PDP-12 Restoration at the RICM

Michael Thompson michael.99.thompson at gmail.com
Sun May 10 09:42:43 CDT 2015

The RICM is restoring a PDP-12. This system was manufactured in December of
1972, so it is very late in the life of the PDP-12. The Priority Interrupt
and the Data Multiplexer are hardwired in two extra columns in the
processor chassis. These options were in separate chassis in earlier
models. It came with an Omnibus expansion chassis that connects to the
Posibus from the PDP-12. The LP01, RK05, and PC04 controllers are in the
Omnibus chassis. The VR14 and TU56 controllers are in the processor
chassis. We got the LP01 too.

The donor did a great job of preserving the machine, and has all of the
original documentation and software. The processor and RK8-F prints are
newer than what I can find on the Web, so I will scan them and send the
PDFs to Bitsavers.

Yesterday we reformed the caps in the power supply and powered it on for
the first time in 24 years. It is going to need some debugging, but it does
show some signs of life.

The CRT in the VR14

Michael Thompson

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