Okay,
here' s a dumb question. What do I type at the ">>>" prompt
 to boot from the SCSI controller. This is a TD Systems Viking
 controller. I tried just "boot" but that seems to attempt to and
 fail to boot from the ESDI hard drive. I have the MVII technical
 manual and looked up the boot command but all it says is "boot
 <device>" but doesn't say what the choices are for "device".
What
 would I enter as a device name to skip over the ESDI drive and
 boot from the CD-ROM attached to the Viking controller? Also, the
 CD-ROM drive is set for unit 4 if that makes a difference.
 Thanks,
 David 
 IIRC, it should be DUx:  It's been a while since I booted my
 PDP-11, and I've never put one in a MicroVAX.  Here is the manual.
 
ftp://ftp.avanthar.com/dan/viking_scsi/
 The important question is what version are your ROMs.  I did a
 bunch of work with these boards a few years ago, and as near as I
 was able to determine it you need a fairly new version of firmware
 to use a CD.  I believe that you need higher than V3.4 firmware.
 I've used DEC RRD-42, Plextor 6x & 8x caddy drives with the Viking
 QDT.  As I've mentioned before the use of caddy drives is in part a
 personal choice as the caddy's are handy since there aren't that
 many PDP-11 CD's.  I did try a 4x tray drive that worked in my DEC
 Alpha's, and it wouldn't work. 
 
My controller has a ROM that says "Viking Q/B A4.1" on it. I guess
that means it's version 4.1? The CD-ROM drive I'm using has been used
on a VAXstation 4000 VLC successfully before. It's a Toshiba
TXM3401E1 drive with a caddy.