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Showing posts from June, 2014

Register Construction: Completed A and D 8-bit Registers Full Test

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The A/D Register card is now complete and looks like this:
As usual I've put a video together that demonstrates this card in operation. This time I don't show testing the card on its own as the A/D register is pretty much the same as the B/C register shown last time around ... needless to say I did test the card fully off camera and everything worked fine (first time believe it or not). As I've now got the three ALU cards and four registers I'm finally able to perform multiple operations and accumulate the result. I demonstrate this in the video by performing a series of arithmetic operations by hand.

One thing I was curious about is how much heat is being generated by the relays when as many as possible are turned on and how much heat can escape from the enclosure. My multimeter has a handy temperature setting so I stuck the probe in to the card pack and turned everything on:
The temperature steadily climbed over a couple of minutes and eventually levelled out at 41 d…

Register Construction: A and D 8-bit Registers

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I haven't posted in nearly a month but in between bouts of enjoying the rare British sunshine I've been  plodding away at the A/D register card and it's now finally ready for testing. The A/D register card is effectively a slightly simplified version of the previously covered B/C card and so a lot of the content in this post is going to be pretty similar. Despite this though I'll go through all the steps taken to construct the A/D register card for the sake of completness ... primarily in photos and then with extra text where anything odd or different came up compared with the B/C card.

The first step was to solder down the LEDs and ribbon cable sockets. Here's some pictures, front and back, of the card following this first round of soldering:
I've continued the trend of applying a line of super glue to the board when placing the LEDs (to stop them moving about while soldering) and I've also removed the negative wrapping post behind each LED again to make …