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PDP-12 - S/N 103

PDP-12 and PDP-9 at Olles cellar
During the autumn of 2014 we was contacted by a person that claimed to have a PDP-9 and a PDP-12 computer that was sitting in his cellar and now he was unable to keep this storage. That sounded almost too good to be true. But it was true. Actually it was one and a half PDP-12. One complete with two TU55 and a VR12 and one where only the essential parts were rescued, like the logic, the VR12 and the two TU55 drives. Then there were a PDP-9 with a TC02 and two TU55 drives. Since our museum already had a PDP-9 it made little sense to have another one so this one has been take care of by Anders.
PDP-12 at the musuem

The history behind the machine is that it originally was used by AGA in Täby and the given away to the Stacken computer club at the Royal Institute of Technology in Stockholm. Around 1996 Stacken got expelled from the space they had and had to get rid of most of their big computers. A lot of old computers were dumped in containers all over the campus area. 

But the donator rescued this PDP-12 (and the PDP-9). To be able to ship it, it was slightly dismantled. The power supply was removed to make it less heavy and the control panel was taken of to not damage it. But all parts are preserved so it should be able to make it 

We brought the one and a half PDP-12 to our museum where it is now awaiting restoration, starting with the power supply, replacing the PCB filled AC capacitor in the ferro resonant circuit of the power supply and then reforming all electrolytic capacitors.

Below is the fantastic control panel of the PDP-12. It was removed prior to shipment back in 1996 and has never been reinstalled since then.

Control panel

Spare logic
The spare logic from the "half" PDP-12. A very good source for spare parts when trying to revive this fantastics machine.

Core memory boards
With the machine came several core memory boards. But it turned out that all but two of them were from the PDP-15 computers that had been scrapped by Stacken at the same time as this PDP-12 and PDP-9. So only two 4k core memory modules would fit the PDP-12. But that is enough anyway. But we have five extra PDP-15 modules that we is available for trade!

This machine has serial number 103.
Serial number