Update: short update today. Added a lamp test feature to test all of the light-emitting elements on the PCB. How do I accomplish this? Feeding 8s to the 74LS47 during the normal 61 Hz refresh cycle, turning on all of the LEDs directly controlled by the MCU, and then performing a 35 Hz refresh of the day LEDs (required as they are controlled by the 74HC238 and therefore can only be turned on one a time normally).

My camera appears to have caught the day LEDs between refreshes so some of them appear to be off - but to the human eye, they appear to all on at the same time.

How do you trigger the lamp test? Press SW7 to dim the lights, then press SW8 to activate the lamp test. Press any button after that to exit the lamp test.