Anyone ever done assembly on one of the IBM 360/70/90 beasts??  Man those 4K 
pages were a pain...

Personally, I think trying to port any of the *nix's to the IBM 3x0 machines 
would be a royal pain...  the I/O channel architecture would be quite an 
effort to try and incorportate into the system, and how exactly would you 
plan on handling those 3270/80-type bi-sync terminals that operate 
half-duplex in line-by-line mode...  the old IBM's seem to like dealing with 
everything like a deck of punched cards (yuck).