YPbPr ouput mod for SNES consoles

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Pasky
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Re: YPbPr ouput mod for SNES consoles

Post by Pasky » Thu Apr 04, 2013 7:47 pm

Just bought a later model snes (motherboard says SNS-CPU-RGB-02) and it has a S-RGB encoder chip. I was a bit disappointed upon seeing this, but thought I'd double check. It's not possible to get Component out using this encoder is it?

If anything I got the superior video on this snes so RGB -> Component may not be such a bad alternative. I just don't have a scart to component converter yet.

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kriskizlyk
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Re: YPbPr ouput mod for SNES consoles

Post by kriskizlyk » Fri May 31, 2013 2:06 pm

Thanks everyone for the ideas here...I tried the amp with the 2n3904 transistor and it was a bad idea as the picture at the top of the screen would heavily distort.

I got so frustrated and went straight back to the basics of what kyuusaku had mentioned right at the start of this post. So lets do this one right...and I am mostly looking for peoples opinions, especially kyuusaku's, about my circuit that I have posted. I think I have covered most of the angles but I feel like I am missing something. I could possibly throwing in some POTS instead of resistors for tweaking of the color, and a variable cap on the output. Once I have enough opinions I will order some parts and start testing this baby out.

Once this is finished I would like to mass produce professional circuit boards as the ease of cost comes in mass production (10 minimum for the best price break)! This means I would be more than willing to pass on my extras to whom ever is wanting a copy of the board. Lastly, I do not plan to sell this design or make money off it as I strongly believe it should be completely open source.
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mikejmoffitt
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Re: YPbPr ouput mod for SNES consoles

Post by mikejmoffitt » Sun Jun 02, 2013 7:34 am

I also want to point out that while the 1CHIP revision of the SNES definitely offers the clearest video, be it RGB, S-video, or composite, I've noticed that the ones I have had with the BA6295 and component capability have much sharper rising edges on the aforementioned analogue outputs compared to the SNS-RGB-0X revisions.

Once we have this component business sorted out, let's try to work on a fix to get the SNS-RGB-0X revisions looking good.

Pasky
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Re: YPbPr ouput mod for SNES consoles

Post by Pasky » Sun Jun 02, 2013 7:51 am

The SNS-RGB revision 1's all appear to have jailbars, at least all 3 of mine do, they're most noticeable when using RGB. The jailbars seem to be a result of the encoder. The SRGB 2 found on 1Chip Snes's including the mini's seems to have fixed the issue.

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mikejmoffitt
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Re: YPbPr ouput mod for SNES consoles

Post by mikejmoffitt » Mon Jun 03, 2013 10:49 am

Pasky wrote:The SNS-RGB revision 1's all appear to have jailbars, at least all 3 of mine do, they're most noticeable when using RGB. The jailbars seem to be a result of the encoder. The SRGB 2 found on 1Chip Snes's including the mini's seems to have fixed the issue.
I've noticed 1px-wide every other pixel jailbars on the RGB outputs of the SND-RGB revisions, but not through s-video or composite. Through all of the formats, the smeared video can be seen.

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kriskizlyk
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Re: YPbPr ouput mod for SNES consoles

Post by kriskizlyk » Wed Jun 05, 2013 7:38 am

My parts from Digikey have arrived! I have built the circuit designed above and something just wasn't right. I realized then that I forgot the DC decoupling capacitors on the input resulting in the video only showing Black and White. The black and white was prevalent because I was saturating the Pr and Pb video so much that it was clipping off all the signal on the output...I did this once before in a OpAmp lab back in the day.

Now, one thing I am not quite sure about and probably because my lack of knowledge with video signals...I am using 0.1uF plastic cap for the "input capacitors" and the images are sharp but solid Red Blue and Greens "runs" (runs, similar to when you put a red sock in white laundry) horizontally across where the image is present. When I increase the capacitance to 10uF tantalum the colour "runs" start to fade away but the video is now less vibrant...however the vibrancy loss is minimal. Too much capacitance, 220uF, and the vibrancy is lost, I am sure this has to do with good old AC theory...as capacitance increases so does resistance in high frequencies. I am sure there is some "magical input voltage level" that I am looking for...however I do not know what it is and 10uF seems to be the ticket. I did see people mention that 1.6Vrms was a favourite number.

What I really need is a capacitor set! I will buy some more capacitors with different values and shoot for this voltage level. I have also seen people sticking in a 1M ohm resistor in parallel after the capacitor. The good thing about that is it is a high pass filter and you can adjust a resistor easier than a capacitor, bad thing is your creating a filter and potentially degrading/distorting the video where the cut-off frequency is if you design it wrong.

More to come...
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kriskizlyk
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Re: YPbPr ouput mod for SNES consoles

Post by kriskizlyk » Wed Jun 05, 2013 11:24 pm

Well, the amplifiers work fine...I used 4.7uf on the input and no problem.

My biggest issue now is the Y component, Luma. Its distorted, I am at a loss for what I should do now as the exact same thing is happening with the transistor amp that I tried earlier in this forum. It appears very clear in the middle but as the screen gets closer to the top or bottom the whites and blacks seem to get very jagged on objects. I have nailed it down to my receiver at this moment and not the circuit. It has something to do when it sends it out via HDMI to the projector since straight into the projector...works flawlessly. This is kind of lame as then it defeats the purpose of having HDMI and now I have to run a component cable to my projector. Oh well...the Retron 5 will be coming out later this year and it has HDMI out...so it may possibly be exactly what we all have been waiting for.

Ok, I will update my circuit and post it to the forum when I am finished.

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kriskizlyk
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Re: YPbPr ouput mod for SNES consoles

Post by kriskizlyk » Sun Jun 09, 2013 2:23 pm

Ok, my final circuit is complete, tested and off to the board manufactures. I did some final tweaks just for my purposes but, all in all...here you go. I will post pictures of the board when it comes in roughly a month from now.
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whicker
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Re: YPbPr ouput mod for SNES consoles

Post by whicker » Sun Jun 09, 2013 10:22 pm

kriskizlyk wrote:Oh well...the Retron 5 will be coming out later this year and it has HDMI out...so it may possibly be exactly what we all have been waiting for.
I've seen a functioning Retron 4 (5) test hardware and empty plastic case.
Yes the HDMI was working as expected (barring some trash lines).
The genesis game they were predominantly showing was rock solid.

Either NES or SNES was working, but I don't recall more than the title screens.
I never saw the GBA/GB portion working. Nor the save system. Nor the menu system other than exiting and launching a game.

What I'm saying is, while I think that overall it's a great progression of a clone system, where they're actually trying to make it correctly by using good plastic and proper engineering principles, and striving for 100% compatibility, they have fallen into the trap where they haven't given a realistic time estimate.

So please, just carry on what you're doing. It'll be out when it's out, and may or may not do absolutely everything they and their focus group wanted, but yes it'll totally have HDMI and wireless controllers.

I think this system is part emulator (fpga?) because with their other consoles it was getting to be extremely difficult to source some of the chips. I hope they don't get roasted for this for using custom hardware, because of inevitable higher projected price tag.

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marvelus10
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Re: YPbPr ouput mod for SNES consoles

Post by marvelus10 » Tue Jun 11, 2013 7:22 pm

whicker wrote:
kriskizlyk wrote:Oh well...the Retron 5 will be coming out later this year and it has HDMI out...so it may possibly be exactly what we all have been waiting for.
I've seen a functioning Retron 4 (5) test hardware and empty plastic case.
Yes the HDMI was working as expected (barring some trash lines).
The genesis game they were predominantly showing was rock solid.

Either NES or SNES was working, but I don't recall more than the title screens.
I never saw the GBA/GB portion working. Nor the save system. Nor the menu system other than exiting and launching a game.

What I'm saying is, while I think that overall it's a great progression of a clone system, where they're actually trying to make it correctly by using good plastic and proper engineering principles, and striving for 100% compatibility, they have fallen into the trap where they haven't given a realistic time estimate.

So please, just carry on what you're doing. It'll be out when it's out, and may or may not do absolutely everything they and their focus group wanted, but yes it'll totally have HDMI and wireless controllers.

I think this system is part emulator (fpga?) because with their other consoles it was getting to be extremely difficult to source some of the chips. I hope they don't get roasted for this for using custom hardware, because of inevitable higher projected price tag.
Apparently it is Android based emulation.

sazyario
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Re: YPbPr ouput mod for SNES consoles

Post by sazyario » Sun Jul 14, 2013 7:29 pm

Hey everyone!
So... I know a lot of you guys are working on technical things to try and make the best possible YPbPr mod.

I am looking for a "Its simple and works" mod.

I just tried taking the 3 Pins off of the S-ENC (9328) encoder chip to RCA jacks and got a white washed picture that shakes on my Plasma TV.

Can anyone help me?

I know that for Green/Y I need to take it off of Pin 7 from the AV Multiout. (Should fix the white washed image)

But as far as Red and Blue go I'm lost to what to do. There are so many differing ideas in this thread I'm lost.
I'm hoping that putting either a 10uF or 220uF cap plus a resistor on the Red and Blue lines will work.

Please anyone help? Other than my image being whitewashed(Which I know how to fix now) and shaking... I liked what I seen.

Is there any way to kill the image shaking?

lidnariq
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Re: YPbPr ouput mod for SNES consoles

Post by lidnariq » Mon Jul 15, 2013 11:09 am

sazyario wrote:I am looking for a "Its simple and works" mod.
Is there a reason you're skipping the very simple RGB out?
Most editions of the SNES natively have RGB on the AV multi-out connector on the back.
If yours doesn't, http://gamesx.com/wiki/doku.php?id=av:snes2rgb
and http://gamesx.com/wiki/doku.php?id=av:nintendomultiav

The shaking is because you weren't providing a proper sync signal. Once you switch to s-video luma it should work.

tepples
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Re: YPbPr ouput mod for SNES consoles

Post by tepples » Mon Jul 15, 2013 11:23 am

I'm guessing that some TVs require RGB input to be at least 350p (EGA res), while YPbPr input can be 480i. Some TVs, like my VX32L, support 240p S-Video and 480i YPbPr but not 240p YPbPr. I'd recommend just using a GameCube S-Video cable; at 5.4 MHz dot clock, there isn't much of a difference between S-Video and either flavor of component.

sazyario
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Re: YPbPr ouput mod for SNES consoles

Post by sazyario » Mon Jul 15, 2013 4:59 pm

lidnariq wrote:
sazyario wrote:I am looking for a "Its simple and works" mod.
Is there a reason you're skipping the very simple RGB out?
Most editions of the SNES natively have RGB on the AV multi-out connector on the back.
If yours doesn't, http://gamesx.com/wiki/doku.php?id=av:snes2rgb
and http://gamesx.com/wiki/doku.php?id=av:nintendomultiav

The shaking is because you weren't providing a proper sync signal. Once you switch to s-video luma it should work.
I'm not using RGB because my TV doesn't have a SCART input.
I'm NTSC-U. The best I can do is Component and none of my TVs have S-VIDEO.
Hence why I'm doing the Component Mod.

lidnariq
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Re: YPbPr ouput mod for SNES consoles

Post by lidnariq » Mon Jul 15, 2013 8:09 pm

A TV with component but not S-Video? That's confusing. (But I believe you, I'm just confused by it)

A s-video to component converter might be reasonable? Google seems to suggest DVD recorders are probably the cheapest way to get the encoding converted.

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