Page "Bulletin board system" Paragraph 15

The first BBSes used homebrew software, quite often written or customized by the SysOps themselves, running on early S-100 microcomputer systems such as the Altair, IMSAI and Cromemco under the CP / M operating system.

Soon after, BBS software was being written for all of the major home computer systems of the late 1970s era-the Apple II, Atari, Commodore and TRS-80 being some of the most popular.