[sdiy] Yamaha TG-77 hardware mods?

[Glen]

Hello,

I'm looking for any information regarding hardware mods for a Yamaha TG77
synth. I'm particularly interested if anyone has ever:

1)  customized the internal wave ROMs

2)  created custom wave ROM cards, or even better, wav cards using ram instead.

3)  created a card reader, emulator, or programmer for a PC

4)  created an SRAM based wave memory that could be easily loaded with
custom samples

5)  Has anyone ever documented the format that waves are stored in? (Either
internally, or on an external ROM card.)

6)  added digital audio outputs

7)  Anything else of note, regarding an SY77 - TG77 - SY99 modification.


thanks,
Glen