Re: A86: interrupts
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Re: A86: interrupts
Kirk Meyer wrote:
>
> i see no reason for pushing & poping - there's nothing to be saved if
> you disassemble the int handler. if you're using the built-in int
> support then you CAN skip the calc's interrupt - at the end, do the
> following:
What does the rest of the interrupt do? I can't tell what's going on
those ports.
>
> pop hl
> exx
> ex af,af'
> reti
<reti> loads (sp) into pc. This will crash since you already popped the
program counter. But, if you take out <pop hl> it will speed up the
interrupt. :-))
>
> and you should go back to where the interrupt was called from. in this
> way the slow-down "feature" of the 86 could be avoided during games.
> such a feature would be useful in ase or rascall (hint hint :)
>
> Dux Gregis wrote:
> >
> > I have two questions:
> >
> > Will the disable interrupt instruction disable the interrupt in
> > interrupt mode 2?
> > And, if instead of pushing the registers in an interrupt routine you did
> > <pop hl>, would you have the program counter in hl from where the
> > routine was called? I don't think this would be possible using the
> > regular interrupt because you would destroy the registers, but maybe
> > using interrupt mode 2?
>
> --
>
> =====================================
> = =
> = Kirk Meyer (mailto:_@ibm.net) =
> = http://www.bigfoot.com/~kirkmeyer =
> = =
> = "Set your affection on things =
> = above, not on things on the =
> = earth." Colossians 3:2 =
> = =
> =====================================
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