Hi Jonathan, Let me know if this diagram has what you are looking for: https://github.com/erangell/VCFEast2019/blob/master/KeyboardDecoder.png When a key is pressed, it will connect a Pad to a Rail, so the Q key connects pin 12 to pin 21. The decoder can then send current through each pin and see if any of the other pins are receiving the voltage. Control and Shift can be read independently of other keys using pins 2, 3, and 23. My encoder board is from The Keyboard Company, model # KB20-0016-00. The encoder chip is labelled: 331-0931-B KR3600-070 SMC 8151 with another marking of 8-82. Eric