James Robinson <jrobinson@stisierra.com> wrote:
> 3) The Unibus doesn't have a KDB50 controller. (prices anyone??)
   You need to distinguish between UNIBUS and BI. Your VAX has both, but
its native and preferred bus (not counting CI) is BI. You can have an MSCP
controller either on the BI, in which case it has to be a KDB50, or on the
UNIBUS, in which case it has to be a UDA50. I don't know much about 8200s,
but common sense suggests to me that having the MSCP controller on the BI
will be faster (and I think it's supported). So if you are sticking with
SDI for your Winchester disk drive interface, I think that you should be
looking for a KDB50 (I think they are still available from DECdirect :-)).
> 1) Is it beter to go scsi, and is there a BI or Unibus controller that
> would work with NetBSD?
   I would suggest that you first check whether your RA82s work. If they
do, you have almost 2 GB of disk space. If I were you in this situation, I
would stick to the RA82s and look for a KDB50. If they don't work, that's a
different story. I don't think that you would want to look for other RA
disks (I wouldn't if I were you), so you'll probably be looking for a
different interface. Note that it doesn't mean SCSI, there are also ESDI
and SMD. I find the latter two more fun than SCSI. In any case you should
be able to find an MSCP controller for the interface you want. The only
caveat is that it might be difficult to find it for BI, UNIBUS would
probably be easier (and slower...). Don't worry about NetBSD/vax
compatibility, all of these controllers are MSCP and look identical to the
host system.
> 2) The drive is a RX50, can I replace it with a TK50 or TK70?
   If you are thinking about replacing the console drive, just forget it.
Those things are cast in stone. On the other hand, _adding_ a tape drive to
the VAX itself (as opposed to the console) should be doable. For whatever
drive you choose you'll need a UNIBUS TMSCP controller. For TK50 it's
TUK50. For TK70 it should be called TUK70 if it exists (it probably does,
but I'm not sure). I don't know if there are tape controllers for BI, but
even if there are, they are not supported.
   
   Sincerely,
   Michael Sokolov
   Phone: 440-449-0299
   ARPA Internet SMTP mail: mxs46@po.cwru.edu