Xenix on Acorn machines

[paulb]

We've been here before, I'm sure, but perusing "The History of XENIX" on the Abort Retry Fail blog, I saw this:

1983 saw the first releases of XENIX 3.0 based on UNIX System III with enhancements from BSD. This was first made available on the Altos 586. In early 1984, the Intel 310/380, and machines from Acorn received UNIX ports of this newer version.

I don't think this final part is true at all. Previous enquiries have indicated only that Acorn was working with people from Logica, and that noises were being made about the challenges of the port to the ABC 200 series (later Acorn Cambridge Workstation), but no products were delivered and I haven't seen any indications of any working software. Someone did claim an "unofficial port" or such on a Wikipedia page without any citation (of course), but that is barely anything more than hearsay.

It would be nice to get to the bottom of this, disappointing though I suspect the conclusion would be, but I doubt that we ever will.

[atsampson]

I had a hunt through the utzoo Usenet archive, and the only mention of Acorn and Xenix together there is a different unsourced rumour, posted on 18th May 1984 by Dave Gurr from Westfield College:

With reference to my previous articles about the BBC micro, I thought that maybe someone would be interested to know that the proposed 16032 second processor is looking less and less likely to be produced. Apparently Acorn are now working on a Z8000 second processor in conjunction with Torch
Computers Ltd (who also make a 68000 + Z80 second processor running UNIX or CP/M). It is not yet clear whether this Z8000 processor will be running
Microsoft's Xenix or Unisoft's Uniplus - these seem the most likely two contenders.

[paulb]

I had a hunt through the utzoo Usenet archive, and the only mention of Acorn and Xenix together there is a different unsourced rumour, posted on 18th May 1984 by Dave Gurr from Westfield College:

With reference to my previous articles about the BBC micro, I thought that maybe someone would be interested to know that the proposed 16032 second processor is looking less and less likely to be produced. Apparently Acorn are now working on a Z8000 second processor in conjunction with Torch
Computers Ltd (who also make a 68000 + Z80 second processor running UNIX or CP/M). It is not yet clear whether this Z8000 processor will be running
Microsoft's Xenix or Unisoft's Uniplus - these seem the most likely two contenders.

Fascinating! I personally think a Z8000 second processor would have been unappealing and an unlikely product. The Z8000, unlike various processors that get classified as "16-bit" but are architecturally 32-bit (for example, the 68000), really is a classic 16-bit processor, lending itself to competing with systems like the PDP-11. However, 68000-family systems like Torch's Unicorn and 32016-based systems like the one Acorn wanted to make were trying to compete with the VAX.

Consequently, the era of opportunity for the Z8000 passed very quickly indeed, and Zilog's own systems division actually switched to AT&T's WE32000 series. Olivetti persisted with the Z8000 for a few years, but they were pretty incoherent with their technological strategy, following up with a seemingly exotic variant of the 68000 for the models that replaced those based on the Z8000.

The available drawing office records don't mention any Z8000 products, but maybe insiders can share any insights they might have. I suppose a Z8000 card (see also the Trump Card - no, not that one, thankfully) might have permitted a simpler version of Unix to run, maybe getting away with 256K of RAM since it wasn't going to be a multi-user system, but it wouldn't have been workstation-class, exactly.

Of course, Acorn did produce their 32016 (originally 16032) second processor, and they split up with Torch quite definitively, so the rumour was quite wide of the mark.