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NFG Forums => RGB + Video Discussions => Topic started by: Talasonic on January 21, 2004, 02:47:43 AM

Title: RGB -> S-video
Post by: Talasonic on January 21, 2004, 02:47:43 AM
Does anybody make such a conversion box?  

It almost seems like you could build one yourself, using just op-amps, and both the RGB and composite outputs on any deck:
luminance=R+G+B
chrominance=composite-luminance

How does this sound?  Unless the timing were off, it seems like this should work.  No?
Title: RGB -> S-video
Post by: Talasonic on January 22, 2004, 01:56:04 AM
I'm just going to sell my main TV and buy an LCD projector.  They're light enough to ship, the price has gone to down to 200-300, and they handle RGB at 15khz so can hook the genesis right up.  Besides all that, they're of course exceedingly cool!  Of course, it's always good to have a backup TV set.  I'm going to keep a 25" s-video one.  

I may still try my idea of summing up stuff, though.  I'll certainly post if I find out anything.  
Title: RGB -> S-video
Post by: matt on January 25, 2004, 01:43:19 PM
There are various RGB->Composite encoder chips out there that'll give you S-Video.  They've all been covered in this forum at one time or another, so you can probably find them if you search for a bit.
Title: RGB -> S-video
Post by: Talasonic on January 25, 2004, 02:43:31 PM
Ok, thanks for telling me to look harder.  I found a related thread.  

Here (http://nfg.2y.net/forum/index.php?showtopic=172) is one that talks about using CXA1645 and CXA2075 chips, which apparently do the conversion from RGB to S-Video among other things.  Or, maybe they can replace another chip that might already be in the game system, and generate S-Video as well.  I'm not real clear on that part.  Anyway, they come in Genesis 3's, 10% of Genesis 2's, and playstations, apparently.  

I can't find any more at the moment.

NEWSFLASH 1-28-04
http://www.gamesx.com/rgbadd/cxa1645.pdf (http://www.gamesx.com/rgbadd/cxa1645.pdf)
http://www.gamesx.com/rgbadd/genesis3.htm (http://www.gamesx.com/rgbadd/genesis3.htm)

I just found those two on google.  I can't find any link to them from the gamesx site.  It makes me wonder how much other stuff is on here somewhere that I can't find.

Here is a circuit that does it with this chip:
http://www.nexusuk.org/projects/rgb2svid/notes.php (http://www.nexusuk.org/projects/rgb2svid/notes.php)
http://www.epanorama.net/links/videocircui...rgbsvideocvideo (http://www.epanorama.net/links/videocircuits.html#rgbsvideocvideo)

Well that settles it.  I'm buying a Genesis 3.  Talk about simple!  I mean I've never done anything as complicated as that schematic, but I'm sure I could do it.  I think most people could do it if they spend some time (and learn how to solder first).  It would be fun, anyway.  I guess I'll probably buy the projector anyway, but this will be a nice thing to have.  It's sad to scrap the Genesis 3, but oh well.
Title: RGB -> S-video
Post by: RichieB on January 26, 2004, 07:21:28 PM
www.keene.co.uk does a RGB to svideo convertor.

You cannot directly link to it, but its product code - RGB2S

Just go to "come on in", then "products".. input product code RGB2S in the box provided.. Mate of mine says it works a treat.
Title: RGB -> S-video
Post by: NFG on January 26, 2004, 07:46:02 PM
I've actually got a Micomsoft XAV-2s RGB encoder on ebay right now, coincidently enough.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...item=3072459947 (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3072459947)
Title: RGB -> S-video
Post by: Talasonic on January 28, 2004, 05:22:56 PM
Arr, Lawrence, I didn't see this.  I wish you would have emailed me.  I've actually decided to get a projector myself, but my friend might have bought it.  Actually, though, I'm glad I didn't get it since I found out how to build the circuit easily.