Ethan,
yes, I also remember having seen PDP-11/VAX peripherals controlled by a
68000. However, with this board, I am not quite sure if it is Qbus or
UNIBUS at all. I'd have to trace the connections, but before doing so,
my suspicion is that this was some different kind of system with the
Motorola centipede being the main processor.
And, no, I did not notice any particular driver chips like the 1488/1489
(or maybe 75188/75189, or some of those 8-pin chips from the DLV-11/J,
or...). The absence of such chips together with the large number of pins
makes me think this might be a separate memory bus, similar to what the
MicroVAX II had.
On the other hand, it is still possible that there once was another part
of the subsystem, like a distribution panel, which may have included the
level shifter chips. But then again, there are no other large chips,
other than those mentioned, on the board. Everything else is like
SN74...
Sorry for making the task of guessing so hard, I think it's time to get
a digital camera. I hesitate because I don't have access to any computer
with a working USB to upload the pics, and this application alone
wouldn't justify buying Win2000.
Andreas
Ethan Dicks wrote:
>
> --- Andreas Freiherr <Andreas.Freiherr_at_vishay.com> wrote:
>
> > 3) Qbus-like board, supposedly a CPU, handles made by DEC, board is 4
> > slots wide, labelled "PCS" (is that PCS CADMUS?), has Motorola
> > MC68000L10, 4k SRAM (2*6116), 16k EPROM (2*2764), clock chip (MM58167),
> > battery. Between the handles, there are two 40-pin 3M connectors (Berg
> > style). The EPROMs have stickers saying
> >
> > MINITOR MINITOR
> > R900.123 R900.123
> > E9 2.200LO E10 2.200HI
>
> Without a picture, it's kinda hard to guess, but the 68000 was a common
> chip to use in the 1980s for a VAX peripheral (we did it on the COMBOARD,
> DEC did it with the DMB32, etc).
>
> If there are 1488s and 1489s near the BERG connectors, it is probably
> a protocol converter of some sort (like a COMBOARD or Simpact board).
> Otherwise, if there are any other large chips, they might reveal what
> this board did.
>
> -ethan
>
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--
Andreas Freiherr
Vishay Semiconductor GmbH, Heilbronn, Germany
http://www.vishay.com
Received on Mon Jun 03 2002 - 08:23:50 BST