xenocara/driver/xf86-video-rendition/README
2006-11-26 20:10:12 +00:00

6.1 KiB

Information for Rendition (Micron) Verite Users
The XFree86 Project Inc.
9 June 2000, last update by Dejan Ilic <dejan.ilic@home.se>
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Table of Contents
 
 
1. Supported hardware
2. Limitations
3. Important notices
4. Features
5. xorg.conf Option
6. News in the X11R6.8 release
7. News in the XFree86 4.1 release
8. Major changes in this release
9. Bugfixes
10. Known problems in current driver
11. Work in progress (not finished in time for release)
 
 
______________________________________________________________________
 
1. Supported hardware
 
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).
 
 
2. Limitations
 
V1000 cards can only work as primary display card due to hardware
limitations.
 
V2x00 cards can work even if not primary, but primary display card
will be disabled when server is run. This is a driver limitation.
 
Hopefully these limitations were worked around and fixed before final
XFree86 4.0 release.
 
 
 
3. Important notices
 
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).
 
 
15 bits per pixel is only supported on V1000-based cards due to
hardware limitations on V2x00 chipsets.
 
 
If you have problems with hardware cursor use the "sw_cursor" option
to revert back to software cursor.
 
 
This is essentially a port of XFree86 3.3.x driver to the new XFree86
4.0 API, and thus 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.
 
4. Features
 
 
o Hardware acceleration
 
o Hardware cursor
 
o Supported color depths
 
o 8 bits per pixel (256 pseudo colour)
 
o 15 bits per pixel (actually 16-bits with RGB-weight 555, 32768
colors)
 
o 16 bits per pixel (high colour, RGB-weight 565, 65536 colors)
 
o 32 bits per pixel (true colour, sparse 24bit, 16M colors)
 
 
5. xorg.conf Option
 
 
Option
Disables use of the hardware cursor.
 
Option
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.
 
DacSpeed
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.
 
Option
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.
 
Option
Disable probing of DDC-information from your monitor. This
information is not used yet and is only there for informational
purposes. This might have changed before final XFree86 4.0
release. Safe to disable if you experience problems during
startup of X-server.
 
Option
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.
 
Option
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.
 
 
6. News in the X11R6.8 release
 
This driver was originally part of the XFree86 4.4 rc2 release.
 
 
7. News in the XFree86 4.1 release
 
 
o DirectColor support
 
o SilkenMouse support
 
 
8. Major changes in this release
 
 
o Gamma works now for >8bpp
 
 
9. Bugfixes
 
 
o Only some code cleanup done. No real bugfixes.
 
 
10. Known problems in current driver
 
 
o The acceleration code hangs the computer during X-server startup.
 
o DDC-probing does not work correctly yet. No DDC information is
found.
 
o Switching from display to VC and back to display can lock up V2x00
cards.
 
o 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.
 
o Depth 15 & 16 has problems with colors when DirectColor is used.
 
 
11. Work in progress (not finished in time for release)
 
 
o 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.