From: MagerValp (MagerValp_at_cling.gu.se)
Date: 2001-01-06 22:34:32
>>>>> "UvB" == Ullrich von Bassewitz <uz_at_musoftware.de> writes:
UvB> If your assembler code does not call any library routines itself,
UvB> you may freely use ptr1-4 and tmp1-4 (12 bytes total), plus the
UvB> sreg variable with some precautions (it contains the high word
UvB> for long values). The routines most likely used by your code,
UvB> namely popa, popax and all incspxx functions do not use any of
UvB> these zero page locations, so you may use these routines to
UvB> retrieve parameters from the stack. 12-14 bytes should be enough
UvB> for most purposes. But beware: if you are calling other library
UvB> routines, the contents of these zero page locations may get
UvB> destroyed!
I was thinking about having an irq running, and a couple of other
small routines -- what I need are ZP variables that don't get over-
written. I guess I could just check the c64.lib source...
--
___ . . . . . + . . o
_|___|_ + . + . + . . Per Olofsson, konstnär
o-o . . . o + MagerValp_at_cling.gu.se
- + + . http://www.cling.gu.se/~cl3polof/
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This archive was generated by hypermail 2.1.3 : 2001-12-14 22:05:38 CET