The phase wise development of computers on the basis of main component , their size , processing speed , system architecture etc. used by them is known as computer generations . The development of modern computer took into five distinct phases which is called generation of computer . Each generation computer is made improvements over the previous generations in terms of technology . The improvement in technology resulted in computer of lower cost , higher speed , smaller size , greater memory capacity and reliable .
First Generation of Computers (1945 1955)
The first generation computers were built using the technology vacuum tube . A vacuum tube is an electronic device consisting sealed glass which used filaments as a source of electronic and could control and amplify the electronic signals . The vacuum tube based first generation computers could perform operations in milliseconds . The memories of these computers were constructed using electromagnetic relays based on punched cards and they used machine level language for coding . The examples of first generation computers are ENIAC , EDVAC , EDSAC , UNIVAC etc .
TIPS : Vacuum tube was invented by Lee Dee Forest 1908 .
Features of the first generation computers
- They used vacuum tube as main component .
- They were huge in size . Their operating speed was up to milliseconds
- They used machine level language for programming .
- They consumed a lot of electric power .
Second Generation of Computers (1956 1963)
Second Generation Computers The second generation computers used transistor as their main technology instead of vacuum tubes. One single transistor could perform the task of 1000 vacuum tubes. The transistor was made of germanium semiconductor materials instead of glass. These generation computers were small, better and easier to handle than first generation computers. They used the magnetic core memory and operated up to microseconds. The coding language was used by this generation computer.
TIPS: Transistor as invented by a team lead by William Shockley, John Burdeen and Walter H. Brattain in 1949.
Features of second generation computers :
- They used transistor as main component .
- Their operating speed was up to microsecond .
- They used magnetic core memory as internal storage .
- They could understand assembly and high level language .
- They were Smaller and faster than first generation computers .
Third Generation Computers
The technology used in third generation computers was integrated circuit . The IC Was mounted with Small Scale Integration and Medium Scale Integration to form Large Scale Integration instead of earlier transistors . The IC is an electronic circuit consisting of several electronic components like transistors , registers and capacitors grown on a single chip of silicon , eliminating wired interconnections between components . This technology was also known as microelectronics technology . The third generation computers were operated up to nanosecond and used high level language for programming . They also used large magnetic core based Randorn Access Memory and larger capacity magnetic disks .
TIPS : Integrated Circuit ( IC ) was invented by Jack Kilby .
Features of third – generation computers :
- They used Integrated circuits in terms of ( LSI ) as main component .
- They were general purpose computers ,
- They were Small , efficient and reliable .
- They supported a large number of high level languages .
- Their operating Speed was up to nanoseconds .
Fourth Generation computers
The technology used in fourth generation computer was microprocessor based instead of LSI . A microprocessor contains all the circuits needed to perform Arithmetic Logic and Control functions on a single chip . Due to the microprocessor technology ,it is resulted personal computer. This generation computers used semiconductor memories and operated up to picoseconds. They used GUI based advanced software and supported networking and internet systems.
TIPS: The first microprocessor, Intel 4004, was invented by an engineer Marcian Ted Holf of famous American company Intel Corporation in 1971
Features of fourth generation Computer
- They used VLSI based microprocessor as main electronic component.
- Their operating speed is picoseconds and even more.
- They are user friendly and support numerous high-level languages and GUI (Graphics User Interface) programs.
- Their size is reduced to laptops and palmtop computers,
- They supported magnetic and optical storage devices.
Fifth Generation Computers
The technology being used in the fifth generation is based on the ULSI (Ultra Large Scale Integration) and bio-chip which will increase the capability of Computer to many times than the present computers. They will possess artificial intelligence with parallel processing mechanism. The computer will use web based software and imply knowledge based problem solving techniques. The fifth generation computers are not fully developed but the technology is used in different devices such as Robotics.
Features Expected in fifth Generation computers
- They will use ULSI technology as main components.
- They will possess artificial intelligence.
- They will implement knowledge based problem solving technique.
- They will be much faster than present computers.
- They will use Internet based applications.