I forgot to describe the hardware changes I made in the previous project log. The changes were made only to the logic PCB↔anode driver PCB connections (made with individual wires soldered between both boards).

The connector pins are numbered 1 to 16, where 1 is the +240V line coming out of the diode bridge near the big transformer, and 16 is the thick GND trace on the other side. I unsoldered all logic wires (pins 2-13 and 15) and left only +240V (pin 1), +5V (pin 14) and GND (pin 16) connected. Then I soldered the pins on the anode driver PCB except KSI2 (pin 4) to an Arduino Nano (pin mapping can be changed with the #define statements) and added a wire between GND and the Arduino to reference a common Ground in all my signals. The Arduino is powered from USB for now since that makes programming it much easier.

I decided to drive both anode shift register clocks (ASICh pin 2 and ASIN pin 3) from one Arduino pin mostly because it will take less cycles to shift the proper values in.