The document discusses the five generations of computers from the first to fifth generation. The first generation used vacuum tubes and were large, expensive, and generated a lot of heat. The second generation used transistors which were smaller, more reliable, and used less energy. The third generation used integrated circuits which made computers even smaller and more efficient. The fourth generation used microprocessors, making computers more powerful yet compact. The fifth generation focuses on artificial intelligence.

1. Generations of
Computer

2. Table of Contents
 Generations of Computer
o First Generation
o Second Generation
o Third Generation
o Fourth Generation
o Fifth Generation

3. Generations of Computer
 The development of electronic computers can be divided into
generations depending upon the technologies used. Different
generations of computer are:
o First Generation (Vacuum Tubes) 1942-1955
o Second Generation (Transistor) 1955-1964
o Third Generation (Integrated Circuits) 1964-1975
o Fourth Generation (Microprocessor) 1975-Present
o Fifth Generation (Artificial Intelligence) Present and Beyond

4. First Generation Computers
 The first generation were used during 1946-1959.
 The computers of first generation used vacuum tubes.
 The vacuum tube was developed by Lee De Forest.
 First generation computers were very expensive to operate and in
addition to using a great deal of electricity, generated a lot of
heat, which was often the cause of malfunctions.
 Examples of first generation computers are ENIAC and
UNIVAC-I etc.

5. First Generation Computers
Advantages
o Vacuum tubes were the only
electronic
component available during those
days.
o Vacuum tube technology made
possible to make electronic digital
computers.
o These computers could calculate
data in millisecond.
Disadvantages
o The computers were very large in size.
o Consume a large amount of energy.
o They heated very soon due to
thousands of vacuum tubes.
o They were not very reliable.
o Air conditioning was required.
o Constant maintenance was required.
o Non-portable.
o Costly commercial production.
o Limited commercial use.
o Very slow speed.
o Limited programming capabilities.
o Used machine language only.
o Used magnetic drums which provide
very less data storage.
o Used punch cards for input.
o Not versatile and very faulty.

6. Second Generation Computers
 Second generation computers used transistors.
 The scientists at Bell laboratories developed transistor in 1947.
 These scientists include John Barden, William Brattain and William
Shockley.
 Transistors were used because they were cheaper, consumed less
power, more compact in size, more reliable and faster than the first
generation machines made of vacuum tubes.
 Examples of second generation
computers are IBM 7094 series,
IBM 1400 series and CDC 164
etc.

7. Second Generation Computers
Advantages
o Smaller in size
o More reliable
o Used less energy and were not heated.
o Wider commercial use
o Better portability.
o Better speed and could calculate data in
microseconds
o Used faster peripherals like tape drives,
magnetic disks, printer etc.
o Used Assembly language instead of
Machine language.
o Accuracy improved.
Disadvantages
o Cooling system was required
o Constant maintenance was
required
o Commercial production was
difficult
o Only used for specific purposes
o Costly and not versatile
o Punch cards were used for input.

8. Third Generation Computers
 The computers of third generation used integrated circuits (IC's).
 Jack Kilby developed the concept of integrated circuit in 1958.
 The first IC was invented and used in 1961.
 This development made computers smaller in size, reliable and
efficient.
 The examples of third generation computers are IBM 370, IBM
System/360, UNIVAC 1108
and UNIVAC AC 9000 etc.

9. Third Generation Computers
Advantages
o Smaller in size
o More reliable.
o Used less energy
o Produced less heat
o Better speed and could calculate data in
nanoseconds.
o Used fan for heat discharge to prevent
damage.
o Maintenance cost was low
o Totally general purpose
o Could be used for high-level languages.
o Good storage
o Versatile to an extent
o Less expensive
o Better accuracy
o Commercial production increased.
o Used mouse and keyboard for input.
Disadvantages
o Air conditioning was
required.
o Highly sophisticated
technology required for the
manufacturing of IC chips.

10. Fourth Generation Computers
 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.
 It was known as Intel 4004.
 Fourth generation computers became more powerful, compact, reliable,
and affordable.
 The examples of fourth generation
computers are Apple Macintosh &
IBM PC.

11. Fourth Generation Computers
Advantages
o More powerful and reliable
o Small in size
o Fast processing power with less
power consumption
o Fan for heat discharging and thus
to keep cold.
o No air conditioning required.
o Totally general purpose
o Commercial production
o Less need of repair.
o Cheapest among all generations
o All types of High level languages
can be used in this type of
computers
Disadvantages
o The latest technology is
required for manufacturing
of Microprocessors

12. Fifth Generation Computers
 Scientists are working hard on the 5th generation computers .
 It is based on the technique of Artificial Intelligence (AI).
 AI is an emerging branch in computer science, which interprets
means and method of making computers think like human
beings.
 Computers can understand spoken words & imitate human
reasoning.
 All the high-level languages like C and C++, Java, .NET etc are
used in this generation.

13. References
 http://www.tutorialspoint.com/computer_fundamentals/computer_generations.htm
 http://www.tutorialspoint.com/computer_fundamentals/computer_first_generation.htm
 http://latesttechnomanias.blogspot.com/2010/06/first-generation-computer.html
 http://www.byte-notes.com/five-generations-computers
 http://www.tutorialspoint.com/computer_fundamentals/computer_second_generation.htm
 http://www.tutorialspoint.com/computer_fundamentals/computer_third_generation.htm
 http://www.tutorialspoint.com/computer_fundamentals/computer_fourth_generation.htm
 http://www.tutorialspoint.com/computer_fundamentals/computer_fifth_generation.htm