The MITS Altair 8800, introduced in 1975, is widely regarded as the first commercially successful personal microcomputer and the spark that ignited the personal computer revolution of the 1970s. Featured on the cover of the January 1975 issue of Popular Electronics, it transformed computing from an institutional pursuit into a hobbyist phenomenon.
The Altair 8800 was designed by Henry Edward "Ed" Roberts, founder and president of Micro Instrumentation and Telemetry Systems (MITS) in Albuquerque, New Mexico. Originally started in 1969 to sell model rocket telemetry kits and later calculator kits, MITS faced financial difficulties in 1974 due to the collapsing calculator market. Roberts, a former U.S. Air Force officer with an engineering background, saw opportunity in the new Intel 8080 microprocessor and pivoted the company to develop an affordable computer kit. The name "Altair" was suggested by Popular Electronics editor Les Solomon's daughter, inspired by a destination in a Star Trek episode.
Development began in summer 1974, shortly after the Intel 8080's release. Roberts negotiated a bulk price of $75 per 8080 chip (versus retail over $300), enabling a low kit price. The machine was announced in the January 1975 Popular Electronics as the "World's First Minicomputer Kit to Rival Commercial Models." Priced at $397 as a kit or $498 assembled, it included everything needed: case, power supply, motherboard, and CPU board.
Roberts expected to sell about 200 units to break even, but orders flooded in—thousands in the first months, overwhelming MITS. By mid-1975, thousands had shipped, and the company grew rapidly. Later variants included the Altair 8800a (improved switches and 18-slot motherboard) and 8800b (larger power supply and chassis).
The Altair 8800 was powered by the Intel 8080 8-bit microprocessor. Key features included:
Programming was done in machine code via front-panel switches; no keyboard, monitor, or storage was included initially.
The open S-100 bus architecture allowed third-party expansions, fostering a vibrant ecosystem. Most famously, Bill Gates and Paul Allen developed Altair BASIC (Microsoft's first product), demonstrated to Roberts in 1975. This higher-level language made the machine far more usable. Other early software included assemblers and games loaded via paper tape or cassette.
The Altair 8800's success inspired the formation of the Homebrew Computer Club, where future industry leaders like Steve Jobs and Steve Wozniak shared ideas. It led to Microsoft's founding, countless startups, and the rapid evolution of personal computing. Though MITS was sold to Pertec in 1977 and the Altair line faded, its influence endures—the Altair democratized computing, proving powerful machines could belong to individuals. Surviving units are prized museum pieces and collector items, symbolizing the birth of the PC era.