reset key and nmi

[MbeeTech]

Is it safe to say that interrupts really aren't used anywhere on the standard platform save for this and the PIO B RTC bit ( on the PC85 ) ?

Thanks
Tony

The only interrupts that are used are generated by the PIO. 
They are :
RTC interrupt (if fitted) or VSYNC (if linked, PC85 for Pseudo RTC),
Serial port receive,
Parallel port for printer RDY/ACK,
and on the 256TC for the keyboard token available.
Other software / hardware may create interrupts of course (eg: RTTY / FAX on the parallel port etc..)
but that's the extent of the interrupt usage for a regular system.