[sdiy] Looking for keyboard circuits

[David G. Dixon]

I'm in the market for a keyboard circuit, preferably of the matrix scanning
variety.  I've got two keyboards from an old organ I gutted recently, and I
want to adapt them for use with my modular.  They are configured for a
12-row matrix (i.e., by the octave) instead of the usual 8, but I think I
can work around this.

I've looked at Ray Wilson's circuit on MFOS quite closely, and I think I can
adapt this to my needs.  However, I haven't found anything else, and I'm
mostly just looking for other options to compare and get ideas from.