It was designed by Tony Tebby whilst working at Sinclair Research, as an in-house alternative to 68K/OS, which was later cancelled by Sinclair, but released by original authors GST Computer Systems.
Dizajnirao ga je Tony Tebby dok je radio u tvrtci Sinclair Research kao "unutarnje" rješenje za 68K/OS, projekt kojeg je kasnije ugasio Sinclair, no kojeg su izdali izvorni autori GST Computer Systems.