Last night, I had a kernel panic. This was while attempting to build a new
kernel

vm_fault(10c000, 2eaf0000, 1, 0) -> 1
  type 8, code [mmu,,ssw]: 401f24d
trap type 8, code=401f24d, v=2eaf0054
...
kernel: MMU fault trap

at which point I was thrown to the debugger, which locked up when I tried to
enter commands.

NetBSD1.1 (GENERIC) #47: Wed Nov 22 19:17:19 PST 1995
Binaries mostly from 1.0, except text set which is 1.1
Mac IIsi + FPU 17Mb RAM Internal video 640*870
SCSI 0: QUANTUM LP40S   40Mb
SCSI 1: QUANTUM TRB850S 810Mb
SCSI 5: IOMEGA  ZIP100  Offline at the time.

NetBSD lives entirely on SCSI 1.

Anyone have any ideas?

Bernard.