Where can I tap a sync signal for s-video?

[thesteve]

thats an odd configuration, as the Cb,Cr is interleaved in the chip (even if mixed externally)
all 4 signals come out inverted and are fed in to an inverting amp and then a buffer/driver

[Bonknuts]

Now all you need to do is separate Y from sync on the Y+sync line, scale Y down my 92.5% then shift it back up into place (IRE 7.5). Then you'd have true brightness scaling that the Japanese experienced with their NTSC TVs and Japanese consoles. 

 They didn't bother fixing the IRE 0 vs IRE 7.5 issue when they brought out the TG16 and Duo. What does it mean? Makes the brightness of the all the colors closer together, rather than spaced apart. They blend a little better in relation to each other. Of course, that would be over the top or best of the best mod setups. Doubt people are really that ana.. err picky.

[lastcallhall]

These look to be taken from a capture card. Is all that jpeg compression noise coming from there, or can you reduce that somehow?

They are indeed taken from a capture card. But notice the noise on the composite side over the s-video - that makes me think you can clean the composite signal up a bit. I'm out of parts for this stuff ATM, so I'll be submitting an order to digikey shortly to get everything I need to test this out a bit more.

RE: Cleaning and inverting pure Y/C - That would still be a relatively small circuit to construct, no? I wonder how much better the signal would look, and if it's worth it.

[thesteve]

it would depend on the monitor
on some you will get a color mark on hard lum transitions white to black black to white ect, others wont see it at all.
the simplest way is a 2 channel video op amp

[Keith Courage]

Awesome info, I will be trying this out myself at some point once I buy the needed materials.

[thesteve]

if you have any scrap boards around you have the parts

my next task is composite from the express (without an encoder)
I have lum now

[Keith Courage]

Pardon me for being stupid but I don't quite understand the diagram. What is pin 40 and what does it do? Which pins on the transistor get wired up and where to? Also, what is the part marked with a 100 coming off of the transistor?

[ApolloBoy]

Pardon me for being stupid but I don't quite understand the diagram. What is pin 40 and what does it do? Which pins on the resistor get wired up and where to? Also, what is the part marked with a 100 coming off of the transistor?

Pin 40 is luma (brightness) on the HuC6260 chip. On the transistor (not a resistor), assuming it's a standard 2N3904, you wire up the middle pin (base) to pin 40 on the HuC6260, the left pin (emitter) goes to a 100 ohm resistor and then to the luma pin on your S-video jack, and the right pin (collector) goes to 5V, which can be found on the HuCard slot or various other places on the board.

For chroma (color), take the composite video signal, wire it up to a 0.001 uF ceramic cap, and the other end goes to the chroma pin on the S-video jack.

[Keith Courage]

Thank you very much. That makes a lot more sense. I was looking around the internet trying to figure out what the hell pin 40 did. So does this mean no video amplification of any kind will be needed for this to work or does it still output a week signal?

[thesteve]

the transistor is your video amp for pin 40
your taping chroma from amplified composite, so no amp needed

[Keith Courage]

Quite the badass setup. Thanks for the help. I'll get around to doing this on my duo-r in the next couple days I hope.

[Keith Courage]

So both the composite sync and pin 47 from the RGB go to the same pin on the S-video jack? Maybe I am just confused as to where the RGB signals go?

[SignOfZeta]

You aren't using the RGB signals.

[Keith Courage]

Ha yeah, I just figured that out. I just spoke with the steve. I was looking at the completely wrong diagram online. http://jrok.com/hardware/RGB_diagrams/video_output_wiring_v31.jpg

I got it all wired up nicely now. Even made a nice mounting place for it on my DUO-r. Thanks again steve.

[lastcallhall]

Ha yeah, I just figured that out. I just spoke with the steve. I was looking at the completely wrong diagram online. http://jrok.com/hardware/RGB_diagrams/video_output_wiring_v31.jpg

I got it all wired up nicely now. Even made a nice mounting place for it on my DUO-r. Thanks again steve.

Where did you put yours? I've been looking over my Duo-R and can't decide on a location.