[comp.sys.atari.st] Interrupt handlers

SOCS18@vaxb.york.ac.UK (Vision Newspapers) (02/19/90)

Keywords : Interrupts

Re : Writing interrupt handlers in C

The problem with your interrupt routine hanging is probably because you haven't
cleared the Interrupt in SeRvice (ISR) bit of the appropriate MFP register. I
can't remember the correct bit and location offhand -- it's probably in
'ST Internals'.

If you don't clear this bit, then the MFP still thinks that you're handling
the interrupt, and will not let any other interrupts start. This will lock
up the keyboard, mouse, VBL and everything else handled via interrupts.

Hope this helps -
Regards,

Mathew Lodge
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