> -----Original Message-----
> From: Richard Bronosky [mailto:[EMAIL PROTECTED]
> Sent: Tuesday, January 24, 2006 07:59 PM
> To: 'Discussion about mythtv'
> Subject: Re: [mythtv-users] Sync rates for Sharp 32 inch LCD
> 
> I want to make sure that people don't buy/refuse to by on mixed info.  I
> DO have my KnoppMyth box <http://www.bronosky.com/index.php?p=21>
> displaying on my Sharp Aquos LC-32D4U with a simple DVI->HDMI cable.  My
> concern is fixing the overscan.  I want to know the technical
> capabilities of the TV so that I don't hose it with the wrong sync rates.

Well, seeing that you've already lurked in another thread:
   
http://72.14.203.104/search?q=cache:_fHc8RVDkzUJ:mysettopbox.tv/phpBB2/viewtopic.php%3Ft%3D7446%26+LC-32D4U+modeline&hl=en&gl=us&ct=clnk&cd=1&client=firefox-a

... and that you're new to Linux, the best I can do at this point is offer more 
pointers.  Please forgive me if I get too basic.

The gentleman in that thread was having a similar problem as you.  He found 
that, if he starts X using startx --logverbose 6, X would provide him with 
verbose logging, which is normally output to /var/log/XFree86.log.0.  This is 
where he found X had outputted some display ranges.  Armed with this 
information, he went to http://xtiming.sf.net/cgi-bin/xtiming.pl, making some 
small tweaks based on the information he received, in attempts to produce a 
proper modeline without overscan.

While you can easily find modelines for various resolutions on the Internet 
(Google is your friend), the timings that produce these resolutions may not 
coincide with your display adapter, as well as your TV.  If we were back in 
1996, I would say, "Be careful when experimenting with timing modes, and fully 
understand what you're doing before you implement it".  However, in this day 
and age, VESA standards have come a long way, and it's been ages since I've 
seen a display that is not compliant with the latest VESA standards.  Things 
this standard should provide you are:

   - Drop sync with frequency is OOB (Out of Band).  If you throw a timing at 
it that is too high for the display to support, it should drop sync to the 
display and, normally, the power LED on the display will illuminate in orange.

   - DDC (Direct Data Channel).  This is a standard method for communication 
between the display adapter and the display.  This is the channel that is used 
by the display adapter to query the display for EDID information.

   - EDID (Extended Display Information Data).  Displays contain this 
information to tell the display adapter which resolutions and timings it 
supports.
Back in the days, when monitors complied to earlier (or no) VESA standards, 
when one would fiddle with X timings, the documentation 

I'm not sure if your display is fully VESA compliant, so I'll be on the safe 
side here and say, "Be careful when experimenting with timing modes, and fully 
understand what you're doing before you implement it". :-)  That said, check 
out:
   http://www.avsforum.com/avs-vb/archive/index.php/t-546124.html

Also be sure to read and fully understand:
   http://www.tldp.org/HOWTO/text/XFree86-Video-Timings-HOWTO
... be warned; it's not for the faint of heart.

I recently installed Debian (Etch) on a newly purchased clone box I built.  It 
has a EVGA GeForce 7800 GT and is attached to a Westinghouse LVM-37w1.  The 
LVM-37w1 has a native resolution of 1920x1080 and can support the following:
   1600x900
   1280x1024
   1280x720
   1152x864
   1024x768
   800x600
   640x480
In <cough>WinXP</cough>, I can get all of these resolutions besides 1280x720, 
although I know the monitor can display it.  The same for Linux, however, I 
could probably get 1280x720 if I threw it in my Modes line.  In Linux, all I 
had to do was:
   1. Use nVidia's "nvidia" driver, rather than the "nv" driver supplied by 
?the kernel?  The nv driver would hard-lock my box after logging in to GDM 
(Gnome Display Manager).
   2. Modify my /etc/X11/xorg.conf to include the HorizSync and VertRefresh my 
display supports.
   3. Modify my Modes line in my /etc/X11/xorg.conf to:
      Modes     "1920x1080" "1600x900" "1280x1024" "1152x864" "1024x768" 
"800x600" "640x480"

>From here, I restarted X, it read the Modes line from my /etc/X11/xorg.conf, 
>ran some EDID queries via DDC, found the timings my monitor supports, and 
>displayed a GUI.  It was that easy.  However, keep in mind that I mentioned 
>your display may not be fully VESA compliant, may comply to some older VESA 
>standard, or may only support VESA on a certain input.  Your luck may vary 
>with this solution.

Perhaps one of the first things I'd do is to contact Sharp.  I know you've done 
this and they were not much help, but ask them if the monitor will drop sync if 
it's supplied with a frequency that is OOB.  If it does, then you should feel 
safe when experimenting with video timings, as it shouldn't open up the small 
chip with the white smoke.  Dig a little deeper and see if they can answer if 
it supports VESA standards, which VESA standard revision it supports, and if it 
only supports VESA standards on certain inputs.

Secondly, I'd read the X-video-timings HOWTO until my eyes bleed, brain is 
swollen, and I feel confident that I can tweak X timings to match what my 
display could handle.

Once you fully understand video timings, you can work with your currently 
working, yet overscanning, config and tweak it to fit your displays needs.  
This is the only way to go if you're not getting cooperation from Sharp.  The 
road will not be easy, but it's definitely achievable.

Good luck!

- Ken 


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