GUIDE: Telling apart good Genesis 1s and Genesis 2s from bad ones.

[kool kitty89]

There are 2 variants of M1 without the HD logo, the VA6 with similar hardware to earlier models, and the VA7 which is basicly a model 2 in a m1 shell. (and the stereo might actually be slightly worse as it has to go through the headphone amp) One difference witht he VA7 and early M2s is that you're sure to have a good video encoder (usually the Sony CXA1145 it seems), like many earlier model 1s and some early M2's, but many M2s have the "peice of shit" samsung video encoder, distorted and very blury.

Of course, those vertical lines you mention could have been due to the RF modulator as well if he had it hooked up that way rather than composite video. (most RF output on Genesis models seems rather poor, be it on board the model 1 or in the model 2 RF box, often quite noisy, compared to an NES, SNES, or even Atari 2600 my HD model 1 looks poor in RF, the sound is quite clear through RF though, mono only of course)


Very early model 1s (pre TmSS) also tend to have some "rainbow" noise in the composite output, not very noticable though. I couldn't notice it on mine, but I still don't have composite cables yet.


In any case, is your non HD M1 difinitely the VA7? Or could it be the VA6 with the indentation where the DE-9 exp port would go and the AV port closer to the edge.

[Ace]

Apologies for bringing this topic up from page 5, but something this useful shouldn't really be left to die and I have got a couple of questions. First of all, is the 3/4 motherboard Megadrive 2 known to have been available in Europe? I've had multiple systems over the years and never actually seen one of these, and I would like to pick one up to replace my nasty sounding V0-V2 system.

I'm not quite sure if Europe got the VA3 and VA4 motherboard revisions for the MegaDrive II. I think there are some Japanese MegaDrive 2s with a 3/4 motherboard, though you'd have to look around for a European 3/4 motherboard MegaDrive II.

As a word of note, they are EXTREMELY hard to find. Out of about 20 Genesis 2s I saw in one shop, only 2 of them had a 3/4 motherboard in there, which I believe were both VA4s. It's almost impossible to find a 3/4 motherboard MegaDrive II.

Also could anyone tell me what version my asian Megadrive 1 system is? It's equipped with the EXT port, has "AV Intelligent Terminal - High Grade Multipurpose Use" in letters on the black ring, no wires leading to the cartridge slot and seems to have a Sony video chip (if the video chip is the one located on the bottom left corner of the motherboard, otherwise I have no idea). I think it also has TMSS as it shows the "Produced by or under licence from Sega" screen, although it isn't modified so I can't say if it displays that when used in anything other than PAL 50 mode. It's also gives off a very blurry and noisy image running through RF with lots of colour bleeding, the sound is fine though.

Sounds like a VA6. MegaDrive 1s have no wires leading to the cartridge slot, but you can see wires on certain MegaDrive 1s. My Japanese VA5 MegaDrive, for instance, has an orange wire you can see when holding the cartridge slot open, but it doesn't go to the cartridge slot itself. You can see those wires more clearly if you look inside the MegaDrive via the Sega CD slot. This goes for all VA5 and VA6 Model 1s, no matter the region.

Super-blurred and bleeding video is all too common via RF. Better get a Composite cable(or better yet, a SCART RGB cable)

And it kinda hard to tell the pics of the video out puts on the 1st post.

Time to open Fusion and simulate. TV capture cards hide the video problems, so there's no point in using mine to capture video off my numerous Genesis consoles.

Of course, those vertical lines you mention could have been due to the RF modulator as well if he had it hooked up that way rather than composite video.

Absolutely not. Genesis 2s with KA2195Ds all have dirty video, no matter whether you're using Composite or RF. The VA7 Genesis 1, on the other hand, has no such dirty video, and if a VA7 Genesis 1 is used via a crappy RF box, it will add in line noise to the clean video output

EDIT: I've attached a simulation of the blurred and noisy video output from Genesis 2s with KA2195D video encoders. This the "Produced under the supervision of Ayrton Senna" screen from Super Monaco GP II, which clearly demonstrates any and all video problems a Genesis has.

[Christuserloeser]

There are 2 variants of M1 without the HD logo, the VA6 with similar hardware to earlier models, and the VA7 which is basicly a model 2 in a m1 shell.

I was referring to the VA7. (but yeah, there won't be any/much difference to a HDG model 1 at all if you got a VA6)

and the stereo might actually be slightly worse as it has to go through the headphone amp

Nah, the headphone amp is the reason why a VA7 sounds a good bit better than a model 2.

[Ace]

Nah, the headphone amp is the reason why a VA7 sounds a good bit better than a model 2.

I would have to disagree with that. The VA7 Genesis Model 1 sounds just as "hissy" as the VA0/VA1/VA1.8 Genesis 2 no matter whether you're using RF, Mono audio via the Multi-A/V out or Stereo audio out the headphone jack.

[Afcs46]

Absolutely not. Genesis 2s with KA2195Ds all have dirty video, no matter whether you're using Composite or RF.

With, and without him... I have a Megadrive2 with a CXA2075M that have those vertical lines (I don't know if the problem is from my TV as I have to test). My Megadrive2 VA4 and my Jap Megadrive1 VA6 have those lines too. Tested with different cables...

[Ace]

Is it like the picture of Super Monaco GP II simulated with line noise?

[Afcs46]

Not so noticeable, but yeah, it's like that... And in Horizontal too... Like a cross.

[kool kitty89]

Absolutely not. Genesis 2s with KA2195Ds all have dirty video, no matter whether you're using Composite or RF. The VA7 Genesis 1, on the other hand, has no such dirty video, and if a VA7 Genesis 1 is used via a crappy RF box, it will add in line noise to the clean video output.

I meant it could have been the RF noise if it didn't have the Samsung chip. Do VA-7's RF output tend to be even worse than earlier models? I seems to remember something about that, maybe it was just that they burned out more often. (I seem to recall reading M2 RF boxes tend to be flaky as well)


Hey, I don't remember the CXA2075M encoder being memtioned before, was that one not used on US models?

[Afcs46]

No, it was a replacement. There was a MB3514, and I swapped with a ubber rare cxa2075m, the top notch rgb encoder from sony...

[kool kitty89]

Do you have all your MDs hooded up with RGB SCART?

[Ace]

I meant it could have been the RF noise if it didn't have the Samsung chip. Do VA-7's RF output tend to be even worse than earlier models? I seems to remember something about that, maybe it was just that they burned out more often. (I seem to recall reading M2 RF boxes tend to be flaky as well)

Broken RF units is a common problem on ALL Genesis Model 1s, no matter what motherboard is in it. My working VA7 has a fully-functional RF unit, but my other dead VA7 needed to have the cable for the RF box pushed up in order to get a picture on the screen. Same with one of my 2 VA3s. There's also a VA6 I have whose RF unit seems to work when it feels like it. I have to spin the cable around to get the picture to work, and there are other times where it just won't work.

The RF output of all Genesis Model 1s is the same, except for non-TMSS Model 1s, as they still have that "rainbow banding" issue.

And like Afcs46 said, the CXA2075 was never used in any model of the Genesis. I remember reading about people replacing the Samsung piece-of-shit in their Genesis 2s with the CXA2075 in order to get S-Video off it. I'd just get a CXA1145 off a dead VA7 Genesis Model 1 to spare the trouble of actually finding a place selling the CXA2075. But if I can get a little batch for cheap, I'll be sure to get them to put in my NUMEROUS Genesis 2s with KA2195Ds

[kool kitty89]

The RF output of all Genesis Model 1s is the same, except for non-TMSS Model 1s, as they still have that "rainbow banding" issue.

And that's from the composite not the RF noise, right? Are said bands static or do they move kink of liek the RF noise. If static, I haven't been able to see them on mine, at least not through the RF noise. (I have yet to get an av cable, I might not at all if the simple S-Video mod works on our TV) The RF really does look unusually, almost like using one of those crappy radio shack manual switch boxes used with the Atari 2600, a lot noisier than an NES, SNES, or Atari 2600. (when not using the aformentioned RF switch) The SNES in particularly has clean RF, no static and only faint lines and ghosting. (almost as good as composite)

[Ace]

The lines are static, and they are very thick. If you don't have a non-TMSS Genesis Model 1, you will never see them.

I will make note that all Sega consoles I own all have static in their RF output. This is using both a direct RCA>Coax adapter and a Nintendo RF box.

[kool kitty89]

So there's no "rainbow banding" in the composite video output?

Post TMSS RF noise is just the snowy kind of static then (along with typical ghosting), not the awful scrolling, wavy, criscrossing diagonal lines? (the snow's there too, but that doesn't bother my very much) The early (pre-TMSS) models just have poorer quality RF boxes then?

[Azure Phoenix]

I'm not quite sure if Europe got the VA3 and VA4 motherboard revisions for the MegaDrive II. I think there are some Japanese MegaDrive 2s with a 3/4 motherboard, though you'd have to look around for a European 3/4 motherboard MegaDrive II.

As a word of note, they are EXTREMELY hard to find. Out of about 20 Genesis 2s I saw in one shop, only 2 of them had a 3/4 motherboard in there, which I believe were both VA4s. It's almost impossible to find a 3/4 motherboard MegaDrive II.

Thanks for your reply. So does the VA4 MD2 have enough of an improvement in picture/sound quality over the VA6 MD1 to warrant tracking one down, or should I just stick with the asian VA6 and pick up a Mega CD 1 to match it?