Slightly off topic: S-Video?

Hi,

Does anyone know if S7 is backward compatible with the S-Video
standard?  (S7 is S-Video with 7 pins, while S-Video has 4 pins.)  Can
I plug an S-Video (4-pin) cable into the S7 Video output port? I want
to feed the video signal from an S7 ouput port to a TV, using the
normal S-Video-to-RCA-cable?

I have noticed that S7 contains 4 outer pins and three inner pins. 
The four outer pins' positions correspond to that of the S-Video
standard.  Somewhere on the net I have read that the three inner pins
are control pins which can be ignored.  Is this true?

Why do we have the S-Video standard, while laptop manufacturers fit
laptops with the non-standard S7?


Thank you very much
Jaco Versfeld

Jaco Versfeld wrote:



(snip)

> Why do we have the S-Video standard, while laptop manufacturers fit
> laptops with the non-standard S7?

S-video represents the separation of the luminance (black and white)
and chrominance (color) of the NTSC (and probably other) color TV
standard.

Computers generate video as RGB, where the conversion to S-video
represents a loss of some of the signal.

-- glen

Hello,
Can I plug an S-Video (4-pin) cable into the S7 Video output port? I want
> to feed the video signal from an S7 ouput port to a TV, using the
> normal S-Video-to-RCA-cable?
Yes you can. The additional pins are used sometimes to give the 
composite signal additionally. But not always, as I have read. It is 
dependant on the manufacturer of the graphic card (or your notebook).

  > Why do we have the S-Video standard, while laptop manufacturers fit
> laptops with the non-standard S7?
> 
Exactly for the same reason, that every video card for the standard PC 
has 7 pins. :)

> Thank you very much

You're welcome
Pawel Szczupak

"Pawel Szczupak" <pawl6@OHNESPAM.op.pl> wrote in message
news:cmpt49$pn0$1@news.onet.pl...
> Hello,
> Can I plug an S-Video (4-pin) cable into the S7 Video output port? I want
> > to feed the video signal from an S7 ouput port to a TV, using the
> > normal S-Video-to-RCA-cable?
> Yes you can. The additional pins are used sometimes to give the
> composite signal additionally. But not always, as I have read. It is
> dependant on the manufacturer of the graphic card (or your notebook).
>
>   > Why do we have the S-Video standard, while laptop manufacturers fit
> > laptops with the non-standard S7?
> >
> Exactly for the same reason, that every video card for the standard PC
> has 7 pins. :)
>
> > Thank you very much

That makes sense.  My graphics card has a 7-pin S-video output.  It also came
with a little 7-pin DIN to RCA plug cable for composite video signal.  I thought
that somehow the cable was able to convert the signal from S-video to composite
passively, but it makes more sense that the video card generates the composite
signal and the cable just breaks out the correct pins.