Where are video mode settings?

[Doofus]

Hello all,

Where does arachne store the video mode setting info that is configured in
the VGA setup screen?  My panel supports VESA mode 70 (640 x 480 x 256
colors) well but not VESA mode 30 (which seem same as 70 but refresh is
different).  It seems that Arachne wants to use mode 30 if I manually select
640 x 480 x256 colors (512 K).

Any ideas how I can force mode 70 on Arachne?

Thanks,

Robb