We have not had the chance yet to build our OrganDonor midi interface into a RS-101. However, we did install one in a RS-202 and – according to the schematics and a single picture found on the web – they seem to be identical when it comes to the tone generator/gate board.
This means it should be relatively straight forward to use the RS-202 installation manual and apply it to the RS-101.
If you want to try, we will of course assist. You can also contact us and send some pictures of the inside of your RS-101. We’ll be happy to help.