Apple Macintosh PowerBook 145 - Manual (Page 29)

4. Being careful not to roll the trackball, press the
trackball button twice in quick succession.
Now your screen should look like the following illustration:
5. Roll the trackball to move the arrow over the picture of
the man labeled “Macintosh Basics.”
Make sure the tip of the arrow is over the picture of the man,
not over the words “Macintosh Basics.”
continues .
Chapter 1: Setting Up Your Macintosh PowerBook 13