EPROMS in Battle Kid carts

Hello, NESDEV.

I have recently ordered the original "Battle Kid: Fortress of Peril" homebrew for the NES. I was viewing pictures of the cart online and noticed that the PRG ROM chip is what appears to be an EPROM.

I am no fan of the EPROM chips, as they erase themselves over time.

So, my question here is to anyone who has recently purchased this cart: Do they still contain this type of chip?

I have noticed that the newer Battle Kid 2 contains no windowed chips, so I am suspecting that RetroZone in now using one-time burnable ROMs instead.

Also, what memory management controller do the Battle Kid games use?

Thanks!

What chips are on the Battle Kid board, other than the ROM, RAM, and CIClone? If you're uncertain of what mapper you're seeing, that might help you understand what's going on under the hood.

As I understand it, OTP chips nowadays are just UV erasable roms without the window. They will still suffer from bitrot over (a long) time.

The good news is that you can just overwrite any eprom with the data thats supposed to be on there to "refresh" it, that is if it has suffered from bitrot. Don't even have to erase it.

The newer ones use EEPROMs (possibly Flash variant) instead of UVEPROMs. Both have a lifetime somewhere between 20 to 100 years. Both have comparable total reprogramming cycles. The only difference between them is one of them is less tedious to reprogram later.

The set-up cost for a Mask ROM (as you are implying you want) is sufficiently large it's apparently not even close to economically feasible until you're ordering ICs in quantities of millions.

Only the very best games sells millions of copies. I don't know the market, but inserting "tousands" instead of millions in your sentence would probably make it correct. The situation evolved since the '80s though.

Whoops, it looks like I mixed up the MMC with the Mapper.

I don't know for certain, but I think that either an MMC exists on the cart's pcb or it is somehow built into one of the chips. It is quite a large game, so it looks like some sort of MMC is behind it.

Also, the EPROM in the official stock picture of the cart has no sticker or tape over it. Could that potentially be dangerous to the cart?

Again, you sound unsure, and you're being unspecific. Tell me what chips are on the board, and I'll help you understand where the mapper is.


Consider another "Battle" game. Battletoads doesn't have an MMC, VRC, FME, or any other ASIC mapper, yet it's a large game. Instead, it has a couple tiny unassuming 7400 series integrated circuits that act as the mapper. A "discrete" mapper built out of 7400 ICs is unable to provide quite as many services as an ASIC, but in some games, those services are unnecessary. This way, the manufacturer is unburdened with the higher cost of an ASIC.

That's my point (the anymore bit). Most ROM manufactureres don't even manufacture mask ROMs anymore. It's just not worth it unless they're all spinning up a mask for an entirely new silicon die for other functionality (e.g. microcontroller, northbridge, whatever) and even then, most manufacturers have taken to preferred programmable memory to be able to fix things in case something is broken. Nintendo may well be the last company to have had short-ish runs of bare mask roms, in DS cartridges (although I remember someone insinuating they might have programmable too)—everyone else wanted some kind of cryptographic lock with it, or wanted reprogrammability, or had quantities of millions.
Yeah, that's bad. Put metal foil tape or at least electrical tape over it, if it arrives uncovered. I bet it won't, though.

I'll be sure to let you all know the specifics of the Battle Kid cart when it arrives.

Until then, I have found a picture on Screwattack of Battle Kid 2's prototype:

http://www.screwattack.com/news/battle- ... orking-now

I do know at the moment that all of the Homebrew games available on RetroZone use the "ReproPak" PCB, which supports a large amount of mappers.

I have also noticed that, judging by their stock pictures, RetroZone uses EPROMS in nearly every Homebrew game they sell.



Unfortunately, every Battle Kid cart I have seen on the internet has an exposed EPROM window. I will, however, put electrical tape over it once it arrives. I just hope it doesn't void the 60 day warranty.

Keep it in a dark box when you're not playing it, and wait for the 60 days to pass, and then cover the window. The bits basically only erode on exposure to UV; 60 days in indoor lighting away from windows will be fine.

It takes a pretty long time to erase an EPROM without a proper eraser. You might be worried if the EPROM was programmed a long time ago, but a recently programmed one isn't going to be erased unless you make a habit of leaving it out.

I don't think I've seen any Battle Kid cartridge pictures that show the use of an UV EPROM. Even if they did, the colored cartridge case will provide some protection and if you store it in the black dust sleeve that is common it will be just fine. But I think most if not all Battle Kid cartridges (excluding bootlegs) probably use EEPROMs.

On this site, there is a picture of the cart. Although difficult to see, There is a circular shape on the PRG-ROM, which I believe is an EPROM window.
http://chipmusic.org/forums/topic/1093/ ... ed/page/2/

Also, I think I may be getting a little too paranoid about it , but I found this article:
http://my.ais.net/~xtreme/SF/Bit-Rot/

So, I have been wondering, has the technology behind these EPROM chips improved since 1980/1990, so that they are less likely to erase over time?

UVEPROMs have gotten better, and even matured before both types of EEPROMs.

That said, you're really overestimating the rot rate: we're talking about decades for even the first 'PROMs with proper protection, and centuries now.

I can dig up 30-year-old UVEPROM datasheets that specify 20-30 year retention times, and 15-year old ones that specify 150-250 years.
For EEPROMs, those numbers are closer to 15 years old and 8 years old.

tepples has been insisting you say what ICs are on the board so he can tell you what the mapper is, but if you look around you'll see that this question has been answered a long time ago, and tepples has been hinting at the answer you first asked! =)

I am hoping the cart contains UVEPROMS rather than EEPROMS, now that you have mentioned this. And judging by the pictures on the net, I would say they definately do contain UVEPROMS!



Thanks for bringing up that post! So it looks like the game is a UNROM cart.

Then I suggest to make a backup copy; you can then reprogram the EPROM chip if the data is lost.

I would like to do this, however I am not sure if RetroZone/Sivak would allow for it. I like to stay on the legal side of things, so unless the manufacturer gives me permission to, then I probably will not back it up.

On a side note, it would be helpful if RetroZone offered some sort of service that would do that for you. But, it appears that the UVEPROMS, being modern, will last at least a century if kept in good condition, and any copyright on the game should expire by then anways, so that would make it legal to burn a ROM of the game back onto the cart.

Does anyone know if Sivak or RetroZone has mentioned this issue before?

EDIT: I have just emailed their Customer Support now about this, so I will post what they tell me when I get a response.

The cartridges haven't been out for long enough to have any bit rot show up, honestly.

IANACopyrightLawyer, but legal precedent seems to be that if you make the back-up copy yourself and you don't have to circumvent a copy-protection device to do so ("thanks" DMCA) and only one copy is in use at a time, you seem to be ok. And that's the only thing I'll say about it.

After I got my o-scope I read that it has EEPROMS. Lacking a dumper, I still pulled them out and swapped them with ROMs in other things and programmed them to dump them, just so I could have backups for when they rot. Imagine having a nice piece of equipment that has failed simply because some trapped electrons in a component have migrated a few nanometers.

Provided that Disney doesn't dupe legislatures into extending the copyright term again.

RetroZone's support just sent me an email. They basically said:

-The Battle Kid carts do not use UVEPROMS
-There is nothing to tape over (no UV exposure window)
-Opening the cart would not void the warranty anyways
-If something did happen to the game, they are willing to reprogram it
-A problem with the game is extremely rare

I asked them what type of chip they use, but they did not say in the email. The good thing is that, it appears whatever they use is not only reprogramable, but durable as well. I'm not very knowledgeable on computer chips, but if I had to guess, I think they might actually use Flash-NAND chips. According to ebay prices, they seem to be cheap to buy in bulk, they are reprogramable, and, (assuming the data is not erased and written often) supposedly very durable.

When I get the cart I will take a look at the chips and post what I find here.

It's most certainly not NAND, probably NOR if it is indeed flash...

Popped open my BK2 cart and it has a SST 39SF040 which is NOR flash IIRC.

Something I never noticed before though, looks like retrozone doesn't bother to put ANY capacitors on their carts... My BK 1, and Nomolos don't have caps either. Their boards have locations for them, but they're not populated.

Pics or it didn't happen. Front and back. I find that hard to believe.

I looked at my BK1, and it too had unpopulated places for capacitors.

Full resolution in all it's glory. Also funny that the BK2 board says "repropak MMC3" on it, I'm guessing he used his mmc3 board as a starting design and missed the bottom layers silk still being there cause that ain't no mmc3 board...

https://dl.dropboxusercontent.com/u/18341918/nesdev/IMG_0022.JPG
https://dl.dropboxusercontent.com/u/18341918/nesdev/IMG_0021.JPG

Considering the fact they're doing through-hole for everything still it's not too surprising I guess. You can get by without them, and they're a pain to install. It boggles my mind they haven't made the switch to surface mount after all these years and all those carts.

So it appears that the PRG-ROM is Flash Memory-based! Thanks for posting this!

I find it strange that there are no capacitors on the PCB, because every NES game I have opened up contains at least one capacitor. Could this be potentially dangerous to the cart and system?

Also, is the CHR chip a CHR-RAM? It has the circle-imprint on it, which I usually see on SRAM chips.

Battle Kid series uses CHR RAM for juxtaposition.

I hate to ask such a noob question, but will the Battle Kid cart, for the fact that it has no capacitors, wreck my NES (model 001) or itself?

The only carts I have seen with no capacitors are glob-top famicom carts and multicarts, so I assume that they aren't 100% necessary. But Battle Kid has full-sized chips on the board, so I think it might be a different case.

Also, in the case that the cart is damaging, could I solder in capacitors to repair it?

No. The absence of capacitors may make it fail to work, but will not damage anything.

I was just looking at the pictures of the Battle Kid 1 cart infiniteneslives posted and I noticed that the PRG-ROM chip is an ST M27C2001 10B1, which is a OTP EPROM. RetroZone's customer support told me that if a problem occured with the game, it could be reprogrammed. In addition to this, the Battle Kid 2 cart in the picture has a FLASH-NOR EEPROM holding the data, which is guaranteed to hold its data for at least 100 years. So, from what I can gather:

-Pre-Battle Kid 2 carts contain OTP EPROMS
-Post-Battle Kid 2 carts (most likely) contain Flash-NOR EEPROMS

When I get the cart, I will confirm this information.

Also, the ReproPak manual states that U*ROM carts should have three 0.1uF capacitors on the PCB. Should I add them to the Battle Kid cart when it arrives (It shipped today )?

My BK 1 is ~3 years old, I'm guessing he's stopped using OTP EPROMs since then and when I got my BK2 and Nomolos a year ago.

Either way, as long as you don't store your carts on your car's dashboard I'd bet the data will out live you.

Flash is actually nice because you can potentially reflash it yourself using hotswapping or something like a CopyNES. There seem to be some pads on the board that enable/disable writing to different banks of the flash, presumably just gating the write signal.

Good news, I have the cart now .

The PCB revision is 2011, and clearly says "UNROM" under the RetroZone logo. The board contains an SST FLASH-NOR chip for the PRG . The strange thing is, there are three tantalum capacitors on the PCB. I have not seen any Battle Kid 1 or 2 carts (or any RetroZone carts, for that matter) online that visibly contain capacitors, so I am assuming Bunnyboy has started adding them only recently.

I have played the cart for multiple two-hour-long sessions and experienced no trouble whatsoever. Overall, I am pleased with the build quality of the cart .