X Window System (X11)

On a modern Linux system, the middle mouse button does four incredibly useful things:

• It performs fast pasting. Highlight something in one window, then click the middle mouse button in another window (or another part of the same window) and the highlighted text or graphics gets pasted in. Copy'n'paste only takes a few seconds more, but I use this so often that I'm sure the seconds would add up to days.
• It goes to a URL or performs a search in a web browser. Highlight a URL anywhere and then middle-click in a blank part of your Firefox (or Konqueror, or Galeon, or Epiphany) browser window and you'll go to that page. Or highlight a word or phrase without punctuation and click the middle mouse button in Firefox to perform an "I'm feeling lucky" Google search.
• It opens a link in a new tab in Firefox, leaving your original page open.
• It scrolls to a particular spot in your scrollbar area. If you want to scroll halfway through a document. put your cursor halfway down the scroll area and middle click -- the scrollbar will jump to where your cursor is located.
  
  

X11 conventions power some of these features, toolkits or applications power others, and some of these can be configured on other operating systems. But they're there by default on Linux, and I love the way they save me time.

No middle mouse button? Press in your scroll wheel or click the left+right buttons at the same time.

I recently updated the Nvidia drivers on my multihead Linux system and had a rude shock: the newest driver does not support my PCI-based Nvidia cards (two NV18's [GeForce4 MX 4000] and an NV17 [GeForce4 MX440]). After experimenting a bit, I realized that the Nvidia "Legacy" driver doesn't offer what I need either -- there seems to be a third driver, which is legacy-but-not-declared-legacy, the 96xx series. (On Livna, the package name for the driver is xorg-x11-drv-nvidia-96xx).

I think it's a mistake for Nvidia to stop supporting the GeForce4 video cards with the 'current' driver while those cards are still being sold. The PCI versions of the GeForce4 cards are great for multihead systems -- they have reasonable power consumption, are available in fanless versions, are inexpensive, and provide sufficient performance for basic 3D purposes (including Google Earth and even Compiz). I'm considering upgrading my 4-head home system system to a dual-core 64-bit motherboard with two PCI-Express x16 slots which will power two seats, and using two of the fanless PCI GeForce4 cards (from the existing system) for the other two seats, but I'm concerned about long-term driver support. It seems a shame to waste two perfectly good (and still available at Retail) video cards...

I just upgraded my 4-user multiseat system to Fedora Core 6 from FC4+X.org 6.9. The installation went fairly smoothly (though Anaconda fought with my [admittedly odd] RAID configuration and wanted to install the Grub bootloader code on /dev/md1; I switched to vt2 and used the Grub shell to set things right before rebooting).

One thing I wanted to try was AIGLX/Composite/Compiz. I thought that the OpenGL drivers for the cards might get tangled up, but that is not the case -- it actually works well, but the performance hit is heavy. It looks like a dual-core system and/or the upcoming AIGLX optimizations will be necessary to make it really usable.

It's also worth noting that X.org 7.1 seems to work better than 6.9 for multiseat operation; for example, the Zap key combination (Ctrl-Alt-Backspace) works fine on all seats. The old xorg.conf file needed only minor editing to take into account path and module changes and to add the Nvidia closed-source driver's AddARGBGLXVisuals option.

I read an interesting blog post at ZDnet (referring to a blog posting from Rob Scoble) that proposed that fonts might be slowing the adoption of Linux on the desktop.

You read that right: fonts. The article suggests that Linux fonts and font handling are not as good as XP's. I found that interesting, since I did a side-by-side comparison the other day in preparation for a XWN740 class.

Just for interest sake, to make it easy for you to compare fonts and font renderings, here is an image showing Windows XP and SUSE 10.1 rendering the same page (zdnet front page) in Firefox using the default font settings:



The upper portion is Windows, the lower portion is SUSE. I used the default settings because that's what most users will see.

Continue reading "Windows vs. Linux Fonts" »

Several people have reported that their attempt to create a multiseat configuration has resulted in a situation where:

• The displays initialize in sequence, but


• Only the last display is active (the mouse pointer moves, the cursor blinks, and so forth) even though all displays show a valid image (e.g., session login display from kdm or gdm).

This problem is apparently caused by card initialization problems. The BIOS code on some cards tries to initialize other cards, which can produce this symptom, display shutdown on other cards, or system lockups.

Continue reading "Multiseat Issues with Nvidia Cards" »

I keep getting inquiries about multiseat X configuration under X11R6.9/7.0 and Linux. It's no longer necessary to patch the kernel or the X server to get this to work - you can set everything up in the xorg.conf file.

Here is a temporary mini-Howto document that I've put together. I'll write a better one when X11R6.9/7.0 is finalized (and time permits ) ... and there will be a chapter on the topic in one of my upcoming books. In the meantime, have fun! -- please let me know what experiences you have trying this out (positive or negative) -- in particular, it would be great to have reports on which video card combinations work or do not work.

(For those new the term "Multiseat X", it means creating a system with mulitple video monitors, keyboards, and mice for simultaneous use by multiple users -- like my home system).

Continue reading "Multiseat X Under X11R6.9/7.0" »