On January 8, Michael Sokolov wrote:
> > Incidentally, I don't see an
> > SDI disk controller in there anywhere...weird...
>    Well, if the VAX works, it must have either a KDB50 on the BI or a UDA50
> on the UNIBUS (the latter seems unlikely to me, although I don't know
> anything about the architecture of VAX 82xx, common sense suggests to me
> that if BI is its native bus and UNIBUS is not, the disk controller should
> be on the BI). Maybe that "BI adapter data transfer module" is a KDB50? Or

  That's not the KDB50...The KDB50 consists of two BI boards, the
T1002 processor and the T1003 SDI interface.

> it may just be the case that the same kids who used the unit plugs as goal
> posts for hockey used the KDB50 as a cover for a frying pan :-( (If this is
> indeed the case, those kids should be spanked until they can't stand.)

  Yes.

  If there's no KDB50 or UDA50 (the Unibus version of the controller),
I'd guess the machine was running from a cluster interface...

>    And you have said there is an RX50 in the CPU box? Then it's probably
> for the console. If it were for the VAX itself, there would have to a
> controller for it on some bus, and the drive would have to be either in the
> same box as the controller or external.

  The RX50 controller is internal, not a separate BI board...That's
the console processor's drive.  It's used for diags and microcode
updates.

                  -Dave McGuire
                   mcguire@neurotica.com