Here’s everything you never wanted to know about the APU, which makes the sounds on the NES. You can promptly forget everything once you start using a tool like Famitracker. Go download this Sound Test NES file, written by SnoBrow I rewrote it so it would work on a real NES and all emulators https://github.com/nesdoug/NES_SOUND/blob/master/SNDTEST2.NES Pressing ‘select’ … Continue reading 14. Intro to Sound