The Apple Macintosh IId
Once technology had advanced to the point where many circuits could be etched onto a single silicon chip, the microprocessor was developed. A microprocessor is a chip that contains the portions of the CPU that control the computer and perform arithmetic and logic operations. It may also contain some memory. The micropro-cessor became the foundation for the microcomputer, also called the personal computer.
Microcomputers are the most popular type of computer today. The demand for microcomputers continues to increase. Even the stock market crash of October 1987, did not have an adverse effect on the sales of microcomputers. In addition, the sale of microcomputer software is greatly increasing.
The prefix micro applies more to size and cost than to capability. They may fit on a desktop or in a briefcase (see Figure below). Some dedicated microcomputers designed for home use cost as little as $100, while microcomputers for professional use may cost over $10,000. Typically, fully featured microcomputers for home use cost in the neighborhood of $1500. Yet current microcomputers are very powerful for their size. Microcomputers cannot perform as many complex functions as today's large computers, and they have much smaller memories; however, technology continues to give them more speed and memory at decreasing costs.
The Apple Macintosh IId
Most microcomputers are single user systems. As such they must be easy to operate. One important aspect of microcomputer design involves the development of user-friendly hardware and software; that is, equipment that is easy to learn and easy to use. The concern for user friendliness has overflowed into the development of other computers, too.
Microcomputers are available in computer stores, office supply stores, and de-partment stores. In some cases, they are sold much as an appliance, like a television or a videocassette recorder. Microcomputers often use packaged software, that is, standardized software for solving a wide range of problems, but many users like the challenge of developing their own and many businesses and custom developed soft-ware. Chapter 8 provides a detailed discussion of microcomputers.