[Meat Miracle]

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The fact that I've seen several SCART-XRGB mini adapters with sync stripper circuits installed tells me otherwise.

There are several machines in the XRGB line mind you. I've been told that previous XRGBs can only take c-sync, but the Framemeister (the newest xrgb) can take composite video as well. It would be nice if someone could verify this however.

Quote

From everything I've read on this on assemblergames and Sega-16, the jailbars from an RGB signal come sfrom the colourburst on the comp video signal which is bleeding into the RGB signal. If it's the mod I think you're talking about removes the subcarrier information from the composite video signal so it can still be used for sync but removes the "bleed". Theoretically using a pure sync signal instead will do exactly the same job, but of course some TVs don't like using csync instead of comp video, or need the sync signal significantly boosted (which apparently this new cable I've ordered does).

The bleeding happens inside the video encoder, not in the cable, so a c-sync cable would make very little difference. I've made a SCART plug that could switch between c-sync and video, and it had jailbars on both.

[mentski]

Meat Miracle, on 07 September 2013 - 08:35 AM, said:

There are several machines in the XRGB line mind you. I've been told that previous XRGBs can only take c-sync, but the Framemeister (the newest xrgb) can take composite video as well. It would be nice if someone could verify this however.

The old XRGBs had JP21 pin sockets on them, though. The converter cables are specifically for the mini, which is the only one in the range to use a DIN for RGB in.

I know the mini/Framemeister accepts a comp video signal to be upscaled (why you'd want to is anybodies guess) but as far as I was aware it still has issues using it as a sync signal for RGB.

This post has been edited by mentski: 08 September 2013 - 03:59 AM

[mentski]

A quick update: I got my Cable from Retro Console Accesories and I've got to say: The build of the cable is leaps and bounds ahead of the one I got from Retro Gaming Cables.

As for the MD jailbar issue that Meat Miracle claimed is down to that subcarrier line inside the MD itself: I'm starting to believe that maybe there's truth in both. This boosted raw sync cable has reduced the jailbars to almost nothing on my LCD, all that's left is some VERY faint interference which probably wouldn't be noticeable if it was a CRT.

I happily concede that the encoder in MD1's is more than likely the source of the jailbars (and I'm sure cutting the subcarrier line would remove that last bit of interference), but bugger me sideways, the difference between the "strength" of those jailbars when using csync verses comp video is like night and day.

Cable build comparison.

Test 1: Sonic the Hedgehog

Output through Retro Gaming Cables cable.

Output through Retro Console Accessories cable.


Test 2: After Burner Complete

Output through Retro Gaming Cables cable.

Output through Retro Console Accessories cable.


I know this isn't a Saturn cable (and apologies for the slight thread derailment - Maybe this should be split off to a different thread so people find this info easier, or something.), but at least I can happily give a thumbs up to Retro Console Accessories for selling far better cables for roughly the same price... even after figuring in the shipping from the US. At least from my experience.

[TmEE]

The jailbars happen because :

1) The subcarrier trace is right next to the blue trace as they leave from the VDP on the PCB in MD
2) Cheap cables have unshielded individual signals, this means audio will get a buzz in it, and composhit video will bleed into RGB lines and this produce extra jailbars effect.

To fix 1 you have to run the RGB lines in shielded cable from VDP to the RGB encoder. This will remove any traces of jailbars from the video singal. This is primarly a problem for MD1. MD2 tends to have the subcarrier line a little bit further away from the RGB ones.
To fix 2 :
*Get proper cable with audio, RGB and cvideo separately shielded. This is probably impossible. I don't know if official cable has that, the leads seem a lot thicker so there's a chance.
*Get cable with Csync as sync instead of Cvideo. Buzzing in sound will remain but since sync is fixed the buzz will not change either as it would with Cvideo bleeding into sound. Sync is also outside screen area so it will not show up on the RGB lines. This will not jailbars caused by problem 1.
Most Csync SCART cables do not buffer the sync line, and this will cause problems on many TVs. The Csync line in MD is not able to drive a 75ohm load. Your mileage will vary.

This post has been edited by TmEE: 13 September 2013 - 08:24 PM

[Kushami]

Beyond cables, I'm actually curious what you guys would suggest in terms of a Scart -> HDMI converter on the NTSC US end of things.

[Shadow Hog]

Kushami, on 27 September 2013 - 09:47 PM, said:

Beyond cables, I'm actually curious what you guys would suggest in terms of a Scart -> HDMI converter on the NTSC US end of things.

XRGB-mini?

[mentski]

Shadow Hog, on 27 September 2013 - 10:05 PM, said:

Kushami, on 27 September 2013 - 09:47 PM, said:

Beyond cables, I'm actually curious what you guys would suggest in terms of a Scart -> HDMI converter on the NTSC US end of things.

XRGB-mini?

I agree. It's certainly the best, but also incredibly expensive.

It's up to you to determine if 300 quid for excellent scaling of 240p signals with virtually unnoticeable processing lag is worth it, though.

[Meat Miracle]

Does the xrgb allow for aperture mask overlays, or does it just scale properly and add scanlines?

[Shadow Hog]

The latter, as far as I know. (I'm assuming "aperture mask" is that red/green/blue dot thing you get from looking too closely at a TV? Dunno, really.)

It does have a filter to add black gradients to the side of the screen, but I have no idea who in their right mind would ever use that.

[Meat Miracle]

The black gradients would simulate oldschool non-flat TVs, I guess.

By aperture mask I meant an overlay that would act as a pixel mask, making the output look like an actual CRT shadow mask or aperture grill. You need 4x prescaling (or was it 5x) for them to look right, but they look more like an old TV than the scanlines do. And technically all that has to be done for it is to mix the output signal with a semi-transparent image pattern. I have one set up for mame, and it looks wicked for older titles with low resolutions.

[ICEknight]

If it's what I'm thinking, those black gradients are also used in the Final Fight/Magic Sword conversions for Xbox Live, when selecting the arcade monitor filter. Not sure if I've ever seen a CRT screen look like that, though (although it looks way better than the filter they used for Darkstalkers).

I hope that, somewhere, there's a dedicated community properly researching this kind of screen peculiarities so they can be faithfully reproduced in emulators. None of that "hey, I did something and now it kinda looks like the old thing to me!" bullshit (see: TV mode in Sonic 1 3DS), but in the lines of Blargg's in-depth research for his (sadly discontinued) NTSC filter.

This post has been edited by ICEknight: 29 September 2013 - 08:01 PM

[Meat Miracle]

ICEknight, on 29 September 2013 - 07:41 PM, said:

If it's what I'm thinking, those black gradients are also used in the Final Fight/Magic Sword conversions for Xbox Live, when selecting the arcade monitor filter. Not sure if I've ever seen a CRT screen look like that, though (although it looks way better than the filter they used for Darkstalkers).

I hope that, somewhere, there's a dedicated community properly researching this kind of screen peculiarities so they can be faithfully reproduced in emulators. None of that "hey, I did something and now it kinda looks like the old thing to me!" bullshit (see: TV mode in Sonic 1 3DS), but in the lines of Blargg's in-depth research for his (sadly discontinued) NTSC filter.

I've heard Byuu talk about something like that once.

[mentski]

ICEknight, on 29 September 2013 - 07:41 PM, said:

I hope that, somewhere, there's a dedicated community properly researching this kind of screen peculiarities so they can be faithfully reproduced in emulators. None of that "hey, I did something and now it kinda looks like the old thing to me!" bullshit (see: TV mode in Sonic 1 3DS), but in the lines of Blargg's in-depth research for his (sadly discontinued) NTSC filter.

MAME's HLSL mode is probably the most advanced CRT simulation available, not to mention incredibly customisable. To quote one of the MAME devs, R Belmont: "HLSL does a full mathematical simulation (when you enable YIQ mode) of all of the electronics and electromagnetics of a CRT monitor." It's quite GPU heavy, though.

http://mamedev.org/s...s/hlsl.txt.html

This post has been edited by mentski: 29 September 2013 - 10:07 PM

[ICEknight]

mentski, on 29 September 2013 - 10:06 PM, said:

ICEknight, on 29 September 2013 - 07:41 PM, said:

I hope that, somewhere, there's a dedicated community properly researching this kind of screen peculiarities so they can be faithfully reproduced in emulators. None of that "hey, I did something and now it kinda looks like the old thing to me!" bullshit (see: TV mode in Sonic 1 3DS), but in the lines of Blargg's in-depth research for his (sadly discontinued) NTSC filter.

MAME's HLSL mode is probably the most advanced CRT simulation available, not to mention incredibly customisable. To quote one of the MAME devs, R Belmont: "HLSL does a full mathematical simulation (when you enable YIQ mode) of all of the electronics and electromagnetics of a CRT monitor."

I've just tried it and... EDIT: Something was wrong with the configuration that upped the bloom to some absurd levels; it does look really nice.

This post has been edited by ICEknight: 30 September 2013 - 11:44 PM