Jones Telecommunications and Multimedia Encyclopedia

Powered by steam and as large as a locomotive, the computer proposed by the English mathematician Charles Babbage in the 1820s would have looked nothing like today's computers. But it would have stored a computation program, calculated equations, and printed out the results. It was not until the 1940s and '50s that modern computers were born. Still large-one model was half the size of a football field-with miles of wires and thousands of vacuum tubes, these high—priced machines calculated at rapid speeds; but only the U.S. government could afford them. By the 1970s, computers had shrunk both in size and price. By the early 1980s, ordinary people were buying personal computers-or PCs-for their homes, schools, and offices. Now small enough to fit in a briefcase or in the palm...