VGA(3)                                                     VGA(3)

     NAME
          vga - VGA controller device

     SYNOPSIS
          bind #v /dev

          /dev/vgactl

     DESCRIPTION
          The VGA device allows configuration of a graphics controller
          on a PC.  Vgactl allows control over higher-level settings
          such as display height, width, depth, controller and
          hardware-cursor type.  Along with the I/O-port registers
          provided by arch(3), it is used to implement configuration
          and setup of VGA controller cards.  This is usually per-
          formed by vga(8).

          Writing strings to vgactl configures the VGA device.  The
          following are valid commands.

          size XxYxZ chan
               Set the size of the screen image to be X pixels wide
               and Y pixels high.  Each pixel is Z bits as specified
               by chan, whose format is described in image(6).

          actualsize XxY
               Set the physical size of the display to be X pixels
               wide by Y pixels high.  This message is optional; if
               this size is smaller than that specified in the size
               message, the screen will pan to follow the mouse.  This
               is useful on systems with small displays, such as lap-
               tops.

          type ctlr
               Set the type of VGA controller being used.  Ctlr is one
               of ark200pv, clgd542x, clgd546x, ct65545, cyber938x,
               hiqvideo, mach64xx, mga2164w, neomagic, s3, and t2r4.

               Note that this list does not indicate the full set of
               VGA chips supported. For example, s3 includes the
               86C801/5, 86C928, Vision864, and Vision964.  It is the
               job of vga(8) to recognize which particular chip is
               being used and to initialize it appropriately.

          hwgc gc
               Set the type of hardware graphics cursor being used.
               Gc is one of ark200pvhwgc, bt485hwgc, clgd542xhwgc,
               clgd546xhwgc, ct65545hwgc, cyber938xhwgc, hiqvideohwgc,
               mach64xxhwgc, mga2164whwgc, neomagichwgc, rgb524hwgc,
               s3hwgc, t2r4hwgc, tvp3020hwgc, and tvp3026hwgc.  A

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     VGA(3)                                                     VGA(3)

               value of off disables the cursor.  There is no software
               cursor.

          palettedepth d
               Set the number of bits of precision used by the VGA
               palette to d, which must be either 6 or 8.

          blank
               Blank the screen.  This consists of setting the hard-
               ware color map to all black as well as, on some con-
               trollers, setting the VGA hsync and vsync signals so as
               to turn off VESA DPMS-compliant monitors.  The screen
               also blanks after 30 minutes of inactivity.  The screen
               can be unblanked by moving the mouse.

          blanktime minutes
               Set the timeout before the screen blanks; the default
               is 30 minutes.  If minutes is zero, blanking is dis-
               abled.

          hwaccel mode
               Depending on whether mode is on or off, enable or dis-
               able whether hardware acceleration (currently for rect-
               angle filling and moving) used by the graphics engine.
               The default setting is on.

          hwblank mode
               Depending on whether mode is on or off, enable or dis-
               able the use of DPMS blanking (see blank above).

          linear size align
               Use a linear screen aperture of size size aligned on an
               align-byte boundary.

          drawinit
               Initialize the graphics hardware.  This must be sent
               after setting the type.

          Reading vgactl returns the current settings, one per line.

     EXAMPLES
          The following disables hardware acceleration.

               echo -n 'hwaccel off' >/dev/vgactl

     SOURCE
          /sys/src/9/pc/devvga.c

     SEE ALSO
          arch(3), vga(8)

     BUGS

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     VGA(3)                                                     VGA(3)

          There should be support for the hardware graphics cursor on
          the clgd54[23]x VGA controller chips.

          The hardware graphics cursor on the et4000 does not work in
          2x8-bit mode.

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