Joe Allen

Nice! Interesting that you got a bad 4017.. But the board has other problem. It cannot run the build in problem (enter 10 then run). I will start a new post. There is a tuning step: you need to find relays that work correctly in the flip-flops by swapping them. There is some text about this in the build guide.

Hi, Why don't you contact me on Tindie- I can send you a replacement U24. Also they are easy to program right on the board if you have the PICKit: buying a blank part and programming your own might be faster if you are not in the USA. Thanks, Joe

Slow Tetris, this is awesome! We need a video :-)

Oh, you are correct, the documentation is wrong. When ROR is set, the input is from A_DATA. I think I originally wanted to rotate the add/and output for more instruction possibilities, but this ends up requiring more relays. The reason is that the condition logic wants inverted carry, but it's not available at the add/and output (but is available in A_DATA). I think I also considered putting the rotate logic in the A_DATA path, but then you wouldn't have access to the carry out from the rotate. The...

jameco has ULN2803A: https://www.jameco.com/z/ULN2803A-Major-Brands-Transistor-Darlington-NPN-50-Volt-0-5-Amp-18-Pin-PDIP_34315.html Amazon.com has them also.

Adafruit has L293, but very expensive: https://www.adafruit.com/product/807 Amazon.com also has them, much cheaper. Just search for L293.

Adafruit has L293, but very exxpensive: https://www.adafruit.com/product/807 Amazon also has them, much cheaper. Just search for L293.

Adafruit has L293, but very exxpensive: https://www.adafruit.com/product/807