Winn L. Rosch Hardware Bible, Sixth Edition

TouchPads

In their developmental years, notebook computers used a variety of pointing devices. Several tried integrated trackballs. The designer's whims determined placement—sometimes at the corner of the screen, sometimes below the keypad. In any case, the balls were small (they had to be to fit in a portable system), and the perfectly located trackball was rare, indeed.

Hewlett-Packard developed a pop-out mouse tethered to the right side of the system. The system detected mouse movement through the thin, flat tether, so you could hold the mouse in the air and its movements would nevertheless register. The downside was the need for space on the right, either air or desktop, a requirement not easily met in crowded aircraft.

The notebook industry ...