[TUHS] Is there a good, even definitive, list of reimplementations of the Unix kernel? What would good cut-off criteria be?

[Niklas Karlsson via TUHS]

I am a little too young to really have been active back in the day, but my
dad has been running an electronics business since the early 80s. I know
that early on, he had a 6809-based workstation that variously ran FLEX and
OS/9. I should ask him about that sometime.

Best regards,
Niklas

Den tis 21 apr. 2026 kl 13:27 skrev Brad Spencer via TUHS <tuhs at tuhs.org>:

> Phil Budne via TUHS <tuhs at tuhs.org> writes:
>
> > Wesley Parish wrote:
> >> Not forgetting, Doug Braun's UZI - Unix for the Z80
> >
> > How about UniFLEX and OS-9 for the 6809?
>
> I worked a whole lot with OS-9 on a Radio Shack CC2 and CC3 on a 6809
> and 6309 in the '80s and '90s.  It was very much a Unix clone with the
> commands named differently.  If you looked at the block diagram for the
> OS it looks a whole lot like the early Unix systems, probably around the
> Unix V5 time.  It was also a microkernel, or at the very least, a wholly
> modular system with each and every device driver and device descriptor
> being a module which was mostly just a Motorola S record blob.  You
> concatenated the modules you wanted together and the boot loader loaded
> the concatenation to create the custom system you wanted.  A K&R C
> compiler was available and it wasn't that hard to port some of the Unix
> utilities to OS-9.  I created a varargs library for 6809 OS-9 and ported
> a number of the simpler Unix utilities to the system.  Fun times...
>
>
>
> --
> Brad Spencer - brad at anduin.eldar.org
>