Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!bridge2!pvf
From: pvf@bridge2.ESD.3Com.COM (Paul V. Fries)
Newsgroups: comp.sys.atari.st
Subject: legal way to find SPECIAL addresses
Message-ID: <783@bridge2.ESD.3Com.COM>
Date: 7 Jul 89 17:03:18 GMT
References: <794@uhnix2.uh.edu> <11830044@hpldola.HP.COM>
Reply-To: pvf@diablo.3Com.com (Paul Fries)
Organization: 3COM Corp. , Mt. View. CA
Lines: 38

Sorry to ask again, I am sure I have seen this some time in
the past.

I need to know a "legal" way to determine the locations of
the GEMDOS mouse variables.  I have a mouse trapping
program that was written for the particular ROMS that are
in my 1040ST.  As we all know, TOS 1.4 will soon be here.
I want to fix up the program to be more general so I don't
get bitten when the new TOS arrives.

FYI

My mouse trapping program implements a "gate" at the menu
bar.  To open the gate and enter the menu bar, the right
button must be pressed while attempting to traverse the
gate.  All other mouse functionality remains the same.

The program intercepts mouse packets from the keyboard
processor and modifies the Y coordinate in the new packet
to limit the vertical travel.  It needs to know what GEMDOS
has recorded as the mouse position in order to make the
decision.

The program is about 180 bytes of code written in Laser
"assembly" language.  NO "C" code is used.  The in-line
assembly code is linked as the very first and only object.
Even init.o is not included, so the OS just dumps control
at the first instruction.  The program sets some hooks and
then does a Ptermres() call (in assembly, of course).

It is run from the auto folder, and has never seemed
anything but invisible since, i.e., it seems quite bug-free
to me.  I would be happy to post the source if there is any
interest.

The functionality was inspired by some other mouse trapping
program that I got from somewhere, but didn't like the
particular way it was done.  I wrote my program instead.