nfg.forums

NFG Forums => RGB + Video Discussions => Topic started by: l_oliveira on May 15, 2008, 02:26:08 PM

Title: Mega Drive / Genesis 1 S-Video mod
Post by: l_oliveira on May 15, 2008, 02:26:08 PM
Is there any interest on this ?


TV2008051501090400.jpg  <- CVBS
TV2008051501092500.jpg  <- SVIDEO
Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: Endymion on May 16, 2008, 07:06:14 AM
Absolutely! We've discussed Genesis S-video mods here before but show us what you've put together. :)
Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: blackevilweredragon on May 16, 2008, 08:30:07 AM
I use Component video.  :p
Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: Richter X on May 16, 2008, 02:36:58 PM
I'd love to get my hands on a chip that can do both S-Vid and component. It seems very strange that most of them out there will do YCrCb internally, but then they downconvert that to S-Video.
Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: l_oliveira on May 17, 2008, 06:49:58 AM
Right now I tried to hook the CXA1145 "directly" to the TV (using the same interface circuit as I would use for a CXA1645) but turns out that certain luminance levels cause image distortion. At the moment I am researching on the best way to isolate the output from the CXA1145 chip.

As you could see on the pictures, the luminance levels on the Mega CD screen were not high enough to cause issues. As a game is started the "Licenced   or manufaturated by Kabushiki Kaisha SEGA enterprises" screen distorts due to the white background. It stabilizes once it turns black.

I'll post the circuit and pictures once it's complete.
Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: l_oliveira on May 17, 2008, 04:13:26 PM
Turned out this stuff has been done before. I scrapped what I've done and did this S-Video mod:
The RF Modulator was removed and the S-Video connector took it's place.


http://www-unix.ecs.umass.edu/~dhowland/mod/

This is how my video looks like now:

TV2008051702112000.jpg (Composite Video)
TV2008051702112900.jpg (S-Video)
Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: blackevilweredragon on May 18, 2008, 02:53:13 AM
you uploaded the same file twice.

but anyway, i think the component video mod has been more interesting to me anyway, though the most expensive..  but the results are spectacular.


Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: Tiido Priimägi on May 19, 2008, 03:44:48 AM
The component thing is not really a mod... just a pre made RGB to Component converter which you hook up to your RGB outputting device... but it is the best choice for people without RGB inputted TVs... I want something that works the other way, Component to RGB...
Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: blackevilweredragon on May 19, 2008, 09:19:43 AM
It's as much as a mod as the S-video one is, since the VDP is RGB only.  You should know this.

An encoder is an encoder.  One is internal, one is external.
Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: l_oliveira on May 19, 2008, 11:40:54 AM
1st-  composite
2nd- s-video

Now properly uploaded.

You might laugh but I don't have a TV set with component video input. So I'm pretty satisfied with S-Video...
Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: Vertigo on May 24, 2008, 10:03:48 PM
I hate to gloat but... oh the joys of having a SCART socket on my TV :)
I've been RGB on my Megadrive since the mid-90s and very happy thanks.
Title: Re: Mega Drive / Genesis 1 S-Video mod
Post by: Tiido Priimägi on May 25, 2008, 05:37:41 AM
unfortunately US people had to be happy with the oh so good composite and RF... I hate FC and their clones... no RGB of any kind !!!