help needed, collectors value cpu??

[archeonist]

Hi all,

Found these boards at my local dump store, I got them for free. There are a few ceramic cpu's on there that seem rare, I never saw them. Now before I destroy any of them, I need to know if the collectors value is higher than the value in gold.
I specifically mean the two chips that are totally gold plated on the front and have the hp logo on them.
Thanks so far!

 

[g_axelsson]

I would put them on ebay with a start price of 10-20 dollars each.

Göran

 

[Anonymous]

You don't mean the complete boards do you Goran?

 

[g_axelsson]

No, just the CPU. Never seen that one before so I guess there will be some interest.

Göran

 

[archeonist]

Goran, if you have never seen these than they have to be rare I guess. I definitly won't crush them. Still I am wondering what these are, it must be from an early 80's computer.

 

[Anonymous]

It's a mix of HP Unix kit and DEC. The larger square procs are very high yield.

Taking them from the boards in one piece can be done but outside/inside a fume cabinet - you can melt the solder from behind with a blowtorch and gently lever the processor out.

It's messy and take care but you can get them out in one clean and tidy piece.

 

[Barren Realms 007]

Take very good care of those.

Go to CPU World and check the thread I had over there and see what I got for them a few years ago. They will sell good there if I remember right.

 

[Barren Realms 007]

It's a mix of HP Unix kit and DEC. The larger square procs are very high yield.

Taking them from the boards in one piece can be done but outside/inside a fume cabinet - you can melt the solder from behind with a blowtorch and gently lever the processor out.

It's messy and take care but you can get them out in one clean and tidy piece.

Don't use a blow torch. Try to use a heat gun with a desolder bulb to keep the pins in good shape.

 

[Anonymous]

Yeah that would work too.

 

[g_axelsson]

I'm using a heat gun as a torch easily scorch the board before all solder has melted. As much else, it's a craft and experience comes from training on different boards. It's also practical that you can turn it on or off with a flick of your finger.

Göran

 

[Anonymous]

True but it also depends on whether you have to do 3 boards or 100 boards. Time is a factor when you're not just playing around as a hobby.

 

[silversaddle1]

If you have a good heat gun, those can come off pretty quick. My heat gun will start fires if you leave it in one place too long. That's a good heat gun!

Scott

 

[Anonymous]

Maybe I'm confusing a paint stripping gun with a hairdryer. 8)

 

[g_axelsson]

If I had 100 boards with CPU:s I could sell for $15 each, then I think I prefer the heat gun. If it's a board with good gold on it it goes straight into the batch for external refining anyhow.

My heat gun has 2 kW of power and smooth setting of the temperature. When it glows orange from the heating coil is usually the sweet spot. You could also stand it on it's end on the table and with two pliers, one for holding the board and one for holding the component, it's a quick thing to remove gold plated connectors from floppy boards or other small boards with just a few components worth refining.

But as in so many other cases, your situation dictates which method is the best.

Göran

 

[Barren Realms 007]

If I had 100 boards with CPU:s I could sell for $15 each, then I think I prefer the heat gun. If it's a board with good gold on it it goes straight into the batch for external refining anyhow.

My heat gun has 2 kW of power and smooth setting of the temperature. When it glows orange from the heating coil is usually the sweet spot. You could also stand it on it's end on the table and with two pliers, one for holding the board and one for holding the component, it's a quick thing to remove gold plated connectors from floppy boards or other small boards with just a few components worth refining.

But as in so many other cases, your situation dictates which method is the best.

Göran

If you had 100 of them you probably would not be able to sell all of them for $15.00 because you would flood the market place.

 

[Grelko]

It's a mix of HP Unix kit and DEC. The larger square procs are very high yield.

Top picture (round gold plating) looks like a cross between DEC-NVAX and DEC-Alpha 21164a

Didn't find the other one.


CPU museum, many of them have pictures. Doesn't have every type though, but there's a lot to see.

http://gecko54000.free.fr/

 

[silversaddle1]

I just clamp the board in a vice so I can get to both sides of the board with the heat. Removal is much quicker that way.

 

[patnor1011]

I would not desolder them. Or better said, desolder what you can but leave CPU on board. Then cut cpu with 1-2 cm of board on sides. Some collectors prefer them cut out not desoldered.

Let them do it, you may apple more heat then you want and you can ruin that CPU. Some monolithic capacitors may get desoldered and value goes down...

 

[archeonist]

Patnor, I think I'll keep these and leave them on the board. In the years to come they'll only get more valueable.