Commodore AMIGA Introduction Manual page 67

Scrolling the Contents of a Window
For many windows, you can't display everything that can appear within the
window at once. Because of this, windows often have Scroll Bars that let
you move what appears in the window:
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Scroll Arrow
Scroll Box
Scroll Bar
Scroll Arrow
You can move half a window at a time by selecting a Scroll Arrow at either
end of the Scroll Bar:
Pressing the Shift Key while selecting a Scroll Arrow moves the window one
pixel .
4-22 Using the Workbench