Is there a possible way to do this without modding the system? Pin 54 seems to be the pin that takes the audio info in the NES. And that pin 54 connects to the expansion port pin 9. Would it be possible to like plug something into the expansion port that ran pin 9 (MMC5 audio data) to pin 21 (audio out) so that the NES can play MMC5 audio without modding the NES in any way (just plugging something into the expansion port. thx ^_^