Look in the BIOS setup under "Standard CMOS Setup" Change the "Video" to CGA 40 or 80.
From the GITOX3 Manual :
Video
This category selects the type of video adapter used for the primary
system monitor. Although secondary monitors are supported, you
do not have to select the type in Setup. The default setting is EGA/
VGA (BIOS default, Setup default).
EGA/VGA Enhanced Graphics Adapter/Video Graphics Array. For
EGA, VGA, SVGA and PGA monitor adapters.
CGA 40 Color Graphics Adapter. Power up in 40-column
mode.
CGA 80 Color Graphics Adapter. Power up in 80-column
mode.
Mono Monochrome adapter. Includes high resolution
monochrome adapters.
There is also a BIOS update if you need it:
http://www.itox.com/pages/support/download.php