ComputerVoltageSources

this is posted more to entertain than inform...

but 
 at this address:

http://www.musicsynthesizer.com/DIY/Mike/DrMabuse.htm

third picture down...

you will see a box i built in the early nineties to interface the user
port and the SID chips of a C64 to my analogs. This was done (as are
most of my goofy-ass contraptions) to render a composition i was
working-on at the time. (named: 'Mulberry House' for the erstwhile
location of the Electronic Music Studio at one of my alma maters)

  The piece was eminently forgetable but software for the interface
still exists....... ON DATA CASSETTE! (you can see the corner of it
poking into the pic at the upper right)
  It turned out that the data casette proved to be a more durable and
robust medium (after 20 years) than the the 1541 5-1/4 floppy dive.
Especially when this rig had to be transported to the hall for
performances!
   I used the C64 user port and the SID chip as CV outs (and a couple
of Gate IN's on the user port) BASIC was plenty fast (and maintainable
on the fly) for most of this app. on the user port but.... when i
needed something faster i used the SID chip as a CV source. 

   just thought this might send a shiver of nostalgia down the spines
of some of you old-schoolers!
... but if anybody really wants a copy of that data-cassette send me
an S.A.S.E. for a 4oz. package and i'll copy one for ya.

10 POKE 54291,17:POKE 54292,255
20 POKE 54287,100:POKE 54296,15:POKE 54290,33
30 ? PEEK(54299):GOTO 30

=)
-doc