The Altair 8800 is a microcomputer designed in 1974 by MITS and based on the Intel 8080 CPU. Interest grew quickly after it was featured on the cover of the January 1975 issues and was sold by mail order through advertisements there In Radio-Electronics, and in other hobbyist magazines. The Altair is widely recognized as the spark that ignited the microcomputer revolution as the first commercially successful personal computer. The computer bus designed for the Altair was to become a de facto standard in the form of the S-100 bus, and the first programming language for the machine was Microsoft's founding product, Altair BASIC.
Source: Wikipedia, "[en.wikipedia.org/wiki/Altair_8800 Altair 8800]", available under the CC-BY-SA License.