The Scroll Copy/Preset dialog is one of the six CDG instruction editing dialogs. The other five dialogs are:
Tile Block Normal and Tile Block XOR
The Scroll Copy dialog has the following layout:
The Scroll Preset dialog looks like this:
The only difference between the two dialogs is the presence of the Preset color selector, used to select the color that is used to fill the newly revealed column or row.
For each scroll direction - horizontal and vertical - you select the desired Scroll mode and Pixel offset.
For more information about this and other CDG instructions and their usage please refer to The CDG graphics format.