Midification of Yamaha CS50 & SK20

Hi.

 

I wonder if either (or both) the Yamaha CS50 or SK20 synths could be midified. I’d only be looking for note on/off. I know the CS50 has a MIDI kit already, but that’s very expensive and adds a bunch of features I wouldn’t necessarily want. 

 

Service manuals are here:

 

http://www.cem3374.com/docs/Manuals/Yamaha/CS-50_SM.PDF

 

https://dl.dropboxusercontent.com/u/4447157/yamaha_sk20_synthesizer_sm.pdf

 

Thanks.

Hey did you ever get an answer to this? Currently want to do same thing.