Yamaha CS80

Hi all.

Crow is doing great work to build new CS-80 voice cards with
off-the-shelf parts.  But, as we all know, the sound engine is only
half the point of the CS-80.  It doesn't look like anyone (Roland,
Fatar, M-audio, CME) is going to release a poly-aftertouch MIDI
keyboard anytime soon.  Therefore, we have to come up with one.

I'm hoping that someone can tell me any details about the
channel-aftertouch sensors used in current controllers.  I'm hoping
there's a way to modify the existing sensor (with lots of added
circuitry) to turn it into poly-aftertouch.  Anybody know?  Any
pointers?  Does anyone have specs on the raw Fatar keyboards that the
other companies use?  Who else makes the raw/OEM keyboards that have
channel aftertouch?

 David