PERSONAL COMPUTER

Personal Computers, microcomputers were made possible by two technical innovations in the field of microelectronics: the integrated circuit, or IC, which was developed in 1959; and the microprocessor, which first appeared in 1971. The IC permitted the miniaturization of computer-memory circuits, and the microprocessor reduced the size of a computer's CPU to the size of a single silicon chip.
The invention of the microprocessor, a machine which combines the equivalent of thousands of transistors on a single, tiny silicon chip, was developed by Ted Hoff at Intel Corporation in the Santa Clara Valley south of San Francisco, California, an area that was destined to become known to the world as Silicon Valley because of the microprocessor and computer industry that grew up there. Because a CPU calculates, performs logical operations, contains operating instructions, and manages data flows, the potential existed for developing a separate system that could function as a complete microcomputer.

The first such desktop-size system specifically designed for personal use appeared in 1974; it was offered by Micro Instrumentation Telemetry Systems (MITS). The owners of the system were then encouraged by the editor of a popular technology magazine to create and sell a mail-order computer kit through the magazine. The computer, which was called Altair, retailed for slightly less than $400.
The demand for the microcomputer kit was immediate, unexpected, and totally overwhelming. Scores of small entrepreneurial companies responded to this demand by producing computers for the new market. The first major electronics firm to manufacture and sell personal computers, Tandy Corporation (Radio Shack), introduced its model in 1977. It quickly dominated the field, because of the combination of two attractive features: a keyboard and a cathode-ray display terminal (CRT). It was also popular because it could be programmed and the user was able to store information by means of cassette tape.