Note also that there's enough documentation in the Mach microkernel
source (see the kernel/chips/dec_lic/ directory) code to, perhaps,
cons up glass-tty console and mmap() support for the PMAG-C, PMAG-D
and PMAG-F.

I don't know what the legal status of that code is, though.
But if someone with a PMAG-C wanted to work on a driver -- or at
least a match/attach routine -- that would be cool.