Re: [cc65] Changes in Interrupt Handling

Hi Greg,

First all thanks for taking the time to review the change :-)

> 1) The actors' priorities are wrong.  They should be the same as they were
> when the code was in the start-up module:  "irq_init" should run _before_
> all other actors; and, "irq_done" should run _after_ all other actors. That
> order will guarantee that the IRQ trap will handle any IRQs that any other
> constructors create.  So -- "irq_init" could be set at 32, at least. And,
> "irq_done" should be set at 1.

That was my original intention too. However Uz explicitly asked me to
do it differently: Choosing a medium prio allowing each constructor /
destructor to choose if it wants to be executed before/after
hooking/unhooking the interrupts.

I roughly looked through the existing constructors / destructors for
dependencies on interrupts but didn't find any.

> 2)  In many cases, "initirq" can load the new interrupt pointer into the .XA
> pseudo-register, then jump into "doneirq".  That second subroutine can
> disable interrupts, store the pointer, and re-enable interrupts -- for both
> subroutines.

I see. Thanks for pointing out.

> P.S., I recommend that you create a macro that generates those Apple2
> byte-table text messages.  It would be similar to the CBM and Atari
> "scrcode" macroes.  It would reverse the text; and, set the high bit.

I personally dislike macros for purposes like this. I use macros only
for re-use purposes, which I don't see here.

> P.P.S., Does "libsrc/apple2/irq.s" really need to .include "zeropage.inc"?

Nope, actually not. I'll remove it.

Regards,
Oliver
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