese etc will be used and make more user
friendly.

14. Reference
 http://www.mystudyroom.com.np/classnotes.php?na
n=75&fire=2&cake=20&sun=8&rnd=3321549784df8a8f3
5e5765.03103944
 http://www.turbosquid.com/3d-models/diode-3-3d-
c4d/370854