[SMS/VGM] Investigate Rhythm Mode F-ON write values

[bazz1tv]

https://github.com/bazzinotti/XPMCK/blob/7f56a09af17df5358c518addeb77aeb95826091f/src/vgm.e#L714-L716

These are not the same values as mentioned are required in the "Address/Data" table at http://www.smspower.org/maxim/Documents/YM2413ApplicationManual#iii17

I'm curious about this. I also noticed that our Rhythm Mode reference material YS 1 uses different values too!

YS 1 2nd VGM (decoded using vgm2txt)

Reg 0x16 Data 0x20
Reg 0x17 Data 0xB0
Reg 0x18 Data 0x01

Reg 0x26 Data 0x05
Reg 0x27 Data 0x01
Reg 0x28 Data 0x01

XPMCK (re-arranged)

Reg 0x16 Data 0x20
Reg 0x17 Data 0x57
Reg 0x18 Data 0x57
Reg 0x26 Data 0x05
Reg 0x27 Data 0x01
Reg 0x28 Data 0x01
# there are later writes to these registers as well .-.
# I haven't learned why

SMS Power

Reg 0x16 Data 0x20
Reg 0x17 Data 0x50
Reg 0x18 Data 0xC0
Reg 0x26 Data 0x05
Reg 0x27 Data 0x05
Reg 0x28 Data 0x01

Is there an audible difference from different values!! It's worth an experiment!!