Information for ARK Logic Chipset Users
  Harm Hanemaayer (hhanemaa@cs.ruu.nl)
  26 June 1995

  1.  Supported chipsets

  The "ark" driver in the SVGA server is for ARK Logic graphics
  chipsets.  The following chipsets are supported:

     ARK1000PV (ark1000pv)
        Chipset with 32-bit DRAM interface, supports fast DRAM timing,
        for VESA and PCI bus. Has powerful "coprocessor" for graphics
        acceleration which is not yet used in the current driver.  The
        max supported resolution/refresh depends on the RAMDAC used on
        the card; expect 256 colors up to 80 or 110 MHz dot clock.

     ARK1000VL (ark1000vl)
        Older chip, VLB only. More or less compatible with ARK1000PV.

     ARK2000PV (ark2000pv)
        64-bit version of the ARK1000PV. Note that a ARK2000PV equipped
        with 1Mb of DRAM is about equivalent to the same card with an
        ARK1000PV chip; 2Mb is required for 64-bit operation. Again the
        RAMDAC used on the card determines the max supported dot clocks.
        The current driver is however limited to 80 MHz at 256 colors.

  The chipset may not be detected automatically. In this case use a line
  like Chipset "ark1000pv" in the Device section of the XF86Config file.

  2.  Supported RAMDACs

  If no RAMDAC is specified, a standard RAMDAC supporting 256 colors up
  to 80 MHz dot clock frequency is assumed. The following RAMDAC types
  can be specified in the Device section of the XF86Config file (e.g.
  Ramdac "att20c490"):

     att20c490
        Industry-standard 8-bit RAMDAC. The RAMDAC used on the basic
        Hercules Stingray Pro is compatible. 16bpp color depth is
        supported up to 40 or 55 MHz, depending on the DAC speed rating.
        This is the only RAMDAC that has been tested with the current
        driver.

     att20c498
        Industry-standard 16-bit RAMDAC. The RAMDAC used on the Hercules
        Stingray Pro/V and the Stingray 64/V is compatible. 16bpp is
        supported up to 80 MHz dot clock frequency.

     zoomdac
        This is the actual DAC used by the Hercules Stingray Pro/V and
        64/V.  It is treated mostly as an ATT20C498, but with dot clock
        limits set correctly (16bpp up to 55 MHz with ARK1000PV, up to
        at least 110 MHz with ARK2000PV).

     stg1700
        Completely untested.

  The Dacspeed keyword can be used to indicate the speed rating of the
  RAMDAC, but it must be used with care.

  To run XF86_SVGA at 16 bpp, pass options to the X server as follows:
  startx -- -bpp 16               5-6-5 RGB ('64K color', XGA)
  startx -- -bpp 16 -weight 555   5-5-5 RGB ('Hicolor')



  3.  Basic configuration

  It is recommended that you generate an XF86Config file using the
  `xf86config' program, which should produce a working high-resolution
  8bpp configuration, although the modelines might need reshuffling for
  optimal screen refresh. You may want to include mode timings in the
  Monitor section that better fit your monitor (e.g 1152x900 modes).

  In order to prevent stress on your monitor, it is recommended that you
  turn off your monitor during clock probing (X -probeonly), which also
  happens if you start the server with no Clocks line present in the
  Device section of the XF86Config. The following Clocks line can be
  used for the Hercules Stingray Pro using an ARK Logic clock generator
  (so there's no need to probe clocks for this card, just insert the
  following line in the Device section of the XF86Config file):

      Clocks 25.175 28.3 40 70 50 75 36 44.9
      Clocks 0 118 80 31.5 110 65 72 95

  The higher frequencies have not been tested, there might be a mismatch
  in the 60-80 MHz range.

  If are having driver-related problems that are not addressed by this
  document, you can try contacting the XFree86 team (the current driver
  maintainer can be reached at hhanemaa@cs.ruu.nl), or post in the
  Usenet newsgroup "comp.windows.x.i386unix".

  Generated from XFree86: xc/programs/Xserver/hw/xfree86/doc/sgml/ark.sgml,v 3.1 1995/07/07 15:40:20 dawes Exp $