Serial followup
Found out why the null modem wouldn't work last week.
I don't need a null modem; I need a "normal" modem cable. As in, a straight one, not a crossed one. Never heard of something you run an operating system on which needs a straight serial line to work. Oh well.
Now for playing with it a bit, so that I understand the system, and then I can go test debian-installer for m68k VME hardware. Cool.