Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!bbn!bbn.com!slackey
From: slackey@bbn.com (Stan Lackey)
Newsgroups: comp.sys.atari.8bit
Subject: Re: G.U.I.
Message-ID: <49367@bbn.COM>
Date: 7 Dec 89 17:21:44 GMT
References: <19010@watdragon.waterloo.edu>
Sender: news@bbn.COM
Reply-To: slackey@BBN.COM (Stan Lackey)
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Organization: Bolt Beranek and Newman Inc., Cambridge MA
Lines: 52

In article <19010@watdragon.waterloo.edu> rrwood@lotus.waterloo.edu (Roy Wood) writes:
>And while I think of it, has anyone tried to hook-up a mouse to their 8-bit?
>I don't suppose it would be that hard, though you'd then have to write all your
>own software to take advantage of it.  That might make a good project...hmm.
>Does anyone know where I can get a cheap mouse with basic technical specs?

I have done the following:

Connected the Trak-ball to the 8bit, and written a handler

Connected the Commodore mouse, and written a handler

Notes:

The Trak-ball (in native mode, not joystick-compatible mode) is
claimed by net-people to have the same characteristics as the ST 
mouse.  Clocks and directions come in over the four joy direction
pins.  It was a matter of writing a small handler, which I put in
page 6 and installed with a timer interrupt, that looks for changes
and asynchronously changes xy coordinates in memory for whatever
application to read (Basic, etc).

I got sick of the trak-ball; only one button, too bulky, pressing the
button is too clumsy.  I thought about mouses, and noticed that the
Commodore one has 2 buttons and is plug compatible.

The CBM has 2 modes - proportional and joystick.  Prop mode has analog
outputs to the two paddle inputs, which don't work on the Atari; whenever
I read mine I get the value 3.  So I use it in joy simulation mode,
after changing the handler to "integrate" the 4 joy direction lines.
(Note: games like millipede and missle command work real good with the
CBM mouse in joy mode, as well as some of the elementary drawing programs
like the one that came with the pen plotter.)

The two buttons are read 1) in prop mode, as trigger and one of the
directions and 2) in joy mode as trigger and one paddle input.  2 is
usable, although 1 would be better.

One other note: when I added VBI/DLI's to my application (drawing using
5-color character graphics) there was an interaction between the VBI
and the timer interrupt.  I ended up changing the DLI to interrupt every
line, count lines, and call the mouse handler every like 8 lines; this
eliminated the need for the timeer interrupt.

I use player/missle graphics for the screen pointer.  The top level
application calls a subr every time around the loop that updates the
pointer position.  You don't miss mouse movements, but the pointer 
can skip around the screen when the appl is busy.  Works pretty good.

I have plans to make a graphic OS version of MYDOS.  Wish me luck (in
finding the time, that is.)
I have truly been having fun.  -Stan