What were the most early Unix type OSes for x86?

Question

Minix was released in 1987 - if internet is correct it was meant to run on IBM PC.I know that Polish IPIX (not much is known about it tho other than it was written to run on Polish Krak-86 computer https://pl.wikipedia.org/wiki/IPIX) was already POSIX compliant in 1988. I don't know much more about it's age - is it "older" than 1988 or not. History of communist era hardware and software are not part of teaching program in Poland and only few hobbyists seems to care about collecting and keeping software, hardware and documentation from these times as well as recording history of that era of computerization in Poland.I see no mentions of any other UNIX type OS on x86 platform this much back in time. Only 386BSD that was being developed since 1989 (which makes it younger than Minix and IPIX).Were there any other notable or obscure attempts or successes in creating "UNIX for x86"?

thedday · Accepted Answer

I think Coherent, of Mark Williams, is a bit older. According to Wikipedia it was first released in 1980, but probably was for the PDP-11, at that point. I used it on an 80286 for years. https://en.wikipedia.org/wiki/Coherent_%28operating_system%2...

ThrowawayB7 · Answer

Microsoft Xenix (later SCO Xenix) is probably among the first, if not the first, x86 UNIX: https://en.wikipedia.org/wiki/Xenix"The first 8086 port was for the Altos Computer Systems' non-PC-compatible 8600-series computers (first customer ship date Q1 1982). ... SCO Xenix for the PC XT shipped sometime in 1984 ..."

ggm · Answer

MKS. Might not fit your ontology of "unix" but it pre-dates this, 1985 maybe?
KA9Q was focussed on the IP stack but to implement the IP stack an awful lot of what looks like libc was probably implemented.
The history of C-like ports to 286 architecture probably informs what you're after.

What were the most early Unix type OSes for x86?

I think Coherent, of Mark Williams, is a bit older. According to Wikipedia it was first released in 1980, but probably was for the PDP-11, at that point. I used it on an 80286 for years. https://en.wikipedia.org/wiki/Coherent_%28operating_system%2...

MKS. Might not fit your ontology of "unix" but it pre-dates this, 1985 maybe?KA9Q was focussed on the IP stack but to implement the IP stack an awful lot of what looks like libc was probably implemented.The history of C-like ports to 286 architecture probably informs what you're after.

MKS. Might not fit your ontology of "unix" but it pre-dates this, 1985 maybe?
KA9Q was focussed on the IP stack but to implement the IP stack an awful lot of what looks like libc was probably implemented.
The history of C-like ports to 286 architecture probably informs what you're after.