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  • Joined: 13 Jun 2017
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Official RGB cable?
Post Posted: Thu Nov 23, 2017 11:32 am
Hi,

I've seen there's an official RVB cable for the Mega Drive 1 that looks like quiet complex having a box in the middle probably with a pcb (Model 3085); I was thinking if it will work (if originally intended for) with a PAL SMS 1.
Does it come with some more complex ICs, and was it specifically built also for the SMS and is it better than the usual cheap RGB cables?
Thank
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Post Posted: Thu Nov 23, 2017 12:57 pm
I have a french SMS2 with the official RVB cable. I had it in use for a while and I think I remember it not working with other RGB cables and the RVB cable not working with other consoles.
Also the picture was somehow "wobbly" on the one hand but sharp and colorful, like with an RGB modded SMS2 or a SMS1 on the other hand.
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Post Posted: Thu Nov 23, 2017 1:25 pm
It contains components to convert the RGB outputs (levels, impedance) to match the SCART spec. With a dumb cable you may get an over bright picture and some analogue artifacts.
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Post Posted: Thu Nov 23, 2017 3:01 pm
There is some information about the Adapteur R.V.B. here and here. It is designed to be used with French Master Systems (like this one) which do not include a video encoder chip.

Specifically, most Master Systems connect the output of the video encoder to the A/V port. Third-party SCART cables are designed for these systems, and only need a few capacitors and resistors to convert the video encoder's output to the appropriate levels for SCART.

On the other hand, French Master Systems with no video encoder connect the output of the VDP to the A/V port. Converting its output to SCART is more involved - the Adapteur R.V.B. includes, among other things, an amplifier for each of the R, G and B signals. I assume that on other systems, these amplifiers are within the video encoder.

I don't think a generic third-party SCART cable will work with a French console, because there will be no amplification of the signal. Conversely, using an Adapteur R.V.B. on a system which does include a video encoder may cause the signal to be amplified twice - which I assume would also be problematic?
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Post Posted: Thu Nov 23, 2017 3:21 pm
RetroSpark wrote
There is some information about the Adapteur R.V.B. here and here. It is designed to be used with French Master Systems (like this one) which do not include a video encoder chip.

Specifically, most Master Systems connect the output of the video encoder to the A/V port. Third-party SCART cables are designed for these systems, and only need a few capacitors and resistors to convert the video encoder's output to the appropriate levels for SCART.

On the other hand, French Master Systems with no video encoder connect the output of the VDP to the A/V port. Converting its output to SCART is more involved - the Adapteur R.V.B. includes, among other things, an amplifier for each of the R, G and B signals. I assume that on other systems, these amplifiers are within the video encoder.

I don't think a generic third-party SCART cable will work with a French console, because there will be no amplification of the signal. Conversely, using an Adapteur R.V.B. on a system which does include a video encoder may cause the signal to be amplified twice - which I assume would also be problematic?

Thank you, Maxim and others for your answers.
I was hoping some kind of official = better implementation of the TV connection but being only for the French consoles it'd have no sense to buy one, too bad.
I was quiet not lucky with the RGB cables. I always end up with a cheap one that has sound noise when screen are brighter in games, at least with Mega Drive 2 version and I imagine a similar thing will happen if I go for the RGB on the SMS (/Mega Drive 1). At first I wanted to mod the SMS2 for a composite output but I think I'll keep it original with the RF one, at the end it's not that bad.
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Post Posted: Thu Nov 23, 2017 3:36 pm
386DX wrote
I was quiet not lucky with the RGB cables. I always end up with a cheap one that has sound noise when screen are brighter in games, at least with Mega Drive 2 version and I imagine a similar thing will happen if I go for the RGB on the SMS (/Mega Drive 1).

I remember having similar issues with certain patterns on the screen, so added an audio jack to some of my SMS consoles and added an extra audio cable directly going into the SCART head. No buzzing problems since then.
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Post Posted: Thu Nov 23, 2017 3:46 pm
Just get a decent quality RGB cable. You want something where each core is shielded. This helps prevent crosstalk.

Retrogamingcables.co.uk has been a godsend for me. All my consoles that can output RGB have cables from them.
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Post Posted: Thu Nov 23, 2017 7:54 pm
I use a French Adapteur RGB with a Japanese Master System and it looks perfect.
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Post Posted: Fri Nov 24, 2017 12:44 am
RetroSpark wrote
I don't think a generic third-party SCART cable will work with a French console, because there will be no amplification of the signal. Conversely, using an Adapteur R.V.B. on a system which does include a video encoder may cause the signal to be amplified twice - which I assume would also be problematic?

Maxim wrote
I use a French Adapteur RGB with a Japanese Master System and it looks perfect.

Then I guess it's not a problem to run the signal through two amplifiers. Or maybe the video encoder does not contain an amplifier after all.

Perhaps someone with more hardware knowledge could explain?
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Post Posted: Sat Nov 25, 2017 10:14 am
I have a French RGB MS2 with the RGB adapter box.

The RGB box works great with the French MS2 and with my Japanese Mark III. It does not work with a regular MS console nor does it work with my Japanese MS console, which uses a standard cable for RGB.

I'm guessing there's two main versions of Japanese MS, one that outputs video as per normal and one that requires an amplified signal. I've never owned the latter, all my Japanese MS consoles have worked just fine with std cables.

Conversely, a regular MS RGB scart cable does not work with the French MS2.

I built my own RGB scart cable with a THS7316 video amp incorporated into it and this works beautifully with the French MS2 and Mark III.

Everything else has been mentioned.
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Post Posted: Sat Nov 25, 2017 8:12 pm
Frank_fjs wrote
I have a French RGB MS2 with the RGB adapter box.

The RGB box works great with the French MS2 and with my Japanese Mark III. It does not work with a regular MS console nor does it work with my Japanese MS console, which uses a standard cable for RGB.

I'm guessing there's two main versions of Japanese MS, one that outputs video as per normal and one that requires an amplified signal. I've never owned the latter, all my Japanese MS consoles have worked just fine with std cables.

Conversely, a regular MS RGB scart cable does not work with the French MS2.

I built my own RGB scart cable with a THS7316 video amp incorporated into it and this works beautifully with the French MS2 and Mark III.

Everything else has been mentioned.

Thanks, but with "regular MS console" you mean a NTSC one or a PAL one?
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Post Posted: Sun Nov 26, 2017 12:21 am
Both.

The RGB box will not work with a:

PAL Master System 1 console
NTSC Master System 1 console
Japanese Master System 1 console (perhaps with some exceptions)

The RGB box will work with a:

French Master System 1 console
French Master System 2 console
Japanese Mark III console
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Post Posted: Sun Nov 26, 2017 9:56 am
Frank_fjs wrote
Both.

The RGB box will not work with a:

PAL Master System 1 console
NTSC Master System 1 console
Japanese Master System 1 console (perhaps with some exceptions)

The RGB box will work with a:

French Master System 1 console
French Master System 2 console
Japanese Mark III console


Ok thanks. :)
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Post Posted: Sun Nov 26, 2017 11:48 am
As has been mentioned, the box is merely an RGB amplifier.

Another interesting note, the French consoles require a cable that's wired up for TTL sync. They don't display a picture when the composite video line is used as sync. The Mark III can use either.

I made my own cable for my French MS2 and mark III which incorporates a THS7316 amplifier. This works perfectly and I prefer using it over the box cable. Was a bit tedious cramming the THS chip in the scart housing but I managed to squash it all in there.
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