The early 1970s saw the birth of the microcomputer,or microfor 1
short. The central processor of the micro, called the microprocessor,is built as a single semiconductor device;that is, the thousands of individual circuit elements necessary to perform all the logical and arithmetic functions of a computer are manufactured as a single chip.A 5 complete microcomputer system is composed of a microprocessor, a memory and peripheral equipment. The processor, memory and electronic controls for the peripheral equipment are usually put together on a single or on a few printed circuit boards.Systems using microprocessors can be hooked up together to do the work that until 10
recently only minicomputer systems were capable of doing. Micros generally have somewhat simpler and less flexible instruction sets than minis, and are typically much slower. Different micros are available with 4-, 8-, 12-, 16-bit word lengths, and some new ones use 32-bit chips. Similarly, minis are available with word lengths up to 32 bits. Although 15
minis can be equipped with much larger primary memorysizes, micros are becoming more powerful and converging with minicomputer technology.
 The extremely low price of micros has opened up entirely new areas of application for computers. Only 20 years or so ago, a central processing unit of medium capability sold for a few hundred thousand dollars 20
(U.S.), and now some microprocessors sell for as cheaply as $10. Of course, by the time you have a usable microcomputer system, the price will be somewhere between $200 and $5000 depending on the display unit, secondary storage, and whatever other peripherals are needed.
 The available range of microcomputer systems is evolving more rapidly 25 than minicomputers. Because of their incredibly low price, it is now possible to use only a small fraction of the computer's capability in a particular system application and still be far ahead financially of any other way of getting the job done. For example, thousands of industrial robots are in use today, and the number is growing very rapidly as this 30 relatively new industry improves the price and performance of its products by using the latest microcomputers.
 Microcomputer software is developing rapidly and it now covers a tremendous range of applications. As well as data processing, software can also be written for specialized tasks even as complex as navigating 35
rockets. Some modern micros are even capable of multi-tasking. Inaddition to their extensive use in control systems of all types, they are destined for many new uses from more complex calculators to automobile engine operation and medical diagnostics. They are already used in automobile emission control systems and are the basis of many 40 TV game attachments. There is also a rapidly growing market for personal computers whose application potential in education is only just beginning to be exploited.
 It would seem that the limits for microcomputer applications have by no means been reached. There are those who predict that the home and 45
hobby computer markets, and the education market, will grow into multi-billion dollar enterprises within a decade or so. It would also appear that performance of microprocessors could well increase ten-fold before 1990 while prices for micros could decrease by as much.