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Please help with mystery board -

jackrubin

jackrubin

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Joined
Mar 12, 2004
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Chicago, IL and Buchanan, MI
I received a PDP-8/E system yesterday that includes an unknown (to me) Monolithic Systems OMNIBUS board. It is marked "METS 303-0115-000C" in the front solder layer and "304-0115-001 REV A" on the back. Monolithic made MOS memory boards for the PDP-8 and PDP-11 but this isn't one of them. Chip dates suggest late 1977 manufacture.

Any help or leads appreciated!

Thanks,
Jack

MSC_303-011500-3.jpg

MSC_303-011500-4.jpg
 
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Jack,

The photos aren't fine enough resolution to read the markings on the ICs, but they are all 14 and 16 pin dips. Are they all dead common 7400 TTL or Signetics DCL (like the 380), or are there any special functions there? It is interesting that this board has no other interfaces to the outside world, only to the omnibus.

Lou
 
I'm not sure what specifically it is, but many boards which plugged into a Unibus/Omnibus looking backplane exist that are not any DEC bus, but proprietary boards for third party subsystems. I've got a few from CNC/NC control systems which were simply plugged into an unwired DEC backplane, and had custom wire wrapped connections to the actual Unibus interface that drove them.
 
Glitch,

That makes a lot of sense. My 8/e was that way when I got it. The whole rear section was filled with cards plugged into an application-specific but omnibus-looking backplane. It was a system from DCA (Digital Communications Associates of Atlanta GA) that was a terminal server for a pdp-10.

Lou
 
jackrubin said:
I received a PDP-8/E system yesterday that includes an unknown (to me) Monolithic Systems OMNIBUS board. It is marked "METS 303-0115-000C" in the front solder layer and "304-0115-001 REV A" on the back. Monolithic made MOS memory boards for the PDP-8 and PDP-11 but this isn't one of them. Chip dates suggest late 1977 manufacture.

Any help or leads appreciated!

Thanks,
Jack
Click to expand...

METS - Memory Extension and Time Share?

Marty might know. Didn't he work there?
 
I'm thinking it's an M837 clone too, especially since the system is set up with 16K of core memory but has no M837, and this card is sitting right behind the CPU where an M837 would normally be found. Interesting that it's the only non-DEC card in the chassis, but I only have the 8/E itself at home. The rest of the rack is in storage and has an extension chassis, so more to be discovered there.

I'm amazed at how close the layout is to the M837 drawing that Al posted - close enough to warrant a chip-by-chip compare.

Thanks,
Jack
 
The METS board is an exact clone of the M837 - all the same chips in all the same places, even allowance for the timeshare jumper (though it is open by default). It looks as if Monolithic copied the layout and simply re-taped the traces. I put the METS board into my 8/M system and was able to DEP and EXAM in extended memory fields with no problems. I'll leave it in the machine for a while to see how it works out.

I also found some amusing instructions in the KM8E printset. For preliminary checkout, the tech is advised to "load switch register with 00778." Must have been written by the same guy who was sent out to refill the bit bucket.

Jack
 
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Hi All;

Yes, AL is right, I did Work for Monolithic, But, this was before my time..
All I worked on was Memory Boards, When I was there I was in assembly putting together various Memory Boards, according to what Sales indicated was needed..
I don't recall seeing this Board, but, there were/was much I am sure I didn't see or know about..
In one of the cabinets in Test, where I eventually worked my way up to was all kinds of Test gear for attaching the various Boards to a test unit depending on what/who it was..
I know they did DEC PDP 8 and PDP 11 and Nova Memory Boards.. I also remembering seeing a (I think) MultiBuss 8080 of their own design with lots of wires hanging all over it.. So, there could have been other stuff hidden all over the place that I didn't know about..

I wish I knew some names of who was there who started the Company, to find out what happened to it and where much old the Documents and test gear went..

THANK YOU Marty
 
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