Trouble with Apple Pippin and Framemeister

[unstablewarpfield]

Hey guys!

Posting this because I need some advice. For a while now I have been using my VGA modded Colecovision through a Beharbro's Kenzei box into my Framemeister because my main gaming tv does not have a vga input. I am really happy with the image I am able to achieve through this method.
Recently I acquired a Japanese Pippin and since it outputs vga, I thought it would be easy to hook it up in thesame way I use my Colecovision. However, I am struggling a bit. I feel like the colors are off in most games, and as you can see in the pictures, in Marathon I get a weird black bar in the play area of the game. Marathon 2 will give me odd purple/pink-ish hues in some frames, depending on the pov I set my player to.

Now I have tested this Pippin with a VGA cable directly into a small test tv that does have a VGA input. Like that, it works perfectly, so I know it's not the console. Unfortunately this small tv does not accept 480p over scart so I can't test the Kenzei box with it.

When I look at the status screen in the Framemeister of both consoles, the Colecovision gives me a 59.50 Hz signal. The Pippin says 59.84Hz. It's about the only difference I could find. Might this have something to do with it? Does anyone recognize the anomalies in the pictures I shot?

Marathon 1


Marathon 2

[rama]

... Beharbro's Kenzei box into my Framemeister ...

I think one of those devices has trouble setting the correct clamp location.
Try out the controls you have on your units.
Look for anything that mentions "clamp" or any controls that shift the active video.

[unstablewarpfield]

I am totally clueless here. I tried checking out the framemeister settings and there is CLAMP_MODE setting in the "special" menu under A/D_SET. I tried switching it from standard to special, but other than giving the screen a complete blue hue it did nothing. On the Kenzei there is not much you can change.

Here is a link to the Kenzei sync combiner. There is not much you can set on this device and it works perfectly the way I have it now with my Colecovision. I'd be interested to read up a bit more about the video signals coming out of the Pippin but there is not a lot of documentation to be found, let alone people who have tried what I am doing.

The thing is over the years that I have been perfecting my setup I have (ofcourse) encountered problems along the way. In many cases I could identify the errors and was able to fix the problem. This time I do not even recognize what is going wrong in this perticular situation.

edit:

A couple of observations so far...

*Apple pippin has no problems when I hook it up directly through vga on a small test tv. (unfortunately my main gaming tv has no vga input which is why I needed the Kenzei.)
*vga modded Colecovision works perfectly with the Kenzei.
*vga modded Colecovision shows a dim LED on the Kenzei. Apple pippin a VERY bright LED.
*Sync voltage coming off the Kenzei with the apple pippin is 3,7V (TTL?). Is this why the LED is brighter?
*Sync voltage coming off theKenzei with the Colecovision is about 0,3V.
*RGB voltages coming of the Kenzei with the apple pippin are within spec.

[unstablewarpfield]

In the mean time I tried out my setup on a different tv set with thesame result. The colors are just off and change depending on how the camera turns. It looks like the Kenzei doesn't want to play nice with either the framemeister or the Pippin. I'm leaning towards the pippin since it does work fine with the Colecovision on the Framemeister. Then again... what makes the vga signal of the pippin different from that out of the F18A mod in the Coleco, or the Dreamcast (for which the Kenzei sync combiner was designed).

I am leaning towards building my own sync combiner if nothing else works...

Any advice on or experiences with sync combiners is appreciated

[rama]

I'll attempt a shot in the dark, just to give an example on how the VGA signals can differ.

The Framemeister is a digital device with an analog input section.
This setup requires an RGB clamp pulse to be placed around the incoming HSync pulse.
(The sync pulse determines where the 3 RGB lines will be clamped to ground.)
Determining this clamp position can be a little tricky, and if for some reason the position is bad, the clamp can reach into active video.
When that happens, the colors get badly affected. Bigger mismatches can even cause a black picture.
This is what your pictures look like, a misplaced RGB clamp.

It could be caused by the Framemeister alone, or by the combination Kenzei - Framemeister.
There is some chance that skipping the Kenzei (somehow) can fix the issue.

Sidenote:
Some people noticed color issues with the Framemeister and some evenly coloured surfaces. This can be explained with a clamping issue as well.

[Fudoh]

I would say that there's a good chance that your source will work just fine if you use the RGB input instead of the component input. By default the component input is really made for standard SMPTE resolutions, while the RGB input is very flexible. Get a RGBHV to RGBs sync converter (any of the Extron RGB interfaces) instead. This way you can connect any 31khz VGA source to the front MiniDin RGB input. You just a need a cable that will connect the Extron's BNC output to your FM's RGB input - either directly or through a Scart adapter or scart switch.

Or ditch the FM completely (for your Pippin) and get a cheap VGA to HDMI dongle instead. The FM isn't great for processing 480p sources, so you're not getting your best quality by using the FM for your Pippin in the first place.

[unstablewarpfield]

I would say that there's a good chance that your source will work just fine if you use the RGB input instead of the component input. By default the component input is really made for standard SMPTE resolutions, while the RGB input is very flexible. Get a RGBHV to RGBs sync converter (any of the Extron RGB interfaces) instead. This way you can connect any 31khz VGA source to the front MiniDin RGB input. You just a need a cable that will connect the Extron's BNC output to your FM's RGB input - either directly or through a Scart adapter or scart switch.

Or ditch the FM completely (for your Pippin) and get a cheap VGA to HDMI dongle instead. The FM isn't great for processing 480p sources, so you're not getting your best quality by using the FM for your Pippin in the first place.

The above pictures are results using the RGB input already. I have never used the component input on the framemeister

So... Is there a difference between a sync combiner and a sync convertor then? My Beharbros Kenzei is a combiner and from the looks of it a very basic one. I could detect only one IC on the pcb, while all the combiner schematics I found on the web also contain resistors and caps.

I tried using a cheap VGA to HDMI solution for my F18A modded Colecovision and really didn't like the result of that. I assumed it was because I tried a cheap convertor.

Still... Why would it be that the F18A mod on the colecovision AND the dreamcast work fine through the Kenzei? What is it that makes the VGA out of the Pippin different from those two consoles? It's a shame there is so few documentation on it.

I'll attempt a shot in the dark, just to give an example on how the VGA signals can differ.

The Framemeister is a digital device with an analog input section.
This setup requires an RGB clamp pulse to be placed around the incoming HSync pulse.
(The sync pulse determines where the 3 RGB lines will be clamped to ground.)
Determining this clamp position can be a little tricky, and if for some reason the position is bad, the clamp can reach into active video.
When that happens, the colors get badly affected. Bigger mismatches can even cause a black picture.
This is what your pictures look like, a misplaced RGB clamp.

It could be caused by the Framemeister alone, or by the combination Kenzei - Framemeister.
There is some chance that skipping the Kenzei (somehow) can fix the issue.

Sidenote:
Some people noticed color issues with the Framemeister and some evenly coloured surfaces. This can be explained with a clamping issue as well.

It would be nice to dive a bit into this clamping matter, although I feel like it requires a bit more extensive knowledge on the subject. Any good sources or read ups on where to start?

[Fudoh]

my bad, sorry. I assumed the beharbros box you're using was their transcoder unit (instead of their sync combiner unit). If you want to make this work, I would try pick up one of the Extron RGB interfaces that have picture shifting functions. If the Pippin uses front/sync/back porch timings the FM doesn't like you can alter these using the knobs on the interface.

[rama]

Yeah, the Extron would be able to fix clamping position errors.
That's probably a simple solution for the problem, and comes in handy for all kinds of situations

If you want to learn about this stuff, I'd recommend reading some analog frontend datasheets / programmers guides.
The TVP7002 is popular and has nice documentation: http://www.ti.com/product/TVP7002

[unstablewarpfield]

Would an Extron RGB 160xi suffice for this?

[unstablewarpfield]

Ok, so ever since the new firmware update on the Framemeister I have been getting good results with the Pippin! The colors are as they should be and there is no jitter in the image. Still the Kenzei stays sketchy as a sync combiner to say the least. I feed power to it through a 9V powerbrick as recommended. The strangest thing is that when I switch over to my Colecovision I need to run the Kenzei without that power added or I get no image through the framemeister. An extron RGB interface is on the way so I hope it will solve my VGA problems and I can move on with my life

[unstablewarpfield]

In the mean time I have received an Extron RGB 160xi. I tried to plug in the Pippin and my little LCD test tv refused to work. It showed me a pure white screen with a vertical black bar more or less in the middle. Thesame happened on my VGA modded Colecovision. I decided to plug it into my framemeister on my main (samsung LED) gaming TV and lo and behold... it worked on both consoles, but not the way I want it to.

The screen shows signs of a wavy pattern on the edges where colors meet. Most visible on the sides of the screen and on text and rolling slowly up untill they stop and roll down, only to repeat this pattern. No matter what settings I try on the Extron (I also checked the jumpers inside) I can't get it right. On top of that, my Hydra scart switch really doesn't like the signal the Extron spits out. Directly into the Framemeister it is fine, but with the Hydra in between I get a weird screen on my Coleco, and no image on the pippin.

As far as I see it, there is only one solution I have left and that is to sell my Extron and my VGA/Audio switch and go for two seperate Kenzei sync combiners, each one dedicated to it's own console and configured for it to work. That way both consoles would work fine without me having to fiddle around the back of the tv to set it up for one or the other. In the future I might add a third one with a loose vga cable connected for VGA upgraded hand helds like a Lynx or a Game gear.

I really had high hopes for the Extron because of the many positive stories I always read about this equipment. Feels a bit like having to start all over again