Saturday, May 21, 2011

generation of computer

third generation of computer
the computer which were made approximately between 1946 & 1971 and have the ICs technology for memory devices are classified as the computer of third generation. integrated circuit are the semi conductor devices which consist of many inter connected transistor & other components . They are constructed a silicon chips. The first IC was developed by Jhon Kilby & Robert Noyce in 1958. Some major features of third generation computer are as fallows:-

  1. Transistor were replaced by ICs.
  2. They were faster than previous generation computer as the processing speed increased to nanosecond.
  3. They were smaller in size, more reliable, accurate then previous generation of computer.
  4. Key board & moniter were used as input and output device respectively for the first time.
  5. Introduction of operating system for automatic processing & multiprogramming.

generation of computer

Second generation of the computer     
The computer which were made approximately between 1956 &1963 & having transistor & diodes as memory device are classified as the computers of the second generation.  Transistor is derived from the two words'transfer'&"register"& it is the device which is made of three terminal semi-conductor material that amplifies the electric signal or opens or closes the electronic circuit. transistor were invented by three scientists. they are John Bardeen, William Shockley & Walter Bratain in 1947 & won the novel prize in1956 for it.The key
features of this generation of computer are as follow:-
  1. transistor replaced the vacuum tube designing the switching circuit.
  2. power consumption & heat generation was less than the first generation computer.
  3. magnetic core memory was used as internal storage.
  4. magnetic tape was used as secondary storage.
  5. high level language such as COBOL, FORTRAN, and ALGOL etc were used for computer programming.
  6. they were less expansive & smaller in size because 1000 vacuum tube replaced by as single transistor.



generation of computer

Computer generation is the classification of computer into different groups according to their manufacturing date and the memory device & other hardware & software technology used in them. So generation of computer is a step in technology. It provides of the framework for the growth and development of more powerful & more useful computer system.
When computer generation goes higher i.e. from first to second , second to third & so on, then one can find that the speed, processing capability & storage capacity are increasing but size, power consumption, heat generation, cost & complexity are decreasing gradually. There are five generation of computer which are as follows:-
First Generation Computer
The computer which were made approximately between 1940&1956 AD are classified as the computer of first 
generation. All the computers made during the first generation had used the vacuum tubes or valves as memory device. Vacuum tubes were developed by Lee De forest in1908 & used later in computer. The first generation computer have the following features:-
  1. The electronics circuit was based on vacuum tubes.
  2. the computer of first generation were very big in size, unreliable & slower.
  3. human operator had to set the switches before a program could run.
  4. the operating[processing] speed was limited up to millisecond.
  5. machine level languages was used for computer programming which made programming extremely difficult & time consuming.
  6. punched cards were used as secondary storage.
  7. the cost of the computer was very high.
The example of the first generation computer are Mark1 , ABC, ENIAC etc

Friday, May 20, 2011

generation of computer

introduction to computer: To day computer comes form many different ways. Their range form the massive,multipurpose mainframes and supercomputer to desktop-size computers.
             mainframes and large minicomputer are used by many businesses, universities, hospitals and government agencies to carry out sophisticated scientific and business calculations. These computer are expensive an may require a size able staff supporting personnel and a special, carefully controlled environment

             personal computers, on the other hand, are small and inexpensive. In fact, portable, battery-powered "laptop" computers weighing less than 5 or 6 pounds are now widely used by many students and travelling professionals.