Re: A86: interrupts
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Re: A86: interrupts
At 10:07 PM 4/30/98 -0400, you wrote:
>Thanks. So does this mean that you could override certain ROM routines
>by checking the page and the counter?
>
No. The interrupt doesn't get called at the start of a routine, so you
couldn't be sure of catching the ROM routine. And where would you go to to
override the routine?
>>
>> or use exchange, but i don't know if those registers are used for
>> anything:
>
>The shadow register (when in the interrupt) have the preserved regs in
>them. If you exchange the registers in the user interrupt, you'll screw
>up the registers used where the int was called. I was looking at the
>rom just now; it's beyond me why the registers have to be pushed and
>popped -- at the very most only hl register should be.
>
The registers don't have to pe pushed and popped. When I wrote the int demo
program, I had just figured out about the user interrupt, and I just wanted
to be safe. Anyway, you can't exchange registers in the user interrupt, but
if you're using im 2, go ahead.
--Joshua
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