| 1972 -Fourth Generation Computers |
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Computers built after 1972 are often called Fourth Generation computers, based on LSI (Large Scale Integration) of circuits (such as microprocessors) - typically 500 or more components on a chip. Later developments include VLSI (Very Large Scale Integration) of integrated circuits 5 years later - typically 10,000 components. Modern circuits may now contain millions of components. This has led to very small, yet incredibly powerful computers. The fourth generation is generally viewed as running right up until the present, since although computing power has increased the basic technology has remained virtually the same. By the late 1990s many people began to suspect that this technology was reaching its limit, further miniaturisation could only achieve so much. 64 megabit RAM chips have circuitry so small that it can be measured in atoms, circuits this small pose many technical problems - notably the heat created but they are also very susceptible to influence by temperature or radiation. It has been argued fifth generation computers are based on parallel processing and VLSI integration - but are still being developed and I'd be wary of writing the history books until the history has actually occured! Besides computers need to be massively parallel before they give a significant enough advantage to warrent a new generation of computing. |