Samsung SDP-9000DXR User Manual page 33

Adjusting your image with GUI
Divide
Allow to divide the screen to show both of the current image and the image recalled from the memory
simultaneously on one screen.
Click [numbers] menu with the left mouse button, screen is divided and selected number of image is recalled
from memory and activated in menu.
Shift
Allow to shift the recalled image shown in the divided screen from the left to right to show the hidden portion of
the image. Click[Shift] menu with the left mouse button, image is shift from left to right step by step each
request in the divide mode.