Albrechts Blog

from time to time I’ll report some stories about software I’m currently using/configuring etc.

X config for Geode based Hercules eCafe EC-800

This weekend I had to install Jaunty on an AMD Geode based Hercules eCafe EC-800 netbook.

The problem with the graphics hardware is: The X server always thinks that the display is 800×600 but it is 800×480. So you what ever you do, you cant see the bottom part of the screen. It seems, this has been introduced with Ubuntu Jaunty and continues to be that way in Karmic.

After reading the driver source it turned out, that there are (at least) two versions of AMD Geode graphics hardware: GX and LX.

The GX version accepts a PanelGeometry option, where you can specify the panel size in pixels. Most forum posters try to use this without success.

The LX version uses a PanelMode option where the ModeLine has to be specified once more. So if you have

Modeline "800x480" 33.45 800 840 968 1056 480 490 492 525 -hsync -vsync

in Section “Monitor” you need

Option "PanelMode" "33450 800 840 968 1056 480 490 492 525"

in Section “Device”. The first parameter is the pixel clock in Hertz followed by the remaining parameters for x and y resolution.

The full working xorg.conf file is here: http://www.algepop.net/users/alge/xorg.conf.eCafe-EC-800