mysteries...
1. i assumed Music Mouse would have a modem/printer port selection. seems it doesnt. so does it use MIDI Manager? it didnt complain before i installed MIDI Manager though, and after installation it does not show up in PatchBay
2. there is much talk about 1MHz being the "standard MIDI clock rate". this circuit http://www.loadsman.com/jal/midi/Macmidi.html connects a 1MHz crystal to HSKi. so i guess i might need something there. maybe i could generate the 1MHz signal on the RP2040 instead?