I've interfaced my Kurzweil Expressionmate through my PSIM to provide
a ribbon controller and later designed a module using an
AtomPro24 as a dedicated Expressionmate ribbon module.
I just recently bought a Kurzweil PC-2 which is just the passive
ribbon from Sweetwater for $50. It came today and I've written a small
program on the PSIM to control it. The PSIM inputs are 100K to ground.
I drive the ribbon 'potentiometers' from a CV output of 5.6 volts and
put a diode drop to ground. This floats the ribbon from 0.6 to 5.6
volts. If I read <0.6 volts from a ribbon section then there is no
contact. That way I can detect ribbon contact to generate a gate
signal. Right now I am just piecing the three ribbon sections back
together for a continuous output of 0 to +10 volts.
I'm using three inputs (to read the three ribbon sections) and three
outputs (5.6 volts, gate out, and CV out).
I need to come up with a better wiring scheme than this mess of cables
and then I'll wire it into a VCO to see how smooth it is. I haven't
really calibrated the min and max voltages and the offsets for the
three sections but I assume I can get it reasonably smooth.
With the larger number of outputs from the current design I could have
1, 2, or 3 ribbons each with a gate and trigger output.
I put a schematic of the ribbon cable pin out on my site
http://modularsynthesis.com/modules/DJB-011/djb011.htmDave