Hey there folks. I got my hands on a FDS today that almost works 100%. The problem is that in all of the games, the sprites show flickery glitchy areas, some worse than others.
Here's a pic of what happens to Mario on SMB2, if you can tell:
(http://i1117.photobucket.com/albums/k590/Zycrow/2014-04-24231426.jpg) (http://s1117.photobucket.com/user/Zycrow/media/2014-04-24231426.jpg.html)
I also have Metroid, Doki Doki Panic, Baseball, and Moero Twin Bee, and similar issues are present to various degrees on those games.
The former owner of this FDS says he has used it as his personal system, with no issues, for the past four years and I am inclined to believe him; I think the problem lies somewhere in the connection between the FDS and my Famicom. Here are things I have done so far:
- Tested the Famicom with regular cartridge games, just to be sure (they work fine)
- Cleaned the RAM adaptor's pins with brasso/alcohol.
- Cleaned the Famicom's pins using both a game swabbed with brasso and with a t-shirt/credit card combo and alcohol.
After a few rounds of pin-cleaning, the glitchiness was still present.
As a final note, my Famicom is one of the ones that was restored and given AV modification in Japan. Hopefully this is not the issue. Here's a pic of my setup, just for reference sake:
(http://i1117.photobucket.com/albums/k590/Zycrow/2014-04-24231458.jpg) (http://s1117.photobucket.com/user/Zycrow/media/2014-04-24231458.jpg.html)
I'm not sure what else I can do. Does anyone have any suggestions? :help:
I remember reading posts a long while ago on the same problem and I believe it had to do with the memory chips in the ram adapter. Some of them would go bad and you just had to unsolder them and replace them.
Someone else has to chime in with specifics or do some research on that to find the thread.
Here's one of the many threads;
http://www.famicomworld.com/forum/index.php?topic=9232.0
Here's the thread you were looking for http://www.famicomworld.com/forum/index.php?topic=8512.0.
Thanks - I did actually find those threads shortly after I posted this, so later when I get home I'll see if I can open my RAM adapter and check what chip I've got in there.
However, I'm not exactly clear based on those threads on what I would need to do to fix it. Buy a new RAM adapter and hope it's got a better chip? Find a replacement chip and learn how to solder so I can put a new one in? :P
Edit: I see this now:
Quote from: Raverrevolution on April 25, 2014, 06:49:40 am
Some of them would go bad and you just had to unsolder them and replace them.
If that's the case, where would I go to find a new one?
I still don't believe it is the RAM adapter, because I never had this problem once when I used this system all these years. :) The last time I used the system was 2 weeks ago, I don't see how the RAM adapter would suddenly go bad that quick. I still think you need to scrape the surface of the pins in the cartridge connector with a metal file, it works like a charm for me! Although Brasso is great for making the surface of the contacts clean, you may have to get underneath the surface of the pins if the surfaces are a little dull or corroded.
Quote from: zmaster18 on April 25, 2014, 11:25:45 am
I still don't believe it is the RAM adapter, because I never had this problem once when I used this system all these years. :) The last time I used the system was 2 weeks ago, I don't see how the RAM adapter would suddenly go bad that quick. I still think you need to scrape the surface of the pins in the cartridge connector with a metal file, it works like a charm for me! Although Brasso is great for making the surface of the contacts clean, you may have to get underneath the surface of the pins if the surfaces are a little dull or corroded.
That's the next thing I'll probably do - do you know of any reference videos or pics of this process online? I'm sure it's simple but I'm nevertheless wary to approach my old game systems with abrasive metal. :D
It sounds a bit scary and destructive, but it's just a couple little scratches. If you do it, you will have a solid connection. Like I said on ebay, if you have a game in the slot and wiggle it while the power is on, the game won't crash and still runs! I run a metal file 2 or 3 times gently up and down in the cartridge slot in the systems, and then for games you can rub the metal file across the connectors gently and blow out the dust after, and voila! ;) The games are like brand new because the metal is now exposed without any dull layers preventing bad connection. You don't need to use much force, be gentle and any corrosion comes right off and you have the shiniest pins possible. You can finish with brasso for a smooth finish if you'd like! ;D Try it out if anyone reading this has a metal file. You can bump, bend, or wiggle the cartridge while the system is on and it will never crash!
Yeah well cleaning the contacts should be the first thing you rule out. Don't use anything but alcohol. 99% Isopropyl alcohol is usually recommended. For polishing the RAM adapter's pins you probably need a fiberglass brush to be able to reach them. That worked for me anyway, and my games doesn't crash anymore even if wiggling the RAM adapter.
The thing with the RAM chips is that some probably has a manufacture flaw which makes them degrade over time. This may not be immediately noticeable. I can't help you where to find compatible RAM chips though. However I can say that soldering and desoldering chips is not a good beginners soldering project.
Do you have FDS Pro Wrestling available? If so does it have graphical glitches?
Quote from: P on April 25, 2014, 12:36:06 pm
Yeah well cleaning the contacts should be the first thing you rule out. Don't use anything but alcohol. 99% Isopropyl alcohol is usually recommended. For polishing the RAM adapter's pins you probably need a fiberglass brush to be able to reach them. That worked for me anyway, and my games doesn't crash anymore even if wiggling the RAM adapter.
The thing with the RAM chips is that some probably has a manufacture flaw which makes them degrade over time. This may not be immediately noticeable. I can't help you where to find compatible RAM chips though. However I can say that soldering and desoldering chips is not a good beginners soldering project.
Do you have FDS Pro Wrestling available? If so does it have graphical glitches?
I have cleaned the connectors on the RAM at least once and in the Famicom several times.
I don't have Pro Wrestling, just the games mentioned above (SMB2 with Baseball on side B, Doki Doki Panic, Twin Bee, Metroid).
Post Merge: April 26, 2014, 09:08:04 am
All right, here's what I've done since my last post:
- Opened up the RAM adaptor to inspect its innards. It does not appear to have the type of chip that causes graphical glitches, although I'm not 100% certain on this.
- Cleaned the RAM adaptor's pins (again) with alcohol.
- Filed the Famicom's connector pins.
- Filed the RAM adaptor's connector pins.
Same result.
Those faulty chips are still a big mystery. I would suggest to ask at a more technical forum about chips. The people at nesdev are often using ram chips and there's lots of technically knowledgable people there.
Do you have any way of testing the FDS on another Famicom? Then we could at least rule out your main unit.
Quote from: P on April 27, 2014, 03:19:44 pm
Those faulty chips are still a big mystery. I would suggest to ask at a more technical forum about chips. The people at nesdev are often using ram chips and there's lots of technically knowledgable people there.
Do you have any way of testing the FDS on another Famicom? Then we could at least rule out your main unit.
I do have a second Famicom, but it is inoperable (pretty sure I used the wrong type of AC adaptor a few years back). Too bad I can't jam the RAM adaptor into my American NES. ::)
I'll snoop around at nesdev and see if I can get some help there.
(At any rate I'm glad that the system is completely playable. In the case of Doki Doki Panic the garbling is almost totally unnoticeable. It's the worst in SMB2 where half of Mario's sprite is garbled.)
Of all my at least 20 RAM adapters, all but one have worked...
Sometimes people on forums make a big deal and being too inventive that chips will go bad , etc, but I am not aware of any chips for any system that automatically degrades with age. Capacitor, yes (and maybe EEPROMs etc).
Not saying chips can't go bad sometimes.
Since you have had the problem with your famicom since day 1, why think of complicated solutions... Most likely it is something with the famicom.
The FDS + Ram adapter is more complex than a regular cart. It could be something with the timing function/mechanism, which I have some recollection is special on the FDS technically. It may also use different pins than a regular cart so there may be a problem there.
Or, I could be completely wrong. But simplest and cheapest may be to buy an unmodded console and test it with the RAM adapter. Even if you get a bad picture, you'll probably get a picture good enough to tell if it has the ghosting.
Yes I agree that it's best to test it with another Famicom and rule out all other problems before starting to replace chips and such. People often tend to suspect complicated problems like a faulty PPU or CPU even though the most common problem is just dirty or oxidated pins.
Hey there folks. I wanted to update this thread for the purposes of other people having this problem in the future. I took my issue over to NesDev, and we had a lengthy discussion and one of the members even mailed me some of his components so I could mix/match and see what happened. The results were pretty strange. Here's the thread:
http://forums.nesdev.com/viewtopic.php?f=10&t=11202&p=128248#p128248
If you don't feel like reading through all that, here's the short version: Some RAM adapters work with my modded FC, and some don't. When I purchased a second FC (non-modded), the RAM adapter that zmaster sold me worked perfectly on it.
Ah, great to see that the problem was finally resolved after all this time! It's weird how it didn't work on a modded Famicom. However, my Fami is AV-modded and never had a problem with it.
There are really some truly nice people on nesdev. To think they would ask you to send it to them and see if they could fix it for free like that. I hope you thanked Koitsu properly.
It was a strange problem though that we still don't exactly know the cause of (I'm Pokun in that thread btw). Anyway I'm glad that it was solved. :) Have fun with your Disk System!
Why not to replace CHR RAM chip, which is Sony made in mid 86? It also might be latch ('373) degraded over the time. This explains, why same FDS have no issues on different famicom/twin
added
Just read thread on nesdev. Dunno, if you guys like to go to the post office to send boxes, or ebay disputes/claims, but easiest solution at moment is to replace CHR RAM chip with 100ns or faster. I would strictly recommend to ALL resellers, who charging $20+ for FDS, do this procedure. You have to open RAM adaptor for cleaning anyway. 15 minutes and $1 chip might save you losts of time(and money) later.
Still not sure, why some code is so critical to hardware or chips are degraded so badly.
So you think it's bad CHR RAM chips after all? May I ask what kind of 100ns chips I should look for if I don't know much about chips? My local electronics store only has SRAM. 100+ ns SRAM chips are like 15$ a pieace there, so the RAM adapter will end up costing a lot more. Also how do you know if the RAM chips are pin-compatible with the board?
With current staistic i can say yes, degraded(?) CHRRAM chip is an issue. You can use SFC/SNES cart as a donor for 8kb SRAM. These days chips are JEDEC compatible. If you are not sure, you always can download datasheets and compare pinouts.
I see, thanks. The local store doesn't seem to have any 18 pin SRAM chips that works anyway, so I guess looking for loose SNES sports games is the way to go.
28pin, 0.6" and 0.3" are fine since layout of PCB designed to fit both. Just don't solder 0.3" chip over the shortcuts :P
Thanks.
So I've spent a couple of hours now with this problem too...
Glitchy problems happens with:
FDS RAM adapter HVC-FMR-03 (copyright 1985)
AND
A famicom of later revision (the one with FF on the logo)...
Tried with three such consoles, two AV-modded and one not modded, and all were glitchy..
It doesn't happen with:
HVC-FMR-04 (copyright 1986), on any model famicom..
also doesn't happen with a famicom of earlier revision (no FF on front logo) or twin famicom, even with RAM adapter HVC-FMR-03...
I tried the glitchy HVC-FMR-03 with FOUR earlier revision famicoms (all AV modded), and no glitching...
Maybe it is a bug with the HVC-FMR-03 ? One would need to try more RAM adapters. It seems to be a constant problem with this model...
I will add the the later revision famicom (FF logo) has a 1989 motherboard and was released after the FDS which could explain why they are incompatible.
I will try with the AV famicom (HVC-101) when I get another.
Now when you say it, all faulty units have been HVC-FMR-03. My non-faulty RAM adapter is 04 (the one with the older BIOS version).
@fredJ reuesting photos of every PCB you used for test.
Famicom PCBs? I don't know if I have time for that right now, that would be a lot of consoles to open.
But I can say that the RAM adapter had the Sony chip.
Also, today I tried a different -03 RAM adapter that has a "noname" sram chip (? no brand name anyways) and there were no glitching...
The D-Ram chips are different too.
(http://i.imgur.com/vyKsOgq.jpg) (http://imgur.com/vyKsOgq)
The one to the left is the glitchy one...
I'll jump in here to say that I picked up a non-modded FC as well as a junker FDS with a working RAM adapter from Senseiman last month.
My prior RAM adapters worked perfectly on the FC, and the adapter worked with my modded FC. So my problems are all solved, but it still remains to be seen what causes all of this nonsense...
Quote from: fredJ on June 29, 2014, 06:12:49 am
Glitchy problems happens with:
FDS RAM adapter HVC-FMR-03 (copyright 1985)
AND
A famicom of later revision (the one with FF on the logo)...
Tried with three such consoles, two AV-modded and one not modded, and all were glitchy..
It doesn't happen with:
HVC-FMR-04 (copyright 1986), on any model famicom..
also doesn't happen with a famicom of earlier revision (no FF on front logo) or twin famicom, even with RAM adapter HVC-FMR-03...
I tried the glitchy HVC-FMR-03 with FOUR earlier revision famicoms (all AV modded), and no glitching...
I can report the same behavior here.
The glitches seem to happen when combining an early RAM adapter (HVC-FMR-03) with a later revision Famicom (HVC-CPU-GPM-02).
No problem when using the same FMR-03 with two different HVC-CPU-07 boards, or with an AN-505 Twin Famicom.
No problems either on any Famicom with an FMR-04.
My FMR-03s units both have a smooth plastic top enclosure, whereas my FMR-04s have a rough plastic top enclosure. I'm not sure how precise a visual clue that is, since there might be some overslap between the revisions. But if others can confirm this observation, it might be safer to try and avoid smooth plastic RAM adapters in general, especially if you own a Famicom that has the "FF" logo on the front panel.
Edit: a little update, I tried replacing the Sony S-RAM chip with a Hitachi chip (the "no-name" chip on FredJ's pic), and the glitches are still present.
I'll try replacing the D-RAM chips when I have some free time and see how that goes.
After all, those D-RAM pieces are the main difference between FMR-03 and FMR-04, so those might as well be the real culprit here.
Quote from: fredJ on June 30, 2014, 02:48:11 am
Famicom PCBs? I don't know if I have time for that right now, that would be a lot of consoles to open.
But I can say that the RAM adapter had the Sony chip.
Also, today I tried a different -03 RAM adapter that has a "noname" sram chip (? no brand name anyways) and there were no glitching...
64S20?
By the way, there is a RAM test in the BIOS, you can try to perform it on glitchy adaptors, but i very doubt it is accurate.
Quote64S20
I'm not sure what you are referring to... but the picture shows the chips http://i.imgur.com/vyKsOgq.jpg
I have sent the adapter to my colleague now so I can't look at it more.
Yes I tried the RAM testing on the glitching one (Start + Select or whatever it is) and it showed ALL OK.
So, next thing to test, per oare, is to replace the DRAM chips, possibly S-RAM, and I also want try it on an AV Famicom.
But if you check the thread: "Re: ATTENTION!!! FDS users, SNROM, UNROM etc might be affected as well." http://www.famicomworld.com/forum/index.php?topic=8512.msg150032, I think someone tried replaced DRAM without success. (or what does "socketed" mean?).
It's hard to read the chips on that pic though.
Socketed just means he soldered chip-sockets in place of the chips so he can just snap in and out the chips so he don't have to solder them every time.
I've done a few more tests swapping things around. Nothing great to report, but here are the results anyways:
- SONY CXK5864PN-15L (5I 64) and HITACHI HM6264P-20 SRAM with either Motorola MN4264-15 D-RAM and Fujitsu MB81416-12 D-RAM chips cause glitches when used along a Famicom that has an HVC-CPU-GPM-02 motherboard, no matter the configuration of the chips. All were taken from RAM Adapters with a revision number HVC-FMR-03.
However, any configuration of those chips display no problem whatsoever with any of my HVC-CPU-07 Famicom boards, nor with my AN-505 Twin Famicom.
The only chip both boards had in common initially is the hex inverter (BU4069UB).
- SONY CXK5864PN-15L (6I 12) with one single SHARP LH2833-15 D-RAM chip (board revision = HVC-FMR-04) causes no problems on any Famicom board.
The only visible difference between HVC-FMR-03 and 04 boards is the D-RAM: 03 boards have 4 chips, vs 1 chip only for 04 boards.
The next logical step would be to try and slap-in an 04 D-RAM chip in a 03 board. Rewiring shouldn't be very difficult since everything else appears pretty much identical. But I'm wondering if it's worth the hassle; it wouldn't be very practical anyways.
I'm wondering about those NEC D-RAM chips on FredJ's photo, though.
Well, in the other thread, the guy tested and said the glitching went away when he pressed on the chips with his finger...
I think that could be an important clue.
QuoteIf I press onto the solder points of the 4 dram chips with my finger while running the graphics corruption goes away.
If you want better photos, i'll ask my colleague. He is a member here too.
Maybe we could consider what the glitching is? It seems to affect objects that move, sprites that are moving or movable. Such as characters, balls, parts of airplanes, and such. What memory is that?
Sprites are copied from the disk to the CHR-RAM like all graphics. Depending on the game they might be copied from the CHR-RAM to a shadow register before they are sent to the PPU (and thus sent to the TV), but I think those registers are inside the Famicom so the problem must be with the CHR-RAM. But it's only a small fraction of the CHR-RAM so that's why only some games are affected (all games doesn't use the whole CHR-RAM).
Quote from: fredJ on July 04, 2014, 03:12:49 pm
Well, in the other thread, the guy tested and said the glitching went away when he pressed on the chips with his finger...
I think that could be an important clue.
That sounds like there's a bad connection somewhere, but if he recently soldereded them it can't just be old cracked solder that needs reflowing. Maybe he just didn't push the chips down into the sockets properly.
Reflowing the pins was actually the first thing I tried, but to no avail.
Since I've desoldered and resoldered a few of those chips, there's pretty much only fresh solder on those joints now, too, but one can never be sure. Maybe we should try bending the D-RAM pins onto the solder pads and see how that goes?
The thing is, though: why would bad connections whithin the RAM adapter solely affect later revisions of the Famicom, but not cause any issue with hvc-cpu-07 boards?
I'm beginning to think we should start looking for causes not only in the RAM adapter only, but also in the Famicom themselves if we want to find a practical solution?
Sure. There is PPU, CHRRAM and latch. Nothing else ::)
hint: something is slow
The way the 03 board is configured is causing some kind of conflict with newer Famicom boards? I know nothing about electronics so I have no idea.
But didn't someone say that replacing the RAM chips in a 03 RAM Adapter works? If that's the case maybe there's something weird with the chips that makes them behave weirdly in very specific situations (like when a newer Famicom board is involved)? I'm guessing wildly here. :crazy:
http://www.geocities.jp/atx197/FC_HVC-CPU-05_03.pdf here is redrawn diagram. Thanks to Junker.
IIRC some earlier PCB's utilized 74HC373 (which is much faster, but there also was small capacitor on "Clk"), but later revisions 74LS373.
Also eveone knows about different revisions of PPU(i have D, E, G in my collection somewhere in the boxes).
What else? The capacitor on /RD line(it is behind slot, somewhere in the middle).
At moment the fastest and easiest solution - replace CHRRAM chip in FDS adaptor with 120ns or faster. I would go at least 100ns.
Quote from: 80sFREAK on July 05, 2014, 03:28:22 am
http://www.geocities.jp/atx197/FC_HVC-CPU-05_03.pdf here is redrawn diagram. Thanks to Junker.
IIRC some earlier PCB's utilized 74HC373 (which is much faster, but there also was small capacitor on "Clk"), but later revisions 74LS373.
Also eveone knows about different revisions of PPU(i have D, E, G in my collection somewhere in the boxes).
What else? The capacitor on /RD line(it is behind slot, somewhere in the middle).
At moment the fastest and easiest solution - replace CHRRAM chip in FDS adaptor with 120ns or faster. I would go at least 100ns.
That makes sense.
It seems that HVC-CPU(-01) to HVC-CPU-05 use 74LS373 chips, then 06 (maybe not all?), 07 and 08 boards use 74HC373 chips. And then HVC-CPU-GPM-01 and 02 use 74LS373 again.
Here are a few pics:
http://blog-imgs-38.fc2.com/o/f/f/offgao/IMG_0353_.jpg (HVC-CPU)
http://blog-imgs-38.fc2.com/o/f/f/offgao/HVC-CPU-06_OLD_FRONT.jpg (HVC-CPU-05)
http://blog-imgs-38.fc2.com/o/f/f/offgao/HVC-CPU-06_OLD_FRONT.jpg (HVC-CPU-06, interestingly the boards says "HC" but the chip is an "LS")
http://blog-imgs-38.fc2.com/o/f/f/offgao/img007.jpg (HVC-CPU-07)
http://blog-imgs-38.fc2.com/o/f/f/offgao/IMG_0288_.jpg (HVC-CPU-08)
http://blog-imgs-38.fc2.com/o/f/f/offgao/IMG_0483_.jpg (HVC-CPU-GPM-01)
I actually stumbled upon that exact site earlier today, there's an interesting schematic of the different revisions of HVC-FMR.
http://www.geocities.jp/atx197/FC_HVC-FMR-01-04_05.pdf
There are a few more differences than what I thought when I took a quick glance to the boards themselves.
Notably, FMR-04 apparently has a connection to CLK from the D-RAM chip that is absent from the earlier revisions.
The SRAM in the FDS RAM adapter alone can't be the complete answer. I have an FMR-04 which has a CXK5864P-15 chip, and a FMR-03 which has a CXK5864PN-15L.
Both have the exact same response time (150ns), yet the FMR-04 works with HVC-CPU-GPM-02, and the FMR-03 doesn't.
So this LS/HC theory on the Famicom side definitely seems credible.
Quote from: oare on July 05, 2014, 04:32:38 am
The SRAM in the FDS RAM adapter alone can't be the complete answer. I have an FMR-04 which has a CXK5864P-15 chip, and a FMR-03 which has a CXK5864PN-15L.
Both have the exact same response time (150ns), yet the FMR-04 works with HVC-CPU-GPM-02, and the FMR-03 doesn't.
So this LS/HC theory on the Famicom side definitely seems credible.
And you forgot about date code ::)
The dates, I gave in my previous posts (5I 64 for the FMR-03 CXK5864PN-15L chip and 6I 12 for the FMR-04 CXK5864P-15 , if memory serves)
At this point, I'm really skeptical the 8K chip date and maker account for much, honestly.
I mean, at least 3 different makers (Sony, Hitachi and NEC) having a similar issue on chips produced over a 6 months span?
That seems unlikely.
Anyways...
Plot twist!
I took a look at my reference HVC-CPU-07 board. While the board says 74HC373, the chip itself is a 74LS373 (like the 06 board in the links given above).
Here's a pic.
(http://i59.tinypic.com/2mhakp4.jpg)
I've looked at my two other 07 boards, they are both equipped with LS chips too, although the board itself says "HC".
So the practice appears to have at least been common.
Yet, all three work with the HVC-FMR-03 in all previously given configurations (Sony SRAM, Hitachi SRAM, Fujitsu D-RAM, Motorola D-RAM), whereas my ref. HVC-CPU-GPM-02 (obviously also equipped with an LS chip) doesn't.
Back to square one, I guess.
I'll definitely try that 100ns SRAM chip solution as soon as I can.
But IIRC there's apparently at least one user in the other thread who reports a failure with an even faster 80ns chip. So speed may not be the sole issue.
I'm really curious to know what exactly is causing those problems.
4 separate 16K D-RAM chips (FMR-03) vs 1 unique 32K D-RAM chip (FMR-04). A slightly different schematic. Different CPU revisions on the Famicom side. Different GPU revisions. Different motherboards in both the Famicoms and the RAM adapters, even. That's a lot of options...
Maybe it's just wear. But then again... Three different makers, over a span of 6 months at least? Plus a consistent working/non-working behavior depending on the Famicom board revision?
That's far fetched, at best.
You can replace 74LS373 with 74HC373, but you have to add C21.
Quote from: oare on July 03, 2014, 06:35:43 pm
My FMR-03s units both have a smooth plastic top enclosure, whereas my FMR-04s have a rough plastic top enclosure. I'm not sure how precise a visual clue that is, since there might be some overslap between the revisions. But if others can confirm this observation, it might be safer to try and avoid smooth plastic RAM adapters in general, especially if you own a Famicom that has the "FF" logo on the front panel.
Edit: a little update, I tried replacing the Sony S-RAM chip with a Hitachi chip (the "no-name" chip on FredJ's pic), and the glitches are still present.
I'll try replacing the D-RAM chips when I have some free time and see how that goes.
After all, those D-RAM pieces are the main difference between FMR-03 and FMR-04, so those might as well be the real culprit here.
I have now tried another 3 RAM adapters.
1 FMR-04, that worked fine.
1 FMR-03 with smooth plastic - worked fine
1 FMR-03 with rough plastic - glitched a little on one console. Not as much as my last glitching RAM adapter.
Funny thing is, I tried on two GPM-02 consoles. It only glitched on one of them
(http://i.imgur.com/OvVpdg6.jpg) (http://imgur.com/OvVpdg6)
^^ rough plastic, some glitching on one GPM-02 console. (is playable)
(http://i.imgur.com/dysETx9.jpg) (http://imgur.com/dysETx9)
^^ smooth plastic, no glitching
(http://i.imgur.com/Ij2HzkX.jpg) (http://imgur.com/Ij2HzkX)
^^ BUT, my non-glitching famicom GPM-02 is of a late model. Serial no HC52xxxx. Though the chips appear identical to the one on http://famicomworld.com/workshop/tech/square-button-famicom/
It is probably some degenerating problem that affects some chips, in combination with some later consoles that might possibly also have degenerating chips. If they are degenerating, it isn't just because of bad chips but because of lots of use.
Quote from: fredJ on July 06, 2014, 04:11:37 am
I have now tried another 3 RAM adapters.
1 FMR-04, that worked fine.
1 FMR-03 with smooth plastic - worked fine
1 FMR-03 with rough plastic - glitched a little on one console. Not as much as my last glitching RAM adapter.
(...)
Excellent!
Thanks for the report.
The more evidence we gather, the easier it becomes to rule out hypotheses.
This definitely seems to point towards wear as a culprit, on at least one component.
This would be consistent with some of the posts in the other thread: one of the posters claims he possesses one FMR-03 with the 4 16KB D-RAM chips that "runs fine", while another one "causes glitches" (supposing he tried both on the same consoles).
I've tried to look for clues on the Japanese side of the Internet. While some users just brushed off the issue as "a compatibility issues between some Famicom models and some RAM adapters", others were claiming their "RAM adapters
went bad with time", seemingly implying they used the same RAM adapter on a unique console, and witnessed the degrading over the span of a few years. Which, again, would mean some manifestation of wear.
There is, however, very little information available, so nothing conclusive.
It might be components that go bad.
It might even be possible that the issue is entirely mechanical. Maybe its just the cartridge slot.
Or maybe it's components that need reflowing - but not always the same ones.
This would explain why 80'sFreak has had success with simply replacing the SRAM chip, while this solution proved useless for others.
I 'll try reflowing my 03 adapters' cartridge pins, it's pretty much the only area that has been left untouched.
It's a long shot, especially since I have already - unsuccessfully - tried pushing the pins while the device was on (during the loading sequence) in order to see if it was just a contacting issue.
In the meantime, if anybody can make more tests on a wider variety of machines, that would be really helpful.
Maybe you could try replacing the S-RAM with a chip of 100ns or faster?
I think the Hitachi chip you tried is 120nS.
There is one in Dragon Quest V (SFC).
If there is degrading somewhere, maybe we need to increase the speed that data is passed through or calculated.
I made a video that explains
"The mysterious famicom disk system glitching"
https://www.youtube.com/watch?v=7qsfqbfB0IU
Sorry about my crappy camera, I'm trying to find a better (for cheap)...
Thanks for the video.
AFAIK famicoms with "FF" have PPU rev G and twins have rev E. What s the difference? Hard to tell until someone decapsulate both, take photos of the silicon and compare.
Why to replace CHRRAM but the other? Because we have chioce of SRAM chips, not PPU, isn't it?
I think this issue related not only to the speed of the chip, but input capacitance, which loading PPU slightly diffrent and shape of controlling signals might change enough to produce glitches.
I have now tried with an AV Famicom, board hvcn-cpu-02.
And.. it did not glitch.
So that is some good news. Only the 1989 famicom board famicom glitches. It means that high end users don't have to worry and that one could say it is a built in problem with the console model rather than a defective RAM adapter.
Good, what PPU revision does that AV Famicom have?
FredJ sent me a glitchy RAM-adapter to test with.
I noticed some flickering sprites when checking the PRG datalines with my Oscilloscope. So I thought there must be some CMOS/TTL mix?
These are pictures from SMB All night Nippon and Mario Golf Without any modification:
(http://i1286.photobucket.com/albums/a615/Trozze/Disksystem/AfterMario_zps44b0f819.jpg)(http://i1286.photobucket.com/albums/a615/Trozze/Disksystem/Golf1_zps7288d23a.jpg)
If I soldered in a 10Kohm resistor-array on the PRG datalines to Ground, it improved.
(http://i1286.photobucket.com/albums/a615/Trozze/Disksystem/10K_zpse3e53520.jpg)
Mario had no glitches anymore. Golf however had one sprite not working.
(http://i1286.photobucket.com/albums/a615/Trozze/Disksystem/BeforeMario_zpsb23126fb.jpg)(http://i1286.photobucket.com/albums/a615/Trozze/Disksystem/Golf2_zps0dc50121.jpg)
Replacing the 10Kohm resistors with 4.7Kohm solved the problem! I had no resistor-array for 4.7k so i had so make my own Ghetto Style 8)
(http://i1286.photobucket.com/albums/a615/Trozze/Disksystem/47K_zpsd2aa6793.jpg)
(http://i1286.photobucket.com/albums/a615/Trozze/Disksystem/Golf3_zps63adf677.jpg)
Further testing should be done, I don't know if this causes any other problem and damages any components, so it should only be for testing.
well, this method fixed mine! I had some glitchy sprites on golf, mario, and metroid on my fds and I figured I'd give it a shot... I used a 4.7 array as suggested, and viola! everything looks clearer now! Thanks so much for the suggestion!
Side note: lay the resistor array down against the board before soldering it, and it will sit low enough to put everything back in the case when your done.
I'm not very good with this sort of stuff, does anyone have a more in depth tutorial about the above fix? :-[
Sorry for digging this up from the grave.
This is more of an informational post
I am having this problem on my NES front loader. The following values all have shown visual improvement (I don't have O scope). In all cases I am using a resistor array on a -04 ram board. My test condition is the second level of Castlevania, both on a disk and the FDSstick.
3.9k
4.7k
5.6k
5.1k
6.8k
10k
Update 11/21: Tested on a second NES (1st unit is a -08 NES second is a -11), No Change
Tested 10k, no change
Still waiting on the smooth ram adaptor, and I forgot to order a 3.1k. I have a Hi Def NES I need to install, I might install and see if there is a change.
Update 11/27: Hi-Def NES fixed it, however I had the game "crash" in a complete glitch. Could not get the FDStick to work either (audio only, no video). Worked with an actual FDS. Need more time to play around.
Update 12/03: I've bought way too much Nintendo stuff. Glitchy ram adaptor is working on the Hi-Def NES as long as I am using a FDS, not FDSstick. I suspect a power issue. Glitch Ram adaptor is working on a Top Loading NES, and an RetroUSB AVS. My smooth ram adaptor is currently MIA. I may or may not update this post again
Quote from: Jaek_3 on September 30, 2015, 02:26:31 pm
I'm not very good with this sort of stuff, does anyone have a more in depth tutorial about the above fix? :-[
Finally:
(http://i67.tinypic.com/2llp0mv.jpg)
The ground wire is to connect to the resistor pin with a DOT. Important.
So I recently got some RAM adapters and I can also confirm that about half of FMR-03's will have glitchy sprites. Out of the 5 I had, 3 of them had the glitch on my 'FF' GPM-02 Famicom. 1 of the 3 RAM adapters had the smooth plastic casing.
I will attempt the 4.7k resistor fix once I get my hands on some.
Just want to add that I am also getting the glitch sprites problem on all my FDS games. I got my FDS today and was so happy to get 15 games in mint condition with it! 14 of the 15 games work, but all of those 14 have the sprites issue and no other issues.
I did thorough cleaning of my RAM adapter pins and console too, like many. Wiggling the RAM adapter around in the console didn't change a thing.
Famicom model: HVC-101
RAM adapter revision: HVC-FMR-03 with a SONY chip, see pic
I also have an FDStick on the way, but If I read this thread correctly, then that alone won't solve the glitches.
I'll be getting a RetroUSB AVS in the next month or so, perhaps my RAM adapter will work on that.
But at the moment since I suck at soldering (and unaware of possible side effects with that resistor array mod fix), I think my solution will be to just buy another RAM adapter - the 04 model from ebay if I can even ask sellers to open the thing to check - and hope that works on my Famicom AV and AVS.
Wow, so the RAM adapter isn't working on your AV Famicom toploader? This is a new discovery.
I may be able to help you with getting a new RAM adapter. Message me! :question:
Messaged you. Am I the only one in the thread with the problem on the revision 03 adapter with an unmodded toploader?
I got my resistor arrays in the mail the other day and soldered them into 6 glitchy RAM adapters. They all work perfectly now! This method works ;) :star:
can you send me a link to which array you purchased? i actually want to use this on an fds to NES adapter my friend murmasa made. has the sprite glitch with ram adapters but not an N8, and want to see if installing this on one of my ram adapters will remedy the situation a bit.
http://www.ebay.ca/itm/20PCS-Thick-Film-Network-Resistor-SIP9-4k7-4-7K-Ohm-NEW-Array-Resistor-/351588185762?hash=item51dc49f6a2:g:xjAAAOSwHQ9WVWJ4
^ These were the exact ones I have. If you're in a hurry to buy them, I can sell them to you and have them shipped to you faster for cheap.
Hey everyone, I'd just like to confirm that the revision of RAM adapter FMR-02 also has the glitchy sprite problem. The board looks just like a FMR-03.
I also got a second RAM adapter that doesn't boot the game after it loads and stays stuck on a black screen. I have no idea what to do with them, but my guess is that their RAM chips might be bad? If anyone wants to take a look at it, for science's sake, let me know.
The resistor array fix doesn't do anything for it?
I haven't tried it on the non-booting RAM adapter, it just seems like a different problem altogether.
Hi everyone,
Just wanted to let people know that I have now also done the resistor array fix for my version 3 RAM adapter. Thanks to zmaster18 for posting it to me!
This was my first time ever soldering. Many near-misses and almost burnt my hand... I don't recommend doing this after having a cider...
Anyway, the pics might look a bit messy but I did clean the connections up a bit afterward. When I tested it, at first nothing had happened and the glitch sprites were still there. I was just glad the thing was still operational.
But then I re-soldered a connection that I guessed wasn't that well made, tested it again, and now it works fantastically with all my games! Works with FDS Stick too. One happy gamer here ;D If I can do this with no experience and slightly intoxicated, just about anyone can ;)
I'll post an update when I get my AVS NES and original Famicom. Right now all I have is a Japanese A/V Famicom.
Quote from: xwred5 on November 03, 2016, 07:44:51 pm
Sorry for digging this up from the grave.
This is more of an informational post
I am having this problem on my NES front loader. The following values all have shown visual improvement (I don't have O scope). In all cases I am using a resistor array on a -04 ram board. My test condition is the second level of Castlevania, both on a disk and the FDSstick.
3.9k
4.7k
5.6k
5.1k
6.8k
10k
Update 11/21: Tested on a second NES (1st unit is a -08 NES second is a -11), No Change
Tested 10k, no change
Still waiting on the smooth ram adaptor, and I forgot to order a 3.1k. I have a Hi Def NES I need to install, I might install and see if there is a change.
Update 11/27: Hi-Def NES fixed it, however I had the game "crash" in a complete glitch. Could not get the FDStick to work either (audio only, no video). Worked with an actual FDS. Need more time to play around.
Update 12/03: I've bought way too much Nintendo stuff. Glitchy ram adaptor is working on the Hi-Def NES as long as I am using a FDS, not FDSstick. I suspect a power issue. Glitch Ram adaptor is working on a Top Loading NES, and an RetroUSB AVS. My smooth ram adaptor is currently MIA. I may or may not update this post again
i have a hi-def modded av famicom and 2 rev-03 ram adapters. in composite mode: everything plays fine but i get glitchy sprites with both the fdsstick and a real fds, on both adapters. in hdmi mode: everything crashes, including the real fds on both adapters
Quote from: zmaster18 on July 25, 2017, 10:43:52 am
I got my resistor arrays in the mail the other day and soldered them into 6 glitchy RAM adapters. They all work perfectly now! This method works ;) :star:
According to my colleague, the fix forces the correct values into the console, so it is a pretty good fix to do. Also because it is quite difficult to test a RAM adapter on every possible problem console.
Would your colleague know how to fix RAM adapters that simply don't load the game? I have 2 RAM adapters that work fine, load the game, get the black screen with Nintendo copyright text, followed by a black screen. The game doesn't boot after that.
I suspect it's a RAM chip issue, but I really don't know. I'd be willing to mail the adapter to you guys, for scientific research. ;D
My very limited knowledge of digital logic is that when you attach a resistor between a data line and ground like this, it's called a pull-down resistor. It makes sure that voltage is 0 V when nothing is connected (the game is sending 0s) to the data line. Otherwise it's possible that it sometimes reads the 0s as 1s and things gets messed up.
A wild guess is that if some of these data lines that are crucial for anything to be displayed at all, it could be enough that that one gets the wrong value for nothing to work. In other words, maybe the pull-down resistor array is worth a shot on those non-working RAM Adapters as well.