More Than One Version of The SNES Model 1?

[wingzrow]

So I got a spare super nintendo today from the salvation army and immediately tested it out to see if it worked. Sure enough, it boots up just fine, but something was definitely off. Switching back my original snes It hit me. The other one's picture was noticeably more blurry.

I opened both up and the actual insides seem to be different on each. Mainly, one motherboard is labeled 1991, and the other is labeled 1995. The later, being the one that has worse picture. Both were run on the exact same tv with the same S-video cord & power supply.

Can anyone explain this?

Do certain models of the original SNES just not run well in S-video or is there another issue completely here?

[izarate]

There are five revisions of the original SNES SNS-001:

SHVC-CPU-01
SNS-GPM-CPU-01
SNS-GPM-CPU-02
SNS-RGB-CPU-01
SNS-1CHIP-CPU-01

The weird part concerning your post is that video was actually improved. Earlier SNES revs (SHVCs and GPMs) use the old ROHM BA6592F encoder(S-ENC). The RGBs and 1CHIPs use the BA6595F (S-RGB) and SNES Jr. use the BA6596F (S-RGB A).

Maybe the unit you tested is picking up interference? The older SNESes had a bulkier RF shield. Also, a capacitor or some other component on the video circuit might be going out.

[wingzrow]

Interference is unlikely, as I removed the shielding completely under the assumption that that would fix the issue. I guess it's just a dieing system. It's barely noticeable unless you play them side by side but the difference is there.

[BetaWolf47]

Oh great, another system with a bunch of variants in video quality. Please tell me it's not as crazy as the sheer amount of Genesis variants!

[izarate]

It really isn't that different. The most noticeable improvement comes with the BA6596F ("S-RBG A") which doesn't produce the faint vertical lines at the center of the screen:


Apart from that, picture sharpness and quality is almost the same except for a marginal improvement in color separation (most noticeable with S-Video):

Left: BA6592, Right: BA6595/96

[theclaw]

Oh great, another system with a bunch of variants in video quality. Please tell me it's not as crazy as the sheer amount of Genesis variants!

Ugh. The thought of how horrible the video quality of some Genesis units is... My plan is to sell what I've got left and start over with a proper condition one down the road.

[izarate]

At least it's not as crazy as the Genesis since the BA6592 and the BA6595/96 use different support circuitry and their pinouts are different also so they aren't drop in replacements (unlike the CXA1145, MB3514 and KA2195) meaning that you won't find a BA6592 on a newer SNES.

[Retromangia]

Hey Izrate...

thanks for providing this great info! I've always thought some of my SNES have better image quality than others... but could never find any info on this.

My question for you is... which model is best? and where can i find this model # on the system itself? The newer models are so much lighter than the old ones as far as weight goes too I've noticed.

lastly, I've noticed while using S-video on SNES.. there seems to be a fairly thick faint Purple vertical line on the screen... is this due to the model # I'm using? I'm using Monster S-video cables which were brand new in package.

thanks for all your help!

[izarate]

which model is best? and where can i find this model # on the system itself?

I'd say the best is the SNES 2 for the BA6596F encoder; for the SNES 1 I'd say the best are the SNS-CPU-RGB-01 and SNS-CPU-1CHIP-01.

The revision is printed on the PCB:

lastly, I've noticed while using S-video on SNES.. there seems to be a fairly thick faint Purple vertical line on the screen...

I assume you mean this:




Refer to my previous post: http://www.digitpress.com/forum/show...95&postcount=5

[dreamcaster]

I get that faint band occurring on my Super Famicom, but not on my US SNES.

I also get a bit of blurriness around the edges of text and sprites on my SFC, something which my US SNES doesn't do.

[izarate]

A little bit of extra info.

I recently found an SNES PCB rev. SNS-CPU-GPM-02 sporting an "S-ENC B" chip, it being the BA6594F...so, that means that there must be an "S-ENC A" which most likely is the BA6593F.

So:
S-ENC = ROHM BA6592F
S-ENC A = ROHM BA6593F *conjecture*
S-ENC B = ROHM BA6594F
Every S-ENC are pin compatible

S-RBG = ROHM BA6595F
S-RGB A = ROHM BA6596F
Every S-RGB are pin compatible



SNES SNS-001:
Encoders found in rev. SHVCs and GPMs: S-ENC, A, B
Encoders found in rev. RGBs and 1CHIPs: S-RGB (*confirmed*), S-RGB A (*conjecture since they are pin compatible*)

SNES SNS-101:
S-RGB A (I've been through several and all of them have it)



BA6591/92/93/94 pinout:
*working*

BA6595/96 pinout:

[savageone]

Since I have a stack of SNES systems right now I decided to look into hardware revisions so I could decide which to keep. One of the systems I opened has the board SNS-CPU-RGB-02, so I guess there are at least 6 revisions of the model 1 now?

So out of the 4 I opened 3 of them are SNS-CPU-GPM-01 and 1 is SNS-CPU-RGB-02. I have 3 more I don't even think are worth bothering with since they look to probably be the original board (a bit heavier, silver serial # sticker on the bottom).

[savageone]

Okay spent some more time doing a few tests of the SNS-CPU-RGB-02. My notes are:

- Uses S-RGB A BA6596F encoder, same as SNS-101 or model 2 SNES systems. Seems to be the best video encoder for SNES systems according to izarate's findings.
- Does S-Video output native unlike SNS-101/model 2 SNES systems. I'm not sure why the SNES 2 systems don't do S-video off hand but it's a major down side of those systems no doubt.
- My NTSC SNES RGB cable works great with this system where my SNS-CPU-GPM-01 system would display a very bright/washed out picture. There has been a lot of confusion with NTSC SNES RGB cables where an extra cap needs to be installed, this might all boil down to a board revision problem which I've never seen it mentioned.

Hopefully more people can contribute so we can figure out what is truly the "best" SNES board revision and exactly how many exist. A lot of work like this has been done for the Genesis side but not the SNES.

[raylydiard]

very bright/washed out picture happened to me with my gamegube once
i had to replace the cable.

[savageone]

One more thing to note is the annoying faint band/vertical line in the center of the screen is still present with the RGB-02, isn't there some fix for this problem? I guess most people don't notice it but I find it very annoying.

[izarate]

- Uses S-RGB A BA6596F encoder, same as SNS-101 or model 2 SNES systems. Seems to be the best video encoder for SNES systems according to izarate's findings.
- Does S-Video output native unlike SNS-101/model 2 SNES systems. I'm not sure why the SNES 2 systems don't do S-video off hand but it's a major down side of those systems no doubt.
- My NTSC SNES RGB cable works great with this system where my SNS-CPU-GPM-01 system would display a very bright/washed out picture. There has been a lot of confusion with NTSC SNES RGB cables where an extra cap needs to be installed, this might all boil down to a board revision problem which I've never seen it mentioned.

Hopefully more people can contribute so we can figure out what is truly the "best" SNES board revision and exactly how many exist. A lot of work like this has been done for the Genesis side but not the SNES.

WOW! I've never seen that one before!!!

This is very exciting, I thought that I had seen every SNES revision so far. So, yeah, this ups the number of confirmed board revisions to 6.

It's possible to restore the S-Video on a SNES 2. Nintendo just removed the handful of components that were used for the S-Video output: http://www.digitpress.com/forum/showthread.php?t=126959

So you still get the vertical line with the S-RGB A??? I really thought that the S-RGB A was the fix to that.

It might be that the line is a degenerative issue present in the SNES 1 models I've used my modded SNES 2 for 8 years now and the line hasn't shown up. The SNES 2 S-Video mod that I posted doesn't restore every component but almost every modern CRT seemed to process the signal without issue so I left it at that. If I recall correctly, the SNES 1 has a couple of transistors and inductors in the S-Video output in addition to the capacitors so it might be that they are wearing out and that produces the vertical line.

Anyway, the BA6596F (S-RGB A) was the latest ROHM RGB encoder used in the SNES so it should provide the best picture.

[Zing]

I'm planning to acquire a SNES soon, so this thread interests me.

Is this "vertical band" problem only when using s-video? Will composite video not have this artifact on any revision of the SNES?

What is the native output of the SNES? For example, the NES video chip outputs composite. I was under the impression that the SNES video chip outputs RGB, then the video encoder chip(s) convert it to the other types if needed.

Is there any way to know if you have a particular revision based on external markings? I know the difference between the "new" and "old" case (printed vs molded "eject", etc), but if there are several hardware revisions, is there any indication on the outside? Maybe something as simple as a certain serial number range?

[izarate]

Is this "vertical band" problem only when using s-video? Will composite video not have this artifact on any revision of the SNES?

The line is present in both composite and S-Video. RGB seems to not produce it. As far as I can tell, it seems to be a degenerative issue (failing capacitors maybe?) I thought that the S-RGB encoder chips didn't produce the line but others are reporting that it does so maybe it's just that my SNES 2 hasn't shown it yet.

What is the native output of the SNES? For example, the NES video chip outputs composite. I was under the impression that the SNES video chip outputs RGB, then the video encoder chip(s) convert it to the other types if needed.

The ROHM encoders take RGB so I'd say that it produces RGB. I'm not entirely sure, tought.

Is there any way to know if you have a particular revision based on external markings? I know the difference between the "new" and "old" case (printed vs molded "eject", etc), but if there are several hardware revisions, is there any indication on the outside? Maybe something as simple as a certain serial number range?

There are a few things that can help you identify groups of PCB versions:


SHVCs:
- FCC information is in a label underneath the console.
- Molded "EJECT"
- Cartridge connector edges are silver (open the cartridge slot cover and look through the little slits on the edge of the plastic around the connector)
Note: All silver connectors can be replaced.

GPMs:
- FCC information is molded on the underside of the console
- Printed "EJECT"
- Small grey label close to the power switch
- Cartridge connector edges are silver (open the cartridge slot cover and look through the little slits on the edge of the plastic around the connector)
Note: All silver connectors can be replaced.

RGBs, 1CHIPs:
- FCC information is molded on the underside of the console
- Printed "EJECT"
- Small grey label close to the power switch
- Cartridge connector edges are black (open the cartridge slot cover and look through the little slits on the edge of the plastic around the connector)
Note: Black edged connectors are fixed and cannot be replaced.

[cynicalhat]

There are a few things that can help you identify groups of PCB versions:


SHVCs:
- FCC information is in a label underneath the console.
- Molded "EJECT"
- Cartridge connector edges are silver (open the cartridge slot cover and look through the little slits on the edge of the plastic around the connector)
Note: All silver connectors can be replaced.

GPMs:
- FCC information is molded on the underside of the console
- Printed "EJECT"
- Small grey label close to the power switch
- Cartridge connector edges are silver (open the cartridge slot cover and look through the little slits on the edge of the plastic around the connector)
Note: All silver connectors can be replaced.

RGBs, 1CHIPs:
- FCC information is molded on the underside of the console
- Printed "EJECT"
- Small grey label close to the power switch
- Cartridge connector edges are black (open the cartridge slot cover and look through the little slits on the edge of the plastic around the connector)
Note: Black edged connectors are fixed and cannot be replaced.

I just opened an SHVC-CPU-01 I've had since a teenager and it doest NOT have a molded eject button. it was definitely printed.

*(edit)i think you have the eject button type swapped on the GPM's and SVCH's.

[DaddyLongLegs]

The line is present in both composite and S-Video. RGB seems to not produce it.

Just a head's up, I have an old and new SNES model 1 and they both produce the vertical band in RGB.

SNES2/Jr. completely gets rid of it. However, I really like the design of the original US SNES so it kinda stinks I have to use the SNES2 to get rid of the problem

[Zing]

I assume you mean the SNES model 2 does not have the vertical band when using RGB, as it is definitely there with composite.

I agree with you about the case design. In particular, I dislike the lack of colour. The words "super nintendo" are moulded along with the rest of the case with no colour.

[DaddyLongLegs]

I assume you mean the SNES model 2 does not have the vertical band when using RGB, as it is definitely there with composite.

I just checked, the streak is not there with composite. I have a pretty keen eye for this stuff, so maybe you and I are talking about different things? For reference, I see it on the SNES 1 no matter what (composite, s-video, or RGB).

I agree with you about the case design. In particular, I dislike the lack of colour. The words "super nintendo" are moulded along with the rest of the case with no colour.

Yeah, it looks cheap, most of my friends think it's a bootleg, and it loses all nostalgia points. If there were only a way to get the SNES 2 video quality out of an SNES 1!

[MrMikeCH]

hi everyone

sorry for my interuption.
i have a snsp-cpu-02 mainboard with an s-enc a encoder.

i want to tap the rgbs signals before the enter the encoder (im really sorry for ppl and regions which need encoders) and then adjust the levels.

are there no pinouts for the s-enc a or better for the ppus to tao the signals right at source??

again sorry if im interupting but this was the best place to ask i found

[Zing]

I just checked, the streak is not there with composite. I have a pretty keen eye for this stuff, so maybe you and I are talking about different things? For reference, I see it on the SNES 1 no matter what (composite, s-video, or RGB).

I have the USA model 2, using composite, and the vertical band is very clearly there when playing games such as Yoshi's Island, Earthbound, and Super Metroid.

[xelement5x]

Sorry to necro-bump here, but I just opened up my SNES to try and match it up with those in this thread and it's not listed. The revision states C 1995 Nintendo, SNS-CPU-1CHIP-02. If I wanted to RGB or S-video mod this would I run into any major issues in revisions?