Some of the other options available in the Pointer section are shown in Table 21.6, but you shouldn’t add them to your XF86Config file unless you’re absolutely sure what effect they’ll have on your system.

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NOTE:  If you have a Logitech mouse, especially one that doesn’t emulate a Microsoft mouse, you may have to experiment with some of the options in Table 21.6.

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The Monitor Section

The Monitor section is probably the most important section of the XF86Config file—and probably the most dangerous. Misinformation in this file can cause catastrophic damage to your system, so be careful!

The SuperProbe program and your manufacturer’s documentation will help greatly in creating this section. You can also use the files /usr/X11R6/lib/X11/doc/modesDB.txt and /usr/X11R6/lib/X11/doc/monitors to search for information on your particular monitor.

A typical Monitor section follows:

Section “Monitor”

Identifier   “Sanyo 1450 NI”

VendorName   “Sanyo”

ModelName    “My 14 inch monitor”

Bandwidth     60

HorizSync    30-60

VeriRefresh  50-90

#Modes:    Name     dotclock   Horizontal Timing     Vertical Timing

ModeLine   “640x480”   25      640 672 768 800       480 490 492 525

ModeLine   “800x600”   36      800 840 912 1024      600 600 602 625

ModeLine   “1024x768i” 45      1024 1024 1224 1264   768 768 776 816

EndSection

Your Monitor section can have more than one monitor defined, so for each monitor you must supply the information shown in Table 21.7.

For each resolution, you’ll need a ModeLine entry in the Monitor section. The entry has the following format:

ModeLine “name” dotclock     Horizontal Freq Vertical Freq

The horizontal and vertical frequencies are a series of four values expressed in kHz. You can get most values from running the xf86Config program (discussed later in the section “Running the xf86Config Program”) or from the various documentation files included with the XFree86 package. For your initial test, it’s best to enter a standard configuration from the documentation and then let X probe your system for more appropriate values.

The Device Section

The Device section describes the system’s video card to XFree86. The Device section for Standard VGA looks like the following:

Section “Device”

Identifier    “SVGA”

VendorName    “Trident”

BoardName     “TVG89”

Chipset       “tvga8900c”

VideoRam      1024

Clocks        25.30 28.32 45.00 36.00 57.30 65.10 50.40 39.90

Option        ...

EndSection

The only values that might be hard to come by are the clock values. You video card uses these values to generate the clock signals that in turn provide the various frequencies needed to display information on your monitor. If you get these values really wrong, you can blow your monitor! You can get this value by running X with a special parameter, -probeonly, which allows X to scan your system without much chance of physical damage to your system (-probeonly is discussed later in this chapter). X then generates a report with most of the values needed for your configuration.

Your server may also require optional parameters. These optional entries in the Device section are detailed in the appropriate man page for your server.

The Screen Section

Your XF86Config file can contain many monitor and device entries. These entries are tied together in the Screen section to create your X desktop for your X server. A sample Screen section follows:

Section “Screen”

Driver     “vga2”

Device     “SVGA”

Monitor    “Sanyo 1450 NI”

Subsection “Display”

Depth      8

Modes      “1024x768” “800x600” “640x480”

ViewPort   0 0

Virtual    1024 768

EndSubsection

EndSection

The Screen section uses the identifier names from the Device and Monitor sections. The Driver value tells what X server you’re running and can have one of the following values:

•  Accel

•  SVGA

•  VGA16

•  VGA2

•  Mono

Within the Screen section are display subsections, which describe the various modes available for a particular resolution. Each Mode value refers back to each ModeLine value defined in the Monitor section.