Working with RGB .. for the non-SCART forum members ..

[leonk]

I wanted to start a new thread for non-SCART members of the forum (ones living in North America, using PVM/BVM or other non-SCART input devices) that want to use RGB as output from their consoles/input into their display devices. This is a continuation of the NESRGB discussion where I wrote the following:

I'm glad I'm not the only one that found this interesting (for us folks living in non-SCART world). As far as I understand it, the NESRGB sends 5V on pin 5 of the 8P mini DIN. This 5V gets pumped up to 12V inside the custom SCART cable and sent out on pin 8 of the SCART connector. By convention, 12V on SCART pin 8 tells SCART TVs that the signal is ON and of 4:3 aspect ratio.

If you live in North America or do not use SCART devices (e.g. use a PVM, BVM or other non-SCART RGB display device) then the 5V output of the NESRGB is useless to you. Please don't hook it up the the 8P DIN!

As RGB was never a standard in North America, there doesn't seem to be a connector standard for RGB purists. So lets try and come up with a list of different connectors, pros and cons for each and in the process enabling members to choose what is best for them. I will periodically update this post as we get more input. In addition, if this sort of information already exists elsewhere (blogs, web sites, etc) Lets get them linked below.

SCART

Background: http://en.wikipedia.org/wiki/SCART

As far as I know, the only consumer video standard that supported RGB. As such, adopted by many in North America as an interconnect between consoles as their display device. A typical hookup will look like this:

game console --> game console cable to SCART --> SCART Switcher (optional) --> ***see below*** --> Display device

Connecting to PVM/BVM: a custom SCART to BNC cable is used for the Video/Audio. Can be purchased on eBay as well as online forums.

Connecting to HDTV: can be accomplished by either

• 1. Use RGB SCART to Component converter box

• 2. Use an external scaler (like XRGB) along with a custom SCART to 8P DIN cable made for this application

Pro:

• *It is a standard. Proprietary game console connectors to SCART cables can be easily found with minimal external modifications to the console (some internal modifications might be required to force console to output RGB)

• *It is a standard. SCART Switchers can be found for multiple consoles being fed to a single display device.

• *SCART to component or SCART to BNC (BVM/PVM professional display devices) can be easily purchased

Con:

• There are 2 major standards (Euro and Japan) - most use the Euro standard. As long as you stick to one, you should be fine. The only place you run into trouble is when you try to connect to XRGB. A special adapter is required.

• *PRICE: GOOD SCART console cables tend to be custom made and sell for 20-30$ each. Good SCART switchers aren't cheap.

• Cheap SCART cables tend to add extra noise / interference to the signal

• Overly complicated - too many things can, and sometimes do, go wrong

• Even with good SCART cables, some noise might be detected with some consoles - traditional SCART feeds audio and video in a single cable

Separate RCA Connectors

Background: http://en.wikipedia.org/wiki/RCA_connector

As far as I know, the most widely used interconnect (for video and audio, SD and HD) As such, common around the world. A typical hookup will look like this:

game console (modified) --> RCA cables --> RCA Switcher (optional) --> display

Connecting to PVM/BVM: can't be any simpler. You use standard RCA cables (R, G, B and Sync) to feed the video signal to simple RCA to BNC converters (1$ per plug) The audio can be fed to your stereo or stand alone speakers.

Connecting to HDTV:

• 1. Use an external scalar (like XRGB) along with an 4 RCA plugs to 8P DIN cable (do these exist?)

Pro:

• *It is a standard. Connectors, cables, switchers are all readily available and cheap

Con:

• Your console will need to be modified - 4-6 RCA connectors will need to be added (Red, Green, Blue, Sync, Audio Left, Audio Right)

• Connecting to modern HDTV

9-pin DSUB connector

Background: http://en.wikipedia.org/wiki/VGA_connector

... to be completed ...

External Links

• http://retrorgb.com - good primer for RGB

• http://members.optusnet.com.au/eviltim/ ... escart.htm - Game Console RGB SCART Cable Diagrams

• http://www.mmmonkey.co.uk/oldindex.htm - mmmonkey console modification

• http://www.chrismcovell.com/gotRGB/index.html - I want my RGB with great screenshots

History

October 21 - Initial version

[matrigs]

Just for clarification - it's "scaler", not "scalar"

Use SCART to Component converter box (video quality is so so - no that much better than feeding composite to your HDTV)

Why would that be? It's simple colour conversion and shouldn't be any worse than using RGB directly.

[antron]

Yeah, component converted from SCART looks far better than composite, on any TV. If you came over and saw my PS1 on the 47" LCD, you would swear it was an emulator running in VGA. The pixels are clear-cut blocks.

[leonk]

fixed.

[RGB32E]

As RGB was never a standard in North America, there doesn't seem to be a connector standard for RGB purists.

There have been multiple standards pinouts for RGB in the US - BNC, DIN, and DB connectors! The standard process for cables has been to terminate a RGB cable for the particular display/device you're connecting to. Did you start this thread in hopes of enticing people with the idea of using RCA connectors for RGBS?

The RGB21 and SCART standards are really only useful if you're selecting a switcher, or actually have a device with either type of connection. If you're really interesting in getting the best picture quality it really comes down to having the least number of connections from source to destination (aside from cable construction/quality). Hence, it really just comes down to knowing your destination device. If you're an XRGB-mini user, cables terminated with the 8 pin mini din connection work best. If you're using a PVM-xx30, use cables terminated with a DB25F + 2 RCAs. A standard connector is always compromise if you have to use a second adapter.

[leonk]

There have been multiple standards pinouts for RGB in the US - BNC, DIN, and DB connectors! The standard process for cables has been to terminate a RGB cable for the particular display/device you're connecting to. Did you start this thread in hopes of enticing people with the idea of using RCA connectors for RGBS?

No. I was hoping to find out what is the best interconnect to use as an intermediate. It seems most people have chosen SCART. I'm questioning that choice. I don't suggest we all go and install RCA jacks on our consoles (imagine how silly that will look on a top loader!) But if not that, then what? It seems that even console manufacturers haven't decided (hence so many standards for output connectors on consoles)

The RGB21 and SCART standards are really only useful if you're selecting a switcher, or actually have a device with either type of connection. If you're really interesting in getting the best picture quality it really comes down to having the least number of connections from source to destination (aside from cable construction/quality).

That's not what I've noticed. It's common practice to use standard console to SCART cables (with some, like SNES, requiring modifications for NTSC users) feeding into female SCART to BNC connector for most PVM users. Only the most recent PVM's (such as the PVM-xx30) terminate with a DB25F. Most do not. Most are BNC only.

For HDTV users, there's a ton of different RGB SCART to component converters out there. So once again, SCART wins.

Is that really the best choice for NTSC users in North America?

[alamone]

As an intermediary connector, a 9-pin D-sub works fine for me. Enough for RGB, sync, ground, left/right audio, easy to solder to and get connectors and hoods.

As a panel connector, 9-pin D-sub is a little annoying since there's no way to easily drill a D-sub shaped hole. It might be better to use a DIN connector
or something that's round so all you have to do is drill a hole.

Personally I don't really like mini-din because the connector feels flimsy, comes loose easily, and the pins will get bent if you're not careful.
That stupid 21 pin adapter that comes with the XRGB-mini falls out all the time. I'd rather use a full size DIN for more mechanical strength.

Another option would be to use the panel-mount Neutrik connectors, they have a RJ45 passthrough and you could just use ethernet cables.
8 connectors, that is enough for RGB and audio. Minus point is that the Neutrik connector juts out a lot, so you need enough space.
Also, ethernet cables are not shielded, but for short cable runs it shouldn't be a problem.

[rCadeGaming]

I unified all my console cables to a common pinout on D-sub connectors at the end of the cable. I hacked the cables from SCART cables in order to use the pre-existing output connectors on the consoles at that end.

The NES is the one exception which doesn't have a pre-existing output with enough pins. I ordered one of Tim's kits, and I'm going to just install a D-sub connector on the back of my front-loader. A DIN or mini-DIN would be a good choice at this end as well, but I'd use an 8 pin to carry RGBS+5V+audio in the same cable, rather than having a seperate 3.5mm jack for audio (just preference).

Check out the first link in my signature for details.

[Thamiel]

Did you start this thread in hopes of enticing people with the idea of using RCA connectors for RGBS?

I'd be very interested in this. It's actually easier and cheaper here in Australia to find Extron CrossPoint switches than it is to acquire SCART switches.

[leonk]

Omfg!! People actually have those beast of a switcher in their homes!?! One of those units should be able to switch every console ever made and a spare backup hooked up all at once! Does it come with a diesel generator to run it??

[rCadeGaming]

Hmm, that's nice, but you'd still have to switch audio with something else. Anyhow, 6 connectors (RGBS + LR audio) take up way too much space.

VGA switch boxes are cheap and common:

http://www.monoprice.com/Product?seq=1& ... 4Aod7w0AHA

[Thamiel]

Mine switches audio as well just fine. But hey, if ssomeone wants to start selling console RGB cables terminating in a db15 I'd be down.

[rCadeGaming]

Must be a different model I guess. The one I saw just did video. Anyhow, 6 RCA connectors take up about 3 times more space than one d-sub. Multiply that by the number of inputs.

[ApolloBoy]

Anyhow, 6 RCA connectors take up about 3 times more space than one d-sub.

Some consoles don't even have that much room for six RCA jacks; try doing that on a PC Engine without it looking like crap.

[rCadeGaming]

Yeah, in that case it's best to put another mini-DIN with enough pins where the existing one was.

I'm suggesting D-sub's at the end of the cable going to the switcher. At the end of the cable going to the console, its best to use the existing connector type where possible. No need to modify the console itself, just the cable.

[leonk]

Yeah, in that case it's best to put another mini-DIN with enough pins where the existing one was.

I'm suggesting D-sub's at the end of the cable going to the switcher. At the end of the cable going to the console, its best to use the existing connector type where possible. No need to modify the console itself, just the cable.

OK. Makes sense. I like the idea of using a D-sub as there are a ton of switchers and high quality cables out there (good enough for 1024x768 SVGA, good enough for 240p) Some systems do need modifications as they never had RGB (e.g. NES) in this case, it's either install a 15-pin D-sub, 8 pin DIN (and hack custom 8-pin to whatnot cable) or steal a multi-AV port from SNES or broken Famicom AV.

It really reminds me of what I did with my JAMMA New Astro City candy cab. Only 4 cables needed to fully swap systems:

- cable for Video (15 pin D-SUB)
- cable for 6 buttons, joysticks, etc (25 pin D-SUB)
- 8mm audio
- power plug

At this time, I have 2 PCB setups which I quickly swap between:

- MAME PC (running with JPAC)
- Naomi 2 system with CF adapter + UVC

It seems D-SUB is looking good for systems that have no ability to get cable hacked to support RGB.

[markfrizb]

If you we're to add the audio lines to a DB15 (VGA), which pins would you use? Pin 9 is +5v, pins 1,2,3 are RGB, etc... So I guess my question is -- were there every audio lines on VGA connections? If so, which pins?
I ask because I'm considering using a Dsub15 on my top load NES with Tim's NESRGB board and just want to use 1 connector.


Thanks

[leonk]

I wouldn't do that. I'd use DB-15 for video and add 8mm jack for audio where RF port was.

[ApolloBoy]

I wouldn't do that. I'd use DB-15 for video and add 8mm jack for audio where RF port was.

There's no such thing as an 8 mm jack for audio, don't you mean 3.5 mm?

[Ed Oscuro]

I think he means a phone connector, tip-ring-sleeve.

[undamned]

I wouldn't do that. I'd use DB-15 for video and add 8mm jack for audio where RF port was.

There's no such thing as an 8 mm jack for audio, don't you mean 3.5 mm?

If you wanna be a boss you could use XLR jacks.
-ud

[rCadeGaming]

If you we're to add the audio lines to a DB15 (VGA), which pins would you use? Pin 9 is +5v, pins 1,2,3 are RGB, etc... So I guess my question is -- were there every audio lines on VGA connections? If so, which pins?

It doesn't matter what pinout you use, as long as you send everything to the right place in the end. So you can carry video audio on whatever pins you want, run it through a switch box, take the output from the switch box and then make sure the right signals go to the right places from there (video to display/processor, audio to amplifier/whatever).

If you want to make sure it will be safe in case you plug it directly into a VGA jack by accident you can use this pinout:

1 - red
2 - green
3 - blue
5, 6, 7, 8, 10 - ground
9 - +5V (optional; to power/activate a sync splitter)
11 - L audio
12 - R audio
13 - H sync (if applicable)
14 - V sync (if applicable)
15 - C sync (if applicable; you can put it here or on pin 13, depending if you're using a sync splitter, and how it's set up)

I set my switch box up with a sync splitter inside, so that you can feed it RGBHV or RGBS. For RGBHV sources, I leave pin 9 disconnected, and it will simply pass it through. For RGBS sources, I wire the cable to include +5V on pin 9, which automatically activates the sync splitter. See the link in my signature for more info.

You don't have to modify the switch boxes if you don't want to though. You can just include an audio breakout and/or sync splitter on the cable coming off of the switch box's output. Then you can also take the switch box out of the equation if you want to, just by using a gender changer to plug the console cable directly into the breakout cable.

[rCadeGaming]

I wouldn't do that. I'd use DB-15 for video and add 8mm jack for audio where RF port was.

Then you're modifying all your consoles and running twice as many wires. There's no need. Just carry video and audio on the same cable, then connect that to an audio breakout before it gets to the display. If the audio breakout is after switching, that simplifies switching a lot as well.

You shouldn't even need to open the consoles unless one needs RGB modding.

[leonk]

I think it makes sense to not run audio in the dsub-15 for the following reasons:

- easier to hookup to external audio amp / audio amp to switch inputs
- less likelyhood of introducing noise into audio or video (cross talk) - this is an issue with a lot of SCART cables

[antron]

^ that's probably why Tim used separate ports and cables for his NESRGB kit (until they had to be merged in the SCART connector).

[rCadeGaming]

I think it makes sense to not run audio in the dsub-15 for the following reasons:
- easier to hookup to external audio amp / audio amp to switch inputs

You mean you want to have to switch audio and video seperately?

- less likelyhood of introducing noise into audio or video (cross talk) - this is an issue with a lot of SCART cables

When I first started with RGB I ran SCART cables to a CVS-287 with an audio breakout. It had a lot of noise, but I found that it was caused more by improper grounding at the that end than crosstalk. Crosstalk is certainly a possibility, but with my current setup you can't detect it unless the volume is up way past a comfortable level.

[leonk]

When I created my swappable pcb system that goes inside my NAC candy cab, I had an different motive: mount mame and naomi inside the cab. Have the mame PC through hyper spin load games onto the naomi. Then with 2 flicks (1 video 1 controls using one of those simple 2-in-1 switchers) change to the naomi system, play the game and switch back. It always worked fine except for one major problem. There was faint ghosting between light and dark transitions.

Most people wouldn't have noticed it, but since I sit 3 feet away from a 29" CRT and know how it's supposed to look like, I noticed it. I was also using high end (expensive) VGA cables and unlike the proposal here, the video signal is actually stronger!! (5v from UVC and 5v from JPAC)

The fix was to bypass the switcher and plug VGA cable directly into jamma harness. This time around, the custom VGA cable on both jamma in and JPAC out were kept as short as possible. Ghosting went away.

My point for this rambling? There's a lot of talk of switching VGA. I'm not crazy about that. My goal is straight rgb line into pvm. There's a reason why good PC VGA switchers are all powered ones. I'm wondering if anyone else noticed ghosting from long VGA cable runs (2 standard VGA cables through one of those cheap switchers)

[viletim]

The fix was to bypass the switcher and plug VGA cable directly into jamma harness. This time around, the custom VGA cable on both jamma in and JPAC out were kept as short as possible. Ghosting went away.

VGA cables usually contain coax cable. Arcade video is not impedance controlled or terminated and this will cause reflections and ringing if connected through any significant length of 75 ohm coax cable.

[rCadeGaming]

What viletim said. That doesn't usually happen with normal 0.7v RGB signals.