Large-scale integrated circuits (LSI) are used for logic elements and main memory of computers. The so-called large-scale integrated circuit refers to an integrated circuit that integrates 1000~2000 or more transistors on a single silicon chip, and its integration level is more than 1~2 orders of magnitude higher than that of small and medium-sized integrated circuits. At this time, the computer has developed to the stage of miniaturization, low power consumption and high reliability. Large scale integrated circuits have developed military industry, space technology and atomic energy technology. The vigorous development of these fields has put forward higher requirements for computers and effectively promoted the unprecedented development of the computer industry. With the rapid development of large-scale integrated circuit technology, computers are not only developing towards supercomputers, but also towards

Fly towards subminiature and microcomputer. 197 1 At the end of the year, the world's first microprocessor and microcomputer were born in Silicon Valley in the south of San Francisco, USA, which ushered in a new era of microcomputers. Since then, various microprocessors and microcomputers have mushroomed and flooded the market, becoming the best-selling products at that time. This momentum is still in the ascendant today. Especially after the birth of IBM-PC series computers, the world microcomputer market was almost unified, and various compatible computers came out one after another.