GitHub - socphoenix/pico-midicizer: midi controller board and guide for building a vpo based on a Conn 650 theater organ. Analog organ midicizer compatible with Grandorgue (and likely Hauptwerk)
github.com
midi controller board and guide for building a vpo based on a Conn 650 theater organ. Analog organ midicizer compatible with Grandorgue (and likely Hauptwerk) - GitHub - socphoenix/pico-midicizer: ...

Found an old Conn 650 organ on Craigslist that was a little bit worse for wear on the original (analog) cards about a year back. I built a system to read the keys/buttons/pedals/shutter shoes and feed those into GrandOrgue. This allowed an old system from the 1960s to update into the modern era and play organ samples. You can see a video of the sound before/after here.