x server on a '20?

[drstrip@isrc.sandia.gov (David R. Strip)]

I tried last night to bring up the x-server on a '20. My base
world already has ip-tcp loaded. I Load'ed system x-server (and
then sat back and waited a long time). It loaded, but with a lot
of whining about packages (nothing that required a user response, 
however). I then tried to edit the namespace to add
service: x-window-system tcp x-window-system.
It claimed that the host host only supported x-window-system via
local-(mumble).
Obviously (?) I am missing something, perhaps some prerequisite package.
I recall trying this once, long ago on an XL, so some additional network
stuff was preloaded. Do I need rpc, embedding-support ...?
Thanks