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NAME

       xorg.conf - Configuration File for Xorg

INTRODUCTION

       Xorg  supports several mechanisms for supplying/obtaining configuration
       and run-time parameters: command line options,  environment  variables,
       the   xorg.conf   configuration   file,  auto-detection,  and  fallback
       defaults.  When the same information is supplied in more than one  way,
       the  highest  precedence  mechanism is used.  The list of mechanisms is
       ordered  from  highest  precedence  to  lowest.   Note  that  not   all
       parameters can be supplied via all methods.  The available command line
       options and environment variables (and some defaults) are described  in
       the  Xserver(1x)  and  Xorg(1x)  manual pages.  Most configuration file
       parameters, with their  defaults,  are  described  below.   Driver  and
       module  specific configuration parameters are described in the relevant
       driver or module manual page.

DESCRIPTION

       Xorg uses a configuration file called xorg.conf for its initial  setup.
       This  configuration  file  is searched for in the following places when
       the server is started as a normal user:

           /etc/X11/<cmdline>
           /usr/etc/X11/<cmdline>
           /etc/X11/$XORGCONFIG
           /usr/etc/X11/$XORGCONFIG
           /etc/X11/xorg.conf-4
           /etc/X11/xorg.conf
           /etc/xorg.conf
           /usr/etc/X11/xorg.conf.<hostname>
           /usr/etc/X11/xorg.conf-4
           /usr/etc/X11/xorg.conf
           /usr/lib/X11/xorg.conf.<hostname>
           /usr/lib/X11/xorg.conf-4
           /usr/lib/X11/xorg.conf

       where <cmdline> is a relative path (with no ".." components)  specified
       with  the -config command line option, $XORGCONFIG is the relative path
       (with no ".." components) specified by that environment  variable,  and
       <hostname> is the machine’s hostname as reported by gethostname(3).

       When  the  Xorg  server  is started by the "root" user, the config file
       search locations are as follows:

           <cmdline>
           /etc/X11/<cmdline>
           /usr/etc/X11/<cmdline>
           $XORGCONFIG
           /etc/X11/$XORGCONFIG
           /usr/etc/X11/$XORGCONFIG
           $HOME/xorg.conf
           /etc/X11/xorg.conf-4
           /etc/X11/xorg.conf
           /etc/xorg.conf
           /usr/etc/X11/xorg.conf.<hostname>
           /usr/etc/X11/xorg.conf-4
           /usr/etc/X11/xorg.conf
           /usr/lib/X11/xorg.conf.<hostname>
           /usr/lib/X11/xorg.conf-4
           /usr/lib/X11/xorg.conf

       where <cmdline> is the path specified with  the  -config  command  line
       option  (which  may  be  absolute or relative), $XORGCONFIG is the path
       specified by that environment variable (absolute or relative), $HOME is
       the  path  specified  by  that  environment  variable (usually the home
       directory), and <hostname> is the machine’s  hostname  as  reported  by
       gethostname(3).

       The  xorg.conf  file  is  composed of a number of sections which may be
       present in any order.  Each section has the form:

           Section  "SectionName"
               SectionEntry
               ...
           EndSection

       The section names are:

           Files          File pathnames
           ServerFlags    Server flags
           Module         Dynamic module loading
           InputDevice    Input device description
           Device         Graphics device description
           VideoAdaptor   Xv video adaptor description
           Monitor        Monitor description
           Modes          Video modes descriptions
           Screen         Screen configuration
           ServerLayout   Overall layout
           DRI            DRI-specific configuration
           Vendor         Vendor-specific configuration

       The  following  obsolete  section  names  are  still   recognised   for
       compatibility  purposes.   In new config files, the InputDevice section
       should be used instead.

           Keyboard       Keyboard configuration
           Pointer        Pointer/mouse configuration

       The old XInput section is no longer recognised.

       The ServerLayout sections are at the highest level.  They bind together
       the input and output devices that will be used in a session.  The input
       devices are described in  the  InputDevice  sections.   Output  devices
       usually  consist  of  multiple independent components (e.g., a graphics
       board and a monitor).  These multiple components are bound together  in
       the  Screen  sections,  and  it  is  these  that  are referenced by the
       ServerLayout section.  Each Screen section binds  together  a  graphics
       board  and  a monitor.  The graphics boards are described in the Device
       sections, and the monitors are described in the Monitor sections.

       Config file keywords  are  case-insensitive,  and  "_"  characters  are
       ignored.    Most  strings  (including  Option  names)  are  also  case-
       insensitive, and insensitive to white space and "_" characters.

       Each config file entry usually takes up a  single  line  in  the  file.
       They  consist  of  a keyword, which is possibly followed by one or more
       arguments, with the number and types of the arguments depending on  the
       keyword.  The argument types are:

           Integer     an integer number in decimal, hex or octal
           Real        a floating point number
           String      a string enclosed in double quote marks (")

       Note:  hex  integer values must be prefixed with "0x", and octal values
       with "0".

       A special keyword called Option may be used to provide  free-form  data
       to  various  components of the server.  The Option keyword takes either
       one or two string arguments.  The first is the  option  name,  and  the
       optional  second  argument  is  the  option  value.  Some commonly used
       option value types include:

           Integer     an integer number in decimal, hex or octal
           Real        a floating point number
           String      a sequence of characters
           Boolean     a boolean value (see below)
           Frequency   a frequency value (see below)

       Note that all Option values, not just  strings,  must  be  enclosed  in
       quotes.

       Boolean  options  may optionally have a value specified.  When no value
       is specified, the option’s value is TRUE.  The following boolean option
       values are recognised as TRUE:

           1, on, true, yes

       and the following boolean option values are recognised as FALSE:

           0, off, false, no

       If  an  option  name  is  prefixed  with "No", then the option value is
       negated.

       Example: the following option entries are equivalent:

           Option "Accel"   "Off"
           Option "NoAccel"
           Option "NoAccel" "On"
           Option "Accel"   "false"
           Option "Accel"   "no"

       Frequency option values consist of a real  number  that  is  optionally
       followed by one of the following frequency units:

           Hz, k, kHz, M, MHz

       When  the  unit  name  is omitted, the correct units will be determined
       from the value and the expectations of the  appropriate  range  of  the
       value.  It is recommended that the units always be specified when using
       frequency option values to avoid any errors in determining the value.

FILES SECTION

       The Files section is used to specify some path names  required  by  the
       server.  Some of these paths can also be set from the command line (see
       Xserver(1x) and Xorg(1x)).  The  command  line  settings  override  the
       values specified in the config file.  The Files section is optional, as
       are all of the entries that may appear in it.

       The entries that can appear in this section are:

       FontPath "path"
              sets the search path for fonts.  This path is a comma  separated
              list  of  font  path elements which the Xorg server searches for
              font databases.  Multiple FontPath entries may be specified, and
              they  will  be concatenated to build up the fontpath used by the
              server.  Font path elements may  be  either  absolute  directory
              paths,  or  a  font  server identifier.  Font server identifiers
              have the form:

                  <trans>/<hostname>:<port-number>

              where <trans> is the transport type to use  to  connect  to  the
              font  server  (e.g.,  unix  for UNIX-domain sockets or tcp for a
              TCP/IP connection), <hostname> is the hostname  of  the  machine
              running  the  font  server, and <port-number> is the port number
              that the font server is listening on (usually 7100).

              When this entry is not specified in the config file, the  server
              falls  back to the compiled-in default font path, which contains
              the following font path elements:

                  /usr/lib/X11/fonts/misc/
                  /usr/lib/X11/fonts/TTF/
                  /usr/lib/X11/fonts/Type1/
                  /usr/lib/X11/fonts/CID/
                  /usr/lib/X11/fonts/75dpi/
                  /usr/lib/X11/fonts/100dpi/

              The recommended font  path  contains  the  following  font  path
              elements:

                  /usr/lib/X11/fonts/local/
                  /usr/lib/X11/fonts/misc/
                  /usr/lib/X11/fonts/75dpi/:unscaled
                  /usr/lib/X11/fonts/100dpi/:unscaled
                  /usr/lib/X11/fonts/Type1/
                  /usr/lib/X11/fonts/CID/
                  /usr/lib/X11/fonts/Speedo/
                  /usr/lib/X11/fonts/75dpi/
                  /usr/lib/X11/fonts/100dpi/

              Font path elements that are found to be invalid are removed from
              the font path when the server starts up.

       RGBPath "path"
              sets the path name for the RGB color database.  When this  entry
              is  not  specified  in the config file, the server falls back to
              the compiled-in default RGB path, which is:

                  /usr/lib/X11/rgb

       Note that an implicit .txt is added to this  path  if  the  server  was
       compiled to use text rather than binary format RGB color databases.

       ModulePath "path"
              sets  the  search  path  for loadable Xorg server modules.  This
              path is a comma separated list of  directories  which  the  Xorg
              server  searches  for  loadable  modules  loading  in  the order
              specified.  Multiple ModulePath entries may  be  specified,  and
              they  will  be concatenated to build the module search path used
              by the server.

SERVERFLAGS SECTION

       In addition to options specific to this section (described below),  the
       ServerFlags section is used to specify some global Xorg server options.
       All  of  the  entries  in  this  section  are  Options,  although   for
       compatibility  purposes  some  of  the  old  style  entries  are  still
       recognised.  Those old style entries are not documented here, and using
       them  is  discouraged.  The ServerFlags section is optional, as are the
       entries that may be specified in it.

       Options  specified  in  this  section  (with  the  exception   of   the
       "DefaultServerLayout" Option) may be overridden by Options specified in
       the active ServerLayout section.  Options with command line equivalents
       are overridden when their command line equivalent is used.  The options
       recognised by this section are:

       Option "DefaultServerLayout"  "layout-id"
              This specifies the default ServerLayout section to  use  in  the
              absence of the -layout command line option.

       Option "NoTrapSignals"  "boolean"
              This   prevents  the  Xorg  server  from  trapping  a  range  of
              unexpected fatal signals and exiting cleanly.  Instead, the Xorg
              server  will  die  and  drop core where the fault occurred.  The
              default behaviour is for the Xorg server to  exit  cleanly,  but
              still  drop  a core file.  In general you never want to use this
              option unless you are debugging an Xorg server problem and  know
              how to deal with the consequences.

       Option "DontVTSwitch"  "boolean"
              This  disallows  the  use  of the Ctrl+Alt+Fn sequence (where Fn
              refers to one of the numbered function keys).  That sequence  is
              normally  used  to  switch  to  another  "virtual  terminal"  on
              operating systems that have this feature.  When this  option  is
              enabled,  that key sequence has no special meaning and is passed
              to clients.  Default: off.

       Option "DontZap"  "boolean"
              This disallows the use of the Ctrl+Alt+Backspace sequence.  That
              sequence  is  normally  used to terminate the Xorg server.  When
              this option is enabled, that key sequence has no special meaning
              and is passed to clients.  Default: off.

       Option "DontZoom"  "boolean"
              This   disallows   the   use  of  the  Ctrl+Alt+Keypad-Plus  and
              Ctrl+Alt+Keypad-Minus sequences.  These sequences allows you  to
              switch  between video modes.  When this option is enabled, those
              key sequences have no special meaning and are passed to clients.
              Default: off.

       Option "DisableVidModeExtension"  "boolean"
              This  disables  the  parts  of the VidMode extension used by the
              xvidtune client that can be used  to  change  the  video  modes.
              Default: the VidMode extension is enabled.

       Option "AllowNonLocalXvidtune"  "boolean"
              This  allows the xvidtune client (and other clients that use the
              VidMode extension) to connect from another host.  Default:  off.

       Option "DisableModInDev"  "boolean"
              This  disables  the parts of the Xorg-Misc extension that can be
              used to modify the input device settings dynamically.   Default:
              that functionality is enabled.

       Option "AllowNonLocalModInDev"  "boolean"
              This  allows  a  client  to connect from another host and change
              keyboard and mouse settings in  the  running  server.   Default:
              off.

       Option "AllowMouseOpenFail"  "boolean"
              This  allows  the  server  to  start up even if the mouse device
              can’t be opened/initialised.  Default: false.

       Option "VTInit"  "command"
              Runs command after the VT used by the server  has  been  opened.
              The  command  string  is passed to "/bin/sh -c", and is run with
              the real user’s id with stdin and stdout set  to  the  VT.   The
              purpose   of  this  option  is  to  allow  system  dependent  VT
              initialisation commands to be run.  This option should rarely be
              needed.  Default: not set.

       Option "VTSysReq"  "boolean"
              enables  the  SYSV-style VT switch sequence for non-SYSV systems
              which support VT switching.  This sequence is Alt-SysRq followed
              by  a function key (Fn).  This prevents the Xorg server trapping
              the keys used for the default VT switch  sequence,  which  means
              that clients can access them.  Default: off.

       Option "XkbDisable" "boolean"
              disable/enable  the  XKEYBOARD  extension.  The -kb command line
              option overrides this  config  file  option.   Default:  XKB  is
              enabled.

       Option "BlankTime"  "time"
              sets  the  inactivity  timeout  for  the  blanking  phase of the
              screensaver.  time is in minutes.  This  is  equivalent  to  the
              Xorg  server’s  ‘-s’  flag, and the value can be changed at run-
              time with xset(1x).  Default: 10 minutes.

       Option "StandbyTime"  "time"
              sets the inactivity timeout for  the  "standby"  phase  of  DPMS
              mode.   time is in minutes, and the value can be changed at run-
              time with xset(1x).  Default: 20 minutes.  This is only suitable
              for  VESA  DPMS compatible monitors, and may not be supported by
              all video drivers.  It is only enabled for screens that have the
              "DPMS" option set (see the MONITOR section below).

       Option "SuspendTime"  "time"
              sets  the  inactivity  timeout  for  the "suspend" phase of DPMS
              mode.  time is in minutes, and the value can be changed at  run-
              time with xset(1x).  Default: 30 minutes.  This is only suitable
              for VESA DPMS compatible monitors, and may not be  supported  by
              all video drivers.  It is only enabled for screens that have the
              "DPMS" option set (see the MONITOR section below).

       Option "OffTime"  "time"
              sets the inactivity timeout for the "off" phase  of  DPMS  mode.
              time  is  in  minutes,  and the value can be changed at run-time
              with xset(1x).  Default: 40 minutes.  This is only suitable  for
              VESA  DPMS  compatible monitors, and may not be supported by all
              video drivers.  It is only enabled for  screens  that  have  the
              "DPMS" option set (see the MONITOR section below).

       Option "Pixmap"  "bpp"
              This sets the pixmap format to use for depth 24.  Allowed values
              for bpp are 24 and 32.  Default: 32  unless  driver  constraints
              don’t  allow  this  (which  is  rare).  Note: some clients don’t
              behave well when this value is set to 24.

       Option "PC98"  "boolean"
              Specify that the machine is  a  Japanese  PC-98  machine.   This
              should  not  be  enabled  for  anything other than the Japanese-
              specific PC-98 architecture.  Default: auto-detected.

       Option "NoPM"  "boolean"
              Disables something to do with power management events.  Default:
              PM enabled on platforms that support it.

       Option "Xinerama"  "boolean"
              enable or disable XINERAMA extension. Default is disabled.

       Option "AllowDeactivateGrabs" "boolean"
              This  option  enables  the use of the Ctrl+Alt+Keypad-Divide key
              sequence to deactivate any  active  keyboard  and  mouse  grabs.
              Default: off.

       Option "AllowClosedownGrabs" "boolean"
              This  option enables the use of the Ctrl+Alt+Keypad-Multiply key
              sequence to kill clients with an active keyboard or  mouse  grab
              as  well  as  killing  any  application that may have locked the
              server,  normally  using  the  XGrabServer(3x)  Xlib   function.
              Default: off.
              Note     that     the     options    AllowDeactivateGrabs    and
              AllowClosedownGrabs will allow users to remove the grab used  by
              screen saver/locker programs.  An API was written to such cases.
              If you enable this option, make sure your screen saver/locker is
              updated.

       Option "HandleSpecialKeys" "when"
              This option controls when the server uses the builtin handler to
              process special key combinations (such  as  Ctrl+Alt+Backspace).
              Normally  the  XKEYBOARD extension keymaps will provide mappings
              for each of the special key combinations, so the builtin handler
              is  not  needed unless the XKEYBOARD extension is disabled.  The
              value of when can be Always, Never, or WhenNeeded.  Default: Use
              the  builtin  handler  only if needed.  The server will scan the
              keymap for a mapping to the Terminate action and, if found,  use
              XKEYBOARD  for processing actions, otherwise the builtin handler
              will be used.

MODULE SECTION

       The Module section is used to specify which Xorg server modules  should
       be  loaded.   This  section is ignored when the Xorg server is built in
       static form.  The types of modules normally loaded in this section  are
       Xorg server extension modules, and font rasteriser modules.  Most other
       module types are loaded automatically when they are  needed  via  other
       mechanisms.   The Module section is optional, as are all of the entries
       that may be specified in it.

       Entries in this section may be in  two  forms.    The  first  and  most
       commonly used form is an entry that uses the Load keyword, as described
       here:

       Load  "modulename"
              This instructs the server to load the module called  modulename.
              The  module name given should be the module’s standard name, not
              the module file name.  The standard name is case-sensitive,  and
              does  not  include the "lib" prefix, or the ".a", ".o", or ".so"
              suffixes.

              Example: the Type 1 font  rasteriser  can  be  loaded  with  the
              following entry:

                  Load "type1"

       The  second  form  of  entry  is a SubSection, with the subsection name
       being the module name, and the contents of the SubSection being Options
       that are passed to the module when it is loaded.

       Example:  the  extmod  module  (which contains a miscellaneous group of
       server extensions) can be loaded, with the Xorg-DGA extension  disabled
       by using the following entry:

           SubSection "extmod"
              Option  "omit XFree86-DGA"
           EndSubSection

       Modules  are searched for in each directory specified in the ModulePath
       search path, and in the drivers, input, extensions, fonts, and internal
       subdirectories  of  each  of  those  directories.  In addition to this,
       operating system specific subdirectories of all the above are  searched
       first if they exist.

       To  see  what  font  and  extension  modules  are  available, check the
       contents of the following directories:

           /usr/lib/modules/fonts
           /usr/lib/modules/extensions

       The "bitmap" font modules is loaded automatically.  It  is  recommended
       that  at  very  least  the  "extmod" extension module be loaded.  If it
       isn’t some commonly used server extensions (like the  SHAPE  extension)
       will not be available.

INPUTDEVICE SECTION

       The  config  file  may  have multiple InputDevice sections.  There will
       normally be at least two: one for the core (primary) keyboard, and  one
       of  the  core  pointer.   If  either of these two is missing, a default
       configuration for the missing ones will be used.  Currently the default
       configuration may not work as expected on all platforms.

       InputDevice sections have the following format:

           Section "InputDevice"
               Identifier "name"
               Driver     "inputdriver"
               options
               ...
           EndSection

       The  Identifier  and  Driver  entries  are  required in all InputDevice
       sections.  All other entries are optional.

       The Identifier entry specifies the unique name for this  input  device.
       The Driver entry specifies the name of the driver to use for this input
       device.  When using  the  loadable  server,  the  input  driver  module
       "inputdriver"  will  be loaded for each active InputDevice section.  An
       InputDevice section is considered active if  it  is  referenced  by  an
       active  ServerLayout  section,  if it is referenced by the -keyboard or
       -pointer command line options, or if it is selected implicitly  as  the
       core  pointer  or  keyboard  device  in  the  absence  of such explicit
       references.  The most commonly used input drivers  are  "keyboard"  and
       "mouse".

       In  the absence of an explicitly specified core input device, the first
       InputDevice marked as CorePointer (or CoreKeyboard) is used.  If  there
       is  no  match  there,  the  first InputDevice that uses the "mouse" (or
       "keyboard" or "kbd") driver is used.  The  final  fallback  is  to  use
       built-in default configurations.

       InputDevice  sections  recognise some driver-independent Options, which
       are described here.  See the individual input driver manual pages for a
       description of the device-specific options.

       Option "CorePointer"
              When  this  is  set,  the  input device is installed as the core
              (primary) pointer  device.   There  must  be  exactly  one  core
              pointer.  If this option is not set here, or in the ServerLayout
              section, or from the -pointer  command  line  option,  then  the
              first  input  device  that  is  capable  of being used as a core
              pointer will be selected as the core pointer.   This  option  is
              implicitly set when the obsolete Pointer section is used.

       Option "CoreKeyboard"
              When  this  is  set,  the input device is to be installed as the
              core (primary) keyboard device.  There must be exactly one  core
              keyboard.   If  this option is not set here, in the ServerLayout
              section, or from the -keyboard command  line  option,  then  the
              first  input  device  that  is  capable  of being used as a core
              keyboard will be selected as the core keyboard.  This option  is
              implicitly set when the obsolete Keyboard section is used.

       Option "AlwaysCore"  "boolean"

       Option "SendCoreEvents"  "boolean"
              Both of these options are equivalent, and when enabled cause the
              input device to always report core events.  This  can  be  used,
              for  example,  to allow an additional pointer device to generate
              core pointer events (like moving the cursor, etc).

       Option "HistorySize"  "number"
           Sets the motion history size.  Default: 0.

       Option "SendDragEvents"  "boolean"
              ???

DEVICE SECTION

       The config file may have multiple Device sections.  There  must  be  at
       least one, for the video card being used.

       Device sections have the following format:

           Section "Device"
               Identifier "name"
               Driver     "driver"
               entries
               ...
           EndSection

       The  Identifier and Driver entries are required in all Device sections.
       All other entries are optional.

       The Identifier entry  specifies  the  unique  name  for  this  graphics
       device.   The  Driver entry specifies the name of the driver to use for
       this graphics device.  When  using  the  loadable  server,  the  driver
       module  "driver"  will  be  loaded  for  each active Device section.  A
       Device section is considered active if it is referenced  by  an  active
       Screen section.

       Device  sections recognise some driver-independent entries and Options,
       which are described here.  Not all drivers make use  of  these  driver-
       independent entries, and many of those that do don’t require them to be
       specified because the information is auto-detected.  See the individual
       graphics  driver  manual  pages for further information about this, and
       for a description of the device-specific options.  Note  that  most  of
       the Options listed here (but not the other entries) may be specified in
       the Screen section instead of here in the Device section.

       BusID  "bus-id"
              This specifies the bus  location  of  the  graphics  card.   For
              PCI/AGP    cards,    the    bus-id    string    has   the   form
              PCI:bus:device:function (e.g., "PCI:1:0:0" might be  appropriate
              for an AGP card).  This field is usually optional in single-head
              configurations when using the primary graphics card.  In  multi-
              head  configurations, or when using a secondary graphics card in
              a single-head configuration, this entry is mandatory.  Its  main
              purpose  is to make an unambiguous connection between the device
              section and the hardware it is representing.   This  information
              can  usually  be  found  by  running  the  Xorg  server with the
              -scanpci command line option.

       Screen  number
              This option is mandatory for cards where a single PCI entity can
              drive  more  than  one  display  (i.e., multiple CRTCs sharing a
              single graphics  accelerator  and  video  memory).   One  Device
              section is required for each head, and this parameter determines
              which head each of the Device sections applies  to.   The  legal
              values  of number range from 0 to one less than the total number
              of heads per entity.  Most  drivers  require  that  the  primary
              screen (0) be present.

       Chipset  "chipset"
              This  usually  optional  entry specifies the chipset used on the
              graphics board.  In  most  cases  this  entry  is  not  required
              because  the  drivers  will  probe the hardware to determine the
              chipset type.   Don’t  specify  it  unless  the  driver-specific
              documentation recommends that you do.

       Ramdac  "ramdac-type"
              This  optional  entry  specifies  the type of RAMDAC used on the
              graphics board.  This is only used by a few of the drivers,  and
              in  most cases it is not required because the drivers will probe
              the hardware to determine the RAMDAC type where possible.  Don’t
              specify  it  unless the driver-specific documentation recommends
              that you do.

       DacSpeed  speed

       DacSpeed  speed-8 speed-16 speed-24 speed-32
              This optional entry specifies the RAMDAC speed rating (which  is
              usually printed on the RAMDAC chip).  The speed is in MHz.  When
              one value is given, it applies to all framebuffer  pixel  sizes.
              When  multiple  values  are  give, they apply to the framebuffer
              pixel sizes 8, 16, 24 and 32 respectively.  This is not used  by
              many  drivers,  and  only  needs  to be specified when the speed
              rating of the RAMDAC is different from the defaults built in  to
              driver,  or  when  the  driver  can’t  auto-detect  the  correct
              defaults.   Don’t  specify   it   unless   the   driver-specific
              documentation recommends that you do.

       Clocks  clock ...
              specifies the pixel that are on your graphics board.  The clocks
              are in MHz, and may be specified as  a  floating  point  number.
              The value is stored internally to the nearest kHz.  The ordering
              of the clocks is important.  It must match the  order  in  which
              they  are selected on the graphics board.  Multiple Clocks lines
              may be specified, and each is concatenated  to  form  the  list.
              Most  drivers do not use this entry, and it is only required for
              some older boards with non-programmable clocks.   Don’t  specify
              this  entry  unless the driver-specific documentation explicitly
              recommends that you do.

       ClockChip  "clockchip-type"
              This optional entry is used to specify the clock  chip  type  on
              graphics boards which have a programmable clock generator.  Only
              a few  Xorg  drivers  support  programmable  clock  chips.   For
              details, see the appropriate driver manual page.

       VideoRam  mem
              This  optional  entry  specifies the amount of video ram that is
              installed on the graphics board. This is measured in kBytes.  In
              most  cases  this is not required because the Xorg server probes
              the graphics board to  determine  this  quantity.   The  driver-
              specific  documentation should indicate when it might be needed.

       BiosBase  baseaddress
              This optional entry specifies the base address of the video BIOS
              for  the VGA board.  This address is normally auto-detected, and
              should only be specified if  the  driver-specific  documentation
              recommends it.

       MemBase  baseaddress
              This  optional  entry  specifies  the  memory  base address of a
              graphics board’s linear frame buffer.  This entry is not used by
              many  drivers,  and  it  should only be specified if the driver-
              specific documentation recommends it.

       IOBase  baseaddress
              This optional entry specifies the IO base address.   This  entry
              is  not used by many drivers, and it should only be specified if
              the driver-specific documentation recommends it.

       ChipID  id
              This optional entry specifies a numerical  ID  representing  the
              chip  type.   For  PCI cards, it is usually the device ID.  This
              can be used to override the auto-detection, but that should only
              be done when the driver-specific documentation recommends it.

       ChipRev  rev
              This  optional  entry  specifies the chip revision number.  This
              can be used to override the auto-detection, but that should only
              be done when the driver-specific documentation recommends it.

       TextClockFreq  freq
              This  optional entry specifies the pixel clock frequency that is
              used for the regular text mode.  The frequency is  specified  in
              MHz.  This is rarely used.

       Options
              Option  flags  may  be  specified in the Device sections.  These
              include driver-specific options and driver-independent  options.
              The  former  are described in the driver-specific documentation.
              Some of the latter are described below in the section about  the
              Screen section, and they may also be included here.

VIDEOADAPTOR SECTION

       Nobody wants to say how this works.  Maybe nobody knows ...

MONITOR SECTION

       The  config  file  may  have  multiple  Monitor sections.  There should
       normally be at least one, for the monitor being  used,  but  a  default
       configuration will be created when one isn’t specified.

       Monitor sections have the following format:

           Section "Monitor"
               Identifier "name"
               entries
               ...
           EndSection

       The  only mandatory entry in a Monitor section is the Identifier entry.

       The Identifier entry specifies the unique name for this  monitor.   The
       Monitor  section  provides  information about the specifications of the
       monitor, monitor-specific Options,  and  information  about  the  video
       modes  to  use  with  the  monitor.  Specifying video modes is optional
       because the server now has a built-in  list  of  VESA  standard  modes.
       When  modes  are  specified explicitly in the Monitor section (with the
       Modes, ModeLine, or UseModes keywords), built-in modes  with  the  same
       names  are  not  included.   Built-in  modes  with different names are,
       however, still implicitly included.

       The entries that may be used in Monitor sections are described below.

       VendorName  "vendor"
              This optional entry specifies the monitor’s manufacturer.

       ModelName  "model"
              This optional entry specifies the monitor’s model.

       HorizSync  horizsync-range
              gives the range(s) of horizontal sync frequencies  supported  by
              the  monitor.   horizsync-range may be a comma separated list of
              either discrete values or ranges of values.  A range  of  values
              is two values separated by a dash.  By default the values are in
              units of kHz.  They may be specified in MHz or Hz if MHz  or  Hz
              is added to the end of the line.  The data given here is used by
              the Xorg server to determine  if  video  modes  are  within  the
              specifications  of  the  monitor.   This  information  should be
              available in the monitor’s handbook.  If this entry is  omitted,
              a default range of 28-33kHz is used.

       VertRefresh  vertrefresh-range
              gives  the range(s) of vertical refresh frequencies supported by
              the monitor.  vertrefresh-range may be a comma separated list of
              either  discrete  values or ranges of values.  A range of values
              is two values separated by a dash.  By default the values are in
              units  of Hz.  They may be specified in MHz or kHz if MHz or kHz
              is added to the end of the line.  The data given here is used by
              the  Xorg  server  to  determine  if  video modes are within the
              specifications of  the  monitor.   This  information  should  be
              available  in the monitor’s handbook.  If this entry is omitted,
              a default range of 43-72Hz is used.

       DisplaySize  width height
              This optional entry gives the width and height, in  millimetres,
              of  the  picture  area  of the monitor. If given this is used to
              calculate the horizontal and vertical pitch (DPI) of the screen.

       Gamma  gamma-value

       Gamma  red-gamma green-gamma blue-gamma
              This  is an optional entry that can be used to specify the gamma
              correction for the monitor.  It may be  specified  as  either  a
              single value or as three separate RGB values.  The values should
              be in the range 0.1 to 10.0, and the default is  1.0.   Not  all
              drivers are capable of using this information.

       UseModes  "modesection-id"
              Include  the  set  of  modes  listed in the Modes section called
              modesection-id.  This make all of  the  modes  defined  in  that
              section available for use by this monitor.

       Mode  "name"
              This is an optional multi-line entry that can be used to provide
              definitions for video modes for the monitor.  In most cases this
              isn’t  necessary because the built-in set of VESA standard modes
              will be sufficient.  The Mode keyword indicates the start  of  a
              multi-line  video  mode  description.   The  mode description is
              terminated with  the  EndMode  keyword.   The  mode  description
              consists of the following entries:

              DotClock  clock
                  is the dot (pixel) clock rate to be used for the mode.

              HTimings  hdisp hsyncstart hsyncend htotal
                  specifies the horizontal timings for the mode.

              VTimings  vdisp vsyncstart vsyncend vtotal
                  specifies the vertical timings for the mode.

              Flags  "flag" ...
                  specifies  an optional set of mode flags, each of which is a
                  separate string in  double  quotes.   "Interlace"  indicates
                  that  the mode is interlaced.  "DoubleScan" indicates a mode
                  where each scanline is doubled.  "+HSync" and  "-HSync"  can
                  be  used  to  select  the  polarity  of  the  HSync  signal.
                  "+VSync" and "-VSync" can be used to select the polarity  of
                  the  VSync  signal.   "Composite"  can  be  used  to specify
                  composite  sync  on  hardware  where  this   is   supported.
                  Additionally, on some hardware, "+CSync" and "-CSync" may be
                  used to select the composite sync polarity.

              HSkew  hskew
                  specifies the number of pixels (towards the  right  edge  of
                  the  screen)  by  which  the  display enable signal is to be
                  skewed.  Not all drivers use this information.  This  option
                  might   become  necessary  to  override  the  default  value
                  supplied by the server (if any).  "Roving" horizontal  lines
                  indicate  this value needs to be increased.  If the last few
                  pixels on a scan line appear on the left of the screen, this
                  value should be decreased.

              VScan  vscan
                  specifies  the  number  of times each scanline is painted on
                  the screen.  Not all drivers use this  information.   Values
                  less  than  1  are  treated  as  1,  which  is  the default.
                  Generally, the "DoubleScan"  Flag  mentioned  above  doubles
                  this value.

       ModeLine  "name" mode-description
              This  entry  is a more compact version of the Mode entry, and it
              also can be used to specify video modes for the monitor.   is  a
              single  line  format  for specifying video modes.  In most cases
              this isn’t necessary because the built-in set of  VESA  standard
              modes will be sufficient.

              The  mode-description  is  in  four sections, the first three of
              which are mandatory.  The first is the dot (pixel) clock.   This
              is  a single number specifying the pixel clock rate for the mode
              in MHz.  The second section is a list of four numbers specifying
              the   horizontal   timings.    These   numbers  are  the  hdisp,
              hsyncstart, hsyncend, and htotal values.  The third section is a
              list  of  four  numbers  specifying the vertical timings.  These
              numbers are the vdisp, vsyncstart, vsyncend, and vtotal  values.
              The   final   section  is  a  list  of  flags  specifying  other
              characteristics of the mode.  Interlace indicates that the  mode
              is  interlaced.  DoubleScan indicates a mode where each scanline
              is doubled.  +HSync  and  -HSync  can  be  used  to  select  the
              polarity  of the HSync signal.  +VSync and -VSync can be used to
              select the polarity of the VSync signal.  Composite can be  used
              to  specify  composite sync on hardware where this is supported.
              Additionally, on some hardware, +CSync and -CSync may be used to
              select the composite sync polarity.  The HSkew and VScan options
              mentioned above in the Modes entry description can also be  used
              here.

       Options
              Some  Option  flags  that  may  be  useful to include in Monitor
              sections (when needed) include "DPMS", and "SyncOnGreen".

MODES SECTION

       The config file may have  multiple  Modes  sections,  or  none.   These
       sections provide a way of defining sets of video modes independently of
       the Monitor sections.  Monitor sections  may  include  the  definitions
       provided  in  these  sections  by  using the UseModes keyword.  In most
       cases the Modes sections are not necessary because the built-in set  of
       VESA standard modes will be sufficient.

       Modes sections have the following format:

           Section "Modes"
               Identifier "name"
               entries
               ...
           EndSection

       The  Identifier  entry  specifies  the unique name for this set of mode
       descriptions.  The other entries permitted in Modes  sections  are  the
       Mode  and  ModeLine  entries  that  are  described above in the Monitor
       section.

SCREEN SECTION

       The config file may have multiple Screen sections.  There  must  be  at
       least  one,  for  the  "screen"  being used.  A "screen" represents the
       binding of a graphics device (Device section) and  a  monitor  (Monitor
       section).   A Screen section is considered "active" if it is referenced
       by an active ServerLayout  section  or  by  the  -screen  command  line
       option.  If neither of those is present, the first Screen section found
       in the config file is considered the active one.

       Screen sections have the following format:

           Section "Screen"
               Identifier "name"
               Device     "devid"
               Monitor    "monid"
               entries
               ...
               SubSection "Display"
                  entries
                  ...
               EndSubSection
               ...
           EndSection

       The Identifier and  Device  entries  are  mandatory.   All  others  are
       optional.

       The  Identifier  entry  specifies the unique name for this screen.  The
       Screen section provides  information  specific  to  the  whole  screen,
       including screen-specific Options.  In multi-head configurations, there
       will be multiple active  Screen  sections,  one  for  each  head.   The
       entries available for this section are:

       Device  "device-id"
              This mandatory entry specifies the Device section to be used for
              this screen.  This is what ties a specific graphics  card  to  a
              screen.   The  device-id  must  match the Identifier of a Device
              section in the config file.

       Monitor  "monitor-id"
              specifies which monitor description  is  to  be  used  for  this
              screen.    If  a  Monitor  name  is  not  specified,  a  default
              configuration is used.  Currently the default configuration  may
              not function as expected on all platforms.

       VideoAdaptor  "xv-id"
              specifies  an  optional  Xv video adaptor description to be used
              with this screen.

       DefaultDepth  depth
              specifies which color depth the server should  use  by  default.
              The -depth command line option can be used to override this.  If
              neither is specified, the default depth is driver-specific,  but
              in most cases is 8.

       DefaultFbBpp  bpp
              specifies  which  framebuffer  layout  to  use  by default.  The
              -fbbpp command line option can be used  to  override  this.   In
              most  cases  the  driver  will  chose the best default value for
              this.  The only case where there is even a choice in this  value
              is  for  depth 24, where some hardware supports both a packed 24
              bit framebuffer layout and a sparse 32 bit framebuffer layout.

       Options
              Various Option flags may be specified  in  the  Screen  section.
              Some  are  driver-specific  and  are  described  in  the  driver
              documentation.   Others   are   driver-independent,   and   will
              eventually be described here.

       Option "Accel"
              Enables  XAA  (X  Acceleration  Architecture),  a mechanism that
              makes video cards’ 2D hardware  acceleration  available  to  the
              Xorg  server.   This  option  is  on  by  default, but it may be
              necessary to turn it off if there are bugs in the driver.  There
              are  many  options  to  disable specific accelerated operations,
              listed below.  Note that disabling an  operation  will  have  no
              effect  if the operation is not accelerated (whether due to lack
              of support in the hardware or in the driver).

       Option "BiosLocation" "address"
              Set the location of the BIOS  for  the  Int10  module.  One  may
              select  a  BIOS of another card for posting or the legacy V_BIOS
              range located at 0xc0000 or an  alternative  address  (BUS_ISA).
              This  is only useful under very special circumstances and should
              be used with extreme care.

       Option "InitPrimary" "boolean"
              Use the Int10 module to initialize the  primary  graphics  card.
              Normally,  only  secondary cards are soft-booted using the Int10
              module, as the primary card has already been initialized by  the
              BIOS at boot time.  Default: false.

       Option "NoInt10" "boolean"
              Disables  the Int10 module, a module that uses the int10 call to
              the BIOS of the graphics card to initialize it. Default:  false.

       Option "NoMTRR"
              Disables MTRR (Memory Type Range Register) support, a feature of
              modern processors which  can  improve  video  performance  by  a
              factor  of up to 2.5.  Some hardware has buggy MTRR support, and
              some video drivers have been  known  to  exhibit  problems  when
              MTRR’s are used.

       Option "XaaNoCPUToScreenColorExpandFill"
              Disables  accelerated  rectangular  expansion  blits from source
              patterns  stored  in  system  memory  (using   a   memory-mapped
              aperture).

       Option "XaaNoColor8x8PatternFillRect"
              Disables  accelerated fills of a rectangular region with a full-
              color pattern.

       Option "XaaNoColor8x8PatternFillTrap"
              Disables accelerated fills of a trapezoidal region with a  full-
              color pattern.

       Option "XaaNoDashedBresenhamLine"
              Disables accelerated dashed Bresenham line draws.

       Option "XaaNoDashedTwoPointLine"
              Disables  accelerated  dashed  line  draws between two arbitrary
              points.

       Option "XaaNoImageWriteRect"
              Disables  accelerated  transfers   of   full-color   rectangular
              patterns  from  system  memory  to video memory (using a memory-
              mapped aperture).

       Option "XaaNoMono8x8PatternFillRect"
              Disables accelerated  fills  of  a  rectangular  region  with  a
              monochrome pattern.

       Option "XaaNoMono8x8PatternFillTrap"
              Disables  accelerated  fills  of  a  trapezoidal  region  with a
              monochrome pattern.

       Option "XaaNoOffscreenPixmaps"
              Disables accelerated draws  into  pixmaps  stored  in  offscreen
              video memory.

       Option "XaaNoPixmapCache"
              Disables caching of patterns in offscreen video memory.

       Option "XaaNoScanlineCPUToScreenColorExpandFill"
              Disables  accelerated  rectangular  expansion  blits from source
              patterns stored in system memory (one scan line at a time).

       Option "XaaNoScanlineImageWriteRect"
              Disables  accelerated  transfers   of   full-color   rectangular
              patterns  from system memory to video memory (one scan line at a
              time).

       Option "XaaNoScreenToScreenColorExpandFill"
              Disables accelerated rectangular  expansion  blits  from  source
              patterns stored in offscreen video memory.

       Option "XaaNoScreenToScreenCopy"
              Disables accelerated copies of rectangular regions from one part
              of video memory to another part of video memory.

       Option "XaaNoSolidBresenhamLine"
              Disables accelerated solid Bresenham line draws.

       Option "XaaNoSolidFillRect"
              Disables accelerated solid-color fills of rectangles.

       Option "XaaNoSolidFillTrap"
              Disables accelerated solid-color fills of Bresenham  trapezoids.

       Option "XaaNoSolidHorVertLine"
              Disables accelerated solid horizontal and vertical line draws.

       Option "XaaNoSolidTwoPointLine"
              Disables  accelerated  solid  line  draws  between two arbitrary
              points.

       Each  Screen  section  may  optionally  contain  one  or  more  Display
       subsections.     Those   subsections   provide   depth/fbbpp   specific
       configuration information, and the one  chosen  depends  on  the  depth
       and/or fbbpp that is being used for the screen.  The Display subsection
       format is described in the section below.

DISPLAY SUBSECTION

       Each  Screen  section  may  have  multiple  Display  subsections.   The
       "active"  Display subsection is the first that matches the depth and/or
       fbbpp values being used, or failing that, the first that has neither  a
       depth  or fbbpp value specified.  The Display subsections are optional.
       When there isn’t one that matches the depth and/or fbbpp  values  being
       used,  all the parameters that can be specified here fall back to their
       defaults.

       Display subsections have the following format:

               SubSection "Display"
                   Depth  depth
                   entries
                   ...
               EndSubSection

       Depth  depth
              This entry specifies what colour depth the Display subsection is
              to  be used for.  This entry is usually specified, but it may be
              omitted to create a match-all Display subsection or when wishing
              to  match  only against the FbBpp parameter.  The range of depth
              values that are allowed depends  on  the  driver.   Most  driver
              support  8,  15,  16  and 24.  Some also support 1 and/or 4, and
              some may support other values (like 30).  Note: depth means  the
              number  of  bits  in a pixel that are actually used to determine
              the pixel colour.  32 is not a valid depth value.  Most hardware
              that  uses  32  bits  per pixel only uses 24 of them to hold the
              colour information, which means that the colour depth is 24, not
              32.

       FbBpp  bpp
              This   entry  specifies  the  framebuffer  format  this  Display
              subsection is to be used for.  This entry is  only  needed  when
              providing  depth 24 configurations that allow a choice between a
              24 bpp packed framebuffer format and a 32bpp sparse  framebuffer
              format.  In most cases this entry should not be used.

       Weight  red-weight green-weight blue-weight
              This  optional  entry specifies the relative RGB weighting to be
              used for a screen is being used at depth  16  for  drivers  that
              allow  multiple  formats.   This  may also be specified from the
              command line with the -weight option (see Xorg(1x)).

       Virtual  xdim ydim
              This optional entry specifies the virtual screen  resolution  to
              be  used.   xdim  must  be a multiple of either 8 or 16 for most
              drivers, and a multiple of 32 when running in  monochrome  mode.
              The  given  value  will be rounded down if this is not the case.
              Video modes which are too large for the specified  virtual  size
              will  be  rejected.   If  this entry is not present, the virtual
              screen resolution will be set to accommodate all the valid video
              modes   given   in   the  Modes  entry.   Some  drivers/hardware
              combinations do not  support  virtual  screens.   Refer  to  the
              appropriate driver-specific documentation for details.

       ViewPort  x0 y0
              This  optional  entry  sets the upper left corner of the initial
              display.   This  is  only  relevant  when  the  virtual   screen
              resolution is different from the resolution of the initial video
              mode.  If this entry is not given, then the initial display will
              be centered in the virtual display area.

       Modes  "mode-name" ...
              This  optional  entry  specifies the list of video modes to use.
              Each mode-name specified must be in double  quotes.   They  must
              correspond  to  those specified or referenced in the appropriate
              Monitor section (including implicitly referenced  built-in  VESA
              standard  modes).   The  server will delete modes from this list
              which don’t satisfy various requirements.  The first valid  mode
              in  this list will be the default display mode for startup.  The
              list of valid modes is  converted  internally  into  a  circular
              list.    It  is  possible  to  switch  to  the  next  mode  with
              Ctrl+Alt+Keypad-Plus   and   to   the   previous    mode    with
              Ctrl+Alt+Keypad-Minus.   When  this  entry is omitted, the valid
              modes referenced by the  appropriate  Monitor  section  will  be
              used.   If  the  Monitor  section  contains  no  modes, then the
              selection will be taken from the built-in VESA standard modes.

       Visual  "visual-name"
              This optional entry sets the default root visual type.  This may
              also be specified from the command line (see the Xserver(1x) man
              page).  The visual types available for depth 8 are  (default  is
              PseudoColor):

                  StaticGray
                  GrayScale
                  StaticColor
                  PseudoColor
                  TrueColor
                  DirectColor

              The  visual  type  available  for  the  depths 15, 16 and 24 are
              (default is TrueColor):

                  TrueColor
                  DirectColor

              Not all drivers support DirectColor at these depths.

              The visual types available for  the  depth  4  are  (default  is
              StaticColor):

                  StaticGray
                  GrayScale
                  StaticColor
                  PseudoColor

              The  visual  type  available  for  the  depth  1 (monochrome) is
              StaticGray.

       Black  red green blue
              This optional entry allows the "black" colour to  be  specified.
              This is only supported at depth 1.  The default is black.

       White  red green blue
              This  optional  entry allows the "white" colour to be specified.
              This is only supported at depth 1.  The default is white.

       Options
              Option flags may be specified in the Display subsections.  These
              may   include  driver-specific  options  and  driver-independent
              options.   The  former  are  described  in  the  driver-specific
              documentation.   Some  of  the latter are described above in the
              section about the Screen section, and they may also be  included
              here.

SERVERLAYOUT SECTION

       The  config  file  may  have multiple ServerLayout sections.  A "server
       layout" represents the binding of one or more screens (Screen sections)
       and one or more input devices (InputDevice sections) to form a complete
       configuration.  In multi-head configurations,  it  also  specifies  the
       relative  layout  of  the  heads.  A ServerLayout section is considered
       "active" if it is referenced by the -layout command line option  or  by
       an  Option  "DefaultServerLayout" entry in the ServerFlags section (the
       former takes precedence over the latter).  If  those  options  are  not
       used,  the  first  ServerLayout  section  found  in  the config file is
       considered the active one.  If no ServerLayout  sections  are  present,
       the  single  active  screen  and  two  active  (core) input devices are
       selected as described in the relevant sections above.

       ServerLayout sections have the following format:

           Section "ServerLayout"
               Identifier   "name"
               Screen       "screen-id"
               ...
               InputDevice  "idev-id"
               ...
               options
               ...
           EndSection

       Each ServerLayout section must have an Identifier entry  and  at  least
       one Screen entry.

       The  Identifier entry specifies the unique name for this server layout.
       The ServerLayout section provides information  specific  to  the  whole
       session,  including  session-specific Options.  The ServerFlags options
       (described above) may be specified here, and ones given  here  override
       those given in the ServerFlags section.

       The entries that may be used in this section are described here.

       Screen  screen-num "screen-id" position-information
              One of these entries must be given for each screen being used in
              a session.  The screen-id field is mandatory, and specifies  the
              Screen  section  being  referenced.   The  screen-num  field  is
              optional, and may be used to specify the screen number in multi-
              head  configurations.   When  this field is omitted, the screens
              will be numbered in the order that  they  are  listed  in.   The
              numbering starts from 0, and must be consecutive.  The position-
              information  field  describes  the  way  multiple  screens   are
              positioned.   There  are  a  number  of different ways that this
              information can be provided:

              x y

              Absolute  x y
                  These both specify that the upper left corner’s  coordinates
                  are  (x,y).   The  Absolute keyword is optional.  Some older
                  versions of Xorg  (4.2  and  earlier)  don’t  recognise  the
                  Absolute  keyword,  so  it’s  safest  to  just  specify  the
                  coordinates without it.

              RightOf   "screen-id"

              LeftOf    "screen-id"

              Above     "screen-id"

              Below     "screen-id"

              Relative  "screen-id" x y
                  These give the screen’s location relative to another screen.
                  The first four position the screen immediately to the right,
                  left, above or below the other screen.  When positioning  to
                  the  right  or  left,  the  top  edges  are  aligned.   When
                  positioning above or below, the left edges are aligned.  The
                  Relative  form  specifies  the offset of the screen’s origin
                  (upper left  corner)  relative  to  the  origin  of  another
                  screen.

       InputDevice  "idev-id" "option" ...
              One of these entries should be given for each input device being
              used in a session.  Normally at least two are required, one each
              for  the  core pointer and keyboard devices.  If either of those
              is missing, suitable InputDevice entries are searched for  using
              the  method  described  above  in  the INPUTDEVICE section.  The
              idev-id field is  mandatory,  and  specifies  the  name  of  the
              InputDevice  section  being  referenced.  Multiple option fields
              may be specified, each in double quotes.  The options  permitted
              here are any that may also be given in the InputDevice sections.
              Normally only session-specific input  device  options  would  be
              used here.  The most commonly used options are:

                  "CorePointer"
                  "CoreKeyboard"
                  "SendCoreEvents"

              and  the  first two should normally be used to indicate the core
              pointer and core keyboard devices respectively.

       Options
              In addition to  the  following,  any  option  permitted  in  the
              ServerFlags  section  may also be specified here.  When the same
              option appears in both places, the value  given  here  overrides
              the one given in the ServerFlags section.

       Option "IsolateDevice"  "bus-id"
              Restrict  device  resets to the specified bus-id.  See the BusID
              option (described in DEVICE SECTION, above) for  the  format  of
              the  bus-id  parameter.   This  option  overrides SingleCard, if
              specified.  At present, only PCI devices can be isolated in this
              manner.

       Option "SingleCard"  "boolean"
              As  IsolateDevice, except that the bus ID of the first device in
              the layout is used.

       Here is an  example  of  a  ServerLayout  section  for  a  dual  headed
       configuration with two mice:

           Section "ServerLayout"
               Identifier  "Layout 1"
               Screen      "MGA 1"
               Screen      "MGA 2" RightOf "MGA 1"
               InputDevice "Keyboard 1" "CoreKeyboard"
               InputDevice "Mouse 1"    "CorePointer"
               InputDevice "Mouse 2"    "SendCoreEvents"
               Option      "BlankTime"  "5"
           EndSection

DRI SECTION

       This  optional  section  is  used  to  provide some information for the
       Direct Rendering Infrastructure.  Details  about  the  format  of  this
       section can be found on-line at <http://dri.freedesktop.org/>.

VENDOR SECTION

       The  optional  Vendor  section  may  be used to provide vendor-specific
       configuration information.  Multiple Vendor sections  may  be  present,
       and  they  may  contain  an Identifier entry and multiple Option flags.
       The data therein is not used in this release.

FILES

       For an example  of  an  xorg.conf  file,  see  the  file  installed  as
       /usr/lib/X11/xorg.conf.eg.

SEE ALSO

       X(7),  Xserver(1x),  Xorg(1x),  apm(4),  chips(4), cirrus(4), cyrix(4),
       fbdev(4), glide(4),  glint(4),  i128(4),  i740(4),  i810(4),  imstt(4),
       mga(4),   neomagic(4),   nv(4),   r128(4),   rendition(4),   savage(4),
       s3virge(4), siliconmotion(4), sis(4), sunbw2(4), suncg14(4), suncg3(4),
       suncg6(4),    sunffb(4),   sunleo(4),   suntcx(4),   tdfx(4),   tga(4),
       trident(4), tseng(4), v4l(4), vesa(4), vga(4), vmware(4),

AUTHORS

       This   manual   page   was   largely   rewritten   by    David    Dawes
       <dawes@xfree86.org>.