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Computer can classified in to five types according to generations i.e time period
. First generation computer
. Second generation computer
. Third generation computer
. Fourth generation computer
. Fifth generation computer
. First generation computer
Period : 1945 – 1956
Inviter : Lee de Forest
Main processing device : Vacuum tubes
Vacuum tube
Vacuum tube
Vacuum tube
Vacuum tube
Vacuum tubes
Observing Vacuum tube
Observing Vacuum tube
Vacuum tube tester
Punched curds
Punched card voting
Punched card decks
Punched cards models
Large punched cards
. First generation computerAdvantages :
. It was only electronic device
. First device to hold memory
Disadvantages :
. Too bulky i.e large in size
. Vacuum tubes burn frequently
. They were producing heat
. Maintenance problems
Too bulky i.e large in size
Vacuum tubes burn frequently
Maintenance problems
. Second generation computer
Period : 1956 – 1963
Inviter : William Shockley
Main processing device : Transistor
Storage media : Magnetic disc
Transistor
1 2
Transistor board
. Second generation computer
Advantages :
. Size reduced considerably
. The very fast
. Very much reliable
Disadvantages :
. They over heated quickly
. Maintenance problems
. Third generation computer
Period : 1964 – 1971
Inviter : Jack Kilby
Robert Noyce
Main processing device : IC (integrated circuit)
Storage media : Floppies
IC (integrated circuit)
ICs (integrated circuits)
IC (integrated circuit)
. Third generation computer
Advantages :
. ICs are very small in size
. Improved performance
. Production cost cheap
Disadvantages :
. ICs are sophisticated
. Fourth generation computer
Period : 1971– present
Inviter : Ted Hoff
Main processing device : ICs with VLSI
(Very Large Scale Integration)
Storage media : Floppies, CDs.
ICs with VLSI(Very Large Scale Integration)
. Fourth generation computer
Advantages :
. It is a compact
. Less power consumption
. Production cost is cheap
Disadvantages :
. No artificial intelligent.
. Fifth generation computer
Period : present and beyond
Main processing device : ICs with parallel processing
Storage media : Video disksAdvantages : . Artificial intelligence . Expert system
. First generation computer. Second generation computer
. Third generation computer. Fourth generation computer
. Fifth generation computer
Vacuum tubes
Transistors
ICs ICs with VLSI
ICs with parallel processing
Computer is a group of electronic devices used to process the data.
The characteristics of a computer are:
4. Accuracy5. Automation 6. Functionality 7. Tirelessness
1. Speed 2. Reliability 3. Memory capacity
1.Speed: computer process the data at an unimaginable speed. The speed of the computer ranges up to Nano seconds.
2. Reliability: The next important characteristic of a computer is its reliability. we can always rely on the information given by a computer.
3. Memory capacity: The memory capacity of a computer is measured in in bits and bytes. Large amount of the data can be stored in computer and retrieved. Memory capacity of the computer ranges in Giga bytes.
4. Accuracy: Accuracy of the computer is very high it performs calculation with greater accuracy
in less time.
5. Automation: a computer allows automation for any process designed in the from of a program. A program can be executed any number of times to repeat the process.
6. functionality: computer can performs many kinds
of jobs. They not process the data but also can be
Used for plying music, movies, and printing jobs.
It finds its applications in all most all the fields.
7. Tirelessness: A computer never gate tired.
