Using a green screen with other sources

[John Mitchell]

Is it possible to use a green screen with other sources? I have 3 and would like to use them to show information at an event. I'm hoping it's possible to connect raspberry pis to them via composite video.

[ZbyniuR]

Try connect Composite to Synchro and Luminance together. It's nothing danger. But probably vertical line will be wavy.

[bjt]

Once managed to get a GT-65 working with a PlayStation. It looked terrible but it was the only display I had on hand 

[Token]

I would like to connect a MP-3. Especially for my PONG console.
I have SCART and also the PAL version for the VCS (palette is ruined on the french 2600)
I didn't have luck with the C64. (I want to see the grey/brown in green)
Help needed with an old 6128
Didn't tried the 800 XL.
It works with the PCW 8256/512 but no fullscreen, some games will lost graphics.

[VincentGR]

I would like to connect a MP-3. Especially for my PONG console.
I have SCART and also the PAL version for the VCS (palette is ruined on the french 2600)
I didn't have luck with the C64. (I want to see the grey/brown in green)
Help needed with an old 6128
Didn't tried the 800 XL.
It works with the PCW 8256/512 but no fullscreen, some games will lost graphics.

PONG!!!!

What an excellent idea 

[Bryce]

Like because you are scoffing a Guinness (or at least it looks like one) in your avatar! Yes the GT64/65 should be able to display a composite signal from any source.

Bryce.

[Gryzor]

I once connected a MP3 box to my GT and a DTV/media box to it, so I watched Game of Thrones in green

[VincentGR]

I once connected a MP3 box to my GT and a DTV/media box to it, so I watched Game of Thrones in green

I would comment this in Greek because there is no translation:

Έχεις άσχημα γούστα εσύ αγόρι μου. (Σοφόκλας ο πιτσαδόρος)

[Gryzor]

Next up: Poltergeist (2014 version) in 3D, tonight. We're 5 people, pizza will be ordered and we'll try to enjoy it while huddled around the tiny box.

[John Mitchell]

Hi,


Sorry for the late reply, I forgot to turn on notifications and this project had to take a back burner for a while!


Can anyone suggest how I should wire this up? So far the only display I can get is out of sync and thats but connecting the ground (pin 5) to composite ground and luminance (pin 6) to the composite signal.


Just as a bit of extra info, I'm helping pout at this event (SuperByte 2015 | Chiptune, Low-Tech & 8 Bit Arts Festival | Manchester, UK) and hoping to connect the 3 GT65s I have lying around to Raspberry Pis (powered from the monitors 5v) to show running order, general information etc.

[Bryce]

Can you define how it's out of sync? Is it rolling or flickering? MAybe a picture or video would help? It's a purely analogue circuit, so sync is decided by the source.

Bryce.

[John Mitchell]

Here's a video as requested.  This is with composite ground to monitor ground and composite signal to luminance.

[Token]

I had something similar when I tried to connect a C64 to a GT-64:

[Velktron]

I suspect that you should also connect the SYNC input somehow. Many CPC wiring sources are ambiguous about LUMA/SYNC (some even say they are interchangeable, at least for the outputs on the CPC). You could try simply connecting both wires to the same composite signal, and since composite sync is supposed to be at a voltage less than the "black" reference, maybe the monitor will simply understand it.



Otherwise, I suppose you'd need to use a signal splitter of sorts to isolate sync pulses from luminance,  but nobody else here posted something about anything of the sorts.

Other possible sources could be a YPrPb source (connecting just Y, of course) or a RGB source with a separate sync ("sync on green" would have similar problems). You may even be able to connect it to an Atari ST's mono output, which had pretty similar signals and separate sync pins.

[John Mitchell]

I've had time (finally) to come back to this.  Using this circuit (Composite Sync Stripper LM1881 - mmmonkey) I ws able to split the sync and now it works almost perfectly.

[seanb]

"I still function" 

[robcfg]

A crown, Starscream? XD

[Token]

Great work. Thank you a lot for the link, I will try the alternative version.
Yesterday I tried to connect a C64 to a MP-3 to a GT-64 (RGB as LUM), I had a great picture 25% shifted to the left (without that nasty diagonal border) after I disconnect-reconnect the ground. It worked only two time..