okay, it's the first time for me to get along with interrupts and stuff...
the only interrupt handler in the wiring.c that i recognize is in line 324
SIGNAL(SIG_OVERFLOW0)
{
timer0_overflow_count++;
}
it incremets the overflow counter variable, which tells us how often timer0 had an overflow since the controller get power, right?
so i could easily add my midi code here, as long as it's not too long? (and i let it operate only every X-th interrupt, dependent on the tempo i want to have)?