Re: A86: Flags/Libraries
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Re: A86: Flags/Libraries
Hmm.. This is the start of the kollumns source code
This is supposed to clear the _cmdShadow, that is the secondary cache
memory. I don't
see how it is supposed to do that. In fact, I don't think it clears anything
at all, I think it just
shifts 136 bytes of information one byte to the right, which wouldn't affect
anything on
the program itself since the variables would simply overwrite these memory
locations which are unimportant anyway.
You see, I see that hl equals $CFAB, de equals $CFAC, and bc=136. I figured
that LDIR
would copy $CFAB to $CFAC, then $CFAC to $CFAD, until in effect shifting 136
bytes of
data to the right (BC = 136). Hmm.. ld (hl), 0 causes $CFAB to be 0, but
then LDIR is called and
ld (hl), 0 is called only once.
Could someone please explain?
- Cyber Optic
Start:
ld hl,$CFAB ;clear texxtmem 2
ld de,$CFAC ;this puts 0 into the first byte,
ld bc,136 ;then ldir puts 0 into the following bytes
ld (hl),0 ;specified by bc
ldir ;
Follow-Ups: