Kernel driver `bt869.o'
======================

Status: 'Beta' and needs further development and testing

Supported chips: 
  * Brooktree BT869 Video Modulator chips
    Prefix: `bt869'
    Addresses scanned: I2C 0x44 - 0x45 (inclusive)
    Datasheet: Publicly available at the brooktree web site
    (www.brooktree.com)

Author: Frodo Looijaard <frodol@dds.nl>, Philip Edelbrock
	<phil@netroege.com> and Ralph Metzler <rjkm@thp.uni-koeln.de>

Main Contact: Philip Edelbrock <phil@netroedge.com>

Module Parameters
-----------------
* force: short array (min = 1, max = 48)
  List of adapter,address pairs to boldly assume to be present
* force_bt869: short array (min = 1, max = 48)
  List of adapter,address pairs which are unquestionably assumed to contain
  a `bt869' chip
* ignore: short array (min = 1, max = 48)
  List of adapter,address pairs not to scan
* ignore_range: short array (min = 1, max = 48)
  List of adapter,start-addr,end-addr triples not to scan
* probe: short array (min = 1, max = 48)
  List of adapter,address pairs to scan additionally
* probe_range: short array (min = 1, max = 48)
  List of adapter,start-addr,end-addr triples to scan additionally


Description
-----------
This driver provides some access to the Brooktree bt869 found on some video
cards (like the 'Voodoo3 3000').  Typically, the output can be either an
s-video connection or composite video.  Resolutions supported using the
chip's built in configurations are 640x480 or 800x600.  Other possible
implementations may allow for double resolutions with some decimations
(e.g., a monitor running at 1280x960 but the TV out getting every other
pixel for 640x480).


Driver Features
---------------
Stanards: (US) NTSC or PAL (PAL untested)
Resultions: 640x480 and 800x600
Depths: 16 bit or 32 (I forgot if 24 bit worked OK, it probably does)
Colorbars: Switch on the built-in color bar generator. (FYI- using a blue
filter, you should see only alternating bright stripes of equal brightness.
Adjust your TV's color and saturation if this isn't the case.)

In your XF86Config file, you should have these entries for NTSC output:

ModeLine "640x480NTSC"  28.195793   640  656  658  784   480  520  525  600
ModeLine "800x600NTSC"  38.769241   800  812  814  880   600  646  649  735

or for PAL (untested),

ModeLine "640x480PAL"   29.50       640  675  678  944   480  530  535  625
ModeLine "800x600PAL"   36.00       800  818  820  960   600  653  655  750

Also, don't forget to add these modes to the resolutions list in the
'screen' sections of XF86Config.  You can change modes on the fly in X by
pressing (usually) ctrl-alt-+ or ctrl-alt-(minus)  with + and - being the
keys on your numeric 10-key pad.

BTW- My monitor doesn't like these entries very much, and as I've read:
don't run your monitor out of spec or else it will burst into fire.  So,
having the monitor turned on while in any of these modes is at your own
risk.  (I've never heard of a monitor breaking from this, but it seems to
be fashionable to warn about it.)


Chip Features
-------------
The chip is very flexible and customizable for many standards.  Right now
the driver sticks with the chip's built in NTSC and PAL standards.  It also
does some other wacky stuff like closed-captioning, Macro-vision
copy-protection, and other things.  Check out the datasheet for more info.


Issues
------
The depth register doesn't seem to do much?  If you have troubles or
aren't sure the output is working, turn the color-bars on.  If they display
OK, then the chip is syncing correctly.  The next thing to try is the depth
setting.  Lastly, turning off your computer and back on with your TV
connected but you monitor not, may force the video card to configure and
use the BT869 as your primary output device (all bets are off once X is
started).  Let me know if you have problems which you can't figure out 
(phil@netroedge.com).
