The MITS Altair 8800 is widely recognized as the first spark that led to the microcomputer revolution. MITS was founded in Albuquerque, New Mexico in 1969 by Ed Roberts, Forrest M. Mims, Stan Cagle and Robert Zaller who sold radio transmitters and instruments for model rockets out of Roberts garage.
Intel introduced the 8080 CPU in April of 1974. The 8080 processor was capable of addressing up to 64Kb of RAM and was powerful enough to build a real computer. Ed Roberts had designed and manufactured programmable calculators and was familiar with the microprocessors, decided to design an Intel 8080 based computer, and the first prototype was ready in October 1974.
The Altair 8800 was featured on the cover of the January 1975 issue of Popular Electronics, and was sold by mail order through advertisements. The Altair was a complete kit, hobbyist projects up to then were just plans and bare boards requiring people to find the necessary integrated circuits and components.
MITS intended to sell only a few hundred to hobbyists, but were surprised when they sold thousands in the first month.
The Altair 8800 and the Popular Mechanics article inspired the creation of the Homebrew Computer Club by a group of Bay Area enthusiasts, including Steve Wozniak.
Additionally, the Altair excited Bill Gates and Paul Allen who contacted Roberts to write a BASIC language for the machine. When Roberts expressed his interest, the two started work on their BASIC interpreter, using a self-made simulator for the 8080 on a PDP-10 minicomputer. Altair BASIC became the first product for Microsoft.