Information for Cyrix Chipset Users

                          The XFree86 Project Inc.

                                22 June 1999

1.  Supported hardware

This driver (as used in the SVGA (VGA256), VGA16 and VGA_Mono servers) sup-
ports a single chipset `mediagx' that should work on the following Cyrix CPUs
with integrated graphics:

   o MediaGX

   o MediaGXi

   o MediaGXm

2.  Features

   o accelerated

   o hardware cursor

   o support color depths 1, 4, 8 and 16

3.  XF86Config Option

      Option "sw_cursor"
            disable the hardware cursor.

      Option "no_accel"
            completely disables acceleration. Usually not recommended.

4.  Bugs and Limitations

   o On some older chipsets, the driver may trigger an illegal instruction
     just after probing for the ``scratchpad size''.  If this is the case,
     email to hecker@cat.dfrc.nasa.gov with the output of

          XF86_SVGA -probeonly -verbose

     and this will be fixed.

   o There are limitations to the modeline values that can be specified.
     Particularly, the difference between the first two horizontal timings
     (e.g. 640 656, 1024 1048) must be at least 16 and at most 24.  The mode-
     line values are not used in the 3.3.4 server since there is a static
     array used to load the registers.  The modeline only identifies that a
     particular resolution is desired.  The standard VESA modes up to
     1280x768 are supported.  For more specific information, consult the
     source code.

   o The 4 colour server is slow due to the VGA banking mode used.  Moreover,
     it does not work the way it is run by XF86Setup, which is probably due
     to the timing limitations.

   o The 3.3.4 server MAY totally hang the machine at times.  It is reported
     to be stable on a BSD platform using twm.  It has crashed when using
     resolutions greater than 800x600 on a Linux (Debian based) system using
     wm as the window manager.  The safest course is to use the 3.3.3.1
     server instead.  Efforts are under way to resolve this issue and provide
     a more robust server under the 4.x release.

5.  Authors

   o Annius Groenink <Annius.Groenink@cwi.nl>

   o Dirk Hohndel <hohndel@XFree86.org>

   o Brian Falardeau

   o Special thanks to Cyrix and Wyse for helping us with the development of
     this server.  Brian, a Cyrix employee, made the 3.3.4 update possible
     since the new 4.0 server has been our top priority.

     Generated from XFree86: xc/programs/Xserver/hw/xfree86/doc/sgml/cyrix.sgml,v 1.1.2.4 1999/06/24 06:16:44 hohndel Exp $