dvdo edge + neo geo RVBS

[Maturin]

Since it s the first time I post on this forum, hi to everyone there.

I red that forum a lot lately especially about how to connect old machines on lcd screen.
I bought a DVDO Edge and tried to connect my Neo Geo using 4 RCA(RVBS) input and it does not work.
The signal is detected as YCbCr 444 480i and the image lack of luminance(it s very dark and for example the credit are in back instead of white).

Did anyone experienced the same problems ? I guess it must be the same with a mega drive since it s the same input.

Maturin

[Fudoh]

First thing to come to mind is the firmware. There have been firmware versions in the past which were not able to properly detect RGBs signals and 240p. Both was fixed later on. Which firmware are running ? While I had no Neo Geo on hand while I had my EDGE testrun, I've tried RGBs with a few other systems including a SNES (see http://retrogaming.hazard-city.de/ ).

[Maturin]

Thanks for your website which is great !
For the firmware I am using, I tried v1.2.1 and 1.3.
I had the same problem with both.
If there is no other solution I may try to use a rvbs to yuv converter, but I worry it won't solve the problem.

[Fudoh]

Those FW-versions should be fine. Just to make sure: you have your Sync signal connected to the white Sync input, right ? Do you have a composite cable for your NG ? If yes, is the 240p signal correctly recognized with this one ?

[Maturin]

Yes, the sync signal and rgb are connected to the 4 inputs.
Separatly sync + b, sync + g, sync +r, give me respectivly a blue, green or red image. But together the colors lacks of luminance.
I have no composite cable for my NG so I could not try it(I only have a scart).
I use:
scart -> scart to 4 RCA(RGBS) -> dvdo edge
My scart to 4 RCA is working properly(worked when using my rgb dvd player).

[Fudoh]

If you have Scart, you've got composite, just use your Scart->RCA adapter and plug the sync line into the Composite (yellow) input on the Edge. Depending on your NG revision you might have both - composite video and pure sync available on the DIN8 output. I could imagine that the Edge does like the one signal, but would play fine with the other. The cheaper RGBs to YUV converters are really not this great, so I'd try to fix the problem without using another signal converter first.

[Maturin]

It s not composite, it s a rgb scart for NG. From that I use female scart to 4 rca(RGB and sync).

Here is the (terrible) result:

http://img195.imageshack.us/img195/9744/dscn9804n.jpg

You can't see much details from the screenshot, but at least you can see that the color are totally wrong.
If it was composite it will give nothing on these input, and would work on composite input(I tried).

[Fudoh]

It s not composite, it s a rgb scart for NG.

I understand that, but Scart usually carries the composite video for Sync and so it will work on a TV's scart input even if the TV can't do RGB.

From what I see the Edge does misinterpretate the signal. A fix should be easy, if it is what I think. That a look at the NG AV pinput here: http://www.gamesx.com/avpinouts/neoav.htm

You've got Composite Video on Pin 3 and Composite Sync on Pin 7. Check your cable and switch those two pins. Cut the one that's currently running to the Scart-end of the cable and use the other.

[Maturin]

Yes, I think you are right. I am using a modified mega drive scart, and the modification consist of switching composite and synch.
I will try to switch it back and tell you the result.

[Maturin]

I switched the pin and it gave me the same result ...
Something strange is when I put on of these pin on composite video input, It gives me a picture(but bad color and unstable).

[Fudoh]

Can you take a picture of the result when connected to the Composite video input ? Have you tried both switch positions ?
It's possible that your NG does not have c-sync at all and outputs c-video all the time. On the other hand the Edge might not be able to handle this. In this case you'd need a LM1881 installed in the cable (or the NG). In GENEREL NG + Edge is not a problem, so it's related to your specific setup (and probably NG) which makes it a bit hard to diagnose.

[Maturin]

Here are some screenshot of my output when using my "sync" on composite input of the dvdo edge.
Color seems wrong like when using RGBS.

http://img259.imageshack.us/img259/6291/dscn9805.jpg

I moved while doing the pic so it is not clear but the text in japanese should be white instead of black.

http://img32.imageshack.us/img32/7403/dscn9806s.jpg

Someone advised me to use a sync cleaner, is it what you mean by the LM1881 ?
Anyway sync is good using video or rgbs input(the image is stable).

[Fudoh]

Yes, a LM1881 is basically a "sync cleaner". Your problem is that NG doesn't output composite, nor does it output pure sync. In case of composite, you'd get a regular picture on the composite input and in the case of pure sync, you'd get nothing.

[Maturin]

The LM1881 worked, the image is very nice now.
I still have some small problems with the picture but it may be because I forgot 1 condensator, going to fix that.

Thanks

[Maturin]

Just for the info, I was using a japanese 3-5 neo geo. And we tried on my friend NG on an american 3-5 neo geo and had the same ploblems without the LM1881.
Now it works well but the NG is still detected as 480i
It seems that this is needed for the NG to work on the edge at least from a euro scart -> rca
I wonder if it s the same from a mega drive or master system which are using similar scart

[Fudoh]

The RGB specs are terrible. It's really a try & see for each single one of the systems.