68K/OS was a computer operating system developed by GST Computer Systems for the Sinclair QL microcomputer.

68K/OS EPROM expansion card
DeveloperGST Computer Systems
OS familyDisk operating systems
Working stateDiscontinued
Source modelClosed source
Initial release1984; 37 years ago (1984)
PlatformsSinclair QL microcomputer
Default user interfaceCommand-line interface or menu

It was commissioned by Sinclair Research in February 1983. However, after the official launch of the QL in January 1984, 68K/OS was rejected, and production QLs shipped with Sinclair's own Qdos operating system.

GST later released 68K/OS as an alternative to Qdos, in the form of an EPROM expansion card, and also planned to use it on single-board computers based on the QL's hardware.

The operating system was developed by Chris Scheybeler, Tim Ward, Howard Chalkley and others.[citation needed]

The few ROM cards that were made mean that surviving examples now fetch a high price: On Feb 04, 2010 one sold for £310 on eBay.[1]


  • Leon Heller (September 1984). "QL Affairs". Your Spectrum (7). Retrieved 2009-03-26.
  • "SinclairWatch". Your Spectrum (8). October 1984. Retrieved 2009-03-26.
  • "Sinclair QL". Binary Dinosaurs. Retrieved 2009-03-26.
  1. ^ Ebay. "Sinclair QL - GST 68k/OS 68kos VERY RARE!!". Retrieved 2009-02-05.

External linksEdit