Government, universities and businesses were using mainframe computers from the late 1940s. These machines used thousands of vacuum tubes and were beyond the means of the average person.

By the early 1970s, transistors and solid-state circuitry found their way into computer design. In 1971 the Kenbak-1, the first personal computer, came on the market, selling for $750. It relied on switches for input and lights for output

from its 256-byte memory. Only a handful were sold. The Altair 8800 that came out in 1975 was built around the Intel 8080 microprocessor. Ed Roberts, who invented the Altair 8800, coined the phrase "personal computer." Other makes, some in kit form, hit the market.

In 1976, Steve Wozniak and Steve Jobs, designed the Apple I, which led to the highly successful Apple II. The personal computer was here to stay.