[sdiy] breadboard Module and yamaha fm hacks on pf15

[Peter Blackett]

Hi,
not sure if my original post got through ?
its a strange coincidence but I got given recently a breadboard module
with + - 15v psu in it .
with regard to the recent discussion about Yamaha DX and fm synthesis 
I've aquired a Yamaha pf 15 piano that uses the fm synthesis .
[ similar vintage to the dx 7 I think ]
seems like the parameters for the preset sounds are stored in eprom .
so I'm wondering if by altering the eprom I could get different sounds ? 
I guess trying to work out which byte related to what fm parameter is
going to be difficult .[yes I have got the schematics ]
I'll let you know when I manage to copy the eprom data [ its soldered
directly onto the pcb ! ].
regards Peter