Re: A86: String won't go away

To: assembly-86@lists.ticalc.org
Subject: Re: A86: String won't go away
From: Dark Ryder <DarkRyder@cyberdude.com>
Date: Mon, 07 Sep 1998 14:02:16 -0700
Delivered-To: assembly-86-outgoing@towerguard.unix.edu.sollentuna.se
Organization: House of Fish Enterprises
References: <35F43CBC.MD-0.196.AntDog@iname.com>
Reply-To: assembly-86@lists.ticalc.org

A Doggett wrote:
> 
> I'm using TI86 Rom1.2.

Me, too.  Maybe I can help ;)

> 
> Q1:  What can you tell me about this bug/feature?
> 
> My program (AJDNotePad) saves its data in a string.  I decided that I
> wanted to revert back to the version of the string saved on my PC.  I
> sent it to the calc, but although the new string appeared in the
> "Delete/String" menu with its new (much larger) size, when I ran my
> program, the old one was loaded.
> 
> So I tried a second time.  This time I deleted the string manually
> before sending it from my PC (with the TI-Link software).
> Still the old string was there.
> 
> So, I backed up the stuff on my calculator, did a "memory reset",
> copied everything but the "bad" string back, and then the new string.
> but */STILL/* the old string appeared in my program.
> 
> So, I tried Reset/All.  Still no success
> Short of taking the batteries out, how do I remove a string so that
> 

It may be something annoyingly simple - I had a friend who thought that Vertigo
was stuck on his calculator because it asked him to overwrite it even after a
reset (like what you tried).  It turned out that he had two copies grouped
together (but named VERTIGO.86P), and it would send one, then ask to everwrite
it.  Personally, I'm getting a little nervous about all these recent threads
about 'phantom' data.  Makes you wonder who's really in charge:  You, or your
calc?

> Q2:  How are things "deleted" (obviously something is remaining in the
> symbol table)

When a variable is deleted (using DelVar( or the Mem > Delete menus), it doesn't
actually erase the data, it only erases the VAT entry.  The data remains until
that section of memory is used for something else.

> 
> Q3:  Is there some way around this?

In an Asm program, you can overwrite the variable with $00's before you delete
it.  This _really_ destroys it!

> 
> Q4:  Has someone made use of this & created an undelete program?
> (Which would work after crashes too!)

Not yet, but I doubt one will be made.  The data gets overwritten fairly quickly
in most cases.  Even just running a program (using Asm(, at least), modifies the
Ans variable, and it's change in size will probably overwrite part of the old
data, at least.

> 
> Q5:  "Symbol Table"="VAT" ?

Exactly.  VAT = Varable Allocation Table, which means, basically, that it keeps
track of where all the variables are in memory.  'Symbol Table' is just another
name for it.

> 
> Thanks!
> --
> ~~~~~~~~~~~~~~~~~~~~~~~Amiga Forever!~~~
> Anthony J. Doggett                     |
> Mailto:AntDog@iname.com                |
> http://www.users.zetnet.co.uk/doggett/ |
> -------------------------------------- |
> Life is what you make of it.

-- 
Dark Ryder
ICQ#:     8189903
E-Mail:   DarkRyder@cyberdude.com

Happiness is inversely proportional to how much you want to upgrade your
computer.

References:

A86: String won't go away

From: "A Doggett" <AntDog@iname.com>