From: MagerValp (MagerValp_at_cling.gu.se)
Date: 2002-11-26 13:55:48
>>>>> "UvB" == Ullrich von Bassewitz <uz_at_musoftware.de> writes:
UvB> This is not an easy question, especially if you want to stay
UvB> portable between the platforms supported by the SCPU.
This is a C64 only project, but it doesn't hurt to be portable.
UvB> Currently, all platforms with the exception of GEOS have
UvB> contignous zero page locations. GEOS divides them into three
UvB> chunks, but ptr1..4 do still live together. So another solution
UvB> would be to use ptr1/ptr2 for the first and ptr3/ptr4 for the
UvB> second zero page pointer (wasting one byte each time). This would
UvB> work for the C64, the C128 and for both using GEOS.
As GEOS is of no interest here (it has its own way of dealing with
expansion ram), ptr1/ptr2 and ptr4/tmp1 seems like the way to go,
keeping ptr3 free (I need something for the unsigned int length as
well).
MV> Should I use my own area for them (I'm a fan of $5f and up) or can
MV> I count on ptr1..4 and tmp1..4 staying in the same locations
MV> between cc65 releases?
UvB> Why do you need them in the same location between releases? Just
UvB> access them by name, and let the linker move it to the right
UvB> place.
I think I meant relative to eachother, ptr2 following ptr1, etc.
Thanks!
--
___ . . . . . + . . o
_|___|_ + . + . + . Per Olofsson, arkadspelare
o-o . . . o + MagerValp_at_cling.gu.se
- + + . http://www.cling.gu.se/~cl3polof/
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