I have a KA655 in a BA123 with an RQDX3 and RD54.  (The machine was
originally a VAXstation II/GPX, but I pulled the VCB02 and replace the
CPU.  Eventually I may put the VCB02 back in.)

When the machine first comes up, SHOW DEVICE reports the drive as an
RD51.  After several resets, it finally decides that it's an RD54.

Is this normal?  Or is something broken?

Is there a console command I can give that will cuase the system to
not attempt to autoboot?  Right now I've got that by giving it a
SET BOOT with a bogus device name, but surely there's a better way.

Is there a way to abort an attempted boot?  When I first fired up the
box, it was always trying to boot from XQA0, and I had a difficult time
getting a command prompt.  I'd hoped that the halt switch on the front
panel would do that, but it seemed to only make it run the power-up
diagnostics in a loop.

If I add more drives, do I need to install more front-panel inserts for
them?

Can a BA123 handle three RD54s, a TK50, and an RX50?