<!DOCTYPE linuxdoc PUBLIC "-//XFree86//DTD linuxdoc//EN"[
<!ENTITY % defs SYSTEM "defs.ent"> %defs;
]>

<article>
<title>Information for Rendition (Micron) Verit&eacute; Users
<author>The XFree86 Project Inc.
<date>9 June 2000, last update by Dejan Ilic <email>dejan.ilic@home.se</email>

<ident>
$XFree86: xc/programs/Xserver/hw/xfree86/doc/sgml/rendition.sgml,v 1.14 2005/03/04 03:23:52 dawes Exp $
</ident>

<toc>

<sect>Supported hardware <p>
All cards based on the V1000 or the V2x00 should be supported. The server
was tested on a miroCRYSTAL VRX (V1000), Intergraph Intense-100 3D (V1000),
Diamond Stealth II S220 (V2100), Hercules Thriller3D (V2200),
Innovision Warrior3D (V2200) and Genoa V-Raptor (v2200).

<sect>Limitations <p>

V1000 cards can only work as primary display card due to hardware limitations. <p>

V2x00 cards can work even if not primary, but primary display card will
be disabled when server is run.  This is a driver limitation.<p>

Hopefully these limitations will soon be fixed.<p>

<sect>Important notices <p>

Some V1000-based video cards are known to lock up the computer if you
have write-combine activated. Disabling it removes the problem.  Look
for settings in the motherboards BIOS and disable ALL settings that has
to do with write-combine (usually called USWC or just WC for short). <p>

15 bits per pixel is only supported on V1000-based cards due to hardware
limitations on V2x00 chipsets.<p>

If you have problems with the hardware cursor use the "sw_cursor" option to
revert back to the software cursor.<p>

This is essentially a port of XFree86 3.3.x driver to the new XFree86
4.0 API, and so we have put most of effort in making a working driver
with the most basic features. Support for multi-head support and
acceleration are next on the list of features to be included.<p>

<sect>Features <p>
<itemize>
<item>Hardware acceleration
<item>Hardware cursor
<item>Supported color depths
<itemize>
<item>8 bits per pixel (256 pseudo colour)
<item>15 bits per pixel (actually 16-bits with RGB-weight 555, 32768 colors)
<item>16 bits per pixel (high colour, RGB-weight 565, 65536 colors)
<item>32 bits per pixel (true colour, sparse 24bit, 16M colors)
</itemize>
</itemize>

<sect>XF86Config Option <p>
<descrip>
<tag>Option "SW_Cursor"</tag>
Disables use of the hardware cursor.

<tag>Option "Overclock_Mem"</tag>
Run the memory at a higher clock. Useful on some cards with display glitches
at higher resolutions. But adds the risk to damage the hardware. Use with
caution.

<tag>DacSpeed "MHz"</tag>
Set custom ramdac limit. We have currently no way of knowing if the v2x00
chip is a v2100 (170MHz) or v2200 (203MHz and 230MHz) so we assume the
lowest. Use this option to manually override the value.

<tag>Option "FramebufferWC"</tag>
If writecombine is disabled in BIOS, and you add this option in
configuration file, then the driver will try to request writecombined
access to the framebuffer. This can drastically increase the performance
on unaccelerated server. Requires that "MTRR"-support is compiled into
the OS-kernel.

<tag>Option "NoDDC"</tag>
Disable probing of DDC-information from your monitor. This information
is not used yet and is only there for informational purposes. This might
change before final XFree86 4.0 release. Safe to disable if you experience
problems during startup of X-server.

<tag>Option "ShadowFB"</tag>
If this option is enabled, the driver will cause the CPU to do each
drawing operation first into a shadow frame buffer in system virtual
memory and then copy the result into video memory.  If this option is
not active, the CPU will draw directly into video memory.  Enabling this
option is beneficial for those systems where reading from video memory
is, on average, slower than the corresponding read/modify/write operation
in system virtual memory.  This is normally the case for PCI or AGP
adapters, and, so, this option is enabled by default unless acceleration
is enabled.

<tag>Option "Rotate"</tag>
The option expect a value "CW" for clockwise or "CCW" for counterclockwise
rotation of the screen. This is useful when you need more height then
width on the screen. Desktop publishing is one example where a monitor
could display the whole page at once on a monitor laying on the side.
Notice that this option requires "ShadowFB" and automatically enable it.
It also disables the acceleration.  The option is not activated by
default.

</descrip>

<sect>News in the XFree86 4.1 release<p>
<itemize>
<item>DirectColor support
<item>SilkenMouse support
</itemize>

<sect>Major changes in the XFree86 4.1 release <p>
<itemize>
<item>Gamma works now for >8bpp
</itemize>

<sect>Bugfixes<p>
<itemize>
<item>Only some code cleanup done. No real bugfixes.
</itemize>

<sect>Known problems in current driver<p>
<itemize>
<item>The acceleration code hangs the computer during X-server startup.
<item>DDC-probing does not work correctly yet. No DDC information is found.
<item>Switching from display to VC and back to display can lock up V2x00 cards.
<item>When scrolling the virtual display on a V1000 card parts of the
screen will become distorted. Problem disappears when you continue moving
around. V2x00 does not exhibit this problem. Probably a bug in the driver
rather than a limitation of the chip.
<item>Depth 15 & 16 has problems with colors when DirectColor is used.
</itemize>

<sect>Work in progress (not finished in time for release) <p>
<itemize>
<item>Acceleration is disabled for the moment. If you want to play with
it enable the "USE_ACCEL" define in rendition.c file! Beware as it has
several bugs left to clear out before if is stable for general use.
</itemize>

</article>

