Register Construction: B and C 8-bit Registers
The first step was to solder down the LEDs, ribbon cable sockets, relay sockets and finally the wire wrapping posts. Here's some pictures, front and back, of the card following this round of soldering:
This time I've also made a small change to the layout of the relay sockets. On previous cards I've used three sets of triple pin sockets laid out in a 'U' shape. This has always been a bit fiddly and time consuming so I've simplified things this time by just having two rows of five pin sockets. The same relays will still be used but whereas before the bottom middle socket position was unused/unconnected now the two positions one up from the bottom on the left and right are unused. This means wasting one extra socket per relay from the strip of 32 (and those turned pin sockets aren't cheap) but it saves loads of time and frustration when soldering the sockets down.
This card also has extra diodes (in addition to the usual 'flyback' diodes over the relay coil) to stop back feed on the B and C bus lines. At the end of each of these back feed diodes is a single wire wrap post. These were particularly tricky to solder down and so some of these are a bit wonky ... the posts tended to get wonkier as my finger got progressively more burnt. I think in future I'll try and ensure I always solder these posts down in pairs (like the ones up the middle of the card) so I can hold the part in place from one side whilst solder tacking the other side down.
Here's a picture of the LEDs viewed from the front:
The next stage of construction was soldering down the power and ground lines on the solder side of the board:
With all the soldering done the final steps are to lay down all the wire wraps. This is done in stages by laying down each family of related connections then laying the next family on top of that. Here's four pictures of the wraps building up over time:
Finally here is three close up pictures of the final wire wraps (click each for a larger version):