Has anyone actually gotten a VAX 4000/100 (i.e. KA52) system booted with
NetBSD/vax?  In -current, it looks like there's support in the kernel
for the VAX 4000/105A (KA53), and that there are also some provisions
made for its close relatives like the KA51, KA52, KA54, and KA57.

However, I don't see anything obvious in the second stage bootloader
referencing the KA52, and it's during the inital bootstrap where my boot
process is failing.  I can't boot from either CD-ROM or a preinstalled
SCSI HD attached to the external SCSI bus.  My OpenVMS install CDs do
boot fine in CD-ROM drive, so I know it's not a hardware problem.

Thanks for any pointers.

-brian.