A86: Re: ROM viewing (was Willy DO BE DO BE DO)

To: Assembly-86 <assembly-86@lists.ticalc.org>
Subject: A86: Re: ROM viewing (was Willy DO BE DO BE DO)
From: Dan Eble <eble@cis.ohio-state.edu>
Date: Tue, 12 Aug 1997 10:37:24 -0400 (EDT)
In-Reply-To: <Pine.SGI.3.95.970812064730.15664A-100000@world.std.com>
Reply-To: assembly-86@lists.ticalc.org

On Tue, 12 Aug 1997 tmh@world.std.com wrote:

> I'm new to TI-asm programming.  Could someone please explain how you
> examine the ROM to find interesting tidbits like "Willy?"  Do you just try
> calling to different addresses?  Does the ti86asm.inc file give you clues?

In order to do any serious investigation, you have to be able to view the
ROM and disassemble it.  There are two ways:

1) Write a memory viewer program (easy) and a disassembler (not so easy)
   for the calculator.  These are pretty handy (I'll explain why below).

2) Somehow get your ROM onto a computer and use a fileviwer and
   disassembler there.

The second is explained in a few articles at ticalc.org in /pub/text (I 
think).  There are better ways of dumping ROM that what's explained there.
I wrote a simple program to copy parts of the ROM into string variables
and then I transferred them to my computer and pasted them together.  I
have posted it previously, but I will email it to you if you want.

It's nice to have a dump on the computer, but since the ROM is paged, it's
sometimes annoying to have to reload parts of the memory into a
disassembler when you're trying to trace cross-page calls. That's why a
calculator disassembler is nice: it only takes a couple keypresses to flip
to a new page.

--------
Dan Eble (mailto:eble@cis.ohio-state.edu)
         (http://www.cis.ohio-state.edu/~eble)

References:

A86: Willy DO BE DO BE DO

From: tmh@world.std.com