If it lands at the >>> prompt, try typing boot. I *think* the device name would probably be DUA0 for that controller, but if I'm wrong I'm sure someone will correct me. So if boot doesn't get it, try boot dua0. I think. Geez it's been a long time since I had my hands on a microvax II.

When I was a grad school sysadmin, we used a 13mb uVaxII with a pair of ESDI disks (350 megs each, I think) as a file server for our office. Ironically of all the vaxen I worked on at that site, that box is one of the few that's still around, since the terminal server boots from it. :) I'm waiting and salivating for when the University puts all those vaxen in the surplus auction or (I hope I hope) takes me up on my offer to haul them all away for free. They've got a 4000/500 that was brand new when I worked for them that I *want*.