Q:  How can I get my mouse pointer to stop jumping around, and to glide smoothly across the screen? 

A: Type the following command into a shell window:

	% dwrite NeXT1 MouseScaling "string"
	
Where "string" contains a single value indicating the number of integer pairs to follow, followed by the actual pairs.  The integer pairs are (speed, acceleration) pairs.  These integer pairs make the mouse movement on the screen dependent both on the distance the mouse was moved on the pad, and its acceleration and speed.   When you change the mouse speed through the Preferences application, it creates one of these. Here's the format of a MouseScaling argument:

	% dwrite NeXT1 MouseScaling "N x1 a1 x2 a2 x3 a3 x4 a4 ... xN aN"

To give the mouse a smoother motion across the screen, you must make the mouse movement linear (uniform, but slow).  This dwrite will do the trick:

	% dwrite NeXT1 MouseScaling "1 1 1"

This means that if you move the mouse x amount on the pad, it moves it by kx pixels on the screen regardless of how long it took. (k is the constant which translates the mouse pad coordinate system to the screen coordinate system.)

Warning: we cannot guarantee the support of dwrites in future releases, so do not put this in your application or rely on it in any way.

QA775

Valid for 2.0, 3.0, 3.1