Re: enabling x87 interrupts

Alexei A. Frounze <spamtrap@xxxxxxxxxx> wrote:
: 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

Thank you,Alex. Actually, for backwards compatibility, Intel says that it
still asserts interrupts on the PIC. From my correspondence with them, they
say that the 6 exceptions should still trigger INT 75h.

.

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