Path: utzoo!attcan!uunet!mcvax!ukc!warwick!csusw
From: csusw@warwick.ac.uk (Dave Roberts)
Newsgroups: comp.sys.atari.st
Subject: mouse / keyboard processor
Keywords: mouse, keyboard processors, interupts
Message-ID: <25@miranda.warwick.ac.uk>
Date: 15 Feb 89 13:27:34 GMT
Reply-To: csusw@warwick.ac.uk (Dave Roberts)
Organization: Computing Services, Warwick University, UK
Lines: 55


This article is being posted for a friend who seems to be having problems
getting it onto the net.  Please reply via me (due to the frog up in mail
at the moment in Computer Science) and I will forward it onto him.  Unless
of course you wish to reply on the net.

==============================================================================
From: jbu@opal.warwick.ac.uk (J Mark Burton)
	Computer Science, Warwick University, UK.

I have been reading the articles on the problems with the mouse, I have a
simular problem, But one which is definitly a software problem. I have infact
put an article onto the net previously about it, but with no replies.

The  basic problem is alligning the plotting of the mouse icon (onto the
screen) with the beam. If there is a standard way of doing this, could sombody
please PLEASE tell me about it.

Detailed problem:-
        I have a mouse interupt routine, which uses the mouse in relative
mode. However, to stop the mouse cursor flashing when it's moved, I want to
make sure that the mouse icon is not plotted while the beam is scanning acros
it. To do this I tried waiting until the beam was at a known poition on the
screen (ie by reading the video address pointer memory registers). The routine
I use to do this works (I use it elsewear in the programe - I've set it up as
trap #3). However when I impliment this the mouse stops working.
it:-    a)      moves up and down ok if you go v.v.v. slowly
                else it only moves up.
        b)      moves left,right if you go even slower
                else it moves left.
In other words, unless you move increadibly small distances, the mouse
tends towards the origin.

Is this because the interupt routine takes to long, and the keyboard processo
 sends new packets wich corrucpt the first
Is this because the keboard processor doesn't send any more packets, but
corructs it's own varibles because of overflows.
        How else do I do it??????


Mark Burton ( jbu@uk.ac.warwick.cs )

===============================================================================



                              Dave Roberts,
         Computer Science, University of Warwick, COVENTRY, CV4 7AL, UK.

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