<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<TITLE>ET6000 driver features </TITLE>
</HEAD>
<BODY BGCOLOR="#efefef" TEXT="black" LINK="blue" VLINK="#551A8B" ALINK="red">

<A HREF="tseng.html"><EM> Information for Tseng Chipset Users</EM></A>
 <b>:</b> <EM>ET6000 driver features </EM><BR>
<b>Previous:</b> <A HREF="tseng3.html"><EM>ET4000 driver features </EM></A><BR>
<b>Next:</b> <A HREF="tseng5.html"><EM>Clock selection problems with some ET4000 boards </EM></A>


<HR NOSHADE>
  <H2><A NAME="4"></A>4. ET6000 driver features </H2>
<p>In addition to the features in the ET4000 driver, the SVGA ET6000 server
supports all possible color depths in the SVGA server: 8bpp, 16bpp (both at
5-5-5 and 5-6-5 color resolutions), 24bpp and 32 bpp.</p>
<p>Linear memory mode (as opposed to the VGA default, banked memory layout) is
supported. It is required and enabled by default for the 16/24/32 bpp modes.
For 8bpp, the default is linear mode for PCI cards and banked mode for
ISA/VLB cards.</p>
<p>To force linear memory at 8bpp, put the following in the SVGA section of your
<code>XF86Config</code>:
<pre>
  Option "linear"
</pre>
</p>
<p>Acceleration is supported and is enabled by default, and accelerates all
color depths on the ET6000. Acceleration can be disabled by adding the
following in the Device section of your
<code>XF86Config</code>:
<pre>
  Option "noaccel"
</pre>
</p>
<p>The hardware cursor is supported in all color depths. Due to a hardware
limitation in the ET6000, only a limited set of colors is supported (2
significant bits per color component). This may cause some (small) cursor
color errors. If absolute cursor color accuracy is required, the hardware
cursor should not be enabled. However, in most applications, this will not
be a problem. The hardware cursor can be enabled using
<pre>
  Option "hw_cursor"
</pre>
</p>
<p>There is a problem with the hardware cursor at high dotclocks (above
approx. 110MHz) at which point the cursor does strange things when partly off
the left-hand side of the screen.</p>
<p>On older ET6000 chip revisions, DoubleScan modes currently don't work with
the hardware cursor: only the top half of the cursor is visible. If you want
to use DoubleScan modes (320x200 is a popular one), then do not enable the
hardware cursor. Most recent ET6000 cards and the ET6100 do not exhibit this
problem.</p>

<p>On some PCI systems, acceleration may cause occasional font corruption. As
described above, this is caused by a bug in your system BIOS or a wrong
setting of the write combining feature in that BIOS. If you are unable to
fix the BIOS or force the option off, font acceleration may be disabled
using the following in the Device section of your
<code>XF86Config</code>:
<pre>
  Option "xaa_no_color_exp"
</pre>
</p>
<p>When using accelerated high color-depths (24bpp and 32bpp), high-resolution
modes (starting somewhere around 800x600) may cause temporary "garbage"
lines to the right of the screen while the accelerator is busy. The garbage
should not be persistent: it should go away as soon as the server is left
alone. This is a memory bandwidth problem, and thus cannot be resolved
(except by not allowing such modes at all, which is what is done in the
current driver).</p>
<p>Ignoring it is one option (it isn't destructive). Disabling acceleration in
the Device section of the <code>XF86Config</code> file is another option: since
the accelerator is not being used, there is ample bandwidth to avoid such
problems.</p>


 <HR NOSHADE>
<A HREF="tseng.html"><EM> Information for Tseng Chipset Users</EM></A>
 <b>:</b> <EM>ET6000 driver features </EM><BR>
<b>Previous:</b> <A HREF="tseng3.html"><EM>ET4000 driver features </EM></A><BR>
<b>Next:</b> <A HREF="tseng5.html"><EM>Clock selection problems with some ET4000 boards </EM></A>



</BODY>
</HTML>
