A83: Re: Subtraction


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A83: Re: Subtraction




For hl-de:

or a
sbc hl,de

To do hl-a you would:

ld e,a
ld d,0
or a
sbc hl,de

If you are subtracting a constant from hl, just do:

ld de,-500  ; subtract 500
add hl,de

Joe Wingbermuehle
http://www.usmo.com/~joewing/

-----Original Message-----
From: SethirothL@aol.com <SethirothL@aol.com>
To: assembly-83@lists.ticalc.org <assembly-83@lists.ticalc.org>
Date: Saturday, September 19, 1998 11:51 AM
Subject: A83: Subtraction


>
>For subtraction of large numbers, ie:
>
> ld hl,34093
> ld a,23
>
>how would I get hl - a?  Or just, please tell me any way at all to subtract
>one 2 byte register from another.  Thanks..
>