David Brownlee wrote:
> 
>         Two more questions (if anyone can help)
> 
>         Is the KDA50 a Q-bus controller?

Yes... it's just another Q-bus MSCP controller.  It consists of two quad
width boards connected by two ribbon cables.  
Keep in mind that the KDA50 uses a lot of power, so check if you have
enough available before installing one.

>         What is the native interface for a RA90 (and other RA?) disks?

It's SDI, which stands for Standard Disk Interconnect.  (I don't know
anything about the details of the protocol, but I hope you don't need
that)
BTW.  It seems that there are other SDI drives out there besides the RA
series, including some solid state drives and some 3rd party drives.

>         What is the size / capacity of an RA90?

Approximately 1.2 gigs.  If you want a more precise figure, well disktab
will tell you:
ra90|RA90|DEC RA90 Winchester:\
        :ty=winchester:ns#69:nt#13:nc#2649:\
        :dt=MSCP:\
69*13*2649*512 = 1216590336 bytes

-- 
|  Boris Gjenero <bgjenero@undergrad.math.uwaterloo.ca>              |
|  Home page:  http://www.undergrad.math.uwaterloo.ca/~bgjenero/     |
|  "Luke, you're going to find that many of the truths we cling to   |
|  depend greatly on our own point of view." - Obi-Wan Kenobi, ROTJ  |