vga(4) - NetBSD Manual Pages

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VGA(4)                  NetBSD Kernel Interfaces Manual                 VGA(4)


NAME

     vga - VGA graphics driver for wscons


SYNOPSIS

     options VGA_CONSOLE_SCREENTYPE="??x??"
     options VGA_CONSOLE_ATI_BROKEN_FONTSEL

     vga0 at isa?
     vga* at pci?
     wsdisplay* at vga? console ?


DESCRIPTION

     This driver handles VGA graphics hardware within the wscons(4) console
     framework.  It doesn't provide direct device driver entry points but
     makes its functions available via the internal wsdisplay(4) interface.

     The vga driver supports text-mode hardware acceleration on the VGA hard-
     ware.  Currently, the driver runs the display with a 720×400 pixel reso-
     lution.  The VGA text-mode accelerator divides the display into fixed-
     size character cells.  The size of the character cells specifies the num-
     ber of characters available on the screen and the resolution of the font.
     The wsdisplay screen ``types'' supported by the vga driver are described
     by the number of character cells available on the screen.  See below for
     a complete list of supported screen modes in the vga driver.

     Each screen mode requires a suitable font to be loaded into the kernel by
     the wsfontload(8) utility, before the screen can be used.  The size of
     the font and the screen mode must match for use on the 720×400 display.
     For example, a screen mode with 80 columns and 40 rows requires a font
     where each character is 8 pixels wide and 10 pixels high.  The vga driver
     can display fonts of the original IBM type and ISO-8859-1 encoded fonts.
     A builtin font of 256 characters and 8×16 pixels is always present on the
     VGA hardware.

     The colour VGA hardware supports the display of 16 different colours at
     the same time.  It is possible with VGA colour systems to use fonts with
     512 characters at any one time.  This is due to the fact that with VGA
     adapters one can specify an alternate font to be used instead of bright
     letters (used for highlighting on the screen).  As an experimental fea-
     ture, the ``higher half'' fonts of the former NetBSD/i386 pcvt driver
     distribution can be used too if the kernel option
     ``WSCONS_SUPPORT_PCVTFONTS'' was set at compile time.  This is only use-
     ful with the ``*bf'' screen types; a font containing the ASCII range of
     characters must be available too on this screen.

     Currently, the following screen types are supported:

     80x25   This is the standard VGA text mode with 80 columns and 25 rows.
             Sixteen different colors can be displayed at the same time.
             Characters are 8×16 pixels, and a font consists of 256 charac-
             ters.

     80x25bf is a modified version of the previous.  It only allows 8 colors
             to be displayed.  In exchange, it can access two fonts at the
             same time, so that 512 different characters can be displayed.

     80x40   A text mode with 80 columns and 40 rows.  Similar to the standard
             mode, 16 colors and 256 characters are available.  Characters are
             8×10 pixels.  For this mode to be useful, a font of that charac-
             ter size must be downloaded.

     80x40bf is analogously to ``80x25bf'' a version with 512 displayable
             characters but 8 colors only.

     80x50   A text mode with 80 columns and 50 rows.  Similar to the standard
             mode, 16 colors and 256 characters are available.  Characters are
             8×8 pixels.  For this mode to be useful, a font of that character
             size must be downloaded.

     80x50bf is analogously to ``80x25bf'' a version with 512 displayable
             characters but 8 colors only.

     80x24   is a variant of the ``80x25'' screen type which displays 24 lines
             only.  It uses the standard 8x16 VGA font.  This mode might be
             useful for applications which depend on closer DEC VT100 compati-
             bility.

     80x24bf Analogously, like ``80x24'' but with 512 character slots and 8
             colors.

     If you have an Ati videocard and you are experiencing problems with fonts
     other than 80x25, you can try to set options
     VGA_CONSOLE_ATI_BROKEN_FONTSEL in you kernel configuration and see if it
     helps.

     The vga driver supports multiple virtual screens on one physical display.
     The screens allocated on one display can be of different ``types''.  The
     type is determined at the time the virtual screen is created and can't be
     changed later.  Screens are either created at kernel startup (then the
     default type is used) or later with help of the wsconscfg(8) utility.


SEE ALSO

     isa(4), pcdisplay(4), pci(4), wscons(4), wsconscfg(8), wsfontload(8)


BUGS

     Only a subset of the possible text modes is supported.

     VGA cards are supposed to emulate an MDA if a monochrome display is con-
     nected.  In this case, the device will naturally not support colors at
     all, but offer the capability to display underlined characters instead.
     The ``80x25bf'', ``80x40bf'', ``80x50bf'' and ``80x24bf'' screen types
     will not be available.  This mode of operation has not been tested.

NetBSD 2.0                        May 4, 2003                       NetBSD 2.0