What is the S-100 bus (also known as IEEE-696 bus)?
(Herb Johnson) Among the earliest microcomputers offered to electronic hobbyists in the mid-1970’s was the Altair 8800 by MITS. It was offered as a $400 kit in an article in the January 1975 issue of Popular Electronics magazine. Each functional block of the computer, such as the processor, memory, or I/O required at that time many logic or memory chips each. So a card was designed for each function, connected together by plugging into a common bus of parallel connections or “motherboard”. The function and timing of signals on the 100 pins of that bus became known as the “S-100 bus”. The Altair was distinctive for its “front panel” which displayed binary address and data on LED’s and which provided toggle switches to control the processor, much like minicomputers of the era. While not the first microcomputer or microcontroller to be offered for public sale, the Altair 8800 is often cited as the “first personal computer” as it was a widely accepted and visually recognized product; it re
