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Conference 7.286::atarist

Title:	Atari ST, TT, & Falcon
Notice:	Please read note 1.0 and its replies before posting!
Moderator:	FUNYET::ANDERSON

Created:	Mon Apr 04 1988
Last Modified:	Tue May 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	1433
Total number of notes:	10312

483.0. "How to clock a mouse." by STKHLM::OBERG (The galaxy rider.) Wed May 17 1989 11:24

	Hello.

	I have just by a ATARTST 520. And I like to
	use a Marconi trackerball, (heavy stuff) instead
	of the mouse. The trackerball have no logic
	inside, just a lamp and two photo-transistors
	per direction.

	Anyone out there who know what is coming out from
	the original mouse. I think it not a big one to
	build an interface between the trackerball and the
	ATARI
			Anders.             
					New and happy ATARIST-owner.

T.R Title User Personal
Name Date Lines

483.1 Brief description PRNSYS::LOMICKAJ Jeff Lomicka Wed May 17 1989 21:58 9

T.R	Title	User	Personal Name	Date	Lines
483.1	Brief description	PRNSYS::LOMICKAJ	Jeff Lomicka	`Wed May 17 1989 21:58`	9
	Just buffer the signals out of the four photodiodes with ordinary LSTTL buffers. You should then get ordinary quadrature signals out of it. Try connecting the two signals from the X encoder wheel through the buffers to the two X inputs on the mouse connector, and also the Y. If the cursor moves the wrong way, swap the wires on the offending axis. You might also need to play with the polarities until it comes out right. I don't know what to do about current limiting resistors - if that's not already installed.

Just buffer the signals out of the four photodiodes with ordinary LSTTL
buffers.  You should then get ordinary quadrature signals out of it.  Try
connecting the two signals from the X encoder wheel through the buffers
to the two X inputs on the mouse connector, and also the Y.  If the
cursor moves the wrong way, swap the wires on the offending axis.  You
might also need to play with the polarities until it comes out right.  I
don't know what to do about current limiting resistors - if
that's not already installed.