This is the front with the backplanes closed. Normally the cards are covered by plastic covers. The bracket to hold the memory selector cards in the upper left hasn't been reinstalled. The processor is running Focal. The lighting I used to get a decent picture makes the bulbs look dimmer than they normally look. If you look closely at the card in the upper right you can see a modification where a wire was added. The card is a W501 schmitt trigger. This is to connect contact P to the logic on the card. Later revisions of the card card have this change incorporated. In the next picture you can see the same pinkish wire that was used implement the wiring change. The modified wiring agrees with the later version of the processor schematics I have. Different color wiring was frequently used when wiring modifications were made. I don't know if it was changed in the factory or in the field.
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