PDP-11/45: CPU Backplane and logic

Mounted the CPU backplane, and slotted in the CPU and MMU logic cards. The empty slots on the right are for the FPU -- I have those on hand but figure I'll wait to slot them until I've got the basic CPU up and running.

One kind of interesting thing: the logic boards were stored vertically for several decades, and on some of the cards with plastic ribbon-cable connectors the plastic seems to have flaked and shed and fallen down the boards. The flaky substance then grew some impressive crystals between some of the solder traces. Scrubbed these out with some anhydrous IPA.

A tip copied from a fellow restorer: Alconox detergent for removing grime from various plastic components. Parts soaked overnight come out looking nearly new (here you can see the cleaned plastic card guides).

Also pictured here are the characteristic bloody knuckles that are obtained whenever wrestling with PDP backplanes, logic cards, and terminators in close confines. That really takes you back...