[comp.sys.amiga.hardware] Trackball

dlarson@blake.u.washington.edu (Dale Larson) (11/10/90)

i have just purchased an atari track ball (for $4.99 new!).  I'd like to
use it with my amiga as a mouse replacement, but just plugging it in
to the mouse port doesn't work.  Really I have two problems.  1) it doesn't
move the cursor, 2) neither fire button seems to select or to pull down
menus.  Is there software to make trackballs work like mice?  To make
joysticks work like mice (the trackball can emulate a joystick with the
flip of a switch)?  Is there software other than MarbleMadness which
supports a trackball?

Is there a way to hack the hardware of the trackball to make it act like a
mouse?

Thanks for your email replies.  I will summarize and post if the replies
warrant it.
--
-Dale Larson  (dlarson@blake.u.washington.edu)

raible@cbmvax.commodore.com (Bob Raible - LSI Design) (11/13/90)

	Let me preface this message by stating that instructions have
posted many times on how to hack an Atari Trakball, hopefully some kind
soul will email(I will if I can dig it up). Now for the bad news - I 
also obtained an Atari Trakball for $4 or so while on vacation and when
I excitedly disassmebled mine and found to my chagrin that the posted
instructions must have been referring to a different model. If this is
the case email me and I'll try to re-create my steps. It turns out that
Atari has a lot of logic inside to convert mouse(trakball) type
quadrature signals into either joystick position info or some other
weird encoded form, depending on the posiion of the switch on the back
panel labelled JS/TB. The unit black and quite massive with a ball
almost the size of a billiards ball. The only markings other than ATARI
TRAK-BALL is "KM-483   8" on a paper label stuck on the underside.  The
two fire buttons are wired together, but I was easily able to bring both
out with a cut and jumper.

As a note of encouragement, I note that shoot'em ups such as Hybris and
Battle Squadron greatly benefit from this nifty appliance!