YPbPr ouput mod for SNES consoles (Resurrected)

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kriskizlyk
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YPbPr ouput mod for SNES consoles (Resurrected)

Post by kriskizlyk » Tue Mar 11, 2014 2:09 pm

I know the previous topic has been closed because of some people having hurt feelings and egos...whatever...keep that $hit out of this post.

I have grown a little impatient waiting for the Retron 5 as most of you have been aware because of a factory defect. Well, I can't wait any more and I want to play my Super Metroid. I have ressurected my boards if anyone has asking. I had to do a few design changes but I got it pretty much tweaked, installed, tested and fully functional circuit.

I apologize to previous people that have emailed me and contacted me about my boards and I didn't send them out. I had some family things come up personally in my life so therefore may I re-introduce my circuit. I also want to know if anyone else has tried it and what their results were.
Attachments
Zoom of my custom board.
Zoom of my custom board.
Zoom of the video chip.
Zoom of the video chip.
Full install.
Full install.

Markfrizb
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by Markfrizb » Tue Mar 11, 2014 6:50 pm

I don't know much about the component video but doesn't component video have "sync on green"?
I've looked at my tv's component and there's only 3 connections (RGB -- referring to connector colors, not "RGB").

Please educate me here if you don't mind.

Thanks.

tepples
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by tepples » Tue Mar 11, 2014 6:56 pm

Yes, S-Video and component video have sync on luma (Y).

Markfrizb
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by Markfrizb » Tue Mar 11, 2014 7:32 pm

Ah, so the colors of the connectors really don't have anything to do with "colors" on the screen.
So I see 5 connectors on this console. What functions do they all have?

lidnariq
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by lidnariq » Tue Mar 11, 2014 7:46 pm

Component video cables with RGB connectors are respectively Unredness (Y-R = Pr), Brightness (Y), and Unblueness (Y-B = Pb).

Near
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by Near » Tue Mar 11, 2014 7:54 pm

So my understanding is that most component input TVs only accept 480i, 480p + YPbPr (luma, red/blue offset.) Further, you need sync carried on the luma channel.

So how do you get 240p with the SNES' CSYNC+R+G+B lines to display on these TVs? Or do you have to shop for a very special TV to display the output of these component SNES modded consoles?

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kriskizlyk
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by kriskizlyk » Tue Mar 11, 2014 8:29 pm

Markfrizb wrote:Ah, so the colors of the connectors really don't have anything to do with "colors" on the screen.
So I see 5 connectors on this console. What functions do they all have?
Red Green Blue are the video (YPbPr NOT RBG) and the Yellow and Black are the stereo audio. Fortunately the SNES was pre-designed for future designs which allows for just a very simple 6db video amplifier.

On my circuit I did have another option to add a 6db buffer for the Luma (green) but, it is not necessary.
Last edited by kriskizlyk on Tue Mar 11, 2014 9:26 pm, edited 1 time in total.

tepples
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by tepples » Tue Mar 11, 2014 8:50 pm

byuu wrote:So how do you get 240p with the SNES' CSYNC+R+G+B lines to display on these TVs? Or do you have to shop for a very special TV to display the output of these component SNES modded consoles?
Actual RGB works through a SCART cable.

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kriskizlyk
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by kriskizlyk » Tue Mar 11, 2014 9:10 pm

byuu wrote:So my understanding is that most component input TVs only accept 480i, 480p + YPbPr (luma, red/blue offset.) Further, you need sync carried on the luma channel.

So how do you get 240p with the SNES' CSYNC+R+G+B lines to display on these TVs? Or do you have to shop for a very special TV to display the output of these component SNES modded consoles?
From my knowledge the signal that comes out is a Standard video signal and therefore Nintendo has to follow a certain spec, a set of rules, so that it is Universally comparable on every YPbPr device. We are talking the good old Analog world and the circuit I designed is a simple standard video amplifier to bring it back up to spec so therefore you don't need a special TV or Receiver or need to worry about the resistance in the cables blah blah blah. A company already designed the interface chip, boom, tossed it in works great. I have heard of other people using transistors...meh...this chip was designed specifically for what we are trying to achieve. To answer your question, NO you don't need a special TV. I hooked this up to my projector and it works fine. You DEFINITELY can tell the difference the picture is noticeably sharper and more vibrant.
Last edited by kriskizlyk on Tue Mar 11, 2014 9:25 pm, edited 1 time in total.

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kriskizlyk
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by kriskizlyk » Tue Mar 11, 2014 9:23 pm

tepples wrote:
byuu wrote:So how do you get 240p with the SNES' CSYNC+R+G+B lines to display on these TVs? Or do you have to shop for a very special TV to display the output of these component SNES modded consoles?
Actual RGB works through a SCART cable.
Quoted from AVS...

You could do a search and learn the technical differences. (RGB is certainly not crap) In an easy nutshell. YCbCr is a consumer video format and this is the way HD is encoded. RGB is the traditional computer format. One is not superior to the other because each has it's own strengths and weaknesses. YCbCr is preferred because it is the native format.

lidnariq
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by lidnariq » Tue Mar 11, 2014 9:39 pm

kriskizlyk wrote:From my knowledge the signal that comes out is a Standard video signal and therefore Nintendo has to follow a certain spec, a set of rules, so that it is Universally comparable on every YPbPr device.
The point byuu was asking was about 240p vs 480i. Most of the time the SNES produces 240p video.
240p is not standards compliant, and the vast majority of HDTVs (to the best of our knowledge) don't detect it and incorrectly try to deinterlace it.

Even worse than just ordinary deinterlacing is that a lot of HDTVs use sophisticated "3d" deinterlacing that imposes a 100-500ms delay on video frames that go through it. That's sorta ok for RPGs, but not so fantastic for anything remotely caring about reaction time.

For more details, see the 240p test suite, a little homebrew for the Genesis (and its documentation).
kriskizlyk wrote:YCbCr is preferred because it is the native format.
The SNES is actually native RGB. The BA6592F/S-ENC/S-RGB IC first converts RGB to YPrPb and then uses that to form s-video and composite.

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kriskizlyk
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by kriskizlyk » Tue Mar 11, 2014 10:05 pm

Taking pictures without a tripod sucks...anywise. I took some pictures with the circuit. I am saturating the reds a little too much because you can see a little distortion of color on the top. Simple fix... I didn't have the exact components in surface mount than I did with through hole...I would have to order some. The edges are much much smother around images. The pixels are sure noticeable on a 144 inch screen.

Bah, I will do this again for you and get a better tripod and the proper capacitors...but this is the teaser.
Attachments
combined 2.jpg
combined.jpg

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kriskizlyk
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by kriskizlyk » Tue Mar 11, 2014 10:42 pm

lidnariq wrote:
kriskizlyk wrote:From my knowledge the signal that comes out is a Standard video signal and therefore Nintendo has to follow a certain spec, a set of rules, so that it is Universally comparable on every YPbPr device.
The point byuu was asking was about 240p vs 480i. Most of the time the SNES produces 240p video.
240p is not standards compliant, and the vast majority of HDTVs (to the best of our knowledge) don't detect it and incorrectly try to deinterlace it.

Even worse than just ordinary deinterlacing is that a lot of HDTVs use sophisticated "3d" deinterlacing that imposes a 100-500ms delay on video frames that go through it. That's sorta ok for RPGs, but not so fantastic for anything remotely caring about reaction time.

For more details, see the 240p test suite, a little homebrew for the Genesis (and its documentation).
kriskizlyk wrote:YCbCr is preferred because it is the native format.
The SNES is actually native RGB. The BA6592F/S-ENC/S-RGB IC first converts RGB to YPrPb and then uses that to form s-video and composite.
Noted. You obviously know more than me and thank you for clarifying.

Near
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by Near » Tue Mar 11, 2014 10:55 pm

> Actual RGB works through a SCART cable.

Obviously. I have a Sony PVM that I output raw RGB to through a SCART adapter.

I was inquiring about using the SNES with a component input TV.

> 240p is not standards compliant, and the vast majority of HDTVs (to the best of our knowledge) don't detect it and incorrectly try to deinterlace it.

This, and color. I've read that most HDTVs don't accept R/G/B lines through component. They only accept Y/Pb/Pr. They are not equivalent at all. The SNES doesn't output in Y/Pb/Pr format on the MultiAV pins, which seems like a problem for directly connecting it to an HDTV.

> The BA6592F/S-ENC/S-RGB IC first converts RGB to YPrPb and then uses that to form s-video and composite.

Ah, okay. So this chip lets you capture the raw Y/Pb/Pr before it's merged into S-video and composite? Neat.

So with that out of the way, the only issue is finding an HDTV that definitely handles 240p properly. Kind of a shame there's not more in the way of cheap, no-latency line doublers. (you can do it, but that stuff gets so expensive ... culminating in the $500 XRGB Mini.)

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kriskizlyk
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Re: YPbPr ouput mod for SNES consoles (Resurrected)

Post by kriskizlyk » Wed Mar 12, 2014 7:20 am

Sure this is not direct RGB, however doing RGB was not my goal. My goal was to just simply just picked up YPbPr circuit buffered it and put it out. If anyone wants to go deep into it Google has many solutions to creating a RGB to YPbPr converter. For example LT has a LT1395 that will do it for you. With your help of course, I could re-design and create the circuit, run it through my buffer and post my results...only if people enough people are interested. Retrorgb suggests that you use a THS7314DR.

Here is the link http://www.linear.com/solutions/1312 and the circuit.

I got most of my ideas from...http://retrorgb.com/snesminirgb.html, they have modified the SNES mini which has the best output...RGB
Attachments
rgb to ypbpr convertor.jpg

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