Re: A86: A Stack Question

To: assembly-86@lists.ticalc.org
Subject: Re: A86: A Stack Question
From: Dux Gregis <assets@eden.rutgers.edu>
Date: Thu, 02 Jul 1998 17:38:23 -0600
Delivered-To: assembly-86-outgoing@towerguard.unix.edu.sollentuna.se
References: <19980702.163520.9630.0.sampablo@juno.com> <19980702.151301.4782.3.rabidcow@juno.com>
Reply-To: assembly-86@lists.ticalc.org




rabidcow@juno.com wrote:

> On Thu, 2 Jul 1998 16:35:19 -0500 sampablo@juno.com (Samuel P Camp)
> writes:
> >
> >Hi, Sam here with a stack question.
> >Is it possible to make the stack, which is First In Last Out, into
> >Last In Last Out?  Or in other words can you load the SP with a value
> >,and
> >then perform inc/dec on it?
>
> yes, you can do these to sp:
> inc sp
> dec sp
> ld sp,(nn)
> ld sp,hl
> ld sp,ix
> ld sp,iy
> ld sp,nn
>
> you can also add/sub it from hl.
>
> -josh
>

You want to preserve the stack location if you change it, though.  Here's
how I would do it:

 ld ix,0
 add ix,sp

;stack code, possible push/pop of ix

 ld sp,ix

...
or else it will crash when you try to return

References:

A86: A Stack Question

From: sampablo@juno.com (Samuel P Camp)

Re: A86: A Stack Question

From: rabidcow@juno.com