Re: enabling x87 interrupts

Wendy E. McCaughrin wrote:
Is the 8259A (PIC) still used to enable interrupts? I unmasked bit #2
in the master PIC and bit #5 (a.k.a. #13) in the slave PIC it cascades
with, to enable FPU interrupts. I have unmasked all 6 exceptions in
the FPU's control-word and use STI. Yet, INT 75h is never accessed.

Nowadays, there's no external FPU chip that would assert interrupts on the PIC. The CPU itself handles all the FP instructions. And my bet is that it's configured in such a way that you should get exceptions, not interrupts.

Alex

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Relevant Pages

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