[TUHS] Any Bell 8-bit UNIX Efforts?

Bakul Shah bakul at iitbombay.org
Wed Mar 1 05:57:16 AEST 2023

There was Cromix from Cromemco, released in 1979. It was supposed to be a lot like Unix and had its own C compiler.


I did use Leor Zolman's BDS C on my z80 imsai box in 1979-80. Written in Assembly language! Sources here:


> On Feb 28, 2023, at 11:42 AM, Clem Cole <clemc at ccc.com> wrote:
> Just so you know, the folks in Western Electric's Teletype team retargeted the Ritchie compiler to become a Z80 cross-compiler/assembler dev tools suite. That implementation was floating around the Bell System in the 76/77/78 time frame.  I know Karn had brought it with him and started using it for his original KA9Q IP/TCP implementation, initially for his CP/M box and ham radio system; (as he ran it as a cross compiler on my 11/34 at CMU's Mellon Institute -- I trade cycles for access to the compiler).  I don't know if anyone ever tried to use the Teletype Z80 C compiler to build a UNIX or UNIX-like port for the z80 with it. I have since forgotten how complete it was.
> A bit later, Loer Zohlman wrote BDS C,  <https://streaklinks.com/BaWWWKCdXX0VeHglTwPJ67Kb/https%3A%2F%2Fwww.bdsoft.com%2Fresources%2Fbdsc.html>which was pretty darned good/fairly complete C implementation for the time; and a few years back, he put it in the Public Domain [ you can download it from his website].  Missing/lost is/was the UNIX-like system they were working on to go along with the compiler - which I am trying to remember if it was quite complete/much less made it out for sale like his compiler was at the time.  However, at an early Boston USENIX, Leor had it running "good enough" that he brought it and showed it in his room on a dual floppy Z80 IMSAI box <https://streaklinks.com/BaWWWN1JCX6k_N2uxQTLwc9m/http%3A%2F%2Fretrotechnology.com%2Fherbs_stuff%2Fd_imsai.html> with some 4K bank switching HW (I don't remember how much memory - probably 128Kish).  I was there when he demo'ed it to Dennis and a few other hackers.  Dennis's response at the time was it reminded him of the early UNIX efforts.  I just thought it was pretty cool.
> A year or so later, Onyx folks brought their Z8000 based V7 system to USENIX, causing quite a stir
> On Tue, Feb 28, 2023 at 1:59 PM segaloco via TUHS <tuhs at tuhs.org <mailto:tuhs at tuhs.org>> wrote:
>> Sounds like Idris and uNIX are the closest we get with ex-Bell personnel being involved with both projects.
>> I haven't found anything in the surviving Bell streams that suggests any 8-bit attempts internally, and various portability documents suggest 16-bit and 32-bit targets abound but nothing like a 6502 or Z80 running UNIX inside Bell, again not that it would really be that worthwhile of an experiment at the time given their focus on minis.  Anywho, if anything ever does show up in my study I'll happily share the details.
>> - Matt G.
>> ------- Original Message -------
>> On Monday, February 27th, 2023 at 2:57 AM, Jonathan Gray <jsg at jsg.id.au <mailto:jsg at jsg.id.au>> wrote:
>> > On Sat, Feb 25, 2023 at 07:48:45PM +0000, segaloco via TUHS wrote:
>> > 
>> > > So in working on an unrelated 6502 project, I got to wondering about
>> > > UNIX on it and other 8-bits. Did some Googling, and while I was
>> > > able to turn up some attempts at UNIX-likes on 6502 as well as Z80,
>> > > the only one I found that might have some Bell connection is "uNIX"
>> > > as documented here: https://bitsavers.org/pdf/uNIX/uNIX_Jan82.pdf
>> > > 
>> > > A forum post I read suggested those involved were some former Bell
>> > > folks from NJ. In any case, this begs the question for me: Were
>> > > there ever any serious attempts at an 8-bit UNIX in the labs or
>> > > Bell System at large? Certainly it would've provided quite the
>> > > challenge without much return compared with 16 and 32-bit efforts,
>> > > but does anyone know if, say, an LSX/Mini-UNIX-ish attempt was ever
>> > > made at the 6502, Z80, or other 8-bits? Thanks all!
>> > > 
>> > > - Matt G.
>> > 
>> > 
>> > If by Bell connection you mean people. Plauger left in 1975,
>> > joined Yourdon Inc in 1975, started Whitesmiths Ltd in 1978[1].
>> > Whitesmiths created Idris, a clone of Unix.
>> > 
>> > "Idris can run comfortably where UNIX can't event fit: On an
>> > MC68000 with no memory management hardware, for example.
>> > On a bank-switched 8080 or Z80. Or on any LS-11 or PDP-11
>> > with memory management."
>> > Whitesmiths advertisement in Computerworld, Mar 1983 [2].
>> > 
>> > Yourdon Inc, announced Omnix in 1980, a Unix-like system for Z80[3].
>> > By 1981 it "had to be withdrawn when Yourdon were let down by its
>> > developers" [4].
>> > 
>> > [1] https://indico.cern.ch/event/318305/attachments/612388/842557/PJPlauger-ITSeminar-Fifty_years.pdf
>> > [2] https://books.google.com/books?id=RAe4jAHXAgwC&pg=PA50
>> > [3] https://www.tuhs.org/Archive/Documentation/AUUGN/AUUGN-V02.3.pdf
>> > [4] https://dl.acm.org/doi/pdf/10.1145/1164679.1164681
>> > 
>> > The last article is "UNIX on a Micro" by Cornelia Boldyreff.
>> > It briefly mentions other 8-bit Unix-likes: Cromemco's Cromix,
>> > Thinker Toys/Morrow's Micronix, Technical Systems Consultants' UniFLEX.

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