[Xpert]how to get virtual screen of 1024x768 ati mobility m4

[Dev Anand]

Hi,
I have a dell inspiron 8000 with ati mobility M4 32mb
I juat installed redhat 7.3. X windows is working fine
but I am only gettin resolutions of 1280x1024 and 1600x1200.
these resolutionsare too high and the fonts are hardly readable.

Is it possible to have a virtual screen size of 1024x768 ( lower
than these resolutions)

I am attaching my XF86config-4 file
thanks
Dev

# XFree86 4.2.0 configuration generated by Xconfigurator 4.10.7

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

# Red Hat Linux 6.0 and later use the xfs font server for improved
# interactive performance

Section "Files"
        FontPath "unix/:7100"
EndSection

# Module loading section

Section "Module"
        Load  "dbe"             # Double-buffering
        Load  "GLcore"          # OpenGL support
#       Load  "dri"             # Direct rendering infrastructure
        Load  "glx"             # OpenGL X protocol interface
        Load  "extmod"          # Misc. required extensions
        Load  "v4l"             # Video4Linux
        # Load  "record"        # X event recorder
        # You only need the following two modules if you do not use xfs.
        # Load  "freetype"       # TrueType font handler
        # Load  "type1"         # Adobe Type 1 font handler
EndSection

Section "InputDevice"
        Identifier  "Keyboard0"
        Driver      "keyboard"
        Option      "XkbLayout" "us"
EndSection

Section "InputDevice"
        Identifier  "Mouse0"
        Driver      "mouse"
        Option      "Device" "/dev/mouse"
        Option      "Protocol" "PS/2"
        Option      "Emulate3Buttons" "on"
        Option      "ZAxisMapping" "4 5"
EndSection

Section "Monitor"
        Identifier "Dell 1600X Laptop Display Panel"
        VendorName "Unknown"
        ModelName  "Unknown"
        HorizSync 31.5-90.0
        VertRefresh 59.0-85.0
        Option "dpms"
EndSection

Section "Device"
        Identifier "ATI Rage 128 Mobility"
        Driver "r128"
        BoardName "Unknown"
EndSection

Section "Device"
        Identifier "Linux Frame Buffer"
        Driver "fbdev"
        BoardName "Unknown"
EndSection

Section "Screen"
        Identifier "Screen0"
        Device "ATI Rage 128 Mobility"
        Monitor "Dell 1600X Laptop Display Panel"
        DefaultDepth 16
        Subsection "Display"
                Depth 16
                Modes "1024x768" "1280x1024"
        EndSubSection
EndSection

Section "DRI"
        Mode 0666
EndSection