General

I just found Apout, which is described as a "user-level simulator for UNIX a.out binaries". I had to try it immediately, and while the code needed some manual patching to get it compiled on Linux, Apout works like a charm. While Unix V7's /bin/sh shows some bug, all the stuff in /usr/games seems to work. And the great advantage compared to e.g. SIMH is that Apout doesn't hog the CPU.