Re: Re: A85: SBC HL, DE

To: assembly-85@lists.ticalc.org
Subject: Re: Re: A85: SBC HL, DE
From: DorkReMi@aol.com
Date: Tue, 1 Sep 1998 03:18:27 EDT
Delivered-To: assembly-85-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-85@lists.ticalc.org

In a message dated 9/1/98 5:45:07 AM, you wrote:

>The way the carry flag works with subtraction is the same as with
>addition, sbc hl,de is hl-de-carry.
>If carry is set then de+carry>hl (because to subtracted carry also.)
>But it is always set afterwards.

If this is the case, then how might I subtract de from hl without the use of
the carry flag?  What I need to do effectively is:

LD HL, value1
LD DE, value2
HL=HL-DE ;point of conflict
JR C, valu2toobig ;<--I need the carry flag to be altered if DE was greater
than HL
;HL was greater than DE. Subtraction successful. HL is now the difference.

What commands can I use to do this?

-Josh Morris
 DorkReMi@aol.com

Follow-Ups:

Re: Re: A85: SBC HL, DE

From: Humberto Yeverino <humberto@engr.csufresno.edu>