16 Apr
2021
16 Apr
'21
7:17 a.m.
Robert Brockway <robert(a)timetraveller.org> writes:
On Sat, 10 Apr 2021, Dave Horsfall wrote:
I did a lot with OS-9 too, both Level One on the Color Computer 2 and
Level Two on the Color Computer 3. The CC3 had a very primitive memory
manager, no faulting, but would allow 8k chunks from up to a 512k pool
of memory to be mapped into the 64k address space of the 6809. There
was a C compiler, probably K&R based or a bit before for OS-9. I ported
a number of the BSD utilities. I also worked on a implementation of
UUCP and ran a UUCP node and proper domain for email using UUNET as the
provider. I received email and a bit of Usenet. I wrote a clone of rn
to read Usenet on the CC3 with OS-9 Level Two. The block diagram for
6809 OS-9 was very simular to V[small number] Unix, with some notable
differences. OS-9 is a microkernel probably being the biggest thing and
6809 OS-9 is all written in assembly. There was a login program that
you could attach to a serial port and actually login with a username and
password and such. Lots of fun and somewhat Unix like in a lot of
ways. There was also a 68000 version of OS-9 Level One that I saw
once. I understand that it may have been mechanically translated from
the 6809 version. It ran pretty much exactly in the same way.
--
Brad Spencer - brad(a)anduin.eldar.org - KC8VKS - http://anduin.eldar.org
On Fri, 9 Apr 2021, Paul Ruizendaal via TUHS
wrote:
That worked on the old Radio Shack (Tandy) Color Computer 2 as well.
Until this moment I didn't know it had been demonstrated on any other
architecture.
The Operating System OS-9[1] Level One would detect this and use the
bank-switched memory if it was available. Presumably it kept identical
copies of itself in each bank as the entire address space switched.
Microware OS-9 was *nix-like in look and feel although it was very
different internally I think. OS-9 still exists today.
I started with OS-9 and so found Unix a comfortable environment when I
transitioned over.
[1] Which should not be confused with any operating system running on a
Mac. That's another story.
Rob Z80 CP/M machines were still competitive in
1981-1983 (Osborne, Kaypro)
And the Aussie Microbee... Wonderful machine, and easily hacked upon.
For example, you could expand the memory by soldering several chips on top of
each other and addressing the CS* line via bank-switching.