A SCART and FOUR phonos?!

[Ambient Sheep]

No, not a new Peter Greenaway film.

The other day there I was round some friends when I was suddenly asked if I could try to sort out some AV wiring for them.

"We've got a bag of old leads, if it'll help."

Well I looked and it didn't help (mostly bizarre ancient shit) but one thing did take my eye... a SCART to FOUR phonos, still sealed in its original packaging.

Now we all know about SCART to THREE phonos (yellow = composite video, white = left audio, red = right audio)... but this one had FOUR: yellow, white, red and BLACK.  The packaging was saying nothing.

Curious, when I got home I googled, to no avail whatsoever.  Can't even seem to be able to buy one.  If I'd had my test meter with me I could've bleeped it out to see which pin it was connected to but obviously I didn't and besides I've mislaid it anyway.

And no, it wasn't a SCART to three phonos and a black S-Video 4-pin mini-DIN plug (have got one of those myself), it really was just an extra phono plug.

Anybody know what it's for?  I don't actually NEED to know but the curiosity is lightly torturing me...

[Twed]

Oi, no SCART talk. Brexit means Brexit.

[Consignia]

Like this https://www.amazon.co.uk/Scart-Phono-Audio-Video-Switched/dp/B009AAND82 ?

No idea what the extra cable is for, doesn't really seem to shed any light.

[Ambient Sheep]

I don't *think* it was switched (but I could be wrong) but yeah, that's it, basically.  Well done for finding one. :-)

[Uncle TechTip]

Maybe it was for auxiliary control of the TV? A manufacturer specific thing which is why you're not turning up much.

[Bazooka]

Its to plug into one of those sex robots everyone has, allows you see what the robot is seeing on the TV screen

[Sherman Krank]

Apparently it's an RGB SCART cable.

In both cases this can still be an RGB SCART cable. When referring to RGB SCART cables the term composite video can be confused with the more commonly used composite video format (CVBS) which normally uses a cable with two phono plugs (yellow and white) or three phono plugs (yellow, white and red), also known as RCA or Cinch cable. But a phono composite video cable is not the same video format as an RGB SCART cable. An RGB SCART cable transmits on four separate wires (Red - pin 15, green - pin 11, blue - pin 7 & sync - pin 20), which gives it a cleaner picture, as opposed to a phono composite video cable which only uses one wire to handle all the picture data. Sync is a timing signal made up from the horizontal sync (HSYNC) and vertical sync (VSYNC) which tells the television when to correctly display the image.

https://www.retrogamingcables.co.uk/composite-video-vs-composite-sync


Edit - Or at least something similar with the extra wire being for sync.
         Probably best to just wait for Buzby.

[georgetaylor]

Composite video can be separated into Y and C.

[Ambient Sheep]

Yeah I did wonder if it were Sync but since Composite Video includes that I don't know why it would be separate... you sometimes need separate sync for RGB but the pinout is different so wouldn't go with those other three phonos.

It could be the C part of Y/C (S-video) though; looking at the pinout on Wikipedia, when it's in S-Video mode it puts the Y down the Composite Video line (yellow phono) and the C down another pin... which would be our black phono winner.

^{_{I didn't know people ever did S-Video with twin phonos, it's always been either the four-pin mini-DIN connector (domestic and professional) or twin BNC connectors (professional only) on all kit I've either seen or helped to design.}}

Anyway the good news is that yesterday I found my long-lost multimeter (while looking for something else -- unsuccessfully, natch), and I'm going to be going back round there at the weekend, so I'll be able to find out for sure.

Thanks for indulging me.

[Sebastian Cobb]

Pin 8 switching/recording?

[Replies From View]

Edit:  never mind, you seem to have worked it out.

[buzby]

Yeah I did wonder if it were Sync but since Composite Video includes that I don't know why it would be separate... you sometimes need separate sync for RGB but the pinout is different so wouldn't go with those other three phonos.

It could be the C part of Y/C (S-video) though; looking at the pinout on Wikipedia, when it's in S-Video mode it puts the Y down the Composite Video line (yellow phono) and the C down another pin... which would be our black phono winner.

^{_{I didn't know people ever did S-Video with twin phonos, it's always been either the four-pin mini-DIN connector (domestic and professional) or twin BNC connectors (professional only) on all kit I've either seen or helped to design.}}

Anyway the good news is that yesterday I found my long-lost multimeter (while looking for something else -- unsuccessfully, natch), and I'm going to be going back round there at the weekend, so I'll be able to find out for sure.

Thanks for indulging me.

I think yuo are probably right - the black phono (Chrominance/C) should go to pins 13 and 15 on the SCART and the yellow phono (Composite/Luminance/Y) should go to pins 17 and 19 if it's a SCART Output lead.

The phono Y/C connectors were sometimes used alongside the more usual S-Video Mini-DIN. Some old 15kHz monitors used them, and it was Commodore's standard on their monitors (though they used red instead of black for Chrominance, as it was before they had stereo)

[Ambient Sheep]

Well blimey, never seen that before!  That middle one is especially confusing to anybody who knows the traditional colours.

The only Commodore kit I ever used (apart from a couple of 1970s calculators) was my school's beloved PET 3016 that I (more-or-less) first cut my computing teeth on.

Thanks for that.

I shall report back in a few days...


EDIT: Love the fact that the top photo calls it "Commodore Video", like they invented it... :-)

[buzby]

EDIT: Love the fact that the top photo calls it "Commodore Video", like they invented it... :-)

To be fair to them, it was at a time when RF modulators were the standard video output for home computers and consoles (unless you were minted and had an Apple II, Oric or BBC Micro, which had RGB outputs), and if you were lucky you got a Compo video output as well. I think Commodore and Atari (in the 800, though they didn't sell a monitor to go with it) were probably the only home computer manufacturers offering the intermediate level of a seperated Y/C video output at that time.

The S-Video Mini-DIN connector standard didn't come along until 1987 when JVC adopted Y/C video as the output for the improved picture quality of their S-VHS VCRs.