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DEC units on ebay

Makes me feel better that the 8/e I sold for $1500 a few months ago went off to a good home as opposed to the highest bidder.
 
pbirkel said:
What a beauty! https://www.ebay.com/itm/206371144650
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It is all very neat except that the CPU backplane is missing. It should be in the rear door and all that is there are the cooling fans. The photos seem to have been taken to avoid clearly showing this. I only noticed this because I spent a few hours working with Vince on his.

Anyone know what the piece is in the expansion chassis? I can't read the paper label.
 
vrs42 said:
I think the back-plane with some green and magenta cards in it is part of an MM8I.
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Ok, I can see that. But the important stuff is missing from that too.
vrs42 said:
It's unusual that the peripherals are there and looking good, but the CPU isn't.
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There has got to be an interesting story here but we won't ever learn it.
 
Gold salvage is my guess. Also I wonder if there was a FPP12 in the H960 rack at one time.

Sad.
 
It's strange how clean it is. The backplanes are gone but all the cabling has been carefully tied back or secured and either it got a good detailing before it was listed or it's been stored somewhere dry and with little dust.
 
The TU55s, VR14, PDP-12 power supply, and the MM8-I without the core stacks is all that is there. The price needs to come down by 90% to make it worthwhile.
 
hush said:
i'm not terribly familiar with the 12, what are the chances it would ever run again? i'm guessing slim to none?
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It would require a PDP-12 backplane to make it complete, which I figure would have to be robbed from another PDP-12.
 
antiquekid3 said:
It would require a PDP-12 backplane to make it complete, which I figure would have to be robbed from another PDP-12.
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It would make a very fine static museum display. Also an source of some excellent spare bits.

I think it would be a fine platform for developing replacements for the missing backplanes. You'll need to implement an 8, a LINC, and co-processors for the LINCtape and the video.

I'm with Mike about the price.
 
hush said:
i'm not terribly familiar with the 12, what are the chances it would ever run again? i'm guessing slim to none?
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It's in the same boat as my PDP-8/s: the flip chips are all mostly standardized save for two or three specialty items like the core but there's hundreds of them missing. Even if you found backplanes you'll spend forever finding all the flip chips.
 
hush said:
i'm not terribly familiar with the 12,
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The PDP-12 is a LINC-8 implemented using TTL logic. Essentially a PDP-8/i integrated with a TTL implementation of the LINC. There are minor differences between the LINC-8 and the PDP-12 but for the most part code written for one will run on the other.
hush said:
what are the chances it would ever run again? i'm guessing slim to none?
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Extremely unlikely! If you trashed a couple of 8/i's for the backplanes you could rewire those and get a working backplane. You would have all the cards for the 8 portion of the CPU from the donor 8/i's. I don't know if there were any special cards in the LINC portion of the CPU but probably meaning you would need to fabricate those. This would be a few thousand hours of work when you were done. I suspect nobody would knowingly allow an 8/i to be abused in this way much less two of them.

Easier would be to make interfaces to the front panel and the Posibus and run simh on a Rpi. This is like the PiDP-8, 10, 11 replicas only your panel would be real. Still a significant effort.
 
The LINC-8 emulates many of the LINC instructions using PROGOFOP, as I understand it. The PDP-12 implements the LINC instructions in hardware—no PROGOFOP here.
 
DougIngraham said:
The PDP-12 is a LINC-8 implemented using TTL logic. Essentially a PDP-8/i integrated with a TTL implementation of the LINC. There are minor differences between the LINC-8 and the PDP-12 but for the most part code written for one will run on the other.

Extremely unlikely! If you trashed a couple of 8/i's for the backplanes you could rewire those and get a working backplane. You would have all the cards for the 8 portion of the CPU from the donor 8/i's. I don't know if there were any special cards in the LINC portion of the CPU but probably meaning you would need to fabricate those. This would be a few thousand hours of work when you were done. I suspect nobody would knowingly allow an 8/i to be abused in this way much less two of them.

Easier would be to make interfaces to the front panel and the Posibus and run simh on a Rpi. This is like the PiDP-8, 10, 11 replicas only your panel would be real. Still a significant effort.
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thankfully it's well out of my price range and even further out of the scope of my diagnostic and repair (or renewal) abilities, but i do very sincerely hope that someone is able to make a deal with the seller to keep it intact. it is nice to know that there are still some potential practical uses for it! :)
 
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