I'm a new believer in RGB modding! Comparison Pics Inside

[BlueBMW]

So recently I acquired an RGB modded Duo-R with a DIN8 to SCART cable....  then this week, Opethian hooked me up with a SCART to Component converter board.  The result is that I can finally utilize the RGB mod on this Duo-R!  I have always been a bit skeptical about the true benefits of going through all the cost and hassle of getting RGB out of an old system like this, but now I am a believer!

Please excuse the horrible picture quality as they were taken with my only camera (a smartphone)  And the screen shots were taken of the actual TV screen, not from a video capture device of some sort.  Even with the poor pictures, you can definitely tell the difference!

The setup:

Supergrafx + SCDrom via Composite
vs
Duo-R via RGB -> SCART -> Component

on a 56" DLP HD TV  (Samsung HLS-5687w)

/TheTestSetup.jpg

And the Results!

Composite:
/Composite.jpg

RGB:
/RGB.jpg

Another Composite closer up:
/Composite2.jpg

And RGB of the same spot:
/RGB2.jpg


I probably need to adjust some settings on the TV to accommodate this RGB signal better, but so far I think it looks awesome!

[CGQuarterly]

Welcome to the club.  Once you start playing your consoles in RGB, you can never go back.  I play every console I own in RGB (except for my Atari, which is s-video modded).  It's like playing your classic consoles in high def.

Chris

[spenoza]

My only problem is that it sharpens the pixels a bit much. Most older game systems assume a certain amount of video blur and quality reduction, and sometimes the sharpness bites back. It's like using uber-fancy headphones with MP3s. Beyond a point they actually worsen the experience because they highlight the encoding flaws.

[incrediblehark]

Glad to hear you've "seen the light" of rgb and congrats on picking up a scart to component converter! RGB is just so much better than composite, theres no going back. I finally got a pce setup up and running in rgb , a semi-diy repair/mod project for me that i need to post results and pics to, maybe in the next weeks or so.

[Senshi]

Can you show a picture of the converter? I'm interested in this as well.

Edit: I'll settle for Make/Model as well 

[nat]

The composite from the Duo line is good enough that it's actually acceptable in my book. The Duo (and entire Grafx line, for that matter) has some of the best stock composite of any vintage system.

My biggest issue with composite in general is the rainbow effect you get on dithered parts of the picture. If I could somehow eliminate this rainbow effect then I'd have zero issues with the Duo's composite.

[CGQuarterly]

My only problem is that it sharpens the pixels a bit much. Most older game systems assume a certain amount of video blur and quality reduction, and sometimes the sharpness bites back.

I see this logic used a lot as an anti-RGB argument.  If it were true however, nearly every arcade game ever made wouldn't have used RGB.  I'm not saying that there aren't games out there that took advantage of composite's ability to naturally dither graphics, but the vast majority did not.  Games just plain look better in RGB, from the sharper picture to the brighter colors.  That doesn't mean that they don't still look very good in composite, especially from a system that outputs a good composite signal.

Chris

[SignOfZeta]

I've been messing around with RGB modding my consoles for the past few months. I would have to say that its been, probably, the least successful venture I've ever embarked on in my entire life. Its failure at every turn.

I bought a XRGB2+ from a forum member. It arrived broken. I posted a thread saying I'd like to buy another one for a reasonable price. Another forum member offered to sell me his, but then ended up selling it to someone else for more money without even consulting me to see what I would pay. I bought a GBS 8220 to view the RGB signal on a VGA monitor. It works perfectly with MVS boards and with the Saturn I modded. All success stops there.

I pulled the RGB from a PCE and cannot get it to sync with the GBS 8220. I will sync with a Commodore 1080 monitor, but of course it is very dark. I've tried two different kinds of amps and both only manage to turn a dark signal into a non-existant signal.

I bought SNES and Genesis SCART cables, since they also use composite sync they won't work with the GBS 8220. I built a sync separator/amp circuit out of an LM1881 and it basically doesn't function. I built (or at least tried to build) the exact circuit I think other people are using with a SCART to GBS 8220, and I get the same results I'd get without the LM1881.

I tried to do exactly what this guy has done (be warned, he takes fucking forever to get to the point) but I don't know his exact schematic:

I've never had such a problem with electronics before. I've modded...basically every system I've ever owned, on one way or another. I built the ECU running my car right now. I built Heath kits as a kid, etc. This thing though, which is really kind of simple, just shuts me down at every turn.

Part of the problem is a lack of known factors. What pins, exactly am I actually supposed to be using from the SCART socket? Its astonishingly difficult to get this info. Do I get the composite from pin 19 or 20? All SCART cables I've seen are very very poor quality, so that's an issue too. When something doesn't work (which is always) I don't know how to narrow down my list of variables. Is the cable shit? Am I using the wrong pins? Is the amp circuit built correctly? Is there a problem with all three?

[incrediblehark]

Zeta - here are exactly what pins you want to use:

Red - 15
Green - 11
Blue - 7
Sync - 20
+5v - 8
Ground - 21
Audio Right - 2
Audio Left - 6

It sounds like you were able to get rgb fine, just not through an amp? did you have 5v and gnd running to it?

[SignOfZeta]

I did some checking tonight and I noticed that I could open the shroud on my Genesis SCART cable (the SNES one is glued shut). The lines all add up, so that part isn't an issue.

I'm powering the LM1881 off the GBS 8220. This is what the guy in the video did as well.

The SNES signal will actually sync for a few seconds at a time, but the Genesis just syncs on occasion. Performance is more or less identical to the same setup without the LM1881. I assume the signal is at least getting through the amp or I wouldn't get even a hint of sync, it just isn't being amplified/separated like it needs to be.

I could really use a scope...

[BlueBMW]

Can you show a picture of the converter? I'm interested in this as well.

Edit: I'll settle for Make/Model as well 

Sorry I missed this post!

Its made by "retrotek" but I cant find a model number.  According to Ope, the guy wasn't making them anymore or something

/RGB_YUV.jpg

[Mathius]

Blue Blue Blue Blue BLUE! What do I have to do to talk you into doing this RBG mod on my prospective Duo one day??? Good Lord that looks SWEEEEEEEEEET!

[Keith Courage]

So I am curious about RGB mods. Does this mean you could just wire up the green,blue, and red to RCA jacks and run the cable directly to your TV or do you need an amp and converter?

[BlueBMW]

So I am curious about RGB mods. Does this mean you could just wire up the green,blue, and red to RCA jacks and run the cable directly to your TV or do you need an amp and converter?

If only it were that easy....

You have to take the Red Green Blue signals, amplify them, add the composite sync signal to the bunch and feed them into a converter board of sorts in order to output YUV (component) video that our US tvs can read.  The only other option is if you have a monitor that can accept direct RGB, of which there were very few in the US.

In other words  RGB and Component (YUV/YPbPr) are not the same at all.

[Mathius]

So I am curious about RGB mods. Does this mean you could just wire up the green,blue, and red to RCA jacks and run the cable directly to your TV or do you need an amp and converter?

If only it were that easy....

You have to take the Red Green Blue signals, amplify them, add the composite sync signal to the bunch and feed them into a converter board of sorts in order to output YUV (component) video that our US tvs can read.  The only other option is if you have a monitor that can accept direct RGB, of which there were very few in the US.

In other words  RGB and Component (YUV/YPbPr) are not the same at all.

It seems like I saw a TV at work the other day that had a RGB option. Maybe I am just seeing things.

[Keith Courage]

Well the reason I bring this up is because two of the TVs I own have RGB inputs on them. I was just curious what needed to be done to use those inputs.

[BlueBMW]

well just tap the signals, amp them and run them through some connector to those spots.  Search a bit to find more info about building an amp etc.  I also think there is some issue that has to do with sync rate or something.

[Opethian]

I think the RGB  sync on a PCE is 31KHz? I'll have to check when I plug into my LCD monitor it will display the current H/V sync rates

[TurboXray]

I think the RGB  sync on a PCE is 31KHz? I'll have to check when I plug into my LCD monitor it will display the current H/V sync rates

Nope. 15.7khz like other consoles and arcades of the time. 31khz would mean the pixel output rate itself would also have to be twice as fast as well. It's not.

The composite from the Duo line is good enough that it's actually acceptable in my book. The Duo (and entire Grafx line, for that matter) has some of the best stock composite of any vintage system.

My biggest issue with composite in general is the rainbow effect you get on dithered parts of the picture. If I could somehow eliminate this rainbow effect then I'd have zero issues with the Duo's composite.

TVs with better filters will the remove the rainbowing from PCE/TG16 games, but the 'dot-crawl' like artifacts will be there for most motion/scrolling in a game.  S-video would your best bet then, if you didn't want to go the route of RGB.

I see this logic used a lot as an anti-RGB argument.  If it were true however, nearly every arcade game ever made wouldn't have used RGB.  I'm not saying that there aren't games out there that took advantage of composite's ability to naturally dither graphics, but the vast majority did not.  Games just plain look better in RGB, from the sharper picture to the brighter colors.  That doesn't mean that they don't still look very good in composite, especially from a system that outputs a good composite signal.

I don't know about you, but I spent a lot of time in the arcades. Yeah, they used RGB CRTs, but they still weren't as sharp as what every is seeing today on there RGB mods and setups. Those displays BITD still had some analog pixel interpolation.

My only problem is that it sharpens the pixels a bit much. Most older game systems assume a certain amount of video blur and quality reduction, and sometimes the sharpness bites back. It's like using uber-fancy headphones with MP3s. Beyond a point they actually worsen the experience because they highlight the encoding flaws.

You can add analog filtering back into the RGB setup (for horizontal pixels only). As long as you do it to the RGB lines and not SoG line (sync on green).

 My only complaint with the RGB setup (I can add the analog filtering back into the signal when I want to, or make a switch for it, whatever) is the wrong color space. All the PCE/TG/Duo's consoles have a specific artifact in the color space conversion. The composite out is more than just simply RGB->YUV conversion that's sent on its way for modulation. There's a lookup table and low precision one at that. The composite out of the system (VCE) is only using 5bit DACs. That's 15bit color space total (32k colors). You need quite a bit of precision to go from RGB to YUV (even 8bit for 24bit output isn't enough). This internal table gives a bias to certain color ranges (hues as well as brightness) and makes the color palette of the PCE unique. Tapping the RGBs, you completely bypass this. I've been noticing that some games look better in this custom color space than in pure RGB (disregarding anything else).

[Senshi]

Can you show a picture of the converter? I'm interested in this as well.

Edit: I'll settle for Make/Model as well  

Sorry I missed this post!

Its made by "retrotek" but I cant find a model number.  According to Ope, the guy wasn't making them anymore or something

Not a problem. Thank you Beemer for the pic  

[gtsamour]

It seems like I saw a TV at work the other day that had a RGB option. Maybe I am just seeing things.

All TVs in Europe have RGB scart input, even older CRT TVs.
Probably you saw a photo of my SuperGrafx RGB mod.