FME-07 sound emulation

[Shiru]

kevtris said on IRC that he tested FME-07 and it indeed have complete AY-3-8910 inside, with noise and envelope.

I've made test ROM, which plays AY music, and tried to run it in all recent emulators. All of them (with FME-07 support) has limited support for sound part, usually just tone channels, and sometime noise also.

Here is my test ROM, and MP3 recording of how it sounds on actual AY (with slightly different pitch and speed). It should help for emulator authors, if they want to improve emulation accuracy. It can be easily done, there is plenty of ready-made accurate AY emulators around.

note: the FME-07 probably using YM2149F core instead of actual GI's AY. These two has slight difference in sound, because envelope on YM has 32 steps instead of 16, with double speed (so no difference for programmer).