NAME

XF86_VGA16 - 4 bit non-accelerated X Window System server for UNIX on x86 platforms

SYNOPSIS

XF86_VGA16 [:displaynumber] [ option ] ... 

DESCRIPTION

XFree86 is a package of bug-fixes, enhancements, and ports of X11R5 to new OSs, for Intel Unix-like OSs. See the XFree86(1) manpage for details.  XF86_VGA16 is a 4-bit PseudoColor server for VGA cards. 

The XFree86 servers support all MIT-supplied extensions except the X Input Extension.  PEX is not supported on 4-bit hardware. 

NOTE: This server is new and experimental.  It is not as well tested as the other XFree86 servers. 

CONFIGURATIONS

The XF86_VGA16 server supports the following popular SVGA chipset in 16-colour mode. 

Tseng:
ET4000

Additionally it supports generic VGA cards. 

XF86_VGA16 will use up to 256Kb of display memory which yields a maximum virtual resolution of (approximately) 800x650.  XF86_VGA16 does not support the accelerated functions of the supported chipsets. 

OPTIONS

In addition to the normal server options described in the Xserver(1) manual page, XF86_VGA16 accepts some more command line switches, as described in the XFree86(1) manpage. 

KEYBOARD

XFree86 provides several capabilities for easing the use of international keyboards, and generating non-ASCII Latin-1 keysyms.  Refer to the XFree86kbd(1) manual page for more information. 

SETUP

XFree86 uses a configuration file called Xconfig for its initial setup.  See the Xconfig(4/5) manpage for general details. Here only the XF86_VGA16 specific parts are explained. 

The GRAPHICS DRIVER SETUP section for the 16 colour server starts with the keyword vga16.  After this keyword a variety of options may be specified:

chipset "name"
specifies a chipset so the correct driver can be used.  Possible chipsets are:

Tseng:
et4000

Generic VGA:
generic

clocks clock ... 
specifies the dotclocks 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. 

option "optionstring"
allows the user to select certain options provided by the drivers.  Currently the following strings are recognized: legend - for Sigma Legend ET4000-based boards.  This option enables a special clock-selection algorithm used on Legend boards, and MUST be specified for these boards to function correctly.  hibit_low, hibit_high - for Tseng ET4000 chipsets.  With some ET4000 cards, the server has difficulty getting the state of the high-order clocks select bit right when started from a high-resolution text mode.  These options allow the correct initial state of that bit to be specified.  To find out what the correct initial state is, start the server from an 80x25 text mode.  This option is only needed if the clocks reported by the server when started from a high-resolution text mode differ from those reported when it is started from an 80x25 text mode. 

Note that XFree86 has some internal capabilities to determine what hardware it is running on. Thus normally the keywords chipset, clocks, and videoram don’t have to be specified.  But there may be occasions when this autodetection mechanism fails, (for example, too high of load on the machine when you start the server).  For cases like this, one should first run XF86_VGA16 on an unloaded machine, look at the results of the autodetection (that are printed out during server startup) and then explicitly specify these parameters in the configuration file.  It is recommended that all parameters, especially Clock values, be specified in the Xconfig file.

The last section is the TABLE OF VIDEO MODES which starts with the keyword modedb.  This is covered in the Xconfig(4/5) manpage. For details on how to build your own video modes please refer to the tutorial written by Eric Raymond. 

FILES

/usr/X386/bin/XF86_VGA16 The 16 colour X server

/usr/X386/lib/X11/Xconfig Server configuration file

SEE ALSO

X(1), Xserver(1), XFree86kbd(1), XFree86(1), Xconfig(4/5), xdm(1), xinit(1)

BUGS

This server contains a number of known graphics bugs.  It is still in the early stages of development. 

CONTACT INFO

XFree86 source is available from the FTP servers ftp.physics.su.oz.au and ftp.x.org.  Send email to XFree86@physics.su.oz.au for details. 

AUTHORS

The primary developer of this server is

Gertjan Akkerman,  akkerman@dutiba.twi.tudelft.nl

See also the XFree86(1) manual page.