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XDEC(1)							  XDEC(1)


Name
       Xdec - X server for Digital RISC machines

Syntax
       Xdec [ options ]

Description
       The command starts the X server.	 The command supports the
       following hardware configurations:

	  DECstation 2100 Monochrome or Color Workstations
	  DECstation 3100 Monochrome or Color Workstations
	  DECstation 5000/100/200 CX or MX Single or Multiscreen Workstations

       This server should run on reasonable one bit or eight  bit
       Ultrix/RISC  TURBOchannel  displays  of any resolution, if
       correct device driver  support  is  present.   The  server
       queries	the  device  driver  interface	to determine if a
       suitable display device is installed, and if  so,  config
       ures the server appropriately.

       The command that executes the server is specified together
       with its command line options in the file or using  xdm(1)
       and,  therefore,	 is automatically run when your system is
       started in multiuser mode.  Optionally, you can create  an
       file  containing	 device-dependent  command  line  options
       (separated by spaces) and use  it  to  start  the  server.
       Command line options specified in the command starting the
       X server override those specified in the file.

       Start the server in bug compatibility mode  (with  the  bc
       option)	to  remain  bug-for-bug	 compatible with previous
       releases of the server.

Options
       In addition to the normal server options described in  the
       Xserver(1) manual page, Xdec accepts the following device-
       dependent, vendor-specific options.  When  the  server  is
       run  on	multiscreen  capable  platforms, selected device-
       dependent options take  an  optional  screen-specification
       argument.    Omitting  the  screen-specification	 argument
       defines the parameter for all available screens.

       -btn num		   Specifies the number of buttons on the
			   pointer  device.  The default is three
			   for a mouse	device	and  four  for	a
			   tablet device.

       -bp[screen]  color  Sets the color of black pixels for the
			   screen.  The color argument can  be	a
			   named  color	 from  the  database or a
			   number sign (#) followed by a hexidec
			   imal number.




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XDEC(1)							  XDEC(1)


       -class[screen]  visual class
			   Sets	 the  visual  class  for the root
			   window of the screen.  Possible values
			   are and

       -dpi[screen]  num   Sets the dots per inch for the x and y
			   coordinates.

       -dpix[screen]  num  Sets the dots per inch for the x coor
			   dinates.

       -dpiy[screen]  num  Sets the dots per inch for the y coor
			   dinates.

       By default on multiscreen systems, the server presumes the
       left  hand  most	 screen is screen zero, screen one to its
       right, screen two yet further to its  right,  and  so  on.
       The  cursor  will track from the right hand edge of screen
       zero to the left hand edge of screen one, from  the  right
       hand  edge  of  screen one to the left hand edge of screen
       two.  This arrangement can be modified in various ways, to
       support other physical arrangements of monitors.

       -edge_bottomscr1 scr2
			   Attaches the bottom edge of the screen
			   specified by scr1 to the screen speci
			   fied by scr2.

       -edge_leftscr1 scr2 Attaches  the  left edge of the screen
			   specified by scr1 to the screen speci
			   fied by scr2.

       -edge_rightscr1 scr2
			   Attaches  the right edge of the screen
			   specified by scr1 to the screen speci
			   fied by scr2.

       -edge_topscr1 scr2  Attaches  the  top  edge of the screen
			   specified by scr1 to the screen speci
			   fied by scr2.

       -wp[screen]  color  Sets the color of white pixels for the
			   screen.  The syntax for color  is  the
			   same	 as  for  the argument to the -bp
			   option.

       -tb n		   Opens for graphics  tablet  communica
			   tions.

       -pcm n		   Opens   for	Protocol  Control  Module
			   (PCM) communications.   The	two  free
			   serial  ports on the DECstation corre
			   spond to and	 Dial  boxes  and  button
			   boxes  must be connected through these



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XDEC(1)							  XDEC(1)


			   two ports.

Restrictions
       If options not listed in this reference page are used, the
       server may fail. Using invalid options for the X server in
       the file may cause the workstation to behave as if  the	X
       server is hung.

       Multiscreen  configurations  can	 contain  either  two- or
       three-color frame buffer	 display  devices  or  monochrome
       frame buffer display devices.

       Color  and  monochrome frame buffer display devices can be
       installed in the same  workstation,  however  applications
       built before X11 release 5 may become confused due to poor
       initial design of resource files.

       To connect two screens, two command line options	 must  be
       issued.	 Attaching  two	 screens  using only one argument
       produces a one-way mouse-travel path.  You  can	create	a
       wrap-around  mouse  path by attaching noncontiguous screen
       edges.  The arguments are disabled on single  screen  sys
       tems.

       Nonsensical  screen  connections	 are not allowed; the top
       edge of a particular screen must	 be  connected	with  the
       bottom  edge  of	 another  screen, and the right edge of a
       particular screen must be connected with the left edge  of
       another	screen.	 Left and right edges cannot be connected
       to top or bottom edges.

Examples
       The following example specifies that screen has a  resolu
       tion  of 100x100 dots per inch and screen has a resolution
       of 75x70 dots per inch: Xdec -dpi0 100 -dpix1 75 -dpiy1 70

       If no screen is specified, the value specified is used for
       all screens.  If the screen resolution  is  not	specified
       using command line options, a default value based on pixel
       dimensions and screen size is calculated for each  screen.

       The  following  example	specifies  that	 black	pixels on
       screen have the	hexadecimal  value  3a009e005c0	 prefixed
       with  a	number	sign  (#)  and white pixels on screen are
       color "wheat" from the X rgb color  database.   Xdec  -bp1
       #3a009e005c0  -wp1  wheat  For monochrome display devices,
       values of 0 and 1 are the only valid pixel colors.

       To specify the default visual class of a root window on	a
       particular  screen,  append the screen number (0, 1, or 2)
       to the command line option.  Possible visual classes  are:
       StaticGray, StaticColor, PseudoColor, GrayScale, and True
       Color.  The following example specifies	that  the  screen
       root  window  is	 a  TrueColor visual, and the screen root



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XDEC(1)							  XDEC(1)


       window is a PseudoColor visual.	 Xdec  -class0	TrueColor
       -class1 PseudoColor

       The  following  example	attaches  screen above screen and
       screen to the right of screen (an L-shaped configuration):
       Xdec   -edge_top0   1   -edge_bottom1   0  -edge_right0	2
       -edge_left2 0

       The following example is identical to the default state (a
       horizontal  line)  with	the addition of a wraparound from
       screen  to  screen  Xdec	 -edge_left0  2	 -edge_right0	1
       -edge_left1  0 -edge_right1 2 \ -edge_left2 1 -edge_right2
       0

Files
See Also
       X(1X), xdm(1), Xserver(1)
       X Window System: The Complete Reference to Xlib, X  Proto_
       col, ICCCM, XLFD, by Robert W. Scheifler and James Gettys,
       Second Edition, Digital Press, 1990
       "X Window System Toolkit: The Complete Programmer's  Guide
       and  Specification,  by Paul J. Asente and Ralph R. Swick,
       Digital Press, 1990
       OSF/MOTIF  Programmer's	Guide  and  OSF/MOTIF	Reference
       Guide, Open Software Foundation, Prentice-Hall, 1990
































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