Trackball




Trackball

A trackball is a pointing device similar to a mechanical mouse. Its roller ball is on the top (instead of the base) along with the buttons. To move the graphics cursor on the screen we have to roll the ball with hand. As we do not need to move the whole device for moving the graphics cursor, a trackball requires less space than a mouse for operation, and is often attached to or built into the keyboard. Normally, laptops use trackballs built into the keyboard, because laptop users do not always a flat surface for moving the mouse in a small space. Some people think of a trackball as an upside-down mouse, because the roller ball is on the top.

Track comes in various shapes and forms with same functionality. Three commonly used shapes are ball, button, and square. To move the graphics cursor at a desired position on the terminal screen, we have to roll the ball with fingers, or push button with a finger, or simply move a finger on the square platform.

Trackball is a preferred device for CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) applications, because a designer can move the graphics cursor with hand movements of equipment. This is more suitable to the style of working of designers and makes it easier for them to work on large drawings.

Several equipment having embedded computers also use a trackball. For example, an Ultrasound machine usually has track that a sinologist (medical expert in sonography) uses to move the cursor (usually in cross-hair shape) to make the points of reference on the image on the screen.