Yep - Card placement turned out to be the problem. My VAX4200 is now happily
churning out a custom kernel on it's own disks.

Actually, I managed to cobble together a nice little union/nfs mount of the
source tree - I've got the complete source tree on a NetBSD/i386 box, that
gets SUP updated every night. It is NFS mounted Read-Only to /usr/src. Then
I created a /usr/src-work directory, and union-mounted it over the /usr/src
- so now I never have to worry about screwing up the source tree when
compiling for multiple archs on multiple machines. Each keeps it's working
files locally. Sweet.

Also, I got a little dissappointment. When I picked up this box, I was told
that the two CMD443 controllers were dual-channel SCSI controllers. Well,
they do have two connectors, but.. the top one is used if the controller is
in single-ended mode, the bottom one for differential. Humbug.

Anyway - at least it's up and running on the first 5 4G drives I've hooked
up. Now, off to the RAID manpages...