The Sinclair QL Forum

I know, there was an OS-9 implementation for the QL(!).

I unfortunately have never seen it.

OS-9 was even available for 8bit computers (at least based on M6809, e.g. Dragon). But I think the QL must be one of the first (mass) computers, where it was really fantastic (because of the 32bit architecture of the 68000/68008).

Edit: Name is OS-9 NOT OS/9 (I confused it with OS/2.)

I've been looking for that too - I believe it was release by Cumana, and was based on the Microware implementation.

I am not sure if it was actually sold in any quantity - but I did see it advertised in magazines of the time.

Thank's for your answer. Indeed I also have seen it advertised in QL User or QL World (but could not find it after a quick search). So I asked Perplexity. It seems that albeit it was announced (and advertised, as I have seen advertisements in computer magazines), it was most probably never available (as PDQL C, which indeed did exist, but was never released because of copyright problems). Here the answer of perplexity.ai:

Follow-up question to perplexity.ai:
OS-9 has had been advertised in QL World or QL User magazine. If I remember correctly the supplier was Cumana.

Answer (perplexity.ai):
According to the search results, Cumana was indeed planning to release OS-9 for the Sinclair QL. Clive Martin from Cumana described OS-9 as "the operating system of the future for both the QL and the BBC microcomputer"

The key details about the OS-9 for Sinclair QL include:

- It was planned to be available as a hardware add-on in September
- Cumana would provide compatible disc drives and interface
- The system was described as being very "Unix-like"

Planned software for OS-9 included:

- Word processors
- Databases
- A fast version of Basic
- A C compiler
- Potential hard disc support

Martin from Cumana was particularly enthusiastic, suggesting that OS-9 could turn the QL into the "equivalent of a high speed mini computer". This was part of Cumana's strategy to expand the QL's capabilities beyond its original design.

While the OS-9 was advertised and planned, the search results do not confirm whether it was ultimately released or widely adopted by QL users.

URLs this (AI) answer is based on:
https://sinclairuser.com/041/qlnews.htm
viewtopic.php?t=2805&start=30