Planar Dome EX - Manual (Page 17)

Installing the Display | 7
Set the DIP Switch on the Dome DX2 Board
If you are using the Dome DX2 display controller, you need to enable
or disable VGA mode according to your system configuration. Enable
VGA on only one board when you install multiple Dome DX2 display
controllers. Disable VGA on all Dome DX2 display controllers if you
are using a separate VGA card. For VGA mode, slide switch 1 into
the ON position.
For some Dell systems, you may need to enable VESA modes to see
output on the screen during the boot process. If so, slide switch 2 into
the ON position.
For single desktop mode, slide switch 3 into the ON position.
VIdeo 1 port