This document discusses the history and evolution of computers through five generations. It explains that the first generation used vacuum tubes and large mainframe computers. The second generation introduced transistors, making computers smaller and more reliable. The third generation used integrated circuits which made computers faster, cheaper and smaller. The fourth generation saw the development of microprocessors and personal computers. The fifth generation aims to develop artificial intelligence capabilities. Each generation is characterized by the switching technology used and improvements in size, cost, speed and capabilities.

1. Course: B.Sc
Subject: Computations Skills
Unit-1
Operating System Concept
&
Computer Generation

2. History of Computers
• Charles Babbage - father of computer
– 1800’s planned analytical engine
• ENIAC - developed at end of WW II
• 1951 - 1963 1st and 2nd generation
– very large, used unreliable vacuum tubes
• 1963 - present - 3rd and 4th generation
– smaller, faster - use transistors and integrated
circuits
2

3. History - Microcomputers
• Apple
– First sold in late 1970’s
– Developed by Jobs and Wozniak
• IBM Personal Computers
– First sold in 1981
– Was quickly accepted by businesses
– IBM compatibles soon developed
3

4. What Is a Computer?
• A computer is an electronic device that accepts
data and instructions from a user, manipulates the
data according to the instructions, displays the
information in some way, and stores the
information for retrieval later
4

5. What is a computer?
• An electronic device that accepts input,
processes the data and instructions, produces
output from the processing that is useful and
meaningful and stores the results for future use.
5

6. How Does A Computer Know What To Do?
• It must be given a detailed set of instructions that
tell it exactly what to do.
• These instructions are called a computer program,
or software.
6

7. How Does A Computer Know What To Do?
• It must be given a detailed set of instructions that
tell it exactly what to do.
• These instructions are called a computer program,
or software.
7

8. 1st
Generation Of Computer
2nd
Generation Of Computer
3rd
Generation Of Computer
4th
Generation Of Computer
5th
Generation Of Computer

9. The term Computer Generation is after use in relation to
the hard were of computer. Each phase of computer
development is known as separate generation of computer.
Each phase of development is characterized by type of
switching circuits it utilizes.
Most computer today use the idea of stored program.
Computer that was proposed by Dr.John Von Neumann in
1945.The Von Neumann architecture is based in three key
concept that are:
1)Data & instruction (program) are stored in a single read
write memory.
2)The memory content are addressable by location.
3)Excution takes place in sequential fashion.

10. [1949-55]
• The first generation of computer used the
vaccume tube & machine language was used
for giving instruction. The first generation
computer used the concept ‘stored program'.
The computer of this generation were very
large in size & their programming was a
difficult task.

11. Some computer of this generation
are given below:
• ENIAC :-It has very small memory & it was
used for calculating trajectories of missiles.
• EDVAC:-The “Von Newmann” concept of
stored program, was also applied in EDVAC.

12. Some key feature of first
generation:
• Used vaccume tubes.
• Big computers.
• Electrically consumption high.
• Large Ac’s were necessary because the computer
generated heat.

13. 1956-65
• The second generation computer began
with the advent transistorized circuitry,
invention of magnetic core & development
of magnetic disk storage devicer.These
new development made these computer
more reliable. These Industries in the
application’s like Marketing, Production
planning etc.

14. Some key feature of second
generation:
• Transistor replaced vaccume tubes.
• Small in size.
• Less amount of heat was generated.
• Core memory was developed.
• First operating system was developed.
• Programming was in machine language as
well as assembly language.

15. [1966-1975]
The third generation of computer replaced
transister with ‘Integrated circuits’ popularly
known as chips. The IC was inverted by Jack
kilby at Texas Instrument in 1958.The third
generation computer using integrated circuit
Proved to be highly reliable,relatively
expensive & faster.

16. Some key feature of third
generation:
• Integrated circuits developed.
• Power consumption was low.
• Computer were smaller, faster & more
reliable.
• High level languages (HLL) appeared.

17. [1976-Present]
• The advent of the microprocessor chip marked the
beginning of the fourth generation computer.
Very Large Scale Integrated (VLSI) circuits
packing about 50,000 transistor in a chip. The
Hard disks are also available of the size up to 80
GB.For larger disks RAID technology give to
storage hundreds of GB. The CD ROM also
becoming popular day by day. The CD ROM of
today can store up to 650 MBS information.

18. Some key features of forth generation:
• Integrated circuits smaller & faster.
• Portable computer developed.
• Great development in data communication.
• Different types of secondary memory with high
storage capacity & fast access developed.

19. [Coming Generation]
Fifth Generation computing devices based on
artificial intelligence, are still in development.
The goal of fifth generation computing is to
develop devices that response to natural
language input & are capable of learning & self
organization.

20. Some key features of fifth generation:
• Parallel Processing was done.
• Super conductors were used.
• Many processors are grouped to function as one
large group processor.
• A super conductor is a conductor through which
electricity can travel without any resistance
resulting in faster transfer of information between
the components of computer.

21. Reference
1. en.wikipedia.org/wiki/Operating_system
2.INFORMATION TECHNOLOGY APPLICATIONS FOR BUSINESS:
3.Dr. S.Sudalaimuthu and R. Hariharan.: Himalaya publishing house.
4.INFORMATION TECHNOLOGY FOR MANAGEMENT: B.Muthukumaran,
Oxford university press Computer Fundamentals, Goyal, Anita 1st Edition, Pearson
Education.
5.Introduction to Information Technology by Leon and Leon, Vikas Publishing House.
6.Information Systems Today, 2e by Leonard Jessup, Joseph Valacich, PHI
7.Management Information Systems by Laudan & Laudan, Pearson Publications