[A82] Re: writeback?

To: <assembly-82@lists.ticalc.org>
Subject: [A82] Re: writeback?
From: "Henk Poley" <HPoley@DDS.nl>
Date: Wed, 16 May 2001 11:58:29 +0200
Reply-To: assembly-82@lists.ticalc.org


> Van: Kouri <Kouri@ucdavis.edu>
>
> > From: "Henk Poley" <HPoley@DDS.nl>
> >
> > So, ASH and CrASH relocate the program-variable just like Rigel (Ti85)
and
> > Venus (Ti83) do?
> 
> Yes.
> 
> > If so, whats then the 'fix' that's needed for GET_KEY?
> > You know, the Cr_KEYHAND call. I thought that call did move the
> > program-data from $9104 back into the programs variable, call GET_KEY,
and
> > then move the data back to $9104 and return the key that was pressed...
> > (else the TIOS would crash if you pressed [2nd]+[On])
> 
> CR_KHAND does just what you said. It de-relocates the program, calls
KHAND,
> and re-relocates the program afterward.
> This is needed because none of the system pointers in the VAT are updated
> when Cr/Ash does its relocation.

Uhmm, so it moves the all the data within the variable (including
sizebytes?) to $9104, but it doesn't update the filepointers so the TIOS
doesn't know about it? Rigel and Venus do update the pointers, that's why
they are handy in a programcrash (TIOS doesn't come down too).

(been a long time since I've looked at Ti82 asm, so the names got a bit
shuffled up, oops ;)

> > Another question: Is there already found a romcall like _chkfindsym? Or
do
> > you have to do things by hand?
> 
> Taken from 82-ROM.TXT:
> 
> ---- CALL 20EB ---- Search for program by
> [...]

Thank you.

	Henk Poley

Follow-Ups:

[A82] Re: writeback?

From: "Dines Justesen" <dines@aub.dk>