Date   : Mon, 25 May 2009 15:13:46 +0100
From   : info@... (Sprow)
Subject: S-Video mod for Master 128

In article <AAF6E4A2-4CB1-41BF-9DBB-37839D70DF30@...>,
   <me@...> wrote:
> On 25 May 2009, at 11:51, Francis Devereux wrote:
>
> >  - With the S-Video mod in place, the composite video out looks noisy
> > (can anyone explain why?).
>
> The BBC lacks an s-video encoder so it's not possible to get "real" s- 
> video out of it, unless you were to convert it from the RGB signals. 

S-video encoder? There's no such thing. S-video is just the luma content and
syncs on one wire (ie. an ordinary B&W output) and chroma content on another
wire (which is available inside the beeb where it is generated from the RGB
signals via some resistor deviousness).

The big win for S-video is that the receiver doesn't have to unpick the luma
and chroma content (which for high colour high spatial frequency will
overlap considerably) so avoiding cross colour,
Sprow.