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!