I have to agree with Razmo on this. Back then, the waveforms were defined in 6502 assembly language and then loaded at run-time, (i.e in the tune)
vFRTLSS....DFW +10,-10,+10,0:DFL 3,6,3,0,10,%00000101
...............DFL 50,50,0,%00000101:DFW +40,-40,$0400
...............DFL %01000001,$09,$CD,05,100
Above is the Preset for the bass in Ocean Loader 3. (vFRTLSS
I Wish!)
Those values got poked into predefined addresses in the SID chip, defining the waveform, pulse width modulation, etc... then:
fFRTLSS....DFW +40,-50,0,0:DFL 2,13,0,0,00,%00000100:DFW 1250
The Filter settings followed.... and finally....
NEWSPEED.....LDA #4:STA CalcDurations+1:LDX #0:JMP NewDurations
MARTSBIT0....DFL FLoad,VRC:DFW vFRTLSS
...................DFL For,6
...................DFL Rest,24
...................DFL Next
...................DFL CT,-0:DFW MC00
...................DFL CT,-4:DFW MC00
...................DFL CT,-7:DFW MC00
...................DFL CT,-4:DFW MC00
...................DFL CT,-5:DFW MC00
...................DFL CT,-2:DFW MC00
...................DFL FLoad,VRC:DFW vDRONE
...................DFL Transp,-0
...................DFL 19,32,Rest,32,Rest,8
...................DFL Code:DFW NEWSPEED
...................DFL Jmp:DFW LOADER0
MC00............DFL 31,10,26,4,31,4,26,2,29,2,26,2
...................DFL Ret
The Notes get played - 'MARTSBIT0 refers to the begining of the tune before it changes, (a la Martin Galway). The CT values define pitch changes for each time the notes at MC00 get played and the
values at MC00 are in the format 'DFL note, duration, note, duration, (31=D, for 10, 26=A, for 4, D, for 4, A, for 2, C, for 2, A, for 2 - then go to the 2nd CT line and do -4 semitones to the pitch, and
so on).
So! knowing that most SID tunes got programmed in a similar if not identical way, dunno how you extract that in a format for a modern synth....
I gotta credit Paul 'Paulie' Hughes for the above as he was the programmer of what we all now know as the 'Ocean Loader' (i.e. The wavey lines, play the music & pretty picture routine).
If you want to know more about how the SID chip got its preset sounds poked in -
http://www.pauliehughes.com