@NeoBender, you started another thread here https://forum.pjrc.com/threads/73470-How-to-use-teensy-4-1-and-interface-with-a-5v-synth
which gives a pretty clear idea of what you want to accomplish. Have posted a few...
Snuffling around the Matrix, thinking out loud:-
Table at the bottom of page 7 of the service manual looks to me like the whole thing is addressed with a 10x8 matrix so am thinking that 18 mcu pins might do the...
Making the assumption that you want to turn off MIDI Thru wrt Serial or Din Midi.
The MIDI library instantiates with Thru turned on by default. To turn it off, you need to add:-
MIDI.turnThruOff();
After
...
Old codger with advanced soldering iron skills.
Pretty much self-taught Electronics/Automotive/Computer Technician/Hacker/Re-Engineer.
Built an Analog Synth ~1978 pretty much from scratch and life being what it is - what you end up doing whilst being busy with other plans, shelved it.
Forced into isolation by challenging health issues, officially retired and looking for a "mental health" project, dug out the box of remains of the original Synth, caught the bug and currently have a clutch of Roland Synths and other goodies.
To any Hacker worth his salt, off-the-shelf kit don't always give you what you're looking for which is why I'm here...
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