[A83] Re: Ti83- memory layout

To: assembly-83@lists.ticalc.org
Subject: [A83] Re: Ti83- memory layout
From: BRANDON STERNER <bms9019@osfmail.isc.rit.edu>
Date: Mon, 1 Oct 2001 16:52:12 -0400 (EDT)
In-Reply-To: <0b38b19072001a1NET049S@hetnet.nl>
Reply-To: assembly-83@lists.ticalc.org

fpBase equ 930ch ;is the pointer to bottom of the stack
fps equ 930dh ;is the pointer to the top of the stack (where you're going
to add data)

some other stacks equates:

opBase equ 930fh ;the pointer to the bottom of the operator stack
ops equ 9311h ;the pointer to the top of the operator stack

the fp stack has no set location in memory.  it grows in the opposite
direction as the hardware stack and the ops grows in the same
direction as the hardware stack.  the amount you can push onto the fps is
based on the amount of free ram.  also if an edit buffer is open, you
cannot push or pop anything from the fps (or ES for that matter).
as for what is in the ram locations between curgx and plotsscreen,
it appears there are mostly system variables (xmax, ymin, plotstep,
etc) and probably the entry stack ( you know the thing that lets you
recall past entries by pushing 2nd+enter).
You can look at the ti83plus.inc for an idea of whats in that general
area.  Of course the locations are different on the 83 and there are extra
ram locations inserted but the general order of ram locations stayed the
same from the 83 to the 83+

Brandon Sterner
www.detacheds.com

On Mon, 1 Oct 2001, Henk Poley wrote:

> 
> I always thought that about all adresses in RAM on the Ti-83 would be well
> documented, but today made a list of these (similar to 82-ram.txt), and if
> you only rely on Ti, you have a list of about one page printed (hmm, must
> use big font).
> 
> I've looked a bit further, but most things I've found are 'questionable',
> or only mentioned as an adress in the code of some program...
> 
> Some questions:
> Where is the FP-stack located?
> And how big is it (max)?
> Are there any pointers to the begin/end?
> Is the area used for the flags indeed 36 bytes big?
> What are the 1466 bytes between CURGX (886E) and plotSScreen (8E29) used
> for? Must be something usefull, I guess.
> Anybody knows about FMTSTRING (929A - ???), what it's used for besides in
> _formDCplx.
> 
> 	Henk Poley <><
> 
> 
> 
>

References:

[A83] Ti83- memory layout

From: "Henk Poley" <HPoley@DDS.nl>