Discussion:
Looking at a PDP-11 Circuit Board
(too old to reply)
cli...@gmail.com
2022-08-18 11:57:06 UTC
Permalink
Looking at third-party PDP-11 circuit boards for sale on that auction site.
Is there a way to tell just from pictures if the board is QBUS or UNIBUS?
Johnny Billquist
2022-08-18 19:24:13 UTC
Permalink
Post by ***@gmail.com
Looking at third-party PDP-11 circuit boards for sale on that auction site.
Is there a way to tell just from pictures if the board is QBUS or UNIBUS?
It's tricky. I usually search for some identification printed on the
screen layer, or solder layer, that gives me some hints on names to
lookup which could tell what kind of systems used the board.

Just trying to look at traces or components is hard.

Johnny
P.Lj
2022-08-19 10:00:57 UTC
Permalink
Post by ***@gmail.com
Looking at third-party PDP-11 circuit boards for sale on that auction site.
Is there a way to tell just from pictures if the board is QBUS or UNIBUS?
Are you looking for something specific?

^P
cli...@gmail.com
2022-08-20 11:43:03 UTC
Permalink
Post by P.Lj
Post by ***@gmail.com
Looking at third-party PDP-11 circuit boards for sale on that auction site.
Is there a way to tell just from pictures if the board is QBUS or UNIBUS?
Are you looking for something specific?
^P
cli...@gmail.com
2022-08-20 11:44:43 UTC
Permalink
Post by P.Lj
Post by ***@gmail.com
Looking at third-party PDP-11 circuit boards for sale on that auction site.
Is there a way to tell just from pictures if the board is QBUS or UNIBUS?
Are you looking for something specific?
^P
Data Systems Design A4430-4, 440 interface board, PDP-11, floppy/flexible disk
Not that interested in the particular board but it's not the first 3rd party board I've seen that didn't state which bus it was applicable to ...
Bill Gunshannon
2022-08-20 12:11:38 UTC
Permalink
Post by ***@gmail.com
Post by P.Lj
Post by ***@gmail.com
Looking at third-party PDP-11 circuit boards for sale on that auction site.
Is there a way to tell just from pictures if the board is QBUS or UNIBUS?
Are you looking for something specific?
^P
Data Systems Design A4430-4, 440 interface board, PDP-11, floppy/flexible disk
Not that interested in the particular board but it's not the first 3rd party board I've seen that didn't state which bus it was applicable to ...
I have never had a PDP-11 module third-party or otherwise that had
anything on the board that said if it was QBUS or UNIBUS. Always
had to refer to the documentation for that.

bill
pbi...@gmail.com
2022-08-20 13:18:29 UTC
Permalink
Post by Bill Gunshannon
I have never had a PDP-11 module third-party or otherwise that had
anything on the board that said if it was QBUS or UNIBUS. Always
had to refer to the documentation for that.
bill
Not to mention that there are many, many modules that are neither -- they depend on a specific SU (system unit, "backplane") as part of a CPU, device controller, or other assembly that may-or-may-not have a bus interface at an "edge".

Being hex-height doesn't even rule out Qbus (thank you PDP-8/A :->).
pbi...@gmail.com
2022-08-20 13:22:44 UTC
Permalink
Post by ***@gmail.com
Being hex-height doesn't even rule out Qbus (thank you PDP-8/A :->).
Grrr. Omnibus ...

Loading...