The sega 32x, s-video modded

[Drakon]

I recently decided to buy a mega everdrive since krikzz finally started making flash carts that use ram chips therefore the thing will basically last forever. Since the mega everdrive can play 32x roms I bought myself a cheap 32x from ebay (something like 35$ shipped). I didn't get any cables so I was planning on just wiring the system up myself. I asked tiido a lot of questions about what's needed to get it running and it's pretty simple.

After cracking the system open and doing my best to understand the hardware I wired up everything by rgb and externally encoded the outputted rgb to s-video. The picture wasn't bad but it wasn't as good looking as I wanted it to be. I know from experience that re-encoding the rgb over and over will decrease the quality so I decided to see if it's possible to s-video mod a 32x. I found this helpful thread here:

http://www.sega-16.com/forum/showthread.php?16590-32X-S-Video-Mod

Pretty cool thread and it pointed me to where to tap s-video from the system. This thread also mentioned that you need an amp on luma to get a signal. I had a spare luma amp sitting around that I built years ago for the s-video mod on the cxa1145 that's built into my genesis. Here's the amp, just one transistor and I put a custom strength resistor to get the brightness just perfect:

http://www.jamma-nation-x.com/jammax/genesismods.html

I can't even remember what strength resistance I'm using I built that thing so long ago. Anyway wiring up this amp made it work so now I had s-video coming from the 32x. The chroma line didn't need any parts I could just straight wire it. However something was causing the luma to be blurry, like composite quality blurry. After talking to tiido and experimenting a bit I managed to fix the blur. Here's a before and after screenshot:

yeah uhh....night and day. For the sake of comparison here's screenshots of the s-video from a cxa1145 and from a cxa2075 circuit.

These are of course from my capture card that picks up EVERYTHING. For some reason when my cxa2075 circuit is plugged into the system the image flickers....even when I'm getting rgb from the cxa1145. As soon as I unplug my cxa2075 circuit the flickering goes away...oh well.

On my tv however the 32x'ified picture looks perfect. The jailbars are 100% gone, and what's left of the rainbow banding is just as strong as it was from my cxa2075 circuit (so weak it's not annoying at all). Also the colours look better for some strange reason. Therefore I like how it looks on my tv more than the image from my cxa2075 circuit. Also to weaken jaiblars on my cxa2075 circuit I had to branch off a long s-video cable to ghetto filter them and it was annoying. With the 32x I don't need to do any tricks it's just jailbar free....and it plays 32x games!

Here's some pictures of my rig

Why buy expensive cables when I can build one out of old IDE cables

 

[Drakon]

5 minutes of 32x s-video eye candy

 

[ttsgeb]

I approve. Makes me want to grab another sega that much more.

 

[wolborg]

Wow! I'm very impressed.

 

[Drakon]

Thanks! This's as good as s-video will ever get out of a genesis / 32x.

 

[clarky]

Picture looks very good quality as per usual Drakon. Would this mod also work on the Mega CD?

I'll be contacting you very soon with the hopes of you giving me a bit of advice on my Mega Drive producing a poor picture on my LCD.

 

[Drakon]

I have no clue how the megacd mixes its video but if the megacd doesn't have an "av out" port then these fixes should A with it too. My fixes A on anything that's coming out of the genesis av port or the 32x av out port. I actually recently did a rgb jailbar fix that worked great when encoding the rgb to component video. Today I won a usb component capture device for a good price on ebay so when that shows up I'll be able to take a better look. I was able to capture the luma line from the component output on my s-video capture device since s-video and component both have a luma line:

Think of this as a "preview" of my next mod assuming it all works out okay.

Looks good so far just need to wait for my component capture device to show up to see how the colour lines look. There's a few known tricks to clean up a bad rgb picture. The first trick is just a bad video cable that's just got your tv stuck between rgb and composite so it displays both at once if you're using a scart tv. The second trick is bit more nuts it involves lifting pin 50 of the vdp chip off of the genesis pcb. I learned the vdp pin 50 trick from some thread on assemblergames where they were trying to remove rgb jailbars. Lifting vdp pin 50 will remove the ability to have colour in s-video, composite, and rf from the genesis. However when encoding the rgb to component I had weak jailbars but when I lifted vdp pin 50 the jailbars completely went away so it certainly does work!

 

[superben51]

Makes me want to grab another sega that much more.

Thought I left my word censor on..... Lol'ed pretty hardcore.