mmc3 proto board
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Author:  prototector [ Tue Oct 27, 2015 9:49 am ]
Post subject:  mmc3 proto board

A few game prototypes on FDS RAM adapters surfaced online over the years, for example on Yahoo Japan Auction. Most of these that I've seen are mmc3 mapper-based games. A seller I contacted claims to have such a prototype of a game, and it's also mmc3. But I'm kind of hesitant about buying, because every one of his other prototypes, all SFC, look like he just put publicly available game ROMs onto EPROM chips, which were then put on the exact same type of dev board. So I'm wondering: could he have done similar, in that he put an mmc3 game onto EPROM chips and placed them on an mmc3 proto board? Would the game even run like that?

Author:  rainwarrior [ Tue Oct 27, 2015 9:55 am ]
Post subject:  Re: mmc3 proto board

The whole point of the prototype boards was that you could replace the EPROM. During development of a prototype, the EPROM would have been changed many, many times. The EPROM that's in there, if authentic, is merely the last one that happened to be in the board.

Yes it's very easy to replace an old EPROM with a new one today, on such a board.

You'd really have to judge the authenticity of the EPROM based on its contents, I think. I don't know why someone would replace an authentic prototype EPROM, unless they thought they could get more money if it was a prototype of a rarer game?

What's the difference to you if it's the "original" EPROM or a new EPROM with identical data? Are you interested in collecting the original EPROM, or are you interested in the data on it, or just interested in a working cartridge? There's no functional difference between a new and old EPROM (except sometimes old ones lose their data over time, corrupting the ROM). I don't know how you'd go about trying to verify that an EPROM itself is old or new; they are standard components and it's very easy to find new old stock of EPROMs too.

Author:  prototector [ Tue Oct 27, 2015 10:32 am ]
Post subject:  Re: mmc3 proto board

No, its because I'm worried whether the guy is selling a legitimate prototype of the game, or if it could just be the retail game on eproms. He's asking for quite a price, so I'm wondering if its possible he's passing off a fake. Obviously, I don't want to be ripped off. As I said, all his other protos look like that's what he did, just burned games on eprom chips and put onto snes dev boards, selling them for lots of money on eBay.

I don't mind if the eproms aren't original; it's the data.

Author:  rainwarrior [ Tue Oct 27, 2015 11:47 am ]
Post subject:  Re: mmc3 proto board

Well, the EPROMs themselves are probably going to look the same whether they've been replaced or not. I don't think you could tell anything useful from a photograph of the EPROM, in most cases.

The board itself, though, is more difficult to fake. Those were custom made by Nintendo, and aren't something that you can just buy like an EPROM. It's theoretically possible for someone to try to do, but I've never heard of it happening. It would be more like trying to forge a painting, whereas forging the EPROM is just like copying a disk. Unless we're talking about an undumped prototype version of a game, it seems to me like the board itself is a more valuable artifact than the EPROM? (There are modern repro/dev boards which would be functionally equivalent to an original Nintendo board, but in general they're easy to tell the difference; since they aren't trying to be a passable fake, they look completely different.)

You could ask the seller for a CRC of the ROM, perhaps? That would let you compare against retail versions or other known versions of the ROM to see if the data is any different. Of course, if they have the CRC it means they've dumped it for themself already, so you won't be the only person with that data if you got it.

Also, since EPROMs can lose their data over time (usually if exposed to UV light through the window), even if there was no difference between the EPROM and a known ROM dump when it was first burned, errors accumulated over time would change the CRC too. So even a unique CRC is not a guarantee of a valid ROM.

Depends on what you value, maybe?

Author:  prototector [ Tue Oct 27, 2015 1:56 pm ]
Post subject:  Re: mmc3 proto board

Ok, so he can indeed download an (mmc3) NES ROM off the internet, burn it to some EPROMs, put them on a PCB in an FDS RAM adapter; it'll work, so he can pass it off as a genuine prototype version of the game.

I don't doubt that the PCB is real; he probably has one or more of them for this purpose, as he's in Japan and he already seems to have tons of long dev boards for SNES. Probably has a connection for the empty boards. I'm not questioning the EPROM chips themselves; nor any of the physical components.

I'll ask him to send me a CRC of the data, but I'm betting he'll say that he doesn't know how. There are no known

Author:  Teancum [ Thu Oct 29, 2015 12:06 pm ]
Post subject:  Re: mmc3 proto board ... n159522003

^^^ I've seen a few blank prototype carts like this sell on yahoo auctions lately. So it is definitely quite possible someone bought a blank one and dropped eproms in.

Author:  prototector [ Thu Oct 29, 2015 4:19 pm ]
Post subject:  Re: mmc3 proto board

Yeah that's basically what all this guys SNES/SFC protos are. All on the same type of long board (but not what's shown in that link). After asking him if he has protos of another game series, from a different account, and he gave a parallel answer (replace all instances of the first series with the second). Yeah I think this guy is a scammer.

Author:  Memblers [ Thu Oct 29, 2015 7:36 pm ]
Post subject:  Re: mmc3 proto board

I remember a while back (12 years ago at least) there was a guy selling lots of bare TKEPROM boards (MMC3 proto/demo NES boards, not FC) on ebay. I can't remember how many exactly, maybe it was 8 in each lot. Sadly, I wanted to put in a last minute bid but missed the end of the auction, nnd it turned out to be the last lot that they listed. They went really cheap (like under $2 per board IIRC). I was pretty bummed at the time. Always wondered what became of those boards, if they became fake protos or just sat on some collector's shelf. I'd imagine the bare boards are more rare than populated ones, but probably not worth as much.

Author:  prototector [ Sat Oct 31, 2015 11:28 am ]
Post subject:  Re: mmc3 proto board

I'll probably expand this topic in the General sub-forum, but focused more on the seller. Despite all of the suspicious aspects, some people believe it could be legitimate. I'd love to get a solid word on this to be sure.

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