/etc/X11/xorg.conf

PC-BSDのモニターを見ていて、妙に表示面積が小さいなぁ、思っていたら800x600で表示されていた。
で、/etc/X11/xorg.confを開いて、

# Xorg.conf file generated for PC-BSD

Section "ServerLayout"
Identifier     "XFree86 Configured"
Screen      0  "Screen0" 0 0
InputDevice    "Mouse0" "CorePointer"
InputDevice    "Keyboard0" "CoreKeyboard"
Option    "Clone" "off"
EndSection

Section "Files"
RgbPath         "/usr/local/lib/X11/rgb"
ModulePath      "/usr/local/lib/xorg/modules"
FontPath        "/Programs/fonts/"
FontPath        "/usr/local/lib/X11/fonts/cyrillic/"
FontPath        "/usr/local/lib/X11/fonts/TrueType/"
FontPath        "/usr/local/lib/X11/fonts/webfonts/"
FontPath        "/usr/local/lib/X11/fonts/misc/"
FontPath        "/usr/local/lib/X11/fonts/TTF/"
FontPath        "/usr/local/lib/X11/fonts/Type1/"
FontPath        "/usr/local/lib/X11/fonts/CID/"
FontPath        "/usr/local/lib/X11/fonts/75dpi/"
FontPath        "/usr/local/lib/X11/fonts/100dpi/"
FontPath        "/usr/local/lib/X11/fonts/dejavu/"
FontPath        "/usr/local/lib/X11/fonts/local/"
EndSection

Section "Module"
Load           "ddc"
Load           "dbe"
#    Load    "dri"
Load           "extmod"
#    Load    "glx"
Load           "xtrap"
Load           "freetype"
EndSection

Section "InputDevice"
Identifier     "Keyboard0"
Driver         "keyboard"
Option         "XkbModel" "jp106"
Option         "XkbLayout" "jp"
EndSection

Section "InputDevice"
Identifier     "Mouse0"
Driver         "mouse"
Option         "Protocol" "auto"
Option         "Device" "/dev/sysmouse"
Option         "Buttons" "6"
Option         "ZAxisMapping" "4 5"
Option         "Emulate3Buttons"
EndSection


Section "Monitor"
Identifier     "Monitor0"
VendorName     "Generic Monitor"
ModelName      "Generic"


EndSection


Section "Device"
 ### Available Driver options are:-
 ### Values: : integer, : float, : "True"/"False",
 ### : "String", : " Hz/kHz/MHz"
 ### [arg]: arg optional
 #Option     "SWcursor"            # []
 #Option     "HWcursor"      "True"  # []
 #Option     "NoAccel"             # []
 #Option     "ShadowFB"            # []
 #Option     "UseFBDev"            # []
 #Option     "Rotate"              # []
 #Option     "VideoKey"            #
 #Option     "FlatPanel"           # []
 #Option     "FPDither"            # []
 #Option     "CrtcNumber"          #
 #Option     "FPScale"             # []
 #Option     "FPTweak"             #
Identifier     "Card0"
Driver         "ati"
VendorName     "ATI Video Driver"
EndSection

Section "Screen"
Identifier     "Screen0"
Device         "Card0"
Monitor        "Monitor0"
DefaultDepth   24
SubSection     "Display"
 Depth      24
 Modes      "1024x768"
EndSubSection
EndSection

Modes "1024x768"を追記してみるが、XGAの表示とならず。