Showing posts from April, 2016

W Backplane Construction & Power Distribution

Before I can test the new decoder, sequencer and controller cards all working together with the rest of the computer I need to construct the 'W' backplane which the new cards sit on. Generally this backplane is similar in design to the 'Z' backplane that the ALU cards and A/D and B/C register cards sit on. However, whereas each card on the Z backplane has the exact same connectors the W backplane is slightly more complex as the sequencer and control units are spread over two cards each requiring a different set of connectors. The upshot is that the backplane has three 'W1' card slots and two 'W2' card slots. A diagram explains it better:
On the Z backplane each individual connector is joined to it's siblings via a ribbon cable that runs the length of the backplane. The only oddity is that at the bottom of the backplane each pair of wires in the ribbon cable need twisting so that each line comes out in the right place. As you can see from the diagra…