Cart to FDS conversions?

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

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marcosmoutta
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Cart to FDS conversions?

Post by marcosmoutta »

Here's something quite absurd I found.

Image

Is this real? Were these dumped? Could games without mappers/with simple mappers be easily converted to FDS?
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Memblers
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Re: Cart to FDS conversions?

Post by Memblers »

Probably real, no idea if it's dumped.

I'd guess it's almost certainly something for a Game Doctor, or other type of cartridge emulator device that uses the FDS. It wouldn't work with a plain FDS. https://www.famicomdisksystem.com/game-doctor-copiers/

I think NROM and CNROM games would be portable to FDS, it's not necessarily easy though because it would have to be completely reassembled to work at different addresses. Any cart that uses PRG bankswitching is going to need some extreme modifications done to it, too much for anyone to really do in most cases, I'd estimate.
NewRisingSun
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Re: Cart to FDS conversions?

Post by NewRisingSun »

Yes, Rockman for Game Doctor is dumped. :) You may find it "absurd", but there was a whole cottage industry in Taiwan and Hong Kong in the late 1980s and early 1990s about it. Ever since emulation came along in 1996, people have expressed a rather unjustified sneer at these devices, even as technically, they are no different from the flashcarts of today, except that they load games from floppy disks rather than SD cards, and that the earliest devices only supported discrete mappers natively.
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aquasnake
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Re: Cart to FDS conversions?

Post by aquasnake »

Front Fareast implemented the disk system and converted some mappers of NES to its unique image. Bung later expanded some other functions.

For the most complete version of bung doctor PC Jr., it can realize the old mode of mapper #0, #2, #3, #29, #66 including FFE, the expanded mode of mapper #1, #4, #9, and a new mode of customized 8kx4 PRG + 1kx8 CHR
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togemet2
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Re: Cart to FDS conversions?

Post by togemet2 »

Memblers wrote: Thu Jan 27, 2022 11:20 pm I think NROM and CNROM games would be portable to FDS, it's not necessarily easy though because it would have to be completely reassembled to work at different addresses. Any cart that uses PRG bankswitching is going to need some extreme modifications done to it, too much for anyone to really do in most cases, I'd estimate.
If I recall, there were quite a few piracy devices which which could convert any NROM game to disk. I believe those even worked without the need for a Game Doctor or similar device to play them, although of course, any other mappers would require one.
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Memblers
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Re: Cart to FDS conversions?

Post by Memblers »

togemet2 wrote: Tue May 24, 2022 9:17 pm
Memblers wrote: Thu Jan 27, 2022 11:20 pm I think NROM and CNROM games would be portable to FDS, it's not necessarily easy though because it would have to be completely reassembled to work at different addresses. Any cart that uses PRG bankswitching is going to need some extreme modifications done to it, too much for anyone to really do in most cases, I'd estimate.
If I recall, there were quite a few piracy devices which which could convert any NROM game to disk. I believe those even worked without the need for a Game Doctor or similar device to play them, although of course, any other mappers would require one.
The main problem is BIOS on the FDS RAM adapter sits at $E000-$FFFF. So at the least, everything there there must be relocated. If there are some NROM to "stock" FDS conversions, I'd be surprised if they weren't made by hand.
NewRisingSun
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Re: Cart to FDS conversions?

Post by NewRisingSun »

The simplest devices for that purpose were plug-through devices with a switch that just remapped 6000-7FFF to E000-FFFF. The disk would contain the unmodified NROM game, 32+8K, that of course would crash or display a BIOS error message after loading from disk since the reset vector is not where it should be. Then you would flip the memory remap switch and soft-reset the console, and the game would run. These devices were home-made and had no brand name.
lidnariq
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Re: Cart to FDS conversions?

Post by lidnariq »

I see the logic for that is just one chip (a 74'00) and a single-pole-double-throw switch:

+ROMSEL=NAND2(/ROMSEL,/ROMSEL)
/TopQuarter=NAND2(A13,A14)
NROM_MODE_/ROMSEL=NAND2(+ROMSEL,/TopQuarter)

Switch selects between plain /ROMSEL and NROM_MODE_/ROMSEL...

Do we know of any pictures of any such projects? Even though it's simple it'd be neat to see one.
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togemet2
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Re: Cart to FDS conversions?

Post by togemet2 »

Ahhh, guess I must've been mistaken about them being able to run stock then.
Had no clue that they were really that simple. Would also love some photos of the insides of one! :)
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NewRisingSun
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Re: Cart to FDS conversions?

Post by NewRisingSun »

lidnariq wrote: Wed May 25, 2022 2:22 amDo we know of any pictures of any such projects? Even though it's simple it'd be neat to see one.
Only outside view:

https://youtu.be/BhYyrM9VA0c?t=2127

Tomy said it had two TTL ICs inside.
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togemet2
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Re: Cart to FDS conversions?

Post by togemet2 »

Rare footage like this is amazing! Thanks for sharing.
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