Very true. In fact, aside from the big fridge-sized VAXes and some early Sun-3s, I'm pretty sure the Macintosh II of 1987 is the oldest commodity computer that can still run a mainstream and maintained UNIX-like OS. You can even stick 128 MB of RAM in one!

I suppose it's not a commodity PC, but there were PC sized VAXstations.

Netbsd says it supports the VAXstation 2000, which debuted in 1987.

Amigas as well.

Commodore didn't ship an Amiga with an MMU until the 2500/20 in 1988.

Fair enough, got the year wrong.

As info for others,

https://en.m.wikipedia.org/wiki/Amiga_Unix

Installing NetBSD is good fun if you have an old Mac laying around: http://p3k.org/netbsd/