Need advice buying a NES-101 and a flash cart

Discuss hardware-related topics, such as development cartridges, CopyNES, PowerPak, EPROMs, or whatever.

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WedNESday
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Re: Need advice buying a NES-101 and a flash cart

Post by WedNESday »

Ok, so here's the plan.

1. I purchase one of these: https://retrostage.net/?product=retrobl ... rammer-2-0
2. I purchase a American NES cart with battery-backed SRAM (e.g. Zelda 1).
3. I purchase a Game Genie.
4. I purchase a 72 to 60 pin connector (Firstly, the Game Genie was never released in Japan and my NES is Japanese. Secondly, the Game Genie won't fit into a top loader NES anyway and the connector will create some space for it.

Step 1: I flash my ROM to the cart's SRAM
Step 2: I plug it into the Game Genie
Step 3: I plug the Game Genie into the connector
Step 4: I overwrite the reset vector to somewhere within the cart's SRAM
Step 5: Bob suddenly becomes your mother's brother (or at least your father's)

Can anyone see anything wrong with any of the above? :)
lidnariq
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Re: Need advice buying a NES-101 and a flash cart

Post by lidnariq »

Looks fine, but I can't figure out the "why" part...
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Ben Boldt
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Re: Need advice buying a NES-101 and a flash cart

Post by Ben Boldt »

If you use 6-character codes, the same codes will work on any cart.

How about the NMI/v-blank vector? It may create unique challenges to not be able to use that. That will be 4 codes to replace both vectors. You might actually be better off changing the NMI vector only, then when the original game has its first NMI, “re-initializing” in there the first time through.

The 3rd vector is IRQ. If you want MMC3’s scanline interrupts, you probably need 2 genies for 4 (or 6) codes again.

This is going to be an incredibly limited amount of space. You will either need to use the existing game’s CHR-ROM graphics or select a game with CHR-RAM.


Edit:
You know, I think you could make an NSF player this way. The arbitrary code in the PRG-RAM would call the music routines in PRG-ROM exactly the way an NSF file does. Custom code could kludge some graphics, or just have no video enabled. You would have to listen for button presses on the controller to switch tracks, but otherwise I think you could pretty much copy whatever was done in the existing NSF file. It does depend on the music NOT using the PRG-RAM… or working around those areas. It would be an obscure and useless thing, but entertaining to see it. It can be developed with an emulator by editing SAV files.
WedNESday
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Re: Need advice buying a NES-101 and a flash cart

Post by WedNESday »

So I recently got in contact with somebody from https://retrostage.net/ who informed me that their NES flash cart acts the same way as a real NES cart does with no influence over things like open bus behaviour.

So the new plan is to buy one of their programmers and flash boards and do it that way. Then, when I write my test ROM I'll report back to you guys with the results and let you know if that was true or not.
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aquasnake
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Re: Need advice buying a NES-101 and a flash cart

Post by aquasnake »

tokumaru wrote: Sun Jan 02, 2022 4:38 pm The problem with flash carts in general is that while the console is 100% authentic hardware, a flash cart never is. Like Fiskbit said, the menus will temper with the power on state and the mappers will be, at most, as accurate as the reverse engineering efforts made thus far permit. Flash carts are mostly made for players (which are way more numerous), not developers and researchers. If complete accuracy on the cartridge side is a must, I think we're still stuck with what we used to do 20+ years ago: installing sockets on original cartridges and programming EPROMs/FlashROMs...
The flash cart initializes IRAM before entering the game Rom. this initialization may be all 0 or all 1. For some algorithms that rely on the random value of power-on IRAM as pseudo-random number generator, it will generate a fixed status flag, which will always be the same. This is the difference between it and the original cart.


In terms of hardware, small timing differences also exist, but for most game developers or technicians, flash cart is still the most suitable hardware debugging tool
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gauauu
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Re: Need advice buying a NES-101 and a flash cart

Post by gauauu »

In terms of hardware, small timing differences also exist, but for most game developers or technicians, flash cart is still the most suitable hardware debugging tool
I will agree that it's a good first start to ensure your game runs on hardware. But you'll also want to do real testing on "the real thing" for whatever your target board is. Flash carts can and do miss weird edge cases.
WedNESday
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Re: Need advice buying a NES-101 and a flash cart

Post by WedNESday »

gauauu wrote: Wed Jan 12, 2022 8:10 amI will agree that it's a good first start to ensure your game runs on hardware. But you'll also want to do real testing on "the real thing" for whatever your target board is. Flash carts can and do miss weird edge cases.
Fascinating. The support team at retrostage.net assured me that the cart behaves in the exact same manner as a real cart. The board certainly looks simple enough to not have anything on it that would influence anything of importance but only thorough testing will reveal if that's the case or not.

I'm actually already really looking forward to running my tests and reporting what I find on this forum. I have this feeling that it's gonna lead to some interesting comparisons between carts, consoles and flash carts.
calima
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Re: Need advice buying a NES-101 and a flash cart

Post by calima »

Now you've confused wedNESday again :P

When the above two posts say flashcart, they mean Everdrive. Retrostage's boards are *not* flashcarts, they are flashable repro boards.
WedNESday
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Re: Need advice buying a NES-101 and a flash cart

Post by WedNESday »

calima wrote: Wed Jan 12, 2022 9:01 amNow you've confused wedNESday again :P

When the above two posts say flashcart, they mean Everdrive. Retrostage's boards are *not* flashcarts, they are flashable repro boards.
I was using the two interchangeably. :lol:
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gauauu
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Re: Need advice buying a NES-101 and a flash cart

Post by gauauu »

When the above two posts say flashcart, they mean Everdrive. Retrostage's boards are *not* flashcarts, they are flashable repro boards.
Yeah, the terminology is bad.

When I said "flash cart" I meant multi-cart things like the powerpak or Everdrive that use SD or compact flash, and have additional hardware that tried to make it act like a normal mapper.

Retrostage's carts are regular cartridges, but use a flash rom instead of a mask rom. They're not included in what I casually referred to as "flash carts". (The only edge cases with them is the remote possibility where if you sent a specific set of writes to the cartridge, you could erase or reflash the rom. But the chances of that happening accidentally are basically zero and can practically be ignored)
WedNESday
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Re: Need advice buying a NES-101 and a flash cart

Post by WedNESday »

Just a little update for you guys. The console was supposed to come yesterday and according to DHL, it did. The problem is, I haven't received it yet. They claim that it was signed for by somebody with a really weird name and that they are gonna look into it.

I now have this horrible feeling that the package has been lost forever. I did insure it for the correct amount but this particular one was in amazing condition at a really great price. :(

Edit: A neighbour had it the whole time... :roll: :lol:
WedNESday
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Re: Need advice buying a NES-101 and a flash cart

Post by WedNESday »

In a bit of a pickle here. The console came with some random game and I hooked everything up. As soon as I plugged in the power adapter it started to make a loud buzzing sound for about 30 seconds followed by a loud CLICK.

I got a new USB capture device but OBS doesn't receive any signal from the console and there's no LED light to tell if it has power or not. Is the power adapter broken? It was a Japanese one plugged into an EU socket adapter. It doesn't generate any heat no matter how long it is plugged in for.
Joe
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Re: Need advice buying a NES-101 and a flash cart

Post by Joe »

Was that a voltage converter, or just a socket adapter? The Japanese AC adapter works only with 100V. Plugging it in to your >200V will fry it, and might damage the console too.
WedNESday
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Re: Need advice buying a NES-101 and a flash cart

Post by WedNESday »

Joe wrote: Wed Feb 02, 2022 11:45 am Was that a voltage converter, or just a socket adapter? The Japanese AC adapter works only with 100V. Plugging it in to your >200V will fry it, and might damage the console too.
The actual 2 pin power adapter that came with it. It was plugged into this...

https://www.hama.com/00121999/hama-univ ... th-contact

...before being plugged into the wall. Holy shit, I never knew that about voltage. :shock:
Joe
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Re: Need advice buying a NES-101 and a flash cart

Post by Joe »

Sounds like you need a new power adapter.

Hopefully the Famicom still works.
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