1. Computer
The word computer comes from the word
“compute’’ which means “to calculate’’.
Hence Computer to be a calculating device
that can perform arithmetic operations at high
speed.
A computer is an electronic device which
Processes information based upon the
instructions provided the deseire output.a
computer can store processes and retrieve data as
and when desired.

2. Characterstics of computer
• Automatic machine.
• High speed.
• Accuracy
• Versatile
• Storing
• Deligence

3. Limitation of computer
• No IQ
• No feelings
• No learning capacity
• Human dependent
• Hardware and software
dependent

4. Computer generations
• Computer generation is a step in
technology. It provides a framework
for the growth of computer. it has
now extend to include both
hardware and software to make a
computer system

5. 1st GENRATION
(1942-1945)
• These machine use thousands of vacuum
tubes
• These vacuum tube are made up of fragile
glass device which used filaments as a source
of electronics and could control the electronic
signals.

6. 2nd GENERATION
(1955-1962)
• In this new electronic devices are invented
that must called transistors.
• These were more powerful
• Less expensive.
• They use magnetic disk and tape as a
secondary storage medium.
• High-level languages were used in second
genration

7. 3rd generation
(1964-1975)
•
•
•
•
•
In this integrated circuits are used.
The were smaller and less expensive.
Consumed less power and produced less heat.
Mini computers were used.
Time sharing operating system were invented
in this generation.

8. 4th generation
(1975-1989)
• In this micro processor were used.
• Faster smaller and less power consuming then
third generation.
• They were general purpose machine.
• Graphical user interface used.
• hey were use in hTomes and as for personal
use of an human being.

9. 5th generation.
(1989-present)
• This generation increase the power of micro
processor chip.
• VLSI technology become ULSI.
• More user friendly.
• Large primary storage capacity.
• Provide network facility(lan,man ,wan)

10. Basic function of computer
• Inputting
• Storing
• Processing
• Outputting
• controlling