Dell Projector 3200MP - Manual (Page 26)

Computer Image- Note: this menu is only available with computer input signal.
Frequency
Change the display data frequency to match the frequency of your computer graphic card.
If you experience a vertical flickering bar, use the frequency function to make an
adjustment.
Tracking
Synchronize the signal timing of the display with that of the graphic card. If you experience
an unstable or flickering image, use the tracking function to correct it.
Hor. Position (Horizontal Position)
Press to move the image left.
Press to move the image right.