Re: A89: Starting out assembly, need help

To: assembly-89@lists.ticalc.org
Subject: Re: A89: Starting out assembly, need help
From: Daniel7073@aol.com
Date: Mon, 30 Nov 1998 20:34:44 EST
Delivered-To: assembly-89-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-89@lists.ticalc.org

In a message dated 11/30/1998 4:12:37 PM Pacific Standard Time,
TurboSoft@aol.com writes:

> if it moves #10 into the new a0 AFTER it decrements a0, what's the point of
>  decrementing it in the first place?

You only do this if you want to save whatever a0 pointed to before.
Presumably, you are going to eventually use that value again.  This is like
the stack, which, by the way, is probably the most common use of the
predecrement and postincrement operators.

Example:
Ram Addresss: 1500    50
                       1502    75

a7 = 1502

move.w 150, -(a7)

Ram Address: 1500   150
                      1502    75

a7 = 1500

I hope this helps.

Daniel Imfeld

Prev: Re: A89: Distubing assembler error
Next: Re: A89: Quick Redraw?
Index(es):
- Main
- Thread