
"We are working on a replacment processor for the 8021 in Sequential circuit's ProOne. It is a little pcb board with a modern sufacemounted processor. The board has pins that fits to the socket on the ProOne's pcb. So it's just to plug it in. The replacment board has even some more features built in:
* Midi input and output
* Two analog outputs, can be used to midi control for example filter cutoff etc.
* One analog input, have not decided what to use it for. Maybe to send midi data from pitchbend or modwhweel, or other analog signal"
Title link takes you there. via JB