[SOLVED] How do I get the right aspect ratio in xorg?

[hazel]

For the first time I am using xorg without an xorg.conf file. My input devices work OK but my display is distorted. There are quite wide black bars on either side and the image seems stretched in the vertical dimension.

According to xdpyinfo (output attached), my display dimensions are 320x240 mm (1600x1200 pixels). That agrees with my tape measurements of the monitor screen, but the actual illuminated area is more like 280x240 mm. I think I need to put a monitor.conf file in /etc/X11/xorg.conf.d but how do I find out what to put in it?

[Rubberman]

What kind of video adapter do you have Hazel? You can use "Xorg -configure" or if you have an nvidia card, the nvidia-config command to create an xorg.conf file (current xorg versions are not supposed to need them, but sometimes that is not the case) from its take on your hardware. That you can edit to get the effect you need.

[hazel]

I have an onboard i810 chip and I'm using the i810 kernel module with xorg's intel driver. Yes, I know it's prehistoric but that's what I've got. This latest version of xorg from Arch uses KMS but the i810 module doesn't support it. Maybe that's what's causing the problem. It's not fatal but it's annoying.

Would xorg-configure actually help? Surely it would just write out xorg's idea of how my setup works and we already know that xorg has got it wrong.

[Rubberman]

Well, this is just a swag, but it may give you some insight into how it thinks your system is configured so either editing that, or creating a new xorg.conf file may be easier for you. That's why I suggested doing that. At worst, you just delete the xorg.conf file created and be no worse off than you are now. In any case, if you boot into text mode, then you can try different configurations in xorg.conf, run startx, if that works great. If not, then exit the GUI and re-edit xorg.conf, repeating until it is working ok or you give up...

[atreyu]

For the first time I am using xorg without an xorg.conf file. My input devices work OK but my display is distorted. There are quite wide black bars on either side and the image seems stretched in the vertical dimension.

According to xdpyinfo (output attached), my display dimensions are 320x240 mm (1600x1200 pixels). That agrees with my tape measurements of the monitor screen, but the actual illuminated area is more like 280x240 mm. I think I need to put a monitor.conf file in /etc/X11/xorg.conf.d but how do I find out what to put in it?

did u try adding the DisplaySize parameter in Xorg.conf? It'd look something like this:

Section "Monitor"
        DisplaySize  380        300
EndSection

also having the proper VertRefresh and HorizSync values usually help.

you can also put your desired resolution (provided your display supports it) under the Screen section, e.g.:

Section "Screen"
        Identifier "Screen0"
        Device     "Videocard0"
        Monitor    "Monitor0"
        DefaultDepth     24
        SubSection "Display"
                Viewport   0 0
                Depth     16
                Modes    "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     24
                Modes    "1280x1024"
        EndSubSection
EndSection

Note: the display size and mode values are obviously for my system - you'll need to change those.

what i'd try to do is run "X -configure" as Rubberman suggested, then try working in the above suggestions.

[hazel]

In the end I cheated. I copied my Slackbody xorg.conf, which I know works, into a safe place within Arch and then used data from it to make a monitor.conf file in /etc/X11/xorg.conf.d. When I rebooted into Arch, I got a full screen display.

That xorg.conf file has a history! It was originally created by Ubuntu Dapper, then copied from Ubuntu -> Debian -> Crux -> Slackbody. Of course it's been edited a bit since then because a lot of the details that used to be needed for xorg to function are auto-configured now. But I've never fiddled with parameters like mode lines, hsync or vsync because I don't understand them and I understand that you can make your monitor go up in flames if you get it wrong.

Here's the file I made from it: