Great comparison between Mega Drive - Genesis RGB output.

[Syntax]

So why has no one lifted the subcarrier legs on both chips and connected them via a shielded cable whilst grounding the original subcarrier trace to determine if it's a trace design fault?

I'd do it but I removed my encoder completely and can't remember the cap resistor values.

[FBX]

So why has no one lifted the subcarrier legs on both chips and connected them via a shielded cable whilst grounding the original subcarrier trace to determine if it's a trace design fault?

I'd do it but I removed my encoder completely and can't remember the cap resistor values.

Voultar's interview shows him stating it is the traces on the board causing the issue. This was proven to be the case when nakedarthur tried lifting pin 6 and it had no effect on the jail bars. Then when he cut from pin 50 on the VDP side, it worked perfectly. Furthermore, you can actually see the blue trace runs right next to the subcarrier trace on much of its path. Now I should point out this is specifically on these early North American console revisions like the VA2 and VA3. I'm not sure it would be the same case for later revisions.

[Syntax]

You can't really prove it's a trace without rewiring it and checking functionality. Also it would help prove the internal coupling theory wrong if reconnected shows no bars.

I'd much rather find a cure than a dodgy trace cut or pin lift which kills functionality.

[FBX]

I'd much rather find a cure than a dodgy trace cut or pin lift which kills functionality.

I wired a toggle switch to my trace cut, which can be reversed anyway with some solder. As it is now, I just flip the toggle on if I want composite video, and off if I want crystal clear RGB.

[Syntax]

Composite which is encoded from RGB with jailbars...
I'd rather shielded cable and a higher quality composite signal then having to flip a switch...

[FBX]

Composite which is encoded from RGB with jailbars...
I'd rather shielded cable and a higher quality composite signal then having to flip a switch...

As you suggested earlier, the entire subcarrier trace with resistors and caps must be routed elsewhere away from the RGB lines before it reaches the CXA. You're welcome to do that if you're that obsessed with composite video. I'm perfectly happy with the toggle switch, because I don't use composite video anyway. It's only there if I need stock composite for whatever reason. Fair enough?

[MKL]

I've been wanting to do that for quite some time, just wasn't motivated enough to get a megadrive.

[flamie666]

Hi!
I can confirm that this solved my jailbars issue with my Megadrive 1.
My board is a IC BD M5
Thanks!
Edit: I cut the trace near the 315-5313
Did the same for the Genesis 2 VA4, traced and cut the subcarrier near the 315-5960 ASIC and the jailbars are gone.

[MichelinBr]

Hi everyone!

Please allow me to introduce myself. I'm Fabio Michelin. Me and a couple of friends, Fabio Santana and Alex Figueiredo, are fascinated by the subject, and inspired by the work of some of our idols like the fine chaps of My Life in Gaming and Bob over at RetroRGB, we write this article and started a small Facebook group called RGB Inside to gather people with the same passion in Brazil. Then we launched that Medium page, then an YouTube channel as well and even our own podcast (conveniently called RGB Inside Podcast -- yeah, creativity is not our forte ).

About that article, we wrote it and did the tests in order serve as a reference, a starting point so to speak, to people looking to buy a Mega Drive/Genesis and who couldn't test the actual consoles themselves or open to the console to check the board revision. I agree that the text was somewhat superficial, and certainly if we were to do it today, we would do it differently. I also wanted to clarify that we did not test any Genesis with RGB bypass because it's hard to find boards for installation here in Brazil -- we're still looking for some and plan to update the test in the future when we find one. Secondly, the Mega Drive III system that we tested is in fact the same as a Genesis 2 in the US -- Tec Toy, the company that represented Sega in Brazil in the 90s, launched the Genesis 2 here as Mega Drive III, because they already had launched a variant of the first model as Mega Drive II around here before that. Again, to clarify, the Brazilian Mega Drive III is in fact the same as the US Genesis 2, and the one we tested uses a Fujitsu chipset.

I'm going to read all the comments, and take the criticism tips for better and more complete tests in the future -- we are already working on one to compare different SNES revisions/models. Anyway, I was flattered to see comments from people I'm a big fan of, like FirebrandX and Voultar -- thank you for the gigantic contribution you two do to the retro scene,

Thank you all,

[wgogh]

I'll look for that podcast soon!

[AndehX]

So I decided to pull my Mega Drive out again tonight. Previously I had tried lifting Pin 50 on the VDP chip and lifting the pin on the CXA chip and neither of those seemed to make any difference to the jailbars. So I decided to get destructive and completely pull the trace leading from Pin 50, to the CXA chip. Low and behold, the Jailbars are now 90% gone. I can still see them very faintly, but it is 1000000 times better than it was.

[FBX]

So I decided to pull my Mega Drive out again tonight. Previously I had tried lifting Pin 50 on the VDP chip and lifting the pin on the CXA chip and neither of those seemed to make any difference to the jailbars. So I decided to get destructive and completely pull the trace leading from Pin 50, to the CXA chip. Low and behold, the Jailbars are now 90% gone. I can still see them very faintly, but it is 1000000 times better than it was.

Very strange results. I've never encountered a situation where removing the signal from pin 50 didn't work, yet removing the entire trace 'mostly' worked. Normally when you sever the trace near pin 50, the results are 100% jail-bar free. If you're still seeing faint jail bars, then there's likely interference coming somewhere else besides the subcarrier signal.

[AndehX]

So I decided to pull my Mega Drive out again tonight. Previously I had tried lifting Pin 50 on the VDP chip and lifting the pin on the CXA chip and neither of those seemed to make any difference to the jailbars. So I decided to get destructive and completely pull the trace leading from Pin 50, to the CXA chip. Low and behold, the Jailbars are now 90% gone. I can still see them very faintly, but it is 1000000 times better than it was.

Very strange results. I've never encountered a situation where removing the signal from pin 50 didn't work, yet removing the entire trace 'mostly' worked. Normally when you sever the trace near pin 50, the results are 100% jail-bar free. If you're still seeing faint jail bars, then there's likely interference coming somewhere else besides the subcarrier signal.

Yeah I completely understand why lifting pin 50 should be 100% effective, but for some strange reason, I literally had to remove the entire trace from the board before any significant difference was noticed. Very odd, but at least i'm happy with the result. Oh well, at least I don't need to buy an RGB bypass anymore.

[Ikaruga11]

So does the JVC X'Eye really have the sharpest RGB output and cleanest audio? I've also heard that CDs load faster on the JVC X'Eye than any other Sega CD model. Also, I've noticed that all JVC X'Eyes have a BIOS firmware of Ver 2.00 for the CD side, while some Sega CD Model 2 can have a BIOS firmware of Ver 2.21. What's the difference with the extra .21?

Finally, does the 32X improve the RGB output?

[fandangos]

I don't have the JVC genesis but I own different genesis revisions and in my opinion the best RGB output is the modded Pioneer Laserdisc with the sega pak.

And I never did any kind of comparison related to audio but I think it's better than my genesis hd graphics.

[FinalBaton]

So does the JVC X'Eye really have the sharpest RGB output and cleanest audio? I've also heard that CDs load faster on the JVC X'Eye than any other Sega CD model. Also, I've noticed that all JVC X'Eyes have a BIOS firmware of Ver 2.00 for the CD side, while some Sega CD Model 2 can have a BIOS firmware of Ver 2.21. What's the difference with the extra .21?

Finally, does the 32X improve the RGB output?

Why are you bumping 3 different threads to ask the same 1 question???

[Ikaruga11]

So does the JVC X'Eye really have the sharpest RGB output and cleanest audio? I've also heard that CDs load faster on the JVC X'Eye than any other Sega CD model. Also, I've noticed that all JVC X'Eyes have a BIOS firmware of Ver 2.00 for the CD side, while some Sega CD Model 2 can have a BIOS firmware of Ver 2.21. What's the difference with the extra .21?

Finally, does the 32X improve the RGB output?

Why are you bumping 3 different threads to ask the same 1 question???

Because people don't all read the same threads. So I asked this question pertaining to those threads to get more responses.

[Einzelherz]

So does the JVC X'Eye really have the sharpest RGB output and cleanest audio? I've also heard that CDs load faster on the JVC X'Eye than any other Sega CD model. Also, I've noticed that all JVC X'Eyes have a BIOS firmware of Ver 2.00 for the CD side, while some Sega CD Model 2 can have a BIOS firmware of Ver 2.21. What's the difference with the extra .21?

Finally, does the 32X improve the RGB output?

Why are you bumping 3 different threads to ask the same 1 question???

Because that's what he does.

[Ikaruga11]

So does the JVC X'Eye really have the sharpest RGB output and cleanest audio? I've also heard that CDs load faster on the JVC X'Eye than any other Sega CD model. Also, I've noticed that all JVC X'Eyes have a BIOS firmware of Ver 2.00 for the CD side, while some Sega CD Model 2 can have a BIOS firmware of Ver 2.21. What's the difference with the extra .21?

Finally, does the 32X improve the RGB output?

Why are you bumping 3 different threads to ask the same 1 question???

Because that's what he does.

Thanks for the answer, Eizenhower. Now I'll wait for tjstogy to show up and make another shitpost.

[Last Springsteen]

Hi!
I can confirm that this solved my jailbars issue with my Megadrive 1.
My board is a IC BD M5
Thanks!
Edit: I cut the trace near the 315-5313
Did the same for the Genesis 2 VA4, traced and cut the subcarrier near the 315-5960 ASIC and the jailbars are gone.

And wehre did you exactly cut the subcarrier??
I did not find the trace on my Genesis 2 MoBo VA4. I followed pin 6 from the input side of the CXA 1645 backwards, but to my eyes the trace get lost nearby C27...

PLEASE HELP me to get rid of these goddam jailbars!

On my MD 1 VA5, lifting Pin 50 eliminated jailbars around 60 - 70 percent.
But the OSSC is extremly sensitive to jailbars and is showing them in it´s whole
„beauty“

[Last Springsteen]

Hi!
I can confirm that this solved my jailbars issue with my Megadrive 1.
My board is a IC BD M5
Thanks!
Edit: I cut the trace near the 315-5313
Did the same for the Genesis 2 VA4, traced and cut the subcarrier near the 315-5960 ASIC and the jailbars are gone.

And wehre did you exactly cut the subcarrier??
I did not find the trace on my Genesis 2 MoBo VA4. I followed pin 6 from the input side of the CXA 1645 backwards, but to my eyes the trace get lost nearby C27...

PLEASE HELP me to get rid of these goddam jailbars!

On my MD 1 VA5, lifting Pin 50 eliminated jailbars around 60 - 70 percent.
But the OSSC is extremly sensitive to jailbars and is showing them in it´s whole
„beauty“

Encouraged by the posts from FBX and esspeacialy flamie666 I followed the trace of the subcarrier again and the Jailbars are 100 percent gone. I cut just after the ASIC 315-5960 on my MoBo VA4 Genesis 2.
THANK YOU VERY MUCH!

[Unseen]

Furthermore, you can actually see the blue trace runs right next to the subcarrier trace on much of its path.

Actually it doesn't, at least on the board I have pictures for - see here (yellow is subcarrier). If it was just about traces running next to each other, there should be a lot of crosstalk between red/green/blue.

[FBX]

Furthermore, you can actually see the blue trace runs right next to the subcarrier trace on much of its path.

Actually it doesn't, at least on the board I have pictures for - see here (yellow is subcarrier). If it was just about traces running next to each other, there should be a lot of crosstalk between red/green/blue.

That's on your PAL machine. In the Genesis M1 early revisions, it literally is the blue trace next to the subcarrier causing the jail bars:

[Unseen]

That's on your PAL machine. In the Genesis M1 early revisions, it literally is the blue trace next to the subcarrier causing the jail bars:

Ouch. Ok, that's much worse. I've seen the same issue on a PAL machine, but the effect is probably even stronger on NTSC systems?

[FBX]

That's on your PAL machine. In the Genesis M1 early revisions, it literally is the blue trace next to the subcarrier causing the jail bars:

Ouch. Ok, that's much worse. I've seen the same issue on a PAL machine, but the effect is probably even stronger on NTSC systems?

Yeah it's pretty bad. However, by cutting the trace before it follows along the blue line, you end up with crystal clear RGB. At least on the VA2 and VA3 model 1 Genesis consoles I have.