Apple Portables: Two finger trackpad scrolling
Summary
Two finger trackpad scrolling is a new feature introduced in the PowerBook G4 (12-inch, 1.5GHz), PowerBook G4 (15-inch, 1.67/1.5GHz), and PowerBook G4 (17-inch, 1.67GHz) computers. With trackpad scrolling you have the option of scrolling vertically and horizontally in a window that has scroll bars by moving two adjoining fingers on the trackpad. The trackpad scrolling feature is on by default in the Apple portables that support it.
Products Affected
Portable Computers
Using two finger trackpad scrolling
To scroll vertically, move two adjoining fingers up or down the trackpad. To scroll horizontally, move two adjoining fingers left or right on the trackpad.

Note: To move the pointer instead of scrolling, use only one finger on the trackpad; the pointer won't move if you use two or more fingers on the trackpad.
Customizing two finger trackpad scrolling
Depending on your Apple portable, you will have different options for customizing two finger trackpad scrolling. For instance, Apple portables without Multi-Touch trackpads have the option to disable horizontal scrolling or to disable scrolling completely whereas Multi-Touch trackpads can only adjust scrolling speed.
Note: If you have an Apple portable with a glass Multi-Touch trackpad or an Apple portable using Mac OS X v10.5.6 or later, you can customize trackpad scrolling settings in the Trackpad System Preferences Pane. If you are using an Apple portable with a non-glass trackpad or non Multi-Touch trackpad with Mac OS X v10.5.5 or earlier, you can customize your settings in the Keyboard & Mouse System Preferences Pane, in the Trackpad tab.
Apple portables without a Multi-Touch trackpad:

- To disable horizontal scrolling, deselect the "Allow horizontal scrolling" checkbox.
- To disable trackpad scrolling altogether, deselect the "Use two fingers to scroll" checkbox.
- To adjust scrolling speed move the arrow on the "Scrolling Speed" slider.
Apple Portables with a Multi-Touch trackpad and Three Fingers gesture support:

Apple portables with a Multi-Touch trackpad and Four Fingers gesture support:

To adjust scrolling speed on a Multi-Touch trackpad, move the arrow on the "Scrolling Speed" slider.