dear lazyweb

[zwol]

For ages and ages I have thought that my laptop (or rather, the X server) was not on speaking terms with its external monitor socket. However, today I discovered that if I plug the monitor cable in before I turn the laptop on, it works... well, I get nothing on the laptop's own screen, and the display switch hotkey doesn't do anything, but I can live with that. The real problem, though, is that the X server insists on driving the external display at the laptop's screen resolution, which is Wrong. Today's projector valiantly displayed the middle however many pixels of the image, so of course my presentation got cut off at the sides in full screen mode.

How exactly do I kick the thing into resizing its screen down to the appropriate size for the projector?

Comments

[aldren.livejournal.com]

There are a couple of ways to do it. One is to put multiple "Modes" in your Display's section, then toggle through them using Ctrl+Alt+Plus.

Other options vary depending on your video card manufacturer. I seem to recall ATI has special driver options to make multiple screens look like a single screen. nVidia might have a similar configuration section.

A lot of times the video driver will override the hotkey, so it'll work before the computer starts, but once in X you'll need to get a program made for your particular chipset.

Basically, for the quick-and-dirty hack, use Ctrl+Alt+Plus, but to come up with a more permanent solution, you'll need to get a chipset-specific solution.

[zwol.livejournal.com]

This is a laptop. It does not have keypad plus. I guess it has Ctrl-Fn-Alt-semicolon, but that doesn't work. And even if it did, it wouldn't help, because the virtual display would still be the wrong size. I hate and despise the virtual display "feature" and wish it could be killed forever.

[puppygalore.livejournal.com]

I don't suppose xrandr helps?

[zwol.livejournal.com]

Well, perhaps, but xrandr --what? (I did experiment with that at the time without success.)

[puppygalore.livejournal.com]

On my machine, xrandr by itself displays a list of resolutions and refresh rates. You can select these by number, e.g. "xrandr -s 0" for the first resolution in the list, or by name, e.g. "xrandr -s 800x600". I think you need to have several modes listed in your xorg.conf's "Screen" section for this to work usefully, e.g.

Section "Screen"
...
SubSection "Display"
Depth 24
Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubSection
EndSection

It might be worth flashing the BIOS to attempt to improve external monitor handling -- some Dell BIOS revisions have tweaked those bits at least. Be careful though, later versions don't necessarily imply bug fixes -- I've had to roll back to a previous version to get usable graphics out of Linux after "upgrading" before...

[(Anonymous)]

It's probably going to matter what video chipset you're using... latest Xorg can do all sorts of magic on Intel chips (just hitting "xrandr --auto" after plugging in a monitor has been working for me), ATI and nVidia binary drivers have their own weird custom solutions (from some point of view Intel's RandR 1.2 stuff is too, but that's the advantage of getting kp to implement your weird custom solution)...

Gnome ships with a display resolution setting thingamajig in the configuration menus, that uses the RandR extension internally, and RandR is by definition the only way you're going to change resolution without that stupid virtual desktop stuff. Perhaps that will work and let you skip decrypting the command-line tool?

-- Nathaniel