Excerpts from netbsd: 4-Sep-98 Re: minor pcvt(?) problem... "Brian C.
Grayson"@marvi (553*)

>   Me too -- Dell PII 300 machine, keyboard hangs.  For us, this
> machine is the server for 5 other machines, so rebooting it is
> a nuisance.  It's running 1.3F, and uses pcvt.

While this will not solve the original problem: Can you
consider giving the wscons code a try?
The NWSCONS config file will tell you how to enable it.
("MAKEDEV wscons" is needed too)
I didn't hear about hangs with it so far, and it would be good
to give it some testing with "suspect" hardware.
(It's actually not said that the hardware is to blame. However,
the interaction between keyboard and mouse accesses is
quite complex with the pccons and pcvt drivers, and given the
variety of hardware out there this is kind of black magic.)

best regards
Matthias