Re: A86: actual asm help
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Re: A86: actual asm help
sorry i noticed some errors there...that isn't how it is in the program...
basically what i need to know to trouble shoot this is
ld hl,_textshadow
ld a,1
ld (hl),a ......what does h contain...and what does l contain
ld a,(hl)
cp 1 ...........does a now contain 1
ld bc,$FC00
ld (hl),bc.......what does h contain and what does l contain
i really have trouble with keeping in my head what value is in each register
when a 8 bit register is loaded into a 16 bit register....do you have to
clear the upper or lower byte first like m68k asm ?
sorry for the earlier mix up
----- Original Message -----
From: Cassady Roop <croop@oregontrail.net>
To: <assembly-86@lists.ticalc.org>
Sent: Thursday, May 13, 1999 11:46 AM
Subject: Re: A86: actual asm help
>
> I'm not sure I understand your code right, but are you executing a RET
> in a routine that you jumped to? If you are, that will do a nice job of
> screwing up the stack, and then when you try to do something like exit
> the program it will crash. Replace the JP to your char display routine
> with a CALL.
>
> Eugene Dirks wrote:
> > _freemem points to some free mem
> >
> > ld hl,_freemem
> > ld a,1
> > ld (hl),a
> > inc hl
> > ld (hl),a
> >
> > dec hl
> > dec hl
> > ld a,(hl)
> > jp "a routine to display the correct character that i'm pretty sure
> > works
> > it... for example... cp 1
> > jp z,put_1
> > ....then it does a "ret"
>
> don't RET from a jump
>
> > inc hl
> > ld a,(hl)
> > jp "the same char display routine"
> >
> > this always freezes up the calc. I don't see it, but is there something
> > wrong with the above code that doesn't look right? if not then it's in
my
> > char_put routine...
> >
> > thanks for any help you can give
> >
> > billybobIV
> > chad@dirks.com
> > http://chad.dirks.com
>
>
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