[mythtv-users] Hardware for Best TV-Out?

Cory Papenfuss papenfuss at juneau.me.vt.edu
Tue Oct 26 14:49:51 UTC 2004

> 	Now that you've successfully gotten me off on this tangent, I'm 
> looking into the feasibility of using the 14.318Mhz clock that's on the VGA 
> card.  The AD724 datasheet mentions using this for a synchronous system, and 
> I might be able to get ahold of it via the "VGA Feature Connector"  That 
> would greatly simplify the circuit construction/components/tuning since it 
> wouldn't even need a crystal then (and would also be more accurate NTSC).  If 
> that doesn't work, a PLL programmed to reconstruct P/Q times the dotclock 
> from the HSYNC signal might be a very viable alternative.  Of course if you 
> change the modeline, you'd have to reprogram your circuit (Let's see... 912 
> in binary for the DIP switches is...)
 	Quick check on the "VGA Feature Connect."  Doesn't seem to be 
standard.  Some cards output dotclocks, some don't, some divide by a 
number, some only work in console (VGA) but not X.  Bummer... I was hoping 
to get ahold of an easy synchronous signal to build rev2 of the board.


More information about the mythtv-users mailing list