Trackball instead of Mouse?

DoN Nichols dnichols at
Fri Jun 7 06:00:49 AEST 1991

In article <1991Jun6.030543.13411 at> kal at (kevin.lyons) writes:
>Has anyone considered replacing the 3B1 mouse with a trackball?
>I use my UNIX PC at home on a cramped desk, and the d***ed cord
>always gets caught in the drawer when I open it.  Besides, it
>seems a natural -- the mouse never winds up where I need it.
	[ ... ]

>So, does anyone have any practical experience?

	I had considered attempting this, and even went as far as getting a
Logitech trackball (bus version) in perparation for the attempt.  I then
looked at the schematics in the Technical Reference Manual, and discovered
that the mouse used for the unix-pc is in actuality a serial mouse.

	I haven't yet gotten around to hooking up the mouse, stand-alone,
and trying to figure out the baud rate, and codes, with a scope.  Then, I
would have to do the same to a Logitech serial mouse to see if they are
compatable.  (I do know that the footprint of the encoder chip in the at&t
mouse is NOT the same as the space left in the trackball, so we can't just
transplant the chip.)

	Perhaps, the necessary action would be to arrange the switches and
motion-encoders in the trackball to provide input to a partially-gutted AT&T
mouse, and let the AT&T mouse encode the information.  However, this is too
much of a kluge to satisfy me.  I hope that the codes and baud-rates are
compatable between the Logitech serial mouse and the Trackball.

	This summer looks fairly quiet after the next week, so maybe I'll
get back to it.

	Good Luck
Donald Nichols (DoN.)		| Voice (Days):	(703) 664-1585
D&D Data			| Voice (Eves):	(703) 938-4564
Disclaimer: from here - None	| Email:     <dnichols at>
	--- Black Holes are where God is dividing by zero ---

More information about the Comp.sys.3b1 mailing list