Re: A85: **RIGEL - the NEW shell**
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Re: A85: **RIGEL - the NEW shell**
Sam Davies wrote:
>
> Ben Sferrazza wrote:
>
> > Will Stokes wrote:
> > >
> > > what is "daisy-chained interrupt" support?
> > It is essentially mutilple interrupt support. So when you install
> > an
> > interrupt it creates "a chain" to whatever interrupts are currently
> > installed. You can install a grayscale interrupt handler and then
> > install a sound interrupt handler. They are in essence "chained"
> > together, as one is called right after the other when an interrupt
> > occurs.
>
> Well... actually, I think daisy-chained interrupts are the kind that PCs
> use: There is an interrupt vector in memory somewhere, and when a
> program tries to install a new interrupt, it rembers the old address and
> changes the address to its own interrupt handler. Then it makes sure it
> jumps to the address of the old interrupt handlers when it's done. It's
> "daisy-chained" because it's sorta like a link list. It's easy to
> "insert" a new interrupt into the chain. (Usgard uses something a bit
> different -- it's just a normal list of calls which is manipulated by
> the INT_ functions.)
> Sam
>
> --
> Sam Davies <sdavies@mail.trilogy.net>
Exactly, it creates a chain to the previous interrupt handler.
Daisy-chained is a generic term, doesn't necessarily have to be when one
interrupt handler "replaces" another.
References: