[comp.sys.atari.st] MFP and xbtimer

aimd@castle.ed.ac.uk (M Davidson) (04/14/90)

Hi, before my HD trashed I had written a program to re-vector the Timer
B interrupt using XBTIMER. It worked OK but at the end of the interrupt
routine I had to clear the service bit by simply clearing the correct
bit in the MFP register. 

Is that how it's meant to be done? I'm just looking for a cleaner way of
doing it - isn't it possible that the address of the MFP chip may change
at some time in the future. Is there a way of finding out these
addresses without taking them out of a book? Or are all the IO registers
high in memory guaranteed never to change?

Thanx again,
Mark.