  ATI adapters README
  Marc Aurele La France
  23 March 1996

  This is the README for the XFree86 ATI VGA driver used in the
  XF86_Mono, XF86_VGA16 and XF86_SVGA servers.  Users of ATI adapters
  based on the Mach8, Mach32 or Mach64 accelerators should be using the
  accelerated servers (XF86_Mach8, XF86_Mach32 or XF86_Mach64).  The
  unaccelerated servers (XF86_Mono, XF86_VGA16 and XF86_SVGA) should
  still work, but are a waste of capabilities.

  1.  What is the ATI VGA driver?

  The ATI VGA driver is a 256-colour, 16-colour and monochrome driver
  for XFree86.  The driver is intended for all ATI video adapters except
  those that do not provide SuperVGA functionality (such as some early
  Mach8 and Mach32 adapters).  The following approximate maximum
  resolutions (based on the Golden Ratio of x/y = (1 + sqrt(5))/2) are
  possible depending on the video memory available on the adapter (and
  the capabilities of your monitor):

      256k    640x409x256    896x585x16
      512k    896x585x256   1280x819x16
      1M     1280x819x256  1824x1149x16


  Maximum monochrome resolutions are the same as those for 16-colour
  mode, because the monochrome server uses a maximum of one fourth of
  the available video memory.

  2.  What is the ATI VGA driver *not*?

  This driver does not yet support more than 8 bits of pixel depth.
  Even if your manual says that your graphics adapter supports modes
  using more than 256 colours, the ATI VGA driver will not use these
  modes.

  The ATI VGA driver is not an accelerated driver.  If your adapter is
  based on the Mach8, Mach32 or Mach64 video controllers, this driver
  will not use the accelerated functions of the hardware.  It will only
  use the VGA hardware (which, for Mach32's and Mach64's, is integrated
  into the accelerator).  This can make opaque moves, for example, quite
  jerky.

  3.  What video adapters will the driver work with?

  Most adapters harbouring the following ATI video controller chips will
  work with this driver:

  VGA Wonder series:  18800, 18800-1, 28800-2, 28800-4, 28800-5, 28800-6
      Mach32 series:  68800-3, 68800-6, 68800AX, 68800LX
      Mach64 series:  88800GX-C, 88800GX-D, 88800GX-E, 88800GX-F, 88800CX,
                      264CT, 264ET, 264VT, 264VT2, 264GT


  The 264xT series are integrated controllers, meaning that they include
  an internal RAMDAC and clock generator.  Some early Mach32 adapters
  will not work with this driver because they do not provide VGA func-
  tionality.  Also, early Mach8 adapters will not work for the same rea-
  son, unless the adapter also has a video controller from the VGA Won-
  der series (or is connected to one through the VGA passthrough connec-
  tor).

  These adapters are available with a variety of clock generators and
  RAMDACs.  See the XF86Config section below for details.  These

  adapters are available with or without a mouse.

  VGA Wonder V3 adapters use a 18800 video controller and generate dot
  clocks with crystals.  VGA Wonder V4 adapters have a 18800-1 and also
  use crystals.  VGA Wonder V5 adapters also use a 18800-1, but have a
  18810 clock generator.  VGA Wonder+ adapters use a 28800-2 and a
  18810.  Other than these, ATI's adapter naming convention (if it can
  be said that one exists) starts to fall apart.

  The VGA Wonder series was also available through ATI's OEM channel
  under the name VGA1024.  Thus, the ATI VGA driver also supports
  VGA1024, VGA1024D, VGA1024XL, VGA1024DXL and VGA1024VLB adapters,
  among others.

  4.  What should I put in my XF86Config file?

  The chipset will be automatically detected.  The chipset name for this
  driver is "ati".  The driver also recognizes "vgawonder", "mach8",
  "mach32" and "mach64" as chipset names.  In this version of the
  driver, all names are equivalent.  In some future version each name
  will have a different meaning to be documented at that time.

  The clocks line to be specified in your XF86Config depends on what the
  adapter uses to generate dot clocks.

  For all adapters, one of the following clocks specifications (or an
  initial subset thereof) can be used depending on what the adapter uses
  to generate dot clocks:

  Crystals (VGA Wonder V3 and V4 adapters only):

    Clocks  50.000  56.644   0.000  44.900  44.900  50.000   0.000  36.000
            25.000  28.322   0.000  22.450  22.450  25.000   0.000  18.000
            16.667  18.881   0.000  14.967  14.967  16.667   0.000  12.000
            12.500  14.161   0.000  11.225  11.225  12.500   0.000   9.000



  ATI 18810 clock generator:

    Clocks  30.240  32.000  37.500  39.000  42.954  48.771   0.000  36.000
            40.000  56.644  75.000  65.000  50.350  56.640   0.000  44.900
            15.120  16.000  18.750  19.500  21.477  24.386   0.000  18.000
            20.000  28.322  37.500  32.500  25.175  28.320   0.000  22.450
            10.080  10.667  12.500  13.000  14.318  16.257   0.000  12.000
            13.333  18.881  25.000  21.667  16.783  18.880   0.000  14.967
             7.560   8.000   9.375   9.750  10.739  12.193   0.000   9.000
            10.000  14.161  18.750  16.250  12.586  14.160   0.000  11.225



  ATI 18811-0 and ATI 18812-0 clock generators:

    Clocks  30.240  32.000 110.000  80.000  42.954  48.771  92.400  36.000
            39.910  44.900  75.000  65.000  50.350  56.640   0.000  44.900
            15.120  16.000  55.000  40.000  21.477  24.386  46.200  18.000
            19.955  22.450  37.500  32.500  25.175  28.320   0.000  22.450
            10.080  10.667  36.667  26.667  14.318  16.257  30.800  12.000
            13.303  14.967  25.000  21.667  16.783  18.880   0.000  14.967
             7.560   8.000  27.500  20.000  10.739  12.193  23.100   9.000
             9.978  11.225  18.750  16.250  12.588  14.160   0.000  11.225





  ATI 18811-1 and ATI 18811-2 clock generators:

    Clocks 135.000  32.000 110.000  80.000 100.000 126.000  92.400  36.000
            39.910  44.900  75.000  65.000  50.350  56.640   0.000  44.900
            67.500  16.000  55.000  40.000  50.000  63.000  46.200  18.000
            19.955  22.450  37.500  32.500  25.175  28.320   0.000  22.450
            45.000  10.667  36.667  26.667  33.333  42.000  30.800  12.000
            13.303  14.967  25.000  21.667  16.783  18.880   0.000  14.967
            33.750   8.000  27.500  20.000  25.000  31.500  23.100   9.000
             9.978  11.225  18.750  16.250  12.588  14.160   0.000  11.225


  Mach32 and Mach64 owners should only specify up to the first 32 fre-
  quencies.

  The oldest Mach64 adapters use one of the clock generators described
  above.  The possibilities for Mach64 adapters also include
  programmable clock generators.  At bootup, video BIOS initialization
  programmes an initial set of frequencies.  Two of these are reserved
  to allow the setting of modes that do not use a frequency from this
  initial set.  One of these reserved slots is used by the BIOS mode set
  routine, the other by the particular driver used (MS-Windows, AutoCAD,
  X, etc.).  The clock numbers reserved in this way are dependent on the
  particular clock generator used on the adapter.

  If the driver does not support the adapter's clock generator, it will
  try to match the clocks to one of the following specifications.  This
  matching will occur whether or not the user specifies the clocks in
  XF86Config.

  BIOS setting 1:

    Clocks   0.000 110.000 126.000 135.000  50.350  56.640  63.000  72.000
             0.000  80.000  75.000  65.000  40.000  44.900  49.500  50.000
             0.000  55.000  63.000  67.500  25.180  28.320  31.500  36.000
             0.000  40.000  37.500  32.500  20.000  22.450  24.750  25.000



  BIOS setting 2:

    Clocks   0.000 110.000 126.000 135.000  25.180  28.320  31.500  36.000
             0.000  80.000  75.000  65.000  40.000  44.900  49.500  50.000
             0.000  55.000  63.000  67.500  12.590  14.160  15.750  18.000
             0.000  40.000  37.500  32.500  20.000  22.450  24.750  25.000



  BIOS setting 3:

    Clocks   0.000   0.000   0.000   0.000  25.180  28.320   0.000   0.000
             0.000   0.000   0.000   0.000   0.000   0.000   0.000   0.000
             0.000   0.000   0.000   0.000  12.590  14.160   0.000   0.000
             0.000   0.000   0.000   0.000   0.000   0.000   0.000   0.000


  If the driver matches the clocks to the third setting above, function-
  ality will be *extremely* limited (assuming the driver works at all).

  Other clock generators that have been used on ATI adapters (which can
  all be said to be clones of one of the above) might generate non-zero
  frequencies for those that are zero above, or vice-versa.

  The order of the clocks *is* very important, although the driver will
  reorder the clocks if it deems it appropriate to do so.  Mach32 and

  Mach64 owners should note that this order is different than what they
  would use for the accelerated servers.

  If the driver detects a supported programmable clock generator, it
  will ignore any XF86Config clock specification and programme the
  generator as needed by the modes to be used during the X session.

  A clock probe, done with the command "X -probeonly", will help you
  decide which of the above to use for your particular adapter.  If the
  server consistently reports that it has detected an unknown clock
  generator, please e-mail me the stderr output.

  Modes can be derived from the information in XFree86's doc directory.
  If you do not specify a "modes" line in the display subsection of the
  appropriate screen section of your XF86Config, the driver will
  generate a default mode and attempt to use it.  The timings for the
  default mode are derived from the timings of the mode (usually a text
  mode) in effect when the server is started.

  5.  What is the history of the driver?

  The complete history of the driver is rather cloudy.  The following is
  probably incomplete and inaccurate.

  Apparently, Per Lindqvist (pgd@compuram.bbt.se) first got an ATI
  driver working with an early ATI card under X386 1.1a.  This original
  driver may have actually been based on an non-functional ATI driver
  written by Roell.  Then Doug Evans (dje@cygnus.com) ported the driver
  to the ATI VGA Wonder XL, trying in the process to make the driver
  work with all other ATI cards.

  Rik Faith (faith@cs.unc.edu) obtained the X11R4 driver from Doug Evans
  in the summer of 1992, and ported the code to the X386 part of X11R5.
  This subsequently became part of XFree86.

  I (Marc Aurele La France) took the driver over in the fall of 1993
  after Rik got rid of his VGA Wonder card.

  6.  Miscellaneous notes

  Dot clocks greater than 80MHz cannot be used on most adapters as a way
  still needs to be discovered to make the VGA Wonder controller do
  pixel multiplexing.

  Support for more than 8bpp colour depth is pending proper RAMDAC
  handling and banked framebuffer code for >8bpp.

  Video memory banking does not work in the 16-colour and monochrome
  servers on V3, V4 and V5 adapters.

  Video memory corruption can still occur during mode switches on V3, V4
  and V5 adapters.  Symptoms of this problem include garbled fonts on
  return to text mode, and various effects (snow, dashed lines, etc) on
  initial entry into a graphics mode.  In the first case, the workaround
  is to use some other means of restoring the text font.  On Linux, this
  can be done with the kbd or svgalib packages.  In the second case,
  xrefresh will usually cleanup the image.

  Interlaced modes do not work in the monochrome server on 28800-x
  adapters when using a virtual resolution wider than 1024 pixels.

  Some (particularly low resolution) interlaced modes do not work on
  264xT adapters.

  Support for virtual resolutions using more than 1MB of video memory is

  still incomplete.  Specifically, such support works on Mach32
  adapters, and on 264xT adapters, but not on any other Mach64 adapters.

  There is some controversy over whether or not clocks higher than
  135MHz should be allowed on 264xT adapters.  For now, clocks will be
  limited to 135MHz by default.  This limit can only be increased (up to
  a driver-calculated absolute maximum) through the DACSpeed option in
  XF86Config.  Be aware however that doing this is untested and might
  damage the adapter.

  Future development plans include addressing the above problems and
  using accelerated functionality.

  Please e-mail any bug reports, comments, etc. to Marc Aurele La
  France, tsi@ualberta.ca


  Generated from XFree86: xc/programs/Xserver/hw/xfree86/doc/sgml/ati.sgml,v 3.12 1996/05/10 06:58:31 dawes Exp $
  $XConsortium: ati.sgml /main/3 1995/11/12 20:00:33 kaleb $
















































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