DEC microPDP-11/53 Rebuild

For some time I've been interested in getting hold of a DEC PDP-11, I find it to be an interesting piece of history since the C programming language was originally written on one. The first port of Unix was on a PDP-11. Anyway, I have just managed to buy enough bits to build a viable machine. I say 'bits' because I have not bought a working machine, but components taken from several machines. So I need to figure out how to put it all together.  Obviously this is one of the most recent versions of the machine from the 1980s, not one of the blinky light machines from the 70s.  Still, if I'm going to own a minicomputer this will fit easier into my house...

Anyway, the first thing was to put the backplane into the BA23 mounting box, the backplane also has a distribution panel attached, which exposes the connectors for the disk drives amongst other things.  Here is a start:

Starting to put the cables in

I have put the power supply in place.  But I have not worked out which way round the front panel ribbon cables go yet.  The cable which connects the power supply to the backplane seems to only go one way round which is helpful.  The fan was already in the mounting box, as you can see by the level of dust!  I also have attached the front panel:

The front panel

I have the outer enclosure that this mounting box goes inside, but have not found the cover that goes on the front yet.  I need to look for that.  This is a photo of the other side, showing the installed backplane:

The backplane

I need to keep working out where the cables go - and document their positions for future reference.  But my biggest problem so far has been the power supplies.  I managed to obtain two.  When I bench tested them, the first one went bang and threw out a cloud of smoke.  I believe that this was a large capacitor on the incoming power supply which exploded.  However, after that the power supply seemed to keep working.  The second power supply made strange chirping noises, but also seemed to work.  I think that it might be on its last legs.  I will need to get a stable power supply before I can switch it on.

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