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Complete DEC PDP8/I System fair selling value

bellarmine

Member
Joined
May 5, 2014
Messages
21
Location
Canada
Hello all,

To start off, I'm a new user here, though I've been looking around for quite a few months. Hope no-one minds me posting this type of topic as a first post, but I do feel I have something rather special here.....:p

For a number of years now my Dad has been considering what to do with his vintage DEC PDP8/I mini computer. Recently we've both discovered it has quite a following, to put it mildly......:D What I'm wondering is, what is a fair value for the system? So far I've told a couple of younger people in the area (I'm in Northern Ontario Canada), and they seem to be thanking their stars that I even contacted them lol. As to what their offering, I'd like to ask for your more experienced advice on here before I make up my mind. I suppose I should also take into account how well the system will be cared for, I'm sure they would both treat it well. I'd like to cut them a break, but then I don't want to shoot myself in the foot so-to-speak, and give the system away.

Here's some more detailed background: My dad rescued the system in 1982 when it was being de-commissioned from the University of Toronto. He built a facsimile of a DEC rack from scratch with heavy-duty casters to mount the equipment in; he enjoys doing stuff like that. You can see this rack in the pictures. It all worked fine last time he shut it down, which was quite a while ago, was perfectly functional. The UofT used it in the Zoology department; it still has lots of data tapes on fauna, and my Dad tells me, even a couple simple games.

The system consists of the PDP8-I 12-bit CPU unit with 8KB core memory, dual DECTape drives, DMA unit, power supply, terminal, tapes, manuals, schematics and even the invoice and bills! You can't see the power supply, DMA unit and terminal in the pictures, they're in the back behind the tape storage. I've included a couple pics of similar DMA units as examples. It has been kept covered in a corner of our heated / cooled workshop as you can see. My Dad knows more about it than I do, he did it all before my time, I'm still learning.....:) Any technical questions, let me know and I'll ask him!


I see the core memory boards alone selling on eBay for between $300 to $400, not even working. Also in another thread I just saw a PDP8-M go for $2,800!!!!! I'm not sure how the M relates to the I, it seems smaller.

We've been meaning to find a museum that could use it - a piece of history with DEC gone now - but never got around to it. I'd rather not take it apart just to sell the core memory, I think that would be a crime! I've been trying to research it to see what would be a fair price for the entire system. He'd like a bit of money for it, but mainly a good home where it would be used and appreciated.


It's good to be here, I'm amazed what a following some of the older computers, parts and accessories has developed over the years. I feel to be fortunate to have grown up using an XT, so when I hear younger people these days asking what DOS is, it makes me feel old lol!

Please see the included pictures.

Cheers!:cool:

Bellarmine

7-Rack overall.jpg
2-Tape Drives.jpg
4-Computer Unit 2.jpg
6-Manuals.jpg
5-Tape storage.jpg
 
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DaveH

Experienced Member
Joined
Sep 1, 2012
Messages
173
Location
Scotland
Hi,
Now that's a VERY nice system. The PDP8/i is earlier and much more rare than the PDP8/e or m, also the DECTAPE drives are very scarce .
I can see many of the enthusiasts here drooling over these pictures :) .
As for its value, as a bit of a guess, if you put it on the open market I would be surprised if it went for less than 6 or 7 k$ and that's probably on the low side, others here may be better placed to more accurately value it ( David G your THE PDP8 man ).
Dave H
 

Qbus

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Salisbury Maryland
That’s a very valuable system, not just because the PDP-8 the drives and documentation double or maybe triple the value of the system. The problem is that the value of the system is at the point where it exceeds what many of us can afford to pay for it. Maybe the best way forward is to look into a museum or other tax exempt organization and look at donating it? Although I have no idea what Canada’s tax laws are like that would be a good option down here in the states. The other option may be to find someone like a member here who has been doing this sort of stuff for a while and who you know will provide a good home for the stuff and do a private sale to them. It’s just pure speculation on my part but would assume any member serious about owning a collection like that can come up with the two to four thousand dollars or more without much issue. You can get more by selling it on EBay but then you have no idea who will be getting it and what they will do, think the last thing you want to do is sell it to some hack who is just doing this for the money, good luck with figuring out what you’re going to do. Good thing is it looks like you’re on the right track.
 

Lou - N2MIY

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Albuquerque NM / Potomac MD
Bellarmine,

I would suggest you consider keeping this machine yourself and learning how to run it and repair it, unless you are in dire financial straits. My pdp-8/e has a similar story, coming home with my father in 1983 or so (he was a dec field service engineer). I run mine and consider it a family heirloom. The folks on this forum and I would be glad to help you get it running, but I'm sure your father is all the help you'd really need.

Lou
 

bellarmine

Member
Joined
May 5, 2014
Messages
21
Location
Canada
Hello Dave, Qbus & Lou,

Thank you VERY much for your replies, they sure give me something to think about! It's amazing, this time last year I would have thought myself fortunate to get $400 for the machine, but 4 ~ 7k, now that is amazing!

Dave, thanks for the compliment! "Drooling over it" lol, it's just amazing, I never expected such a reaction with this machine, looking online it's like people going crazy over them....;) I have noticed the 8/I seems to be the most sought after unit in the 8 series, even more so than the "straight-8" with the glass doors.

Qbus, you give me some good ideas there. Regarding a tax exemption, I think it'd be similar up here in Canada, but it wouldn't do much for me at the moment. You're right, I need to find someone who will really attend to it's "care and feeding" so to speak....:), I won't sell it to a speculator, that would be just plain dumb. The two chaps I know up here would take good care of it I'm sure, they say as much. One even says he'll donate it to a museum if at some point he can no longer continue to keep it, which sounds fine to me. However, I don't know how much they can afford, being students currently, so money is tight for them. One has made me an offer of $400 (!), he said he could scrape up some more if that's not enough, he calls it a once in a lifetime chance for him! I'll have to talk to them and maybe do it on time, or something...?

Lou, that is a good thought about keeping it. I've expressed an interest in seeing it running, I've thought about it over the years, and so has my Dad, but we both agree we just don't need it, we have a lot of other things on our plates, and if I haven't gotten to it in the past 30 years or so I probably never will!....:p That doesn't mean I'd not be interested in it after the sale, I'd enjoy taking an active part in helping the new owner getting it running. My Dad decided years ago to donate or sell it, and he still thinks that's what we should do. Rather than it just sitting in the corner, better it go to someone who knows all about it and can actually use it and learn from it.


So far, seems to me the bottom line is, if I were to let the system go for anything under a couple grand I'd be REALLY shooting myself in the foot, regardless how much they say they really want it.

Thanks again for your input, keep it coming if you don't mind! It might be a few months before I actually do anything, but I'll be talking to the other two chaps, see how that works out, and whatever happens I'll keep you all informed here.

Cheers! :D

Bellarmine
 

pontus

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Aug 13, 2008
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Uppsala, Sweden
Hi

I just want to give you another datapoint, a recent sale of a PDP-12 for 16,400$ : http://www.ebay.com/itm/161199469414

The 8/I and PDP-12 are from the same era, use roughly the same components and according to at least one source, about the same number was made (arround 3500, not many!). I would say that the PDP-12 is probably more sought after and fetches a higher price. Maybe due to the impressive front panel but more due to the graphics capabilities. That is however my own opinion.

Your 8/I, on ebay, would probably fetch a lot more than the 2,800$ of the 8/M but less than the 16,400$ of the PDP-12.

But I agree with Lou, unless you need that money, keep the machine, give it some love and pass it on to your kids :)
 

Uniballer

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Apr 3, 2014
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Location
USA
I would say that the PDP-12 is probably more sought after and fetches a higher price. Maybe due to the impressive front panel but more due to the graphics capabilities.

The PDP-12 was the follow-on to the LINC/8 (even rarer). It can run DIAL, and LINC software, as well as read LINCtapes. Of course, it can also run any of the PDP-8 software.

Around 1981 I helped a guy who needed to run some DIAL software get a machine going. The system had a whole cabinet full of fixed-head disks (DF32?), and I don't know how much core. The vector graphics display was down, so he suggested using an oscilloscope to view it. We snagged a Tektronix 475A (pretty new at the time) from one of the university labs, but the horizontal output had the wrong polarity, and thus the text was a mirror image of the correct dot pattern from right to left. I realized it would work to flip the scope over and invert the vertical channel so he could read the display. Fortunately the blanking signal (Z-axis) had the right polarity.
 
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Jack.

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Aug 13, 2013
Messages
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Northern Italy
And when i see these for sale, i really feel like:"WHY WHY WHY WHY DO I LIVE IN THIS ARSEHOLE? :angry:"
-
Getting that would be really interesting...
Whatever, i think it's better if you keep working on it. Don't sell/throw it away, it's part of your family.
 

gslick

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Dec 30, 2010
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Seattle, WA
The system consists of the PDP8-I 12-bit CPU unit with 8KB core memory, dual DECTape drives, DMA unit, power supply, terminal, tapes, manuals, schematics and even the invoice and bills! You can't see the power supply, DMA unit and terminal in the pictures, they're in the back behind the tape storage.

What kind of terminal do you have with this system? Is it something interesting of a similar vintage, or something newer and not particularly interesting?
 

bellarmine

Member
Joined
May 5, 2014
Messages
21
Location
Canada
Thanks again for the replies. The price keeps going up, I'm simply speechless, this would be a great help to my parents at the moment, but only as long as I find someone who will cherish it...:^)

Yes, that PDP-12 is a nice looker, still that price is unbelievable! So mine is somewhere in there, very good to know. 3500 is not very many at all, and how many wer4e simply thrown out when they were de-commissioned? Maybe only a couple hundred left. Also, someone mentioned that the DMA unit / TC08....???, which is present, is very rare and hard to find? See a few more pics.

Regarding "speculators", I was wondering how do they make a profit if they buy at those 5-digit prices, isn't their objective to get it at as low a price as possible?

I feel sorry for you Jack, yes the shipping would be astronomical, and it would probably arrive in pieces lol....:^) Best wishes in your search!

Gslick, about the terminal, it's in back of the rack and I can't see it very well. When I get the PDP out at some later date, I'll be sure to take LOTS of pictures, including the terminal. What I can see is it's got black keys, a dark charcoal-grey upper case, and the bottom half is bright orange. Here's what my Dad says: Notice there's a blank space in the rack above the PDP-8 unit, he made that space for the terminal. It didn't come with one from the UofT, so a friend gave him one, which fit nicely in the rack. Later the friend decided to take back that one and gave him another, the one he has now. Unfortunately it was about an inch wider, so it no longer fits in the rack. He says it's "just a terminal, standard run-of-the-mill", he never saw any brand name on it, it's about the same age, if not older than the PDP itself. He says it "looks like a flint-stones type retro style", kind of similar to an ADM-3A. Hope this helps!

Bellarmine

1-DEC PDP8-I.jpg

3-Computer Unit.jpg

8-(EXAMPLE) DMA Unit.jpg

9-(EXAMPLE) DMA Panel.jpg
 

MauriceH

Experienced Member
Joined
Apr 2, 2014
Messages
367
Location
Dordrecht , Netherlands
Very nice complete PDP8 you have.

You started with XT, then PDP is not to hard to understand.
For selling points, keep in mind the money is gone in few day's maybe you buy a TV set from it, that last 5 years max.
A car.. that also a throw a way item, after few years useless.
The PDP8 as you have will alway's last and an Icon of times that were the beginning of.

Have fun with the PDP8 first.
Then after some time you realy find out that it is not your thing sell it as it is.

That complete to get starting to work on it after a very secure safe startup.
Becareful and Do NOT put the plug in right away.
All capacitors in the powersupply are very low on value and have to recharge first time.
Like a dead battery it is and with powerup.
A slow start with no boards in the system or detached from it.
HOW?
Put an old (wire) Lightbulb in series with the powersupply.
Line 1 -------->Lightbulb 60W----->PDP-powersupply ---->Line 2
That will limit the current, if PSU is shorted the light will full up and the curent is max lightbulb value.
P = UxI - 60W=230Vx I => Current max is 260mA
If PSU is good the light will dim after seconds, if stay bright there is a problem.

Then check the voltage levels.
Also with the rest of the equipment.
same way.
ofcourse with running motors like the dectape the light will be bright.
So check only with minium attached to the PSU, that way also the boards that are NOT attached to the PSU
are safe when the levels of the PSU are wrong.

Have fun with it.
 

Jack.

Experienced Member
Joined
Aug 13, 2013
Messages
221
Location
Northern Italy
I feel sorry for you Jack, yes the shipping would be astronomical, and it would probably arrive in pieces lol....:^) Best wishes in your search!

Shipping?
Are you kidding me?
I could buy an Airbus with the money i'll throw in the shipping alone. And it would be safer if you just put the PDP in a stonethrower and sent it flying across the ocean, it would get here less scattered for sure. :D
Anyway, thank you, but it's gonna be hard... :(
 

tradde

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bellarmine said:
Also, someone mentioned that the DMA unit / TC08....???, which is present, is very rare and hard to find? See a few more pics.
It looks like this has a TC01. I remember that display. A TC08 had a front display up top with all the lights. Both are very desirable.
 

bellarmine

Member
Joined
May 5, 2014
Messages
21
Location
Canada
Thanks for the power-up advice Maurice, I was thinking along the same lines, especially as it was known running for my Dad a while back, and has been stored carefully since, it should power up ok with just using my Variac on the power supplies.

Regarding keeping it, me and my Dad have talked about it, and again we just have a lot of other things on our plates, we haven't gotten to it for 30 years, I'd enjoy selling it to someone who will get it powered up and use it, and share it with people, rather than sitting covered in a corner.........:)

Thanks for the model number Tradde, OK so it seems I do have a TC01. The pictures are not actual, as the unit is mounted in behind and I can't see it yet, but my Dad says it looks like those pictures, whole lot of wires lol.


Shipping?
Are you kidding me?
I could buy an Airbus with the money i'll throw in the shipping alone. And it would be safer if you just put the PDP in a stonethrower and sent it flying across the ocean, it would get here less scattered for sure. :D
Anyway, thank you, but it's gonna be hard... :(

Jack, that's a real funny one! I'd like to think that's an exaggeration, but there are some horror stories out there I'm sure.......:^) I meant to mention, my Dad has a number of other DEC "MicroComputers" as they're called from the 90's: a Celebris XL 5100, our very first Pentium (woooo!), a Prioris LX 5120, and a couple Personal Workstation 200i's, Dual Intel PPros - upgraded them to 533mhz via a PowerLeap, look exactly like your 500a with the doors. Also have a Prioris XL6200, that we managed to shoehorn a 933Mhz P3 Tualatin into it (ask me how I did it), 1GB ram, and dual RocketRAID 1640 SATA controllers running 4 - 2TB and 2 - 1TB Seagate drives - 10TB in a server from 1998, pretty good eh?

Also have a multiprocessor daughterboard for a DEC HX5000 server with 512kb cache modules - anyone want it let me know........;)

Cheers!

Bellarmine
 
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Jack.

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Northern Italy
Jack, that's a real funny one! I'd like to think that's an exaggeration, but there are some horror stories out there I'm sure.......:^) I meant to mention, my Dad has a number of other DEC "MicroComputers" as they're called from the 90's: a Celebris XL 5100, our very first Pentium (woooo!), a Prioris LX 5120, and a couple Personal Workstation 200i's, Dual Intel PPros - upgraded them to 533mhz via a PowerLeap, look exactly like your 500a with the doors. Also have a Prioris XL6200, that we managed to shoehorn a 933Mhz P3 Tualatin into it (ask me how I did it), 1GB ram, and dual RocketRAID 1640 SATA controllers running 4 - 2TB and 2 - 1TB Seagate drives - 10TB in a server from 1998, pretty good eh?

Also have a multiprocessor daughterboard for a DEC HX5000 server with 512kb cache modules - anyone want it let me know........;)

Cheers!

Bellarmine

Woah, sorry if i saw it so late. I was kinda busy lately. Damned school.

Yeah, that's exagerated... Or maybe not ;)
Meh, that's a load of stuff... The PWS 200i's look pretty good, i'd love to get one someday... But, well, my wishlist is kinda long, and my collection is all high-end workstations, MSXs and consoles :p
 

bellarmine

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Canada
Woah, sorry if i saw it so late. I was kinda busy lately. Damned school.

Yeah, that's exagerated... Or maybe not ;)
Meh, that's a load of stuff... The PWS 200i's look pretty good, i'd love to get one someday... But, well, my wishlist is kinda long, and my collection is all high-end workstations, MSXs and consoles :p

No problem about the delay Jack, always busy myself.

Yes, my Dad is a bit of a DEC fan, never dreamed in 1995 that they would vanish from the face of the earth 3 years later, 2nd biggest computer company in the world - poof. My Mum had a contact she used to call for tech support for my Dad, at the end the chap would answer the phone with "Hello, this is HP, formerly Compaq, formerly DEC, formerly.....I think that's enough now. And I haven't even moved my desk!" Crazy lol.

I was just posting them for fun, my Dad wants to keep the computers, he spent $10,000 on the XL5100, how about $3,500 for 32MB RAM wooooo, unbelievable! I bet our Celebris XL5100 is about the only Pentium in the world that has never had win9x on it, still running WfW 3.11 lol.

I haven't forgotten about the PDP, still thinking about it, and talking with some other people, will keep you all informed soon as things progress.

Cheers!
 

Jack.

Experienced Member
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Aug 13, 2013
Messages
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Northern Italy
I'm late again! ^^

I guessed so :p

Well... i have a Pentium MMX "box" (It's called frankenstein, actually. I'll post a photo someday...) wich never ran anything but DOS. Now it boots directly into Telix.

That's an awesome beast... Good luck!

TTY Soon!
 

bellarmine

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May 5, 2014
Messages
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Location
Canada
PDP-8/I Sold!!

PDP-8/I Sold!!

Hello All,

It's been a while since my last post, but I've got a big update - I've sold my Dad's PDP-8/I to a member on here!

The chap came to look at it back in May, decided it was just what he wanted, came back in June and loaded it up on his truck. We carefully took it apart from my dad's rack for transport, so it was sure not to get damaged during transit. He's real happy with it, got all the books, tapes and everything, and me and my Dad are happy it's gotten such a good home!

I believe you'll be hearing from him on here sometime when he gets it up and running, guess it's going to take a bit of work to check it out after being mothballed for almost 35 years (longer than me lol). Might not be too bad I'm hoping, as upon opening the plastic it was even better preserved than me and my Dad had hoped, absolutely spotless inside! I was looking at that other PDP restoration from the Rhode Island Museum, theirs had a lot of corrosion, but ours was really like-new inside.

I took a whole pile of pics before he took it away, I've included a couple of it actually un-wrapped for the first time in my existence lol! Let me know if anyone wants to see more of them. By the way, the terminal was a "Lektromedia LEK-100", real odd-ball can't find it anywhere.....:D

I would like to say thank-you to all here for helping me and my Dad sell our PDP-8, we'd never have gotten fair value without your valuable input, it is much appreciated! :D

All the best,

Bellarmine

4593-Rack F Top.jpg

4594-Rack F Bot.jpg
 
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pontus

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Messages
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Uppsala, Sweden
Congratulations :)

I'm curious about the final selling price, since I gave a rather big interval in my estimate (between 2,800$ and 16,400$) I'm going to guess that you got 8,000$. Lets see how close I was.

It's ok if you don't want to disclose it, perhaps the buyer can?
 

bellarmine

Member
Joined
May 5, 2014
Messages
21
Location
Canada
Hi Pontus,

Thanks for the congratulations, much appreciated!

I just got in touch with the buyer for you, he said he doesn't mind if I mention the selling price.

So Pontus, what is the magic number? You were within 10% of it, excellent guess! We got $8,900 for it, we were asking $9,800, I think it was a fair deal all around.

He told me he's going to be looking into what's invloved in getting it running next week or so, hopefully you'll be hearing from him on here sometime. Here's hoping it's problem free and just needs some standard Variac-ing to boot up this gem.........:)

All the best!

Bellarmine
 
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