I dont quite understand the question, but with the 3100 you get a
monochrome framebuffer on the motherboard. This is routed by the switch
next to the diagnostic led's in the back to either the 16pin male plug or
the i/o (?) plug next to it. I think that plug is called a MMJ plug(?).
Some consoles have also a keyboard...but I dont think the F-keys and
control keys are mapped in netbsd 1.5. WSkbd works nicely if you do
ctrl-shift-F 1-6 or so. Gives you several consoles like alt F1-8 in Linux.
Handy!
The 16 pin plug carries on pin 9 (nine) the mono signal, (pin 3 is ground).
This allows you to hookup a sync-on green rgb monitor with three bnc plugs
, plugin to the green bnc terminal. or a paperwhite single bnc screen. the
output will be mono style. Alternatively you flip that switch and the
output goes to the specific digital console. graphics yes, x no (on the
vt330 eg).
In netBSD 1.5 I set my console to vt220 during boot. That allows my screen
to scroll. I use the 16pin output and a std digital kbd (LK20 or so?) I am
told its faster that way (?). Here too: no kbd mapping unless set in netBSD
by ? kbdconf?

Fred