Need some help converting RGBs to s-video

[thebigcheese]

I'm likely to pick up a consumer Trinitron this weekend, but the best it has is s-video. I don't mind using s-video instead of RGB and most of my consoles have s-video options, but I'm still stuck with a Genesis and PC Engine that don't have that option. I guess I could mod the Genesis, if needed, but there don't seem to be any similar options for the PC Engine. With that in mind, what I'd like to do is convert the RGB SCART signal to s-video (in which case I would not bother modding the Genesis). Problem is, there aren't a lot of ready-made options, particularly for under $100. Right now, here are the options I've come up with (or other people on this board have found for me):

-DIY option using an arcade converter. This would do it all with one board, but obviously I also need to source SCART and RCA components (which Console5 stocks) and an enclosure to put it all in, not to mention a power supply. At the end of the day, then, that $25 adds up to more like $40-50 plus some minor effort.
-Convert to component (maybe with Mike Chi's adapter) and then... find a converter to get to s-video? That's where I get a little lost. This would probably put the total cost over $100 based on what I've seen.
-Try to source a Micomsoft XMD device that provides s-video output for the Genesis. This obviously works for the Genesis, but I can't remember if I wired my PC Engine to use Genesis layout. I suppose I could open it up and rewire it, but then my existing SCART cable would be somewhat useless unless I also rewire that. On top of that, these are hard to come by and likely to be around $100 anyway.
-Convert to a VGA standard (might need to convert to HV sync) and convert that to s-video. I see at least one option on eBay that will do this for about $50 shipped, but the pictures don't show the input side and it's hard to really say what sort of specs it really needs.
-Mod the TV for RGB. This seems to be a pretty cheap option, but... I don't really want to mess with that. Seems kinda fiddly and hacky and I'd rather just leave the TV alone. Plus that seems like a kind of extreme option for two consoles.

Are there some other options I should be looking at? I've contacted a few people (including Mike) that make these things, but no one seems to be interested in making such a device for me I get it, most people have either settled with composite or committed to RGB, but it still stinks to not have any good options in the middle.

[Bratwurst]

-DIY option using an arcade converter. This would do it all with one board, but obviously I also need to source SCART and RCA components (which Console5 stocks) and an enclosure to put it all in, not to mention a power supply. At the end of the day, then, that $25 adds up to more like $40-50 plus some minor effort.

This is the board I went with to adapt Groovymame to a Sharp set that couldn't be modified for RGB, it's worth the effort imo. I also designed a 3D printed enclosure for it and can make you one if you want to go that route.

[thebigcheese]

This is the board I went with to adapt Groovymame to a Sharp set that couldn't be modified for RGB, it's worth the effort imo. I also designed a 3D printed enclosure for it and can make you one if you want to go that route.

I might take you up on that if nothing else comes together. Is that with a SCART input and RCA outputs for audio? I'd be using this SCART connector if that makes any difference. For audio, I was just going to run wires directly from the SCART to the RCA jacks since those don't need any processing or anything.

[Bratwurst]

Nothing so fancy:




The board comes with header connectors for either the VGA side (H+V sync) or the RGBs side, so I just wired one end to the connector I wanted to use. You can get female scart connectors that are enclosed with screw-on strain reliefs just like the male ends traditionally used for cables.

Incidentally, I know of a Chinese device that adapts the RGB signal from the Genesis into s-video with audio RCA breakout:

https://www.youtube.com/watch?v=5GfcmhfbJxg
https://item.taobao.com/item.htm?id=549405113791

And you could look at using a db GrafxBooster which supports s-vid as well, though it costs more. None of the Hong Kong booster clones that I see on eBay and the like have that, could have sworn one of them did at one point.

[orange808]

If you don't already have a supergun, the Time Harvest CBOX supergun v2 has a SCART plug that can be used as input and it can output composite and svideo. I think it converts SCART RGB to component as well, but I haven't tested RGB to component.

I fed it clean sync. I have no idea what it does with composite sync or luma. The svideo output was nice. I briefly tried composite; I think it's okay.

It has the same basic components as the Time Harvest Neo Geo MVS console, so I imagine the component output is fine.

https://www.aliexpress.com/item/32907453394.html

It's more features than OP might want, but if you think it's going to get expensive, you get more for your money with the CBOX supergun.

[azmun]

I'm likely to pick up a consumer Trinitron this weekend, but the best it has is s-video. I don't mind using s-video instead of RGB and most of my consoles have s-video options, but I'm still stuck with a Genesis and PC Engine that don't have that option. I guess I could mod the Genesis, if needed, but there don't seem to be any similar options for the PC Engine.

-Try to source a Micomsoft XMD device that provides s-video output for the Genesis. This obviously works for the Genesis, but I can't remember if I wired my PC Engine to use Genesis layout. I suppose I could open it up and rewire it, but then my existing SCART cable would be somewhat useless unless I also rewire that. On top of that, these are hard to come by and likely to be around $100 anyway.

Are there some other options I should be looking at? I've contacted a few people (including Mike) that make these things, but no one seems to be interested in making such a device for me I get it, most people have either settled with composite or committed to RGB, but it still stinks to not have any good options in the middle.

There is a similar device to Micomsoft's XMD for the PC Engine--dbGrafx Booster https://db-electronics.ca/product/dbgrafx-booster-ttp/ but unfortunately, that too is currently sold out / for pre-order.

[thebigcheese]

That plus I typically have my PCE hooked up to an IFU, so I can't have both hooked up at the same time

[Taiyaki]

Personally rather than convert RGBs to S-video, I'd just get S-video cables for all systems. Most consoles can use S-video without modification, the exception being the Sega Genesis I believe. Frankly there are more systems that need rgb modification than s-video, and cables are far far cheaper (try to stick with official cables when available).

[thebigcheese]

Personally rather than convert RGBs to S-video, I'd just get S-video cables for all systems. Most consoles can use S-video without modification, the exception being the Sega Genesis I believe. Frankly there are more systems that need rgb modification than s-video, and cables are far far cheaper (try to stick with official cables when available).

I've done that already, this thread is about the two that don't - Genesis and PC Engine I suppose most of those s-video cables I got won't be strictly necessary after getting a converter, but unfortunately, I do still need a converter for those last two.

[Taiyaki]

Personally rather than convert RGBs to S-video, I'd just get S-video cables for all systems. Most consoles can use S-video without modification, the exception being the Sega Genesis I believe. Frankly there are more systems that need rgb modification than s-video, and cables are far far cheaper (try to stick with official cables when available).

I've done that already, this thread is about the two that don't - Genesis and PC Engine I suppose most of those s-video cables I got won't be strictly necessary after getting a converter, but unfortunately, I do still need a converter for those last two.

That makes sense, however you have another option as well in that case: modding the systems to output S-video. I'm not familiar with the options for the PC Engine, but for the Genesis it's something any skilled modder here could take care of for you (I've had it done on both my Megadrive 1 and Sega CDX).

[thebigcheese]

I certainly could do that, and I think I touched on it in the OP, but the PC Engine doesn't output a chroma signal, so the only way to get s-video is to encode it from the RGB signal. Meaning, basically, that an external box or a far more complicated internal mod would be necessary. It's not the end of the world, I suppose. It outputs pretty nice composite video all things considered and I don't play it as often as the Genesis, so I could mod the Genesis and just stick with composite on the PC Engine. Not ideal, but not the end of the world.

[Bratwurst]

PC Engine/TG16 composite is some of the cleanest and sharpest I've ever seen among game consoles of the 80s/90s, but the s-video mod's supposed to be pretty simple, just a transistor and some caps:

https://www.pcenginefx.com/forums/index ... #msg206287

You still have to contend with placement of the 4-pin mini din. I'm not a fan of drilling holes in plastic when I can help it...

With the Genesis you can at least remove the RF Modulator and use the hole left behind, which I have done before.

[Taiyaki]

I certainly could do that, and I think I touched on it in the OP, but the PC Engine doesn't output a chroma signal, so the only way to get s-video is to encode it from the RGB signal. Meaning, basically, that an external box or a far more complicated internal mod would be necessary. It's not the end of the world, I suppose. It outputs pretty nice composite video all things considered and I don't play it as often as the Genesis, so I could mod the Genesis and just stick with composite on the PC Engine. Not ideal, but not the end of the world.

I'm not sure that would be optimal either because if you go RGB for the Genesis you will have an off centered image when compared to your other systems using s-video. RGB always shifts the image horizontally to the right when compared to other connections. You could tweak your tv's geometry and move the h shift back in place but then the other systems where you use s-video will be off. I doubt the converter will correct the geometry, but maybe someone who has tried one can chime in.

This is why usually it's best to try and do everything rgb if you go that way at all (some systems will still be a couple lines off center compared to others, but will be as close as possible), some systems can only go up to component but fortunately those systems have horizontal adjustments that can be made within the main system of the consoles (Gamecube and Wii for example). So it's possible to get all consoles to run on their best output on a tv that has either rgb (using a component to rgb transcoder in the setup) or component (using rgb to component transcoder in the setup) but it's a lot of trouble, costs a fortune in cables, switch boxes, transcoder, and in some case mods (to get rgb out of some systems), so whether it's worth it is up to debate.

[thebigcheese]

PC Engine/TG16 composite is some of the cleanest and sharpest I've ever seen among game consoles of the 80s/90s, but the s-video mod's supposed to be pretty simple, just a transistor and some caps:

https://www.pcenginefx.com/forums/index ... #msg206287

You still have to contend with placement of the 4-pin mini din. I'm not a fan of drilling holes in plastic when I can help it...

With the Genesis you can at least remove the RF Modulator and use the hole left behind, which I have done before.

Huh, I was under the impression that it wasn't possible to get s-video from the PCE, but this looks super easy. I'm also not super keen on drilling holes, but a small one for s-video right near the existing output DIN wouldn't be so bad (I've got a CoreGrafx). I don't have any 0.001 uf caps on hand, though, do you happen to know if a 0.01 uf would work fine? I have both film and ceramic caps for that. Seems silly to put in an order for one capacitor... Has anyone tried this and have any thoughts on it?

[thebigcheese]

As a follow-up, I did both mods. The Genesis looks great and is a noticeable improvement, so we'll worth the effort and the hole I drilled for the s-video jack. PCE, on the other hand... It is sharper, but only a bit and it seems like some of the artifacts I'd normally expect from composite are still there (probably because the mod uses filtered composite for chroma). IMO, not worth drilling a hole for it, so I'm taking it back out. Glad I checked before drilling! Anyway, now I know. Thanks everyone!

[mrsmiley381]

-DIY option using an arcade converter. This would do it all with one board, but obviously I also need to source SCART and RCA components (which Console5 stocks) and an enclosure to put it all in, not to mention a power supply. At the end of the day, then, that $25 adds up to more like $40-50 plus some minor effort.

This is the board I went with to adapt Groovymame to a Sharp set that couldn't be modified for RGB, it's worth the effort imo. I also designed a 3D printed enclosure for it and can make you one if you want to go that route.

I ordered one of those and it arrived today. Did a quick test by stripping the cables and jamming them into a Master System I had nearby. Success! Colors looked fairly off and I kept losing the image, but I imagine some dinky cabling, no color adjustments, a composite to component transcoder, an OSSC, VGA converter, etc. in the chain leads to a requirement of better cabling. That I can do. As for the 3D-printed case, any chance I can get one of those? I'm willing to cover expenses, assuming trading on here is still allowed.

For reference, my absurd use case is testing RGB -> composite conversion against console-implemented composite video to see how well composite artifacts persist, then as a bonus using Koryuu -> OSSC -> VGA conversion to see how well composite artifacts survive after all that.