Glide video driver


       glide - Glide video driver


       Section "Device"
         Identifier "devname"
         Driver "glide"


       glide  is  an  Xorg driver for Glide capable video boards (such as 3Dfx
       Voodoo boards). This driver is mainly for Voodoo 1 and Voodoo 2 boards,
       later boards from 3Dfx have 2D built-in and you should preferably use a
       driver separate for those boards or the fbdev(4) driver.   This  driver
       is  a  bit special because Voodoo 1 and 2 boards are very much NOT made
       for running 2D  graphics.  Therefore,  this  driver  uses  no  hardware
       acceleration  (since there is no acceleration for 2D, only 3D). Instead
       it is implemented with the help of a "shadow" framebuffer that  resides
       entirely  in RAM. Selected portions of this shadow framebuffer are then
       copied out to the Voodoo board at the right time. Because of this,  the
       speed  of the driver is very dependent on the CPU. But since the CPU is
       nowadays actually rather fast at moving data, we get  very  good  speed
       anyway, especially since the whole shadow framebuffer is in cached RAM.

       This  driver  supports 16 and 24 bit color modes. The 24 bit color mode
       uses a 32 bit framebuffer (it has no support for  24  bit  packed-pixel
       framebuffers).  Notice  that  the Voodoo boards can only display 16 bit
       color, but the shadow framebuffer can be run in 24 bit color. The point
       of  supporting  24  bit  mode  is  that  this  enables  you to run in a
       multihead configuration with Xinerama together with another board  that
       runs  in  real  24  bit color mode. (All boards must run the same color
       depth when you use Xinerama).

       Resolutions  supported  are:  640x480,  800x600,   960x720,   1024x768,
       1280x1024  and  1600x1200.  Note  that  not  all modes will work on all
       Voodoo boards. It seems that Voodoo 2 boards  support  no  higher  than
       1024x768  and  Voodoo  1 boards can go to 800x600. If you see a message
       like this in the output from the server:

         (EE) GLIDE(0): grSstWinOpen returned ...

       Then you are probably trying to use a resolution that is  supported  by
       the driver but not supported by the hardware.

       Refresh rates supported are: 60Hz, 75Hz and 85Hz. The refresh rate used
       is derived from the normal mode line according to the following table:

       Mode-line refresh rate      Used refresh rate

          0-74 Hz
                                     60 Hz

         74-84 Hz
                                     75 Hz

         84-   Hz
                                     85 Hz

       Thus, if you use a modeline that for example has a  70Hz  refresh  rate
       you will only get a 60Hz refresh rate in actuality.

       Selecting which Voodoo board to use with the driver is done by using an
       option called "GlideDevice" in the "Device" section. (If you don't have
       this  option  present  then  the first board found will be selected for
       that Device section). For example: To use the first Voodoo board, use a
       "Device" section like this, for example:

       Section "Device"
          Identifier  "Voodoo"
          Driver      "glide"
          Option      "dpms" "on"
          Option      "GlideDevice" "0"

       And  if  you  have  more  than  one  Voodoo board, add another "Device"
       section with a GlideDevice option with value 1, and so on. (You can use
       more  than  one Voodoo board, but SLI configured boards will be treated
       as a single board.)

       Multihead and Xinerama configurations are supported.

       Limited support for DPMS screen saving is available. The "standby"  and
       "suspend"  modes  are  just  painting  the screen black. The "off" mode
       turns the Voodoo board off and thus works correctly.

       This driver does not support a virtual screen size different  from  the
       display size.


       The  glide  driver supports any board that can be used with Glide (such
       as 3Dfx Voodoo boards)


       Please refer to xorg.conf(5) for general configuration  details.   This
       section only covers configuration details specific to this driver.

       The following driver Options are supported:

       Option "OnAtExit" "boolean"
              If  true,  will leave the Voodoo board on when the server exits.
              Useful in a multihead  setup  when  only  the  Voodoo  board  is
              connected to a second monitor and you don't want that monitor to
              lose signal when you quit the server. Put  this  option  in  the
              Device section.  Default: off.

       Option "GlideDevice" "integer"
              Selects  which  Voodoo  board  to  use.  (Or  boards,  in an SLI
              configuration).  The value should be 0 for the  first  board,  1
              for  the  second  and  so  on.   If it is not present, the first
              Voodoo board found will be selected.  Put  this  option  in  the
              Device section.


       Here is an example of a part of an xorg.conf file that uses a multihead
       configuration with two monitors. The first monitor  is  driven  by  the
       fbdev  video  driver  and  the  second  monitor  is driven by the glide

       Section "Monitor"
          Identifier      "Monitor 1"
          VendorName      "Unknown"
          ModelName       "Unknown"
          HorizSync       30-70
          VertRefresh     50-80

          # 1024x768 @ 76 Hz, 62.5 kHz hsync
          Modeline "1024x768" 85 1024 1032 1152 1360 768 784 787 823

       Section "Monitor"
          Identifier      "Monitor 2"
          VendorName      "Unknown"
          ModelName       "Unknown"
          HorizSync       30-70
          VertRefresh     50-80

          # 1024x768 @ 76 Hz, 62.5 kHz hsync
          Modeline "1024x768" 85 1024 1032 1152 1360 768 784 787 823

       Section "Device"
          Identifier  "fb"
          Driver      "fbdev"
          Option      "shadowfb"
          Option      "dpms" "on"
          # My video card is on the AGP bus which is usually
          # located as PCI bus 1, device 0, function 0.
          BusID       "PCI:1:0:0"

       Section "Device"
          # I have a Voodoo 2 board
          Identifier  "Voodoo"
          Driver      "glide"
          Option      "dpms" "on"
          # The next line says I want to use the first board.
          Option      "GlideDevice" "0"

       Section "Screen"
         Identifier   "Screen 1"
         Device  "fb"
         Monitor "Monitor 1"
         DefaultDepth 16
         Subsection "Display"
           Depth 16
           Modes "1024x768"

       Section "Screen"
         Identifier   "Screen 2"
         Device  "Voodoo"
         Monitor "Monitor 2"
         DefaultDepth 16
         Subsection "Display"
           Depth 16
           Modes "1024x768"

       Section "ServerLayout"
         Identifier   "Main Layout"
         # Screen 1 is to the right and screen 2 is to the left
         Screen  "Screen 2"
         Screen  "Screen 1" "" "" "Screen 2" ""

       If you use this configuration  file  and  start  the  server  with  the
       +xinerama  command  line  option,  the  two  monitors will be showing a
       single large area where windows  can  be  moved  between  monitors  and
       overlap  from  one monitor to the other. Starting the X server with the
       Xinerama extension can be done for example like this:

       $ xinit -- +xinerama




       Xorg(1), xorg.conf(5), Xserver(1), X(7)


       Author: Henrik Harmsen.