Hi!

> MicroVAX 3100/90 is a supported platform ?

On www.netbsd.org/Ports/vax you can find all supported platforms.

> can it boot from CDROM ?

If it has one, which is not connected to a KZQSA (?), you can.
(That's the only controller from which I know, you can't boot from).
a >>> show device should give you more info.
with >>> b devicename you can boot

Ciao,
	Freddy