In the 01 Sep 2012, cctalk Digest, Vol 109, Issue 1, Topic #2, Brenton Bryant wrote: "Recently I found an incomplete PDP-8/a and need the transformer and backplane to start working on it. If anyone has one or both then please let me know." What type of (incomplete) you PDP-8/A do you have? The power supply is different for the core vs. semiconductor memories and different backplanes used in these machines. There are three different power supplies available, depending on the backplane and the memory. The chassis you have should have a label telling what it is. The PDP-8/A uses the ?76? Power Supply AssembIy which includes: ?9192 Omnibus (10 module slots) G801? Power Supply Module (Semiconductor Memory) Power board Transformer AssembIy Line Set Operator's ????l The PDP-8?100, 8?400, 8?600, & 8?800 use the ?9?00 Chassis AssembIy which includes: ?9194 Omnibus (12 slots) G8016 Power Supply Module (Semiconductor ??????) OR G8018 Power Supply Module (Core ?emor?) Transformer AssembIy Line Set Operator's ????l The PDP-8?420, 8?620, & 8?820 use the ??8-? Expander Chassis AssembIy which includes: ?9195 Omnibus (20 slots) 2 G8018 Power Supply Modules (Core Memory) Transformer AssembIy Line Set Operator's ????l Power Distribution Assembly The above information is from the "PDP8A Minicomputer Handbook 1976-77." (http://www.bitsavers.org/pdf/dec/pdp8/handbooks/MinicomputerHandbook_1976.p…) Paul Anderson *may* be able to provide what you need -- he had a PDP-8/A chassis available at the end of last year and it *may* have what you need (i.e., power supply & backplane). So, what (incomplete) model PDP-8/A do you have? Thanks, Bob