Well, I made some progess with the Mac Portable today. Although I still
don't know what the Sad Mac code $0F means (all the FAQs that I've read skip
from $0E to $10).
IIRC, $0F is a 68K F-line trap. I.e., some sort of invalid instruction
that causes the CPU to go to the FPU emulation vector (there being a lack
of a 68881/2 on a portable). I do not know what kinds of problems cause
this on a Mac, but without OS support, it's fatal to the 68K.
-ethan