Author Topic: Another SCART topic...but with a difference  (Read 11410 times)

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Offline Bryce

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Re: Another SCART topic...but with a difference
« Reply #25 on: 15:26, 24 July 10 »
Not needed, Pin 4 from the CPC (which is connected to pin 16 of the SCART) is fed through a resistor to the sync output of the CRTC and will have a few volts on the line most of the time anyway. The capacitor just buffers the signal for those milli-seconds when the sync line goes low.

Bryce.

Offline orange

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Re: Another SCART topic...but with a difference
« Reply #26 on: 20:57, 08 September 10 »
hey, it worked! :)

I just put 100uF 35V capacitor on SCART pins 16 and 18, like you said.
no more RGB sign in corner, and it seems the jumping picture problem might be gone too!
so it could be even better than +5V and resistor.


(sorry, its been a while, I was busy..)

Offline Shredder11

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Re: Another SCART topic...but with a difference
« Reply #27 on: 01:06, 09 September 10 »
Interesting.......seeing as the battery across the pins did not work for me, I will try this passive method instead.  I'm also looking out for a 15" or 19" 4:3 screen ratio LCD TV that has proper RGB.
Amstrad CPC6128, 3.5" Ext' Floppy, SD HxC Floppy Emulator

Offline Bryce

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Re: Another SCART topic...but with a difference
« Reply #28 on: 11:22, 09 September 10 »
@Orange:
Cool, glad to hear you were successful. If you have time, put together the exact connection details you used (in a picture) and what type of TV you were using, so that others can have a go.

Bryce.

Offline orange

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Re: Another SCART topic...but with a difference
« Reply #29 on: 11:42, 15 September 10 »
Bryce, I've sent you PM with modified cable pinout.

Offline Bryce

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Re: Another SCART topic...but with a difference
« Reply #30 on: 15:12, 20 September 10 »
Hi Orange,
        I took a look at what you said about Stereo output to the SCART connection and it seems you are correct. My SCART schematic and indeed all other SCART connection diagrams on the page: http://www.cpcwiki.eu/index.php/TV_SCART_cable   seem to have the right and left channels swapped (I think I just copied the sound part from the other diagrams, when I was making my diagram). I will update my picture during the week and add the capacitor version. Someone else (whoever has the originals) will have to update the other diagrams. Until then I'll add a note on the page.

Bryce.

Edit: Picture updated with optional (Anti-OSD) capacitor and the left/right sound channels now correct on my picture and notes added on the others (thanks for the tip Orange).
« Last Edit: 17:26, 20 September 10 by Bryce »

Offline orange

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Re: Another SCART topic...but with a difference
« Reply #31 on: 14:16, 22 September 10 »
you're welcome.

I see that you still use separate audio GND wire for audio. pity, because common UTP cables have only 8 wires.
I don't think  that wire is needed, as it seems its connected inside CPC to other GND anyway.

Offline Bryce

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Re: Another SCART topic...but with a difference
« Reply #32 on: 14:50, 22 September 10 »
Yeah, I suppose you could remove one of the GND wires, due to them being the same inside the CPC, but if the Scart cable is too long, this might cause the picture to "ripple" when sound is played or noise on the sound channels. It all depends on how the TVs internal circuits are connected and where they take their ground reference from, so I decided to play safe and leave both there.

Bryce.