Space Invaders SNES rom on GB cart

Discussion of programming and development for the original Game Boy and Game Boy Color.
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Gamester
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Space Invaders SNES rom on GB cart

Post by Gamester »

it is possible to extract/replace the snes rom inside the gb rom that you can play with super game?
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MottZilla
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Post by MottZilla »

You can't replace it with another game like for example, Super Castlevania IV. The SNES Space Invaders is designed specifically to run on the Super Gameboy. I'm not sure on the details but the way things are accessed wouldn't allow for typical SNES games to run that way.

If you knew enough about the Super Gameboy you could make your own GB game/cart that would work with the Super Gameboy hardware to use the SNES hardware. Would be pointless though other than as a technical achievement.
tepples
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Post by tepples »

Might the difference be that Super NES games booted through Super Game Boy have to fit entirely into the Super NES's RAM? I assume so, because that's how the "multiboot" mode on a later Nintendo product works.
Gamester
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Post by Gamester »

thanks for reply

i think that it is a normal snes rom file because its loaded into snes

-how can i indentify the snes rom (maybe some sort of header?)
-it it possible to rip rom the loader ?


ill try to boot mini games (or maybe own code) from gb usb flash cart 64M.

I did some research and found most of the snes space invader code in the gb rom.
Near
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Post by Near »

The game loads from the GB cart into SNES RAM, 128KB of it total. The game and its RAM has to fit in there. Once the code is there, the game takes complete control of the SNES and doesn't utilize the cartridge bus at all again.

Unfortunately, the ICD2 doesn't have a passthru to read the raw Game Boy ROM, so that's all the info you can have.

Ripping that out won't run directly, you'll have to write your own ROM reset vector that transfers the game into RAM and then jumps into it. Shouldn't be too difficult, but good luck all the same.

If you want an "easy" mode, try dumping the 128K WRAM from bsnes while the game is loaded (probably have to add a WRAM dump yourself or look at older debugger builds), write a simple uploader, and read pandocs to see where the SGB BIOS jumps to to start execution, and mimic that jump.
tepples
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Post by tepples »

byuu wrote:Unfortunately, the ICD2 doesn't have a passthru to read the raw Game Boy ROM, so that's all the info you can have.
But can the running SNES program still communicate with the Game Boy in any manner? If so, it could use the Game Boy as a NAS of sorts, requesting files from the Game Boy ROM that get sent through the same link through which borders are sent.

[puts on realist hat]
All this to use your Game Boy flash cartridge instead of your PowerPak. It isn't even easy to find those; perhaps the last made in any sort of quantity were the Visoly GBA carts with the GB Bridge adapter.

[puts on idealist hat again]
But the design of a mechanism to store a file system on a Game Boy cart wouldn't be too different from one to store a file system on a PC link device connecting to controller port 2 or the clock port on the bottom, allowing for real quick debugging of tiny "multiboot" games.
Gamester
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Post by Gamester »

so i replaced the rom in the Europen gameboy version of Space invaders
with the euro snes version and it is booting but says "this gamepak is not
designed for your super famicom or super nes"

so is there a way to turn bsnes into pal mode


its not that i really want to use it as anyday solution therefore i have a
GameDoctor. It just for fun.you know see if it is possible.



edit
tested on real hardware and it work the menu is glichty but the game runs
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MottZilla
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Post by MottZilla »

Byuu, if it loads entirely into RAM, what about the CPU vectors which are still located in banks occupied by the SGB BIOS? Does the game program run without every triggering any need for CPU vectors, or does the SGB have a system, sort of like the FDS BIOS, for handling the Vectors?
mic_
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Post by mic_ »

[puts on realist hat]
All this to use your Game Boy flash cartridge instead of your PowerPak. It isn't even easy to find those; perhaps the last made in any sort of quantity were the Visoly GBA carts with the GB Bridge adapter.
Quite easy actually.
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