G7000 / G7400 RGB output

[misthalu]

Hello all

 

Signed up here to ask for help regarding RGB output for G7000 / G7400.

 

In short, I need to record a bunch of videos of various Videopac games for my project 8bitmemoirs.com

For this reason, one of my mates have modded my G7000 to have RGB output, but it's displaying wrong colours.

I found a video on YouTube demonstrating the exact same problem:

https://www.youtube.com/watch?v=ct6Wv3eyPzM#t=2m20s

 

Notice the red and blue is way too dark. That's not how the colours are supposed to look in that game ("Race").

 

So for a short while I gave up on RGB and asked my mate to instead put in a composite mod, which he did, and it works but the picture is just as awful as an RF signal.

 

Therefor I'm back to hunting a good RGB solution signal now. So I have 3 questions for you all:

 

1) Does anyone know why the colours are too dark with an RGB mod for G7000? Is there anything we can do about it?

2) Is the RGB output better on the G7400? And is it easy to add an RGB mod to the G7400 that doesn't come with one pre-installed?

3) Are there anyone here who has a spare G7400 with RGB output they'd be interesting in selling?

 

Some pictures demonstrating my problem: http://www.amibay.com/showthread.php?88818-Help-requested-for-RGB-output-for-Philips-G7000-Videopac

 

Thanks!

[+grips03]

Are you in USA?

 

Do you have RGB TV? Like Sony PVM?

 

Are you using RGB to HDMI adapter?

 

This type of adapter in known to produce too dark of color with Videopac G7000, G7400 and Odyssey 2, see pic.

 

Micomsoft XRGB2 gives great picture, but it depend on what TV you have

[misthalu]

I'm in Denmark, so I'm after a european model. And from what I've read, I'm supposed to avoid french models because they supply a SECAM L signal....

 

I'm using an XRGB Mini Framemeister from Micomsoft yes, forwarding into a Hauppauge PVR Rocket for recording. This setup has worked really well for all the Amstrad CPC videos I've recorded. And it works great for the G7000 too.

 

The only problem is the wrong colours.

 

So I'm hoping that the RGB output of a G7400 is better / correct. And if so, then I'd like to buy one.

 

The colours are also dark when plugging the scart directly into a TV, so it's not the Framemeister causing the darker colours.

Edited April 13, 2017 by misthalu

[+grips03]

I have G7000, G7400 and Odyssey 2 all with RGB. Connected to Sony PVM they all look great using native RGB.

 

Odyssey 2 looks awesome connected to XRGB2 to via VGA to Sony LCD.

G7000 and G7400 need a box to convert from 50Hz to 60z in order to display on my Sony LCD TV. The converter box I posted pics of in post 2 does this, however it makes the colors a little bit dark. I wish I could find another converter box that does not have that issue.

 

Did your friend build something like the mod here:

http://atariage.com/forums/topic/260238-o2-rgb-mod/

 

Design came from G7200 console schematic with help from Rene on Videopac.nl forum

 

Going to G7400 won't fix your issue.

[misthalu]

I don't know exactly what he's done. He likes to create his own circuits, so I doubt he's used anything existing.

All I know is that the colours are wrong, and that's not good enough when I'm about to record a bunch of videos. No G7000 user will accept videos looking like that, when it's not how the games actually look.

 

The game "Race" uses a bright blue and bright red. This is quite clear when I'm connecting with RF or composite.

But when using the RGB mod my mate has made, the blue and red are dark.

I can see on YouTube that I'm at least not the only one having this problem.

 

I don't transform 50hz to 60hz. All the framemeister does is force the 49.98hz (or whatever) to a straight 50hz signal. This should not affect colours. It didn't affect colours in my Amstrad CPC videos.

The colours are also dark when connected to a TV - i.e. not using the framemeister.

 

I also bought one of those cheaper converters first, but it didn't even work with my Amstrad CPC, so I got the Framemeister instead. Expensive but great. I'm finishing this project whatever it takes. Have spent 5 years on it so far (but a lot of that time has been spent waiting for other people doing stuff like hardware mods and illustrations for me).

 

I don't suppose you could take a photo of your TV displaying "Race"? For comparison?

Any spare G7000 you wanna sell me?

My mate is not going to work any further on this project. He's spent a ton of hours already. It's obvious he can't do it, either because it just can't be done, or else because he doesn't know how. In any case, I have to look for other options now.

Edited April 14, 2017 by misthalu

[+grips03]

Here is my G7000 mod

http://atariage.com/forums/topic/263348-g7000-mod-pics/

 

I'll post pictures of games you want to see here.

[misthalu]

Still struggling a lot with this.

Finally bought a G7400 instead, because I thought this would be better at producing a correct RGB image, but no.

I had a mate apply the components for the RGB part on the board, and the resulting image is sharp and crispy just like on the G7000 - but also wrong colours just like with the G7000.

 

If I want correct colours, the best result so far is a composite mod. Then the colours are all correct, but the picture quality of course isn't that great.

 

I find it weird that I seem to be the only one noticing these wrong colours. Even YouTube videos of G7000 games shows wrong colours.

[carlsson]

Wrong colours, or just too dark colours? The latter perhaps is an issue of too low voltages on the RGB lines (assuming we're talking analog here) but I haven't studied the circuit, if you're lowering what initially are strong signals or are having very weak signals that need to be amplified?

[misthalu]

I say wrong because it looks like some of the colours are alright.

It's not a case of all colours being too dark. Some seem to be ok.

But those that are wrong are generally darker yes.

I'm using the game Race / Speedway mostly to check. And the problem here is that the blue is way too dark. The red is acceptable, and the white is too. Purple is probably a bit off, but I can accept that. The blue however is way too dark, unacceptable.

 

I don't know what circuit was put into my G7000, but the G7400 merely had components added that was already made room for on the motherboard. So at this point I'm guessing that RGB-out just looks like that, which is somewhat disappointing.

Edited July 14, 2017 by misthalu

[misthalu]

Cleaning up my bookmarks, I found this old thread. :-)

 

I never got 100% the correct colours I was after, but had to settle for what I could get in the end.

 

All the videos got recorded, and the project was completed. For anyone interested it can be found here: http://www.8bitmemoirs.com

 

I also made a thread about it here on the forum: http://atariage.com/forums/topic/272652-8-bit-memoirs-issue-1-released/

[Brice T]

Hello I bought a video pack gx7400 but it only has rf, how do I get it to work on an american tv?

[+grips03]

Use RGB

https://www.the-nextlevel.com/odyssey2/articles/g7400guide/rgbmod.php

 

then buy

SCART to HDMI adapter like ebay item # 392861584293

 

I sell G7400 SCART RGB cable in my sales thread or just make your own cable.

[Level42]

If certain colours are too dark with RGB those colour signals are simply too low compare to one or two other of the signals.

There are lots of variables here.

 

Remember that the RGB outputs on the 7400/7401 were designed with the SCART input of TVs in mind. Those SCART inputs are terminated with resistors. If, whatever device you are connecting the RGB signal into has no, or incorrect value terminating resistors, the signal can be overloaded, lowering the actual signal.

 

I have also had high quality RGB cables with PCBs and resistors inside (which were intended well, but were put in there because the guy who builds them misunderstood how SCART termination works)......which ruined the picture, making ALL the colours way too dark....l

 

HOWEVER......do we actually kno the original RF colours are correct ?

maybe they used wrong resistors in the original design making some colours too bright, and making the actual RGB output correct. 
 

Then there is also the fact that the machine was designed as the Odyssey2 in the US and for their NTSC system.

just like with many other systems, colour can appear rather different between Euro and US systems, f.I. the VCS and A8 machines suffer from this (where I , as a European, much prefer the NTSC machines).

 

Is there some kind of test cartridge for O2/Videopac that can show a true colour bar ? If so, that could be used to see what the correct colours should be.