FOUR GENERATIONS OF COMPUTERSThe first vacuum tubes computers are referred to as first generation, and the estimated period of their use was from 1950 to 1959. is an example of these computers which could perform thousands of calculations per second. Thousands of vacuum tubes emitted a large amount of heat and burnt out frequently.milliseconds to microseconds, or millionths of a second. Second generation computers were smaller, faster and more reliable than first generation computers.The computers that were designed for use of integrated technology were called third generation computers, and the approximate time of these machines was from 1960 to 1979. They can perform many data processing operations in nanoseconds, which are billionths of a second.Fourth generation computers have now arrived, as well as integrated circuits that are being developed have been greatly reduced in size. This is due to the miniaturization, which means that the circuit is much smaller than before; as many as 100 tiny circuits are placed now on a single chip.