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<title> Information for ARK Logic Chipset Users
<author> Harm Hanemaayer (<it>hhanemaa@cs.ruu.nl</it>)
<date> 26 June 1995

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<sect> Supported chipsets <p>

The "ark" driver in the SVGA server is for ARK Logic graphics chipsets.
The following chipsets are supported:
<descrip>
<tag>ARK1000PV (ark1000pv)</tag>
	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.
<tag>ARK1000VL (ark1000vl)</tag>
	Older chip, VLB only. More or less compatible with ARK1000PV.
<tag>ARK2000PV (ark2000pv)</tag>
	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.
</descrip>
The chipset may not be detected automatically. In this case use a line
like <tt>Chipset "ark1000pv"</tt> in the <tt>Device</tt> section of
the XF86Config file.


<sect> Supported RAMDACs <p>

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.
<tt>Ramdac "att20c490"</tt>):
<descrip>
<tag>att20c490</tag>
	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.
<tag>att20c498</tag>
	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.
<tag>zoomdac</tag>
	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).
<tag>stg1700</tag>
	Completely untested.
</descrip>
The Dacspeed keyword can be used to indicate the speed rating of the RAMDAC,
but it must be used with care.

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


<sect> Basic configuration <p>

It is recommended that you generate an XF86Config file using the
`<tt>xf86config</tt>' 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 <tt>Monitor</tt> 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):

<verb>
    Clocks 25.175 28.3 40 70 50 75 36 44.9
    Clocks 0 118 80 31.5 110 65 72 95
</verb>
    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 <it>hhanemaa@cs.ruu.nl</it>), or post in the Usenet
newsgroup "<it>comp.windows.x.i386unix</it>".

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





$XConsortium: ark.sgml /main/2 1995/11/12 20:00:30 kaleb $
</verb>

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