[sdiy] PAIA Midi2CV - Replacing DIP Switch with Rotary Switches

[Henry Till]

Hello,

I was perusing Grant Richter's modules at:
http://www.musicsynthesizer.com/Modules/modules.htm

And I noticed that he had modified his PAIA Midi to CV Converter with 
Two Rotary Switches and Binary Encoders to replace the DIP switch in 
the unit.  I though this was a good mod, as I never really liked the 
DIP switch in my midi2cv8.

Could somebody point me in the right direction as to where I can get 
some information on how to do a mod like this myself.  I assume I need 
some 40xx chips, but I don't know which or how to wire them up, and am 
wondering if this kind of mod is documented somewhere.

Any help would be most appreciated...

Thanks,
-H