I Need Help Restoring pdp 8/e

[NicolasF]

Hi,

We have a pdp 8/e system in our museum. The system is currently dissasembled (there are no cards in the main card cage). I was able to locate the cards but since I have no experience with this kind of system there are a lot of things I'm not sure how to do. Here is a list of issued I need confirmation before proceding with this project:

1- There is a type of connector on a side of the power supply and I found what seems to be a jumper that goes there but it was not connected. (I'll attach a picture of it circuled in red for better reference). What is the function of this connector? Should I connect this?

2- Are the slots of the main card cage all the same? I mean, is it ok if I connect the boards in any slot or each card should go in a specific slot?

3- I found the memory cards in a different card cage, not in the main one (by main I mean the one that has the control panel with the lights and switches). All pictures I've seen only show the CPU cards and the RAM cards in the same card cage and not on different ones. Probably someone just put them there so that they don't get lost during transportation but I'm just guessing here.
(I'll attach a picture of this card cage and the current cards installed in it, there are also some unknown connectors on the power supply of this cage)

4- How should I test the system once it has been assembled? I was thinking about writing a simple loop program that would initialized memory positions from lets say 1 to 10 and then examine the memory to see if they numbers are there.

Thank!

 

[m_thompson]

You can find the manuals for the 8/e here: http://www.bitsavers.org/pdf/dec/pdp8/pdp8e/

You can start by removing all of the boards and testing the power supply. If it doesn't regulate correctly you could damage the boards.

If the system has not been powered on for many years, there is a procedure for reforming the electrolytic capacitors that can reduce the probability of damaging the capacitors when you first turn it on.

The manuals describe the recommended board locations. You could start with just one of the core memory board sets and the minimum of CPU boards. One of the core memory board sets will be jumpered to start at address 00000, so that is the set to start with.

There is a listing of simple toggle-in test programs that are very helpful for debugging here: https://www.pdp8online.com/pdp8cgi/query_docs/tifftopdf.pl/pdp8docs/toggle_in_programs.pdf

You can read about restoring my 8/e here: http://www.ricomputermuseum.org/Home/equipment/dec-pdp-8e/pdp-8e-restoration-log