>xfs works just fine.  When I try to get xdm to work it turns out that 
>it is trying to execute /usr/X11R6.1/bin/X.  The only problem is that 
>/usr/X11R6.1/bin/X does not exist.  Everything compiled and installed 
>without problems.  Did I just miss a step?  How do I build X (Xdec) ?

You don't.

The X11R6 Xdec server assumes you're using  the "ws" interface
between the X server and the kernel.  NetBSD/pmax assumes you're
using an older interface, essentially the same interface used for
microvax framebuffers since, uh, time immemorial.

The solution is to use an X11R5 Xserver, or back-port the X11R5
ddx layer into X11R6.1.  Arne Juul's  X11R5 "Xcfbpmax" seems to work
just fine for me.

Note that I'm also about halfway through reverse-engineering and
implementing the "ws" interface.  It's far enough along for an X
server to get to mmap()ing a ramebuffer. Both the ws and older "pm"
style interface use an ringbuffer with input events that's written by
the kernel and read from user-space.  However, the ringbuffer format
is different enough that much of the input-side mouse/keyboard
handling needs to be more-or-less completely redone.  (Merging the
pmax and Alpha framebuffer drivers would be nice, too.)

If anyone wanted to take that on and finish it, I'd be thrilled...

--Jonathan