Help wanted here.
Here is my configuration:

SGI ZX10
GFX: 3Dlabs Wildcat II
OS: Redhat 9 (fully updated)
Monitor: SGI GDM-20E21

My problem:

Wildcat II gfx board is not supported under Linux (except if I want to pay a license to XIG ~$230) but I still want to be able to boot linux on this sytem
and have a decent screen.

The only driver supported is VESA (as I said I'm fine with that); The system is booting and gfx working but X resolution is always 640x480 (depth 24) or 800x600 (depth 16) what ever is the config file I have for XF86. In addition the default X screen is always larger than the monitor

I have tested all depth and all modes , but not able to figure out how to solve this problem. Does someone has a GREAT idea ?

Thanks for all

I suspect it may be easy to fix by tweaking your XF86Config file. Please post the "Screen" section of your /etc/X11/XF86Config-4 file.

Sure I should have started with it first

Here it is
____________________________________
# XFree86 4 configuration created by redhat-config-xfree86

Section "ServerLayout"
Identifier "Default Layout"
Screen 0 "Screen0" 0 0
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "DevInputMice" "AlwaysCore"
EndSection

Section "Files"

# RgbPath is the location of the RGB database. Note, this is the name of the
# file minus the extension (like ".txt" or ".db"). There is normally
# no need to change the default.
# Multiple FontPath entries are allowed (they are concatenated together)
# By default, Red Hat 6.0 and later now use a font server independent of
# the X server to render fonts.
RgbPath "/usr/X11R6/lib/X11/rgb"
FontPath "unix/:7100"
EndSection

Section "Module"
Load "dbe"
Load "extmod"
Load "fbdevhw"
Load "glx"
Load "record"
Load "freetype"
Load "type1"
EndSection

Section "InputDevice"

# Specify which keyboard LEDs can be user-controlled (eg, with xset(1))
# Option "Xleds" "1 2 3"
# To disable the XKEYBOARD extension, uncomment XkbDisable.
# Option "XkbDisable"
# To customise the XKB settings to suit your keyboard, modify the
# lines below (which are the defaults). For example, for a non-U.S.
# keyboard, you will probably want to use:
# Option "XkbModel" "pc102"
# If you have a US Microsoft Natural keyboard, you can use:
# Option "XkbModel" "microsoft"
#
# Then to change the language, change the Layout setting.
# For example, a german layout can be obtained with:
# Option "XkbLayout" "de"
# or:
# Option "XkbLayout" "de"
# Option "XkbVariant" "nodeadkeys"
#
# If you'd like to switch the positions of your capslock and
# control keys, use:
# Option "XkbOptions" "ctrl:swapcaps"
# Or if you just want both to be control, use:
# Option "XkbOptions" "ctrl:nocaps"
#
Identifier "Keyboard0"
Driver "keyboard"
Option "XkbRules" "xfree86"
Option "XkbModel" "pc105"
Option "XkbLayout" "fr"
EndSection

Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "PS/2"
Option "Device" "/dev/psaux"
Option "ZAxisMapping" "4 5"
Option "Emulate3Buttons" "no"
EndSection

Section "InputDevice"

# If the normal CorePointer mouse is not a USB mouse then
# this input device can be used in AlwaysCore mode to let you
# also use USB mice at the same time.
Identifier "DevInputMice"
Driver "mouse"
Option "Protocol" "IMPS/2"
Option "Device" "/dev/input/mice"
Option "ZAxisMapping" "4 5"
Option "Emulate3Buttons" "no"
EndSection

Section "Monitor"
Identifier "Monitor0"
VendorName "Monitor Vendor"
ModelName "SGI 20-inch GDM-20E21"
HorizSync 30.0 - 96.0
VertRefresh 48.0 - 160.0
Option "dpms"
EndSection

Section "Device"
Identifier "Videocard0"
Driver "vesa"
VendorName "Videocard vendor"
BoardName "VESA driver (generic)"
VideoRam 65536
EndSection

Section "Screen"
Identifier "Screen0"
Device "Videocard0"
Monitor "Monitor0"
DefaultDepth 24
SubSection "Display"
Depth 16
Modes "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480"
EndSubSection
EndSection

Section "DRI"
Group 0
Mode 0666
EndSection
_________________________________________________

The strange thing is that if I run xwininfo on my RH system I have

xwininfo: Window id: 0xc00003 "Desktop"

Absolute upper-left X: 0
Absolute upper-left Y: 0
Relative upper-left X: 0
Relative upper-left Y: 0
Width: 800
Height: 600
Depth: 24
Visual Class: TrueColor
Border width: 0
Class: InputOutput
Colormap: 0x20 (installed)
Bit Gravity State: NorthWestGravity
Window Gravity State: NorthWestGravity
Backing Store State: NotUseful
Save Under State: no
Map State: IsViewable
Override Redirect State: no
Corners: +0+0 -0+0 -0-0 +0-0
-geometry 800x600+0+0


So for depth 24 the maximum is 800x600. If I switch for depth 8 I have a window of 1024x768 max, but in both case the visual is not all in the monitor. I have to play with CTRL+ALT + + (numeric pad) to scroll the desktop window.
The result is just like if I have a 640x480 monitor looking at a larger window.

Thanks

Hmm, that is strange. I have a couple of guesses: first, is the "Monitor" section correct? If the HorizSync and VertRefresh are incorrect, it's possible that X is unable to figure out how to get the higher resolutions out of your monitor. If you know those are correct (i.e., have verified them against your monitor's specifications), then you can probably rule that out.

Another thing is that maybe the generic "vesa" driver is not good enough for your video card. Obviously it'd be ridiculous to pay a $230 fee for a mere driver, but perhaps there's another generic video driver that would support your card better than the generic vesa driver. If you've already researched this, though, that may not be an option.

One thing you can check to narrow down the problem is the XFree86 log files. Look in /var/log/XFree86.0.log for messages to the effect of "no usable screens found" or the like. Lines containing errors, for example if it tried to use 1280x1024 and failed, will begin with (EE), so if there are error messages like that in the log, it may tell you what went wrong.

Beyond that, I'm afraid I don't have much to offer... hopefully someone else can lend some advice!