Hey guys, something I have wondered about, that hasn't really been discussed, is if the ADC could be used as a microphone input in cores. You can use a microphone with the Analogue NT and got me curious. I plugged a mic into the MiSTer ADC port and tested with the ADC input tester and if you shout then it does pick it up (although did seem quite faint).
NES is the one core that jumps to mind you could use a mic with, as it was famously used in the Famicom version of Zelda to be able to kill the "rabbits". Right now you can map microphone sound to a button, that generates a noise signal when you press, that was essentially what the microphone was doing, but where is the fun in that.
Microphone was also used in several Famicom Karaoke games (although we don't yet have the Mappers for them):
188 - describes the board used for Bandai's Karaoke Studio
514 - used for the game 小霸王 卡拉OK (Subor Karaoke)
515 - used for 패밀리 노래방 Family Noraebang, a Korean karaoke cartridge
517 - used for 까치와 노래친구 (Kkachi-wa Nolae Chingu), a Korean Karaoke game
I'm curious, what would it take to add support for an actual microphone? Would it be even be possible via the ADC? It is a a niche feature, but it would be an interesting way of using the hardware that hasn't been done on MiSTer before. Maybe an interesting proof of concept for someone wanting to try something a bit different with inputs on cores.