S-Video modded CDX and all 3 Genny systems too!

[D-Lite]

First off, thanks to Segasonicfan for the FAQ on the CDX.  I published it at my website now too:
http://www.aloofhosting.com/dragsy/CDXFAQ.html
(all links may need to be cut and paste)

So, I've done it.  Did the CDX S-Video mod using the "Neo Geo AES" style, transistor based mod.  Details here:  http://www.aloofhosting.com/dragsy/CDX.html

Pics of the system and comparing output from composite and S-Video:


More S-Video comparisons here:  http://www.aloofhosting.com/dragsy/SegaSVid.html

More pics can be found at the links above.  Basically, I had to cut part of the battery compartment out and squeeze everything in there.  Ain't easy.  Especially with the rather large power board there too.

Did the S-Video and various other mods too:

[Guest]

You can see the reds dont bleed like composite, but i cant help but notice your colors are lot more darker! Slap a cap on that C?

[NFG]

I was wondering, D-Lite, why don't you use a mini-DIN connector instead of the RCA+S plugs?  Minimize the external changes, reduce the risk of error by drilling one hole instead of four, and make a custom cable for it.

[D-Lite]

You can see the reds dont bleed like composite, but i cant help but notice your colors are lot more darker! Slap a cap on that C?

You're not seeing the colors as darker, you're seeing them correct.

A typical effect when going from composite to S-Video quality is that the brightness is much more reasonable.  With Sega Genesis and Turbo Grafx games (to a lesser extent), the composite video is always too bright and the contrast is shot.  The reason the image looks darker is that the parts that should be darker are.  Look at the other shots on my website, in particular the shot of Ryu's head.  You'll see that the lighter parts are lighter and the darker parts are darker in the S-Video, yet the composite image is washed out.

[D-Lite]

I was wondering, D-Lite, why don't you use a mini-DIN connector instead of the RCA+S plugs?  Minimize the external changes, reduce the risk of error by drilling one hole instead of four, and make a custom cable for it.

It's a good question Lawrence and the answer is practicality.  Basically, I want Joe Enduser to be able to simply plug in standard cables and not have to rely on bring a custom cable with them to a friends or losing the cable even.

Plus I've done so many holes now that that's the easy part.  But yes, it does take up more space.

[NFG]

I have a devil of a time trying to drill holes in a straight line, I'm absolutely useless at it.  It's very easy to do one in a row, but two or more is tricky.  

I used to use DB9s until I realized round holes were 100x easier to make than trapezoids.  Use a 10pin mini-DIN and wire it to Saturn spec, then use off-the-shelf cables.  Helps that I've got dirty cheap access to used saturn cables.  Rah rah Japan.  

[Guest]

hey thanks for the mention or you site and the post of my FAQ  You did a fantastic job with those S-Video mods.  I'll be posting my portable CDX monster on yahoo photos...it should be all done within the next week or so.  Great site, keep up the good work!

-Segasonicfan

[Segasonicfan]

Also,  you can use my FAQ to do a CDX 50/60 hz mod and JP/US mod.  If you need any help with the details let me know, I have already had one installed on my CDX and it works perfectly

Where did you get the ECG-85s for your S-Video mod?  I can't get the future active page to load...  If you could maybe explain to me how you did the mod that would really be helpful as the Neo Geo one is confusing me by talking about the LS273 chips and such (??)  I just need a basic parts list and run through of the mod...I'd really appreciate it.

Also, looking through my CDX FAQ I noticed there are many more errors than I thought.  Since you found it so benefficial I'll write up a revision of it (including right side up screw placing lol) and send it to ya when I get a chance

[fragment]

can you provide a link that shows hot to s-video mod a genesis 2? I just saw photos on those links. Great job!

[omnedon]

I was under the impression that the Genny 2 S-vid mod was the same or similar circuit to the Neo mod.

I was planning on trying it myself soon.

I'd love to be able to S-vid mod a 32X, but I fear it's impossible, since it utilizes a composite video pass thru from the Genesis itself.  :blink:  

[Segasonicfan]

no, it doesn't feature composite pass through.  It connects to the Genesis' RGB Lines, so S-video should be possible, although challenging for sure.  I have a nicely working RGB output for mine though

[D-Lite]

I was under the impression that the Genny 2 S-vid mod was the same or similar circuit to the Neo mod.

I was planning on trying it myself soon.

I'd love to be able to S-vid mod a 32X, but I fear it's impossible, since it utilizes a composite video pass thru from the Genesis itself.  :blink:

It depends on the video encoder on the board.  You have what seems to be a 50/50 chance of getting either a CXA1145 or a KA2195D, the latter of which is useless for the mods.

@Segasonicfan, RGB, hmm?  Now I'll have to revisit this.  Only problem is squeezing an encoder in the 32X will be a massive screw job.

[omnedon]

So, let me make sure I've got this straight, if the Genny has a CXA1145, you're good to go with the Neo style mod. If it does not are there alternatives? Can the  chips that aren't SONY be tapped differently?

The RGB out of the 32X Segasonicfan, is that a cable/ decoder thing, or an internal mod?

I'm still learning about these circuits, and it's fascinating. I appreciate you guys sharing your hard won knowledge on this stuff.

S-Video modding a CDX looks like nightmare time to me. I've repaired a couple of CDX's, and it is so incredibly tight in there. Good God.  :blink:

[NFG]

squeezing an encoder in the 32X

There's a load of space where the batteries go, how many of us will miss that portable-CD functionality?  Shove all the extras in there. =D

[D-Lite]

squeezing an encoder in the 32X

There's a load of space where the batteries go, how many of us will miss that portable-CD functionality?  Shove all the extras in there. =D

I think you mean the CDX battery compartment, which is where I stashed the S-Video circuits.  But remember you still need to fit the RCA/S-Vid mounts (yes I know you use an 8-pin din, blah blah), and also you have only about half the depth since the power board is fairly large and the cart slot door hinge is in there too.  Pretty f'n tight fit.

[Guest]

Actually, 32X is far simpler than you guys realize.  Looking at the simple A/V pinouts here on GameSX you can see the RGB outputs (same as Gen, Nomad, Genesis 2, CDX, etc.)  All I did was simply wire these to a D-SUB 9 output.  The cable that is  Genesis -> 32X has all the RGB lines, so there's no problem there.  Just connect that cable and make a hole for an RGB output.  I've already tested it in conjunction with my CDX, it works perfectly

D-Lite, could you please respond to my earlier questions concerning the S-Video mod?  Future-Active.com doesnt sell those 3 pin transistors needed for the mod.  If you could tell me how you performed it I would be very grateful.

In addition, I need your email again.  I have finished a revision of the CDX FAQ that makes a LOT more sense.  Let me know your email so I can send it to ya

-Segasonicfan

[captainmorgan]

So okay, I've been reading these forums for a bit now, and some other things on the 'net, and decided to try the s-video mod on my CDX. So I built the little circuit and tried it out. No luck. So I thought to myself, "Okay, I dont really want to ruin anything and loose my precious CDX". So I took it off, and put everything back together.

NO VIDEO!

Thing starts up, and if I have Sonic CD in I can see the title screen, but the colors are all wrong and the vertical hold is all messed up!

Would someone be willing to do a repair, or know of a place that I could get it fixed at? The video chip is the MB3514, which is more than likely fried.