Zilog Zeus

Mark Davidson mdavidson1963 at gmail.com
Thu May 8 14:07:19 CDT 2008

NCR Tower... yes, I used to work for a company that had several of those for
running RM/COBOL.  Interesting little machines.  I *think* they also had a
special OS just for RM work.  I haven't seen one of these in a long time.


On Thu, May 8, 2008 at 7:40 AM, Jeff Jonas <jeffj at panix.com> wrote:

> From: Matthias Knoth <mknoth at earthlink.net>
>> does anybody have information/source code/anything
>> about the Zilog Zeus System? It is a System III Unix derivate
>> running on a Z8001 16bit CPU
> Gaaah, it's coming back to haunt me!
> The NJ Computer Museum has a Zilog System 8000 model 21
> what's probably running that!
> One of my AT&T IS consulting assignments was running URTS
> (Unix Regression Test Suite) on the SVR3 port
> and examining the source code.
> I'm unsure I have any of that on tape or printouts :-(
> The comments were amusing such as the Z8000 CPU
> forcing the Z80's "RETI" instruction
> on the peripheral bus to reset the Z80 peripherals chips
> interrupt daisy chain.  The comments were something like
>        ld  foo ; now watch my lips ...
>        mov bar ; RE-
>        ld  baz ;
>        mov qux ; -TI
> That's the first place I saw "deadbeef" as a magic number.
> I really liked the System 8000 as a development system
> since it had a firmware monitor that could be invoked
> in case of a system crash to poke at the RAM.
> I think that's where I learned how to repair the system
> using the stand-alone bootable tapes such as
> SASH: Stand Alone Shell,
> and SADIE: the diagnostic tape.
> When Exxon owned Zilog (around 1982), they had an office in
> Rockefeller Center (NYC) for their office automation
> featuring the Zilog System 8000 running Zeus.
> Back then, breadbox sized Z8000 systems running Unix System III
> were common, such as the Onyx, so the Unix manuals were all around
> (Then 68k based systems took over, then Intel x86).
> I like in an apartment, so I can't save 'em all :-(
> From: Dave McGuire <mcguire at neurotica.com>
>> I ran a Zilog System 8000 running Zeus daily
>> for quite a while back in the late 1980s.
> But did you get to peek into the kernel
> or use the maintenance programs?
> From: "Mark Davidson" <mdavidson1963 at gmail.com>
>> I'd love to hear what people have as well...
>> I remember "porting" an RM/COBOL system for a doctor's office
>> from a CP/M system to ZEUS and loving the system.
>> I've never seen any on the collector/used market
> I remember seeing 2 on the back of an old pickup truck,
> for sale, at the Trenton Computer Fest in the late 80s.
> Talk about a fall from grace!
> The only RM/COBOL I remember seeing was a manual for the NCR Tower,
> but I was a firm Unix/C kinda guy by then.
> -- Jeff Jonas

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