[TUHS] SUN (Stanford University Network) was PC Unix

Brad Spencer brad at anduin.eldar.org
Fri Apr 16 11:17:13 AEST 2021

Robert Brockway <robert at timetraveller.org> writes:

> On Sat, 10 Apr 2021, Dave Horsfall wrote:
>> On Fri, 9 Apr 2021, Paul Ruizendaal via TUHS wrote:
>>> 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.
> 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

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 at anduin.eldar.org - KC8VKS - http://anduin.eldar.org

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