IRQ

Z80 IRQs can be generated by the YM2610's timers, and are mostly used to time music playback.

The vector address is $0038.

They can be disabled in software (DI/EI) and must be acknowledged via the YM2610.

NMI

Non Maskable Interrupts are triggered when the 68k sends a sound command.

The vector address is $0066.

They can be enabled or disabled through ports $08 and $18. They are disabled after a reset.

They are acknowledged by reading port $00.