[mythtv-users] [ G400 ] Hotwo enable flicker filters

[Cory Papenfuss]

> VGA                                                SCART
>
>   1 -O------------------------------------------O- 15 R
>   2 -O------------------------------------------O- 11 G
>   3 -O------------------------------------------O-  7 B

 	RGB signals, yes
>
>   6 -O------------------------------------------O- 13 R Gnd
>   7 -O------------------------------------------O-  9 G Gnd
>   8 -O------------------------------------------O-  5 B Gnd
>
 	RGB grounds, yes.

 	If possible, keep these lines as short/clean as possible, and do 
not connect all the grounds together anywhere.  You may even try to use 
coaxial cable or something for them.  This is pretty high frequency 
(although not nearly has high as for a computer signal).


>   5 -O-+
>        |
>  11 -O-+
>
 	I don't know what this is for... it might be a matrox-ism.All I 
see is Ground and No Connect, so I wouldn't do it if you want to make a 
generic VGA cable.


>  10 -O------------------------------------------O- 17
> Gnd

 	Sync GND, yes.

>
>  14 -O------------------------+
> -VS                           |
>                               |
>  13 -O------------------------+-----------------o- 20
> -HS                                               -CS
>
 	Here's what you probably don't want to do.  Connecting VGA HSYNC 
and VSYNC together like that means they'll try to drive each other. 
That's what the transistor circuit is for.  Generally, if a video card 
supports CSYNC, it'll come out on the HSYNC pin.  So, just connect 
VGA13->SCART20 and leave VGA14 unconnected.

> 5,6,7,8,Shell ------------------------------------ 5,9,13,17,21,Shell
>

 	I wouldn't run the video GNDs to the shell.  Leave them 
point-to-point.


> Doing the math for the geometry and the timings should be no problem. The 
> thing i'm not clear about is what the flags csync, hsync, vsync, bcast and so 
> an are to be used for. At this point I would understand if you say RTFM  and 
> i will do, but maybe you can wrote some words in general. I know what the 
> hsync and vsync signals are for. But what will the options in the XF86Config 
> modline will do?
> A simple enable/disable?
>

 	The syncs can be either polarity... nominally 0 and then 5v 
(+Xsync) when triggered, or nominally 5v and 0 (-Xsync) for trigger (X = 
h|v|c).  The flags just control their polarity.  The csync flag tells a 
supported card to put out *BOTH* HSYNC and VSYNC out the HSYNC wire (XOR'd 
I believe).  The bcast is a framebuffer-specific option that I don't think 
many/any cards actually support.

 	The hsync/vsync flags in the modeline don't enable/disable them... 
just change the polarity.  The lack of those options just mean default (+ 
I think).

-Cory

*************************************************************************
* Cory Papenfuss                                                        *
* Electrical Engineering candidate Ph.D. graduate student               *
* Virginia Polytechnic Institute and State University                   *
*************************************************************************