1974

First Personal Computer

Henry Edward “Ed” Roberts (1941–2010)

For all the technology contributions and influential people who helped launch the personal computer revolution, the Altair 8800 is generally considered the machine that sparked it. It was designed by American engineer Ed Roberts and his team at Micro Instrumentation and Telemetry Systems (MITS).

In 1974, the only way an individual could own a personal computer was to build one. Microprocessors had been on the market for three years, but the only way a hobbyist could get a personal computer was to draw a circuit diagram, fabricate a case, and purchase the needed parts from a dozen or more different companies. The Altair changed that.

Based in Albuquerque, New Mexico, MITS was founded in 1969 to make electronics kits for hobbyists. In 1974, the company introduced the world’s first microcomputer kit. Roberts wanted a microprocessor more powerful than the Intel 4004 and 8008 already on the market and negotiated a low price for the up-and-coming Intel 8080 chip. Though they were normally $300 apiece, he was able to get them in bulk for $75 a chip. The Altair kit included a metal case, power supply, boards, and assembly instructions. It did not have a keyboard or monitor. Instead, programs and data were toggled into the computer using the front panel switches; results were displayed with lights. The user could only create programs to make the lights blink. (An RS-232 interface card was available as a separately purchased accessory.)

Unbeknownst to Roberts, there was a sizable customer base eager for that experience. Roberts projected he would initially sell around 200 computers but within seven months had shipped more than 5,000, due in part to the machine’s appearance on the cover of Popular Mechanics magazine in January 1975 with the caption “World’s First Minicomputer Kit to Rival Commercial Models.” That edition caught the attention of Bill Gates and Paul Allen, who shortly thereafter approached MITS and offered to write the first programming language for the Altair. This would become Microsoft’s initial product: Altair BASIC.

Cover of the January 1975 issue of Popular Electronics, featuring the MITS Altair 8800.