1st Computer Generations: 1946-1959
- The computers of this generation where ENIAC, EDVAC, EDSAC, Ferrant, Manchester, Mark 1, UniAc etc.
- The main component used in these computers was vacuum tube (a switching device which replaced gear & excels)
2nd Computer Generations: 1959-1965
- The most popular invention of the 2nd generation computer, as well as 20th centuries, was a transistor (Switching device replaced vacuum tube).
it was invented by scientists of Bell laboratory, U.S.A named:
1. William Shockley
2. John Bardeen
3. Walter Brattain
- In the 1st part of the 2nd generation, we used Ge transistor and in the 2nd part Si.
Ge & Si both are semiconductor materials i-e, not a very good conductor and not a very bad conductor.
- Ge was replaced by Si because the chemical bonding and melting-point of Ge were less than Si.
In 1963, DEC(Digital Equipment Corporation, USA) introduced the first 32-bits main Frame computer.
3rd Computer Generations: 1965-1971
- The most popular invention of the third generation computer was IC (Integrated circuit). It was invented by Jack St. Clair an Engineer in Terias Instrument USA in 1958.
- Advantages of Integrated Circuit:
1. Smaller Computer
2. Low-cost computer
- According to pins agreement, there are mainly two types of IC’s:-
1. DIP (Dual In-Line Package): Up to 24 pins agreement
2. PGA (Pin Grid Array): more than 100 pins arrangement
- According to transistor implementation the types of ICs in the 3rd generation where
1. S.S.I – Small scale Integration: 1 to 10 transistor
2. M.S.I – Medium Scale Integration: 11 to 100 transistor
- The computer of this generation is called supercomputer. The 1st supercomputer where made in 1964 named CDC-6600 (Control Data Corporation, USA) and ILLIAC-IV made by Burroughs, USA.
4th Computer Generations: 1971-1980
- This is the period of enhancement in IC Technology Semiconductor Memory, microprocessor etc.
- According to transistors implementations the types of IC in the 4th generation where:
1. L.S.I – Large Scale Integration – 101 to 1000 transistor
2. V.L.S.I – Very Large Scale Integration – 1001 to 10000 transistor
3. U.L.S.I – Ultra Large Scale Integration) – more than 10001 transistor
- Semiconductor Materials:-
The memory which is made of semiconductor materials such as:
1. RAM: Random Access Memory
DRAM: Dynamic RAM
SRAM: Static RAM
2. ROM: Read Only Memory
PROM: Programmable PROM
EPROM: Erasable PROM
EAROM: Electricity Alterable PROM
- Note: The 1st semiconductor memory was DRAM, which could hold only 256bits in 1970.
The single chip processor is termed as the 1st microprocessor was made by Intel a 4-bits microprocessor Chip in 1971.
Intel 4004 – 4 bits – Microcomputer
Intel 8008 – 8 bits – Microcomputer
Intel 8080 – (8-12)bits – Microcomputer
5th Computer Generations: 1980 -till today
- This is the period of enhancement in ICs Technologies, Semiconductor memory microprocessor as well as in AI(Artificial Intelligence).
- Artificial Intelligence:
AI is the branch of computer science which is used to period machines, Robotics that will emulate the human thought process.
The following table shows concluded information about all Five computer generations:
|S.No||Computer Generations||Period of Computer Generation||Description of Computer Generations|
|1||First Generation||1946-1959||Vacuum tube based|
|3||Third Generation||1965-1971||Integrated Circuit based|
|4||Fourth Generation||1971-1980||VLSI microprocessor based|
|5||Fifth Generation||1980-till today||ULSI microprocessor based|