So as I understand this the I/O map as we understand it thus far for this card is : 0x220 is AY control 0x221 is AY register access 0x222 is for DAC writes 0x223 is a mystery or possible alias for 0x222 I think, 0x223 is only for triggering something in GAL. Log with many writes in 0x223/0x222 …