> 
>   Incidentally, if I try to boot the machine from dua0 while closely
> watching the LEDs on the drive (I'm pretty sure it's not bootable but
> I just wanted to see if it'd try to execute a read), it sits there for
> a few seconds and says "DEVOFFLINE".
> 
It your computer firmware says "DEVOFFLINE" then it's because it 
fails to init the drive, not because you miss boot blocks. If you
have a functioning disk without boot, then you will get another
error message.

>   Does the "drive" identifier in the kernel config file actually
> correlate with the unit id on the drive?  Meaning, if I have a "drive
> 9" configured in the kernel, will I have to select id 0009 on the
> ra90, even though it's still on controller 0 at 772150?
> 
It _skall_ be this way; but due to the mix between old and new
config it may malfunction. You better not change the ra disk
numbering, too much is depending on it. This is subject for change.

>   Sorry I'm being so clueless here...rl02s are no problem..even
> rk05s...but these dang ra90s are too much for my brain. :)
> 
:-) My favorite disk system is Massbus disks. They are very easy
to handle and a concrete protocol to the disk.

-- Ragge