i know i don't understand the specific differences between those guns to understand it.
(i didn't downvote because of i that. I just found it to be a poor one)
I admit that the analogy I have used may not suit everyone's taste, and I apologize, but, as always, reality trumps imagination: turns out, there exists a version of UNIX for Z80 called UZI: http://www.dougbraun.com/uzi.html.