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   -It is generally known as electromechanical computers or using vacuum tubes. -It is generally known as electromechanical computers or using vacuum tubes.
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   -Also known as transistor computers. The second generation of computers consist two types of devices, transistors and magnetic core. -Also known as transistor computers. The second generation of computers consist two types of devices, transistors and magnetic core.
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   -Period of third generation was from 1956-1971. It also used integrated circuits (ICs) in place of transistors. -Period of third generation was from 1956-1971. It also used integrated circuits (ICs) in place of transistors.
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    - Between 1971-1980. These computers used the VLSI TECHNOLOGY or The very large scale integrated(VLSI) CIRCUITS TECHNOLOGY.
 
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    - It uses A.I (ARTIFICIAL INTELLIGENCE) technology that includes development of expert systems, Game playing, robotics, natural language understanding, and neural networks.