The January 1975 issue of Popular Electronics introduced the Altair 8800 and hit the newsstands ... There’s a backplane board (about $100) as well as a few boards to fit it available for about ...

At the time, this was a huge deal. Some even argue that it made an AM radio one of the first I/O devices for use with the Altair 8800. At demonstration of the code at a meeting of the Homebrew ...