Sounds to me like it has a picture of the Liberty Bell in the center of the dial?

If so: switches 1-6 off - switches 7-9 on

Dial - Resolution - Output

D - 1024 x 768 - 19" Color

F - 832 x 624 - 16" Color

G - 640 x 480/800 x 600 - VGA/SVGA

H - PAL - PAL

J - 640 x 480 - 13"/14" RGB

L - NTSC - NTSC

M - 1152 x 870 - Apple 2 Page Mono

N - 512 x 384 - 12" RGB

O - 640 x 870 Apple Portrait

P - 1152 x 870 - 21" Color