In my quest to get the input system working, I wired up the keypad and 5-bit baudot encoder to do some testing. I have it bread boarded with a little LED board I created to help with bread board testing that I call Dave's Breadboard Led Trinkit (BLT for short!). The encoding is not standard Binary Coded Decimal(BCD), but a variation of the 5-bit baudot code popular at the time the WITCH was built. I really could have made the diode steering board a lot smaller, but as I noted in another log post ( Keypad Encoder ), I had a bunch of vintage diodes that I thought might look cool to use...