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PDP-8/m Interest/Price Check (Canada)

K

Kalin

New Member
Joined
Jun 1, 2019
Messages
6
Location
Manitoba, Canada
I have a PDP-8/m that has been on the list of future projects for a long time now. It seems like it will be many years before I get enough free time to do the project justice(2 kids under 5 are surprisingly busy). I am trying to find out what kind of interest there would be and what their value is.

Here is a drive link to some pictures I took right out of storage. Drive link
I also took pictures of the original engineering drawings and prints. These have everything from circuit schematics and PCB layout to timing diagrams for the logic. Some of them have penciled in notes that seem to be from the original integration engineer. I have powered it up and it is not working completely correctly. I was able to get it to run a simple addition program, but it was intermittent. I didn't dig into the cause of the issue. It was more just to see if it was operational. I have a scope and could take some diagnostic measurements for a serious buyer

Boards: M837, M847, M848, M849, M8300, M8310, M8320, M8330, G111, PM80(This is a core memory module labelled 8kx12)

I'm not sure what the right price would be. I haven't seen a lot of complete units to compare for price. Here is a forum post from 4.5 years ago saying 3-5k USD and about how they were getting hard to find and how the price was going up rapidly.
Forum post
Here is a non working unit with no documentation but more boards that had a mouse nest and sat in 1 inch of water for a prolonged period and it sold for $2500 USD.
Ebay listing

Any advice or help on value would be appreciated.
Thanks,
Kalin
 
I think that stuff (including PDP-8 and PDP-11) gets listed (by "system breakers"?) at often extraordinary starting/buy-it-now prices in the hope that someone will be desperate for the part or impulse buy it; they are probably happy to sit on such items if they have a big warehouse.

BTW, yes, my interest in it "as a system to own" is triggered (a complication is I live in the UK)!

I am not 100% sure of the monetary value of the system; but would have to think long and hard about USD 3-5K... (esp. as there would be large additional shipping and customs charges attached).

The eBay link in your post is broken (or does not work from the UK) 8-)
 
Kalin said:
Out of curiosity, do you mean the listing are typically too high and don't sell or that the sold listings are more than you think they are worth?
Click to expand...

Both, actually.
People list things for crazy high (think a grand for a PC/XT) because they haven't got anything to lose and are willing to let it sit on a shelf for years (over a decade in some cases) and it isn't costing them anything. And every once in a while someone crazy, stupid, or drunk enough buys something for a lot more than they should.

There's also the issues of sellers using alts to create artificial bid wars, and ebay showing list price instead of (lower, often much lower) sold price in cases of "best offer" lots. For example I bought a board for my Nova for $45. But that's not what you'd see in the "Completed Listings" section, you'd see the listing price of $430, and that the seller had accepted a best offer. So you would be justified in thinking that I paid $350 or thereabouts.

(the second link of the original post, the one directly to Ebay, is also broken for me)
 
Roland Huisman said:
Just watch Ebay now, there is a PDP8/F and see what it does in a few days.
Click to expand...

So, it sold for US $8,100 with a bit of eBay sniper action in the closing seconds.

Things to note: I did ask the seller about its condition and it seems like it is in VGC.
 
Last edited:
Some people on Epay are crazy.

More than 300,000 PDP-8 machines have been produced so these are not a rare by any means.

Compare the $8,100 paid for the 8/f to the SBC6120 kits where only about 100 have been made and one just sold for under $700 on Epay.
Or look at the PiDP-8/I which Oscar still sells for $200. It works reliably, fits on your book shelf, makes no noise, doesn't heat up your room, and needs less than 12 watts of power.

Madness ...
 
thunter0512 said:
Some people on Epay are crazy.

More than 300,000 PDP-8 machines have been produced so these are not a rare by any means.

Compare the $8,100 paid for the 8/f to the SBC6120 kits where only about 100 have been made and one just sold for under $700 on Epay.
Or look at the PiDP-8/I which Oscar still sells for $200. It works reliably, fits on your book shelf, makes no noise, doesn't heat up your room, and needs less than 12 watts of power.

Madness ...
Click to expand...
But it's much more fun having the real thing. I had two 8i's many years ago. Then during a long distance move I sold one and donated the other to a good friend.
 
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