Thanks for the reply and the update!
Another question if you don't mind.
I want to replace the Pi in my Picade with a NUC computer I have.
I want to reprogram the controller to use all of the buttons, especially the side buttons to use as left and right shift for Pinball games.
But I want to set the controller to set the on board amp to about 80% of full volume as I will control the volume settings via the NUC PC.
I assume that the part of the code I want to change is the following found in the picade.h file...
volume_target = EEPROM.read(0) & 0b00011111;
volume_eeprom = volume_target;
I also assume that the variable I want to set to a fixed value is "volume_target".
What should I set it to for 80% volume levels?