If my understanding of the ACI is correct, the output flip-flop that goes to the tape is inverted every time the $C000-$C0FF range is accessed. So to form a complete cycle of the waveform, the firmware makes two pseudo-reads in the ACI I/O range. My question is, how do you reset the flip-flop ? If by chance it's already set when you start to "save" a file, won't the whole recording be inverted? Does polarity matters or is it irrelevant?