Kensington Expert mouse. (evaluation)
by David English
I've used the Macintosh version of this trackball for over a year now. Because it uses an optical sensor instead of mechanical moving parts, it's the only Mac trackball that comes close to the response of a mouse. When I heard that Kensington had developed a trackball for the PC, I was eager to give it a try.
The Expert mouse offers you the same look and feel as the top-selling Macintosh version. The entire unit is large (4 1/2 inches X 5 3/4 inches) and sturdy--but more importantly, the ball itself is large and easy to move (it's about the same size as a billiard ball). The two oversize buttons are on either side of the ball and easy to reach. You can configure the unit as a one-, two-, or three-button mouse and even swap the two buttons for left-handed use.
You can also set up the Expert mouse with a handy click-lock mode. It's possible to configure the device with this option so that pushing and releasing one button (you decide which one) simulates holding the other button down. This option can be useful in graphics programs for drawing lines or dragging objects across the screen.
Kensington supplies its own mouse driver which lets you set the degree of automatic acceleration (the faster you move the ball, the more the cursor accelerates). You can also write your own acceleration curve table to further fine-tune the response. Unless you're using a high-resolution monitor (1078 X 768, or higher), the combination of a 200-dpi trackball and software-based acceleration should be sufficient for just about any of your applications.
As well as they work, trackballs aren't for everyone, so try one before you buy. If you do find you prefer a trackball to a mouse (or don't have the room to use a mouse), the Expert mouse is an excellent choice.