the_duckchild

great stuff everyone thanks! now the other side of a protracted house move and thinking about this again have put one of the UMR-2 copies into a Yamaha CS01 already so might give that a bash armed with this info! thanks.

Ah, thanks -maybe I need to do some more reading, I assumed it worked pretty much like an LED matrix but I guess it's actually that in reverse, pthinking about it... plus the synching bit? the concept is right though I guess - I can get a microcontroller to perform whatever connection a keypress presents and at least get note on/off?

Hi, I have had a little search around and couldn't see any reference to this.... I have an MT-65 and found the service manual here; https://www.synthxl.com/casio-mt-65/ It appears to state in pretty clear terms how the keyboard matrix is wired. I *think* this would allow it to be pretty easily retrofitted for MIDI using a teensy microcontroller or similar. it also appears that the sound engine is actually controlled by the switches sending voltages to the keyboard matrix... this seems to open up the possibility of doing the kind of quick waveform switching that works very well on 8-bit chips of a similat vintage. Just wondering if anyone has seen evidence of anyone achieving similar with old Casiotone keyboards? Or has anything else to share on this....This is probably getting towards the edge of my knowledge, but keen to have a crack at it and see what happens.....