Thankyou for your answer!
I installed MIDIO128, and checked all buttons. They only send a single note on/off each.
I've been looking around in the menues. Here's a bit more detail:
When I select any of A#1 -> A#8 I end up on the OSC page, with (Del) as the leftmost item. Furthermore, (Del) is increased by 5, and (Rel) by 1.
On this page I can select any of the items, which then is blinking, except (Del). When pushing the select button of (Del), It jumps to the leftmost position, and is increased by one. There's also some funky stuff going on when I try to select items in the other sub menues (FIL, LFO etc).
Something seems to be really off here. I checked with my DMM, and the buttons don't seem to be cross connected.
I don't have a rotary encoder, and have [Dec], [inc] and [Exec] on shift register 2. Could this have anything to do with it?
I've attached the setup_8580.asm file I've used.
Cheers
Søren
setup_8580.asm