24 Aug
2005
24 Aug
'05
9:57 a.m.
Paul Koning wrote:
> You have bad html (local filename reference for
the photos); pasting
> the name part into the rest of the URL gets the pictures.
Oops
Sorry a fixed url:
http://personal.riverusers.com/~dponsford/qbus/index.html
> That's definitely not a DEC board. For one
thing, a Qbus board
> wouldn't have gray handles, it would have maroon handles (that's what
> the M in board part numbers refers to).
Well this is a qbus board as it came out of a qbus chassis and the grey
handles do have DEC
on them! But I agree I think this may be a third party/prototype board!
However there is an
assembly number and other production artifacts that lead me to believe
this is not a
prototype board in the strict sense.
My first instinct with the mystery board was that it was a modified
production board rather than a prototype
There is a 24 pin gold-colored chip in the center of the board, labeled :
IM5200CJG
i 7608
and in the lower corner FPLA-1
The CPU board does have the 5th socket filled with the FIS/CIS (
23-003B5) option,
I believe some of the operation of the board has to be a sort of
termination like a TEV11, which
is required for the LSI-11 to operate, and the location, the last board
on the qbus, is the obvious
location for the termination board. Having no photo of the TEV11 or
REV11, I though this may be one!
> Second, the rats nest of wires on the back goes
way beyond anything
> that DEC would ship (far too many wires) and the "slap them anywhere"
> routing is much sloppier than the rework I have seen coming out of
> DEC. It's just barely possible you might see this in a prototype,
> though almost always prototypes would be done a lot more cleanly than
> that. But for sure you would not see that in a production board.
It could be a prototype board, but I do have a few circa 1974 DEC unibus
boards
that do have as much as (or more) wirewrapping!
As this computer was from the U of A, it might have been used in some
intructional/development program.
The chassis is not a DEC product, more of an OEM/ development project.
The front of the computer says:
LSI-11 MICROCOMPUTER
Microprocessor Development System
University of Arizona
with a few micro-toggle swirches (LTC on/off, Enable/Halt and
Initialize) as well as small lights (Running, halt, D.C. On,
Enable )
.
Cheers
Tom