[A83] Re: Running programs

To: assembly-83@lists.ticalc.org
Subject: [A83] Re: Running programs
From: robvanwijk@gmx.net
Date: Thu, 27 Mar 2003 13:24:12 +0100 (MET)
References: <F131jQ4S8Uq5nlhRyZx0000e8a7@hotmail.com>
Reply-To: assembly-83@lists.ticalc.org


Programs (as most other variables) are stored somewhere in user ram.
When the program is executed (I assume you mean assembly), it's
current location is looked up in the VAT (Variable Allocation Table, much
like the FAT on a computer hard disk). Then an amount of space equal
to the program size is freed beginning at progstart (9327h on the 83-,
9D95h on the 83+/83+SE), after which the program is copied to this
location. When the program quits, this space is de-allocated, effectively
deleting the copy.
Apps are run very differently, but that's a question for somebody else,
sorry, can't help you there.

Rob van Wijk

> I can't seem to find the basic structure of how programs are run un
> the ti83. I think they are first copied from VAT to the area called 
> progstart and run from there. And what is the difference in running
> programs 
> and apps?
> I also don't know how the chip interprets the data it's at. Does it just 
> read the data at PC like this (PC) and sends that to the chip port(if that
> exists).
> I also don't know how to trace romcalls with the VTI debugger, and it
> seems 
> rather usefull in development.
> I would be very thankfull if even one of these questions could be
> answered.
> 
> >>/Maarten Zwartbol
> 

-- 
+++ GMX - Mail, Messaging & more  http://www.gmx.net +++
Bitte lächeln! Fotogalerie online mit GMX ohne eigene Homepage!

References:

[A83] Running programs

From: "Maarten Z." <m021085@hotmail.com>