RGB from consoles - Can I go to VGA?

[NayusDante]

I'm starting to delve into the world of making video cables for my old consoles, and RGB output has really caught my eye. Before I go trying to get RGB on my TV from component cables, which may or may not work depending on my TV, I'd like to know if VGA is a valid alternative. I had several old VGA cables sitting around that I could splice up, and two spare PC monitors to mess with. What consoles would work well with this, if any?

Basically, I want to get better picture without messing around with SCART adaptors and stuff like that, if it's possible.

[izarate]

I'm starting to delve into the world of making video cables for my old consoles, and RGB output has really caught my eye. Before I go trying to get RGB on my TV from component cables, which may or may not work depending on my TV, I'd like to know if VGA is a valid alternative. I had several old VGA cables sitting around that I could splice up, and two spare PC monitors to mess with. What consoles would work well with this, if any?

Basically, I want to get better picture without messing around with SCART adaptors and stuff like that, if it's possible.


No, VGA uses a different standard (RGBHV). As with RGB -> component, you'll need a transcoder (VGA box).

[NayusDante]

No, VGA uses a different standard (RGBHV). As with RGB -> component, you'll need a transcoder (VGA box).

So if I went the component route, is that something that I can build myself or would I be better off buying one already made? My goal is to have a box with plugs for several different systems, so I'm more inclined to build one.

[evildragon]

Even then, the scanrates are too low for most VGA monitors. Though some can handle it.

PS: Most monitors can take composite sync in the H input.

[NayusDante]

PS: Most monitors can take composite sync in the H input.

With that said, could you tell me if this pinout would make sense? I'm not too sure about the returns and outputs, and might have them reversed.

Genesis -> VGA
Red - Pin 6 Red return
Green - Pin 7 Green return
Blue - Pin 8 Blue return
Sync - Pin 10 Sync return
Ground - Pin 5 Ground

Given these pinouts:

Genesis 2
http://www.gamesx.com/grafx/32xpin.jpg

VGA


1 Red out *
2 Green out *
3 Blue out *
4 Monitor ID 2 in
5 Ground
6 Red return
7 Green return
8 Blue return
9 no pin
10 Sync return
11 Monitor ID 0 in
12 Monitor ID 1 in
13 Horizonal Sync out
14 Vertical Sync out
15 reserved (monitor ID 3)
Signals marked with * are analogue 0.7V p-p positive signals to 75 ohm load. All other signals are TTL level signals.

[evildragon]

No no, return is a fancy word for GROUND. ;)

[NayusDante]

Ok, is this closer?

Genesis -> VGA
Red - Pin 1 Red out
Green - Pin 2 Green out
Blue - Pin 3 Blue out
Sync - Pin 13 Horizontal Sync out
Ground - Pin 5 Ground

...or do I also need to ground all the returns?

Also, are the monitor ID pins necessary? Will I still get a picture if I leave them unconnected? My TV has an "RGB-VGA" port, so I'm guessing this is worth a try once I figure out the right pinout.

[evildragon]

Monitor ID pins are only for the PC/Macs video card. The monitor merely grounds them or sends EDID info to the card that way. Not needed.

But your pinout is from a video card, you want to the monitor. (They are backwards).

As for grounding the returns, it's not needed, but it can help clean up the picture.

[NayusDante]

But your pinout is from a video card, you want to the monitor. (They are backwards).

So basically, flip the pin numbering of the VGA cable horizontally?

[evildragon]

Well you should check the pinout from the monitor end just to be sure. Those pinouts are available.

[Ed Oscuro]

~$200 seems like it should buy you an RGB to VGA converter...dunno about the exact format these newer converters take though. Or about the required input for that matter.

[Coldguy]

Easiest way: Go to newegg and search for a VGA Box they will swing you from 40-75 bucks and will allow you to hook any RGB signal to a computer monitor. This is what I have:

http://www.newegg.com/Product/Product.aspx?Item=N82E16815260010

[evildragon]

That's not showing RGB input at all. Component is the closest there, but it's not RGB that comes out of the console.

[jb143]

Your not going to be able to just wire pins on a console to pins on the monitor. As someone else mentioned, the scan rates are different. You'd need a scanrate convertor as well. Also, I'm not sure, but the signal timing is probally different too. I don't want to say that you can't build your own, there's probally schematics out there. It's certainly going to be a project though. It will be much easier to buy one.

[evildragon]

On an analog system, I've never heard of signal timing. ;) That's the scanrate if anything.

It's merely scanrate. Been there done that. You need a monitor that can sync to 15KHz horizontal. Vertical is still 60Hz non-interlaced.

[NayusDante]

So I cut up an old VGA cable, checked the pins, and wired it right. No image on my TV, and just test patterns on my LCD monitor. Can't check my CRTs because they have the attached-type cables.

However, I wired up some RCA jacks and plugged in some cables to my component input. One color to each cable, ground to grounds, sync on green. Ignore the cable colors, I forget where my spare component cable is. Anyway, it's too pink...

http://farm4.static.flickr.com/3576/3379883289_c9595efa0b_b.jpg

...but all the colors are there. Look, green! Well, pastel-green.

http://farm4.static.flickr.com/3542/3379885299_4695f645e4_b.jpg

Is there something that I need to do to correct the video? If I'm this close, I can't see spending $200 on a converter box.

[jb143]

By component do you mean YPbPr? I havn't done it but I'd imagine going from RGB to YPbPr component would give funky colored results.

Heres the info for that...

The green cable (Y) carries the brightness information(luma)
The blue cable (PB) carries the difference between blue and luma (B − Y)
The red cable (PR) carries the difference between red and luma (R − Y)
-Green is extracted from the 2

So you can see how wiring RGB into that will cause the colors to be wrong.

Also, audio cables are generally not suited for video (the ohms are wrong) but I don't think that's effecting you here. I think it's only a problem for longer cables.

[NayusDante]

Yes, that's what I mean.

What's the next step to convert the signal into proper YPbPr? I'm guessing that I need to put the green signal somewhere other than the green cable.

[evildragon]

Yea, um, Y/Pr/Pb is NOT RGB..

Y > Luma (Greyscale image with sync)
Pr > Red minus green
Pb > Blue minus green

Whatever is left from Luma is green. If I remembered that right. It's mathmatic. But RGB is Red, Green, and Blue. Just because the connectors are colored RGB doesn't mean Component is RGB. ;)

[evildragon]

I personally use the JROK adapter.

PS, I got the same cable box. !! XD

[jb143]

Yes, that's what I mean.

What's the next step to convert the signal into proper YPbPr? I'm guessing that I need to put the green signal somewhere other than the green cable.

Yeah, you'd need a box in between that would do the math on the signals I put above. Green gets added to the red and blue and the brightness put on it's own signal. I don't think there's a passive way to do it. If you want an electronics project there's probally sites that will show schematics. It will be more than splicing and rerouting wires. There's probally going to amplifiers and IC chips but it shouldn't be toooooo difficult if you've ever done anything like that before. Of course it's still going to be a lot easier to buy a convertor.

[jb143]

Yea, um, Y/Pr/Pb is NOT RGB..

Y > Luma (Greyscale image with sync)
Pr > Red minus green
Pb > Blue minus green

Whatever is left from Luma is green. If I remembered that right. It's mathmatic. But RGB is Red, Green, and Blue. Just because the connectors are colored RGB doesn't mean Component is RGB. ;)

Yeah, I think that's right except I think it's munus Luma instead of green. Luma is basically a standard B&W signal which is R+B+G=B&W. That's how you still have green even though there's no green signal. Luma-R-B = green.

I'm a bit fuzzy on this stuff as well so I might have the details mixed up too.

btw...I'm no expert but I used to build, test, and repair video output boards. I'm a CE though so I never got too far into analog signal processing.

[evildragon]

You might be correct on it being minus luma.

I know that the luma hasn't changed since TV began though. :p It's good ol regular black and white TV.

[drewman21]

Get this. http://www.arcademvs.com/rgbstovga.htm This will let you do both RGBS and Component video to VGA. It is a scaler that will let you meet several resolutions on your monitor and do 4:3 and 16:9 on your screen either way what your monitor will be.

[NayusDante]

Get this. http://www.arcademvs.com/rgbstovga.htm This will let you do both RGBS and Component video to VGA. It is a scaler that will let you meet several resolutions on your monitor and do 4:3 and 16:9 on your screen either way what your monitor will be.

That looks promising, but it doesn't help me without a price or supplier. I'd just wire the console to the 8-pin input on that, right?

At any rate, I'm looking for something closer to the range of $50 than $200...

[evildragon]

I said it before and I'll say it again, JROK.

[HyperDuel]

If you want pure RGB to VGA better get one of the XRGB upscalers. They are the best plus scanlines support.

[drewman21]

Here is the same board as i posted earlier. http://cgi.ebay.com/Arcade-RGBS-CGA-EGA-YUV-TO-2-VGA-CONVERTER-NEW_W0QQitemZ310129709475QQihZ021QQcategoryZ13718Q QcmdZViewItemQQ_trksidZp1742.m153.l1262?_trksid=p1 742.m153.l1262 It is 49$ plus shipping. You can find it cheaper on ebay if you keep a eye out. I have a Jrok too but this has features the Jrok doesn't and is still cheaper.

[NayusDante]

What would I need in terms of a power adaptor for that board? Also, what's the approximate difference between it and the JROK equivalent? This is very helpful so far, so thank you everyone for your information.

[drewman21]

The board takes 5v DC at 1.5 amps. The board only puts out VGA. The Jrok will only do rgb in and kick out composite, s-video, and component. The rgb board can do up-scaleing for vga resolutions. The Jrok board only can pass through what it is given. It can do 480i and maybe 480p. I don't think it can do higher but then again i don't know of any machine that will do a RGB signal above 480p. I would pick what would work best for you. If you have a widescreen LCD i would make sure that your VGA port, if it has one, can do resolutions that the VGA board will output to. If it doesn't you'll not get the most out of it.
Hope that helps. Yell if you have any more questions.