Computer

Generations of computer
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 cards

Punched card voting
Punched card decks

Punched cards models

Large punched cards

. First generation computer
Advantages :
. 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 disks
Advantages :
. 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