[TUHS] Zilog Z80 Unix

Warner Losh imp at bsdimp.com
Thu Apr 20 14:50:16 AEST 2017


There were a number of 8088/8086 ports as well that didn't have memory
protection....

On Wed, Apr 19, 2017 at 10:34 PM, Bakul Shah <bakul at bitblocks.com> wrote:
> Yes, Cromemco was the company, Cromix their unix like OS.
>
> IIRC, in 1981-83 timeframe someone I worked with had mentioned
> he used to work at Cromemco and that they had a unix like OS
> called Cromix. Cromemco were in Mountain View so likely they
> were at the WCCF.
>
> Even though z80 could only address 64k, their system had a
> bank select under s/w control & upto 512K of RAM could be
> added.  Z80 didn't have a supervisor mode but still, the bank
> select must have  afforded enouh protection from bad pointers
> crashing random processes.
>
> On Wed, 19 Apr 2017 23:40:30 EDT Gregg Levine <gregg.drwho8 at gmail.com> wrote:
>> Hello!
>> That was also a board vendor. FYI: The first GASP [GetAway Special
>> Program] a Space Shuttle payload made use of such a board.
>> -----
>> Gregg C Levine gregg.drwho8 at gmail.com
>> "This signature fought the Time Wars, time and again."
>>
>>
>> On Wed, Apr 19, 2017 at 11:09 PM, Bakul Shah <bakul at bitblocks.com> wrote:
>> > On Wed, 19 Apr 2017 18:42:42 PDT "Erik E. Fair" <fair-tuhs at netbsd.org> wrote:
>> >> I have a memory of having seen a Zilog Z-80 (not Z8002 like the Onyx) based
>> >> Unix, possibly v6, at a vendor show or conference - perhaps the West Coast
>> >> Computer Faire (WCCF) in the late 1970s or early 1980s.
>> >>
>> >> I recall asking the people in the booth how they managed without an MMU, and
>> >> don't recall their answer. I do remember thinking that since Unix had "grown
>> >> up" with MMUs to stomp on obvious pointer mistakes, the software ought to be
>> >> relatively well-behaved ... you know: not trying to play "core war" with
>> >> itself?
>> >>
>> >> I searched the TUHS archives cursorily with Google to see if this has been
>> >> previously mentioned, but pretty much all Z80 CPU references have for its use
>> >> in "smart" I/O devices back in the day.
>> >>
>> >> Does anyone else remember this Z80 Unix and who did it? Or maybe that it was
>> >> a clone of some kind ... ?
>> >>
>> >>       looking for a little history,
>> >>
>> >>       Erik Fair
>> >
>> > You may be thinking of Cromemco.


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