Heh component certainly doesn't need a colour subcarrier because the colour data is still separated, just in a different way.Quote:
Originally Posted by lumclaw
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Heh component certainly doesn't need a colour subcarrier because the colour data is still separated, just in a different way.Quote:
Originally Posted by lumclaw
It doesn't. I completely omitted the color subcarrier on my BA6592F-based RGB to Component box and still get full color.
I do wonder why S-Video and Composite need it, though. I never found out why a color subcarrier is needed.
Well color systems are ancient, intended for over-the-air TV broadcasts. I wouldn't be surprised by anything.
Something to do with timing for the colour? Because you're mixing all the colour signals into one?Quote:
Originally Posted by Ace
Picture the subcarrier like a horizontal sync for the color layer on a black and white image. Without it, the color would be waving around, yet the monochrome image is there, with funny color.
I have a tube/SS hybrid TV that had a tube go bad that was responsible for color lock of the subcarrier. It results in this scrolling rainbow color image:
http://img.photobucket.com/albums/v3.../colorlock.jpg
I know it don't look like much, but only the upper middle part of the picture is the right color.
The last. The two color channels in composite and svideo are muxed together using the color subcarrier as a modulator. That EXACT signal needs to be provided to demux the two color channels. Rather than have the signal run the entire time, they only put a small blip of it during the horizontal blank. The TV locks its own subcarrier generator to the blip provided to make sure it can properly demux the channels.Quote:
Originally Posted by Drakon
GAH!!
It was a bad resistor! Well, that, and you HAVE to tap pin 10 on the neo for sync. It won't work otherwise. As far as resistance values go, I protoboarded it with the 147 ohm, 33 ohm, and both with a 1k ohm pulldown - it makes no difference.
Problem solved. Now, for arcade quality NeoGeo goodness... :)
I've never heard of a bad resistor. I have managed bad caps somehow, and they were brand new too (or atleast I thought they were)
I measured it on my multimeter - it was pulling 1 ohm. Not much more to it than that.
Just as a note, I'm going to post an updated schematic of my circuit as I've done a few changes to it:Quote:
Originally Posted by Lastcallhall
1) The 1Kohm pull-down resistors have been relocated to before the transistors amplifying B-Y and R-Y
2) The 147ohm resistor has been replaced by a 75ohm resistor (comparing the Component output of my box to other systems I have with Component, the video was actually a bit too dark)
3) The 33ohm resistors at B-Y and R-Y have been removed
Cool, that might reduce the size and cost of the board.
Actually, it looks like I may need to use something stronger than 75ohms on Luminance as I just put together a test video to see how my DVD recorder handles 240p Component using my PC Engine Duo-R and region-switched VA3 Genesis Model 1 (and see how consoles recorded through Component look like on YouTube) and have noticed certain bright white screens are out of sync on the DVD recorder. I will have to experiment with different resistors to find the one that will give the best brightness without potentially causing sync issues (my guess is 100ohms or 110ohms).
EDIT: Still desyncs a bit with 110ohms, but only on the PC Engine Duo-R. I wonder why neither my Saturn or Genesis desync like that.
EDIT 2: I think I'm gonna pass by my local electronics shop later in the week to check for POTs to put on the Component outputs. This way, you can adjust the Component video to your liking.
Put the pot after the 75ohm resistor so that you have a minimum it doesn't go below. If you have just a pot, you could accidentally go to 0 and blow a circuit.Quote:
Originally Posted by Ace
Maybe the 33 ohm would work in this instance - that value works just fine on the genny.Quote:
Originally Posted by Chilly Willy
Yeah. The whole point is SOME kind of low resistor to keep the pot from going to 0 ohms.Quote:
Originally Posted by Lastcallhall