Apple Macintosh PowerBook 145B - Manual (Page 52)

Use the trackball
Your computer has a two-button trackball. You use the ball itself to
control the movements of a pointer on the screen. The pointer
you’ll see most often is an arrow (8).
You use the buttons to initiate actions that you want the computer
to perform. Both trackball buttons do the same thing. You can
always use whichever one you prefer.
Much of the work you do on the Macintosh uses four trackball
actions: pointing, clicking, pressing, and dragging.
(If you want to return to the Macintosh Basics tour for more
practice with the trackball, see Chapter 1 for instructions.)
Point
You point to an object on the screen by rolling the trackball so the
pointer is positioned over that object. When the pointer is an
arrow, the tip of the arrow must be exactly over the object.
Practice pointing to different objects on the Macintosh desktop,
such as the startup hard disk icon near the upper-right corner, the
Trash icon near the lower-right corner, and the Help menu icon
near the right end of the menu bar.
36 Chapter 2: Working on the Desktop