68K/OS was a computer operating system developed by GST Computer Systems for the Sinclair QL microcomputer.
It was commissioned by Sinclair Research in February 1983. However, after the official launch of the QL in January 1984, where the QL with 68K/OS was demonstrated to the press in the Intercontinental Hotel, 68K/OS was rejected. Production QLs were shipped with Sinclair's own QDOS operating system, developed in-house.
GST later released 68K/OS as an alternative to QDOS, in the form of an EPROM expansion card.
68K/OS was well designed, multi-windowing, single user, multi-tasking system. It had no built-in BASIC language, nor command line shell interpreter. Instead, 68K/OS had "ADAM" user interface with windows and menus.
The operating system was developed by Chris Scheybeler, Tim Ward, Howard Chalkley and others.
(pictures by Urs König)