RGB out of a PC?

[Geezer]

Is this possible at all, I used the TV out for MAME on my TV yesterday to play some tate games and thought it'd be so much better in RGB

Is this possible to do? and more importantly, is it possible to do at a reasonable price?

[Super Stu]

I've never seen it tbh, as you'd need some sort of SCART out init. Some (all?) top ATI cards have component out, if that's owt use.

tbh, you'll be looking to stump up the pennies for some sort of VGA->RGB box, which I gather ain't cheap.

[baddie long legs]

I think you can make a RGB VGA cable which is essentially a VGA cable wired to a scart socket. But I may be mistaken.

[Super Stu]

I thought the timing etc was all different, otherwise there'd be a wee dongle we could all attach to the back of our graphics cards, instead of needed specific tv out?

[Lyris]

I'm sure the timing is different. That and the computer won't already be creating interlaced images.

AFAIK some of the ATI Radeon Cards can have a DVI-to-Component dongle thing, but that's only because the image is already progressive.

[Geezer]

Thanks for the replies guys

I thought this would be the case, as the timing is indeed different

It was a nice idea while it lasted, I thought it might be possible as Mame cabs seem to give a really nice picture so I assumed they would be RGB monitors in there

[Rsdio]

I tend to use TVTool (http://tvtool.info/index_e.htm, I'm pretty sure it has support for RGB output on certain chipsets which requires a modded cable of some kind. Sorry I can't remember the details, but it was a while ago now. If you can't find anything on the site, I'm sure they could answer your question on the forum there.

[Leon Retro]

Yeah, go to the TvTool site and they tell you everything you need to know. Its a great utility aswell, I use it for my Mame sessions on my big Widescreen tv through S-Video

Good Luck!

[NeilMcRae]

The issue is VGA/RGB uses 31. KHz and nromal RGB uses 15.5Khz [or numbers thereabouts]. You need to downscale the VGA image to RGB. Which is liable to be pricey. But check the specs of the monitor some will sync to a 15Khz picture.

[Papercut]

Its a matter of building a VGA -> scart cable, and somehow forcing your graphics card to generate a 15KHz 480i signal, which is what TVTool seems to do for some graphics cards.

[MD]

Yeah it's simple.

Get Red,Green, Blue and Ground signals from VGA and wire them up to Red, Green, Blue on the SCART and Video Ground. Get H-Sync and V-Sync, tie them together, wire a 75 Ohm Resister to it and wire that to Composite Sync / Video. Wire Audio Out to the Left, Right and Ground signals of the SCART. There is no 5V on VGA so you will need to steal that from say the keyboard or mouse PS/2 socket, that needs to be wired to pin 16.

You then have to get MAME to sync to 15Khz, but newer versions don't do this easily and unless you can prove you have these games or at least an original version on something then that's all the help your getting...

[Papercut]

Advance Mame might be able to produce 15KHz video modes, its designed for that sort of thing.

Also when tying H and V sync together, I'd use a couple of signal diodes to prevent cross feed. Alternatively if your video card has composite video out, you could use that instead.

[gIzzE]

Download powerstrip as you can then set your card up to output 15hz (interlaced) all the time if you wish that way you can see your desktop in RGB too.

so you can set up a resolution of 720x480i@60hz which will give you ntsc timings in RGB, or 720x576@50Hz if your tv does not hanle 60hz.

From memory I beleive you can set your card to output, using powerstrip, RGB/h/v , RGsB, component ot RGBs which is what your are wanting for your scart.
Obviously depends on your card but alot are compatible.