ROM Hack GBA ROMs in NES/GB/GBC VC Discussion

[CatmanFan]

Howdy everyone. You might probably know your injected GBA games, with the AGB_FIRM process becoming very popular, and people like @cots and @Asdolo making automated injectors for this. However, it is actually possible to inject GBA ROMs into NES/GB/GBC VC and reveal the underlying GBA emulator that was originally in development by Nintendo.

However, performance with GBA emulation on Virtual Console is slow, and no one has been talking about this anymore, all focused on AGB_FIRM instead. I've been wondering these days how this GBA emulator should work, but there are no videos or screenshots of this yet, just only one single photo from this post:

worth noting the GBA emulation is very poor, very slow and only works on smaller roms i think after about 4MB it will just crash the 3DS

So that's the reason why I created this thread, to discuss about the secret GBA emulator in NES/GB/GBC VC while also begging the question:
How will the New 3DS's souped-up processors affect this emulator?

We can answer this by injecting a GBA ROM into a NES/GB/GBC CIA, then changing the product code to "KTR-P-[XXXX]" rather than "CTR-P-[XXXX]", because KTR refers to the New 3DS (just as CTR refers to the original/old 3DS), and this product code was already in SNES CIAs. This changed product code will flash the CIA to run only on New 3DS systems due to its processing capabilities, throwing up an error message on Old 3DS or 2DS systems. We will then find out how, if possible and/or obvious, this would change the experience. If not, there's pretty much nothing we can do.

Anyone wanting to test this with their 3DS systems is welcome to post their own videos, screenshots or photos in this thread.

 

[ThisIsDaAccount]

I have a n3ds I can test on, but I can't test until probably tomorrow. What good games are under 4 mb?

 

[CatmanFan]

I have a n3ds I can test on, but I can't test until probably tomorrow. What good games are under 4 mb?

Probably Advance Wars (U). Besides that I have a few 4MB GBA ROMs:

• Chu Chu Rocket!
• Ice Age (U)
• Pinky and the Brain: The Masterplan (E)
• The Fairly OddParents: Breakin' Da Rules! (U)
  
• Green Eggs and Ham by Dr. Seuss (U)
• Game & Watch Gallery 4 (U)
• SpongeBob SquarePants and Friends in: Freeze Frame Frenzy (E)
• The Fairly OddParents: Clash with the Anti-World (E)

I'm not probably sure if these can run under the GBA emulator, worth nothing that I don't know if ROMs over 4MB or over and equal to 4MB should crash the 3DS

 

[3DSi Lite & KNUCKLESSSSSS]

@ihaveamac has already made a video of this running in New 3DS mode

 

[ThisIsDaAccount]

Probably Advance Wars (U). Besides that I have a few 4MB GBA ROMs:

• Chu Chu Rocket!
• Ice Age (U)
• Pinky and the Brain: The Masterplan (E)
• The Fairly OddParents: Breakin' Da Rules! (U)
  
• Green Eggs and Ham by Dr. Seuss (U)
• Game & Watch Gallery 4 (U)
• SpongeBob SquarePants and Friends in: Freeze Frame Frenzy (E)
• The Fairly OddParents: Clash with the Anti-World (E)

I'm not probably sure if these can run under the GBA emulator, worth nothing that I don't know if ROMs over 4MB or over and equal to 4MB should crash the 3DS

Ah, ok. If these don't run then I'll try to find something under 4 mb. When I get around to testing these ill report back.

 

[CatmanFan]

@ihaveamac has already made a video of this running in New 3DS mode

It uses HANS to inject GBA ROMs into The Legend of Zelda VC, which I think has the CTR product code instead of the KTR product code with SNES VC. Besides, it's not New 3DS mode anyway. What I want to see is GBA-in-NES CIAs with the KTR product code like with SNES VC, not HANS anyway.

 

[Ryccardo]

We can answer this by injecting a GBA ROM into a NES/GB/GBC CIA, then changing the product code to "KTR-P-[XXXX]" rather than "CTR-P-[XXXX] ...

Nope, memory available and high/low speed are selected by the exheader, and n3ds exclusivity is decided by the icon (smdh)

The product code doesn't matter, in fact if you're making a custom title better use the 15 characters to write something detailed instead of making ugly 4-letter abbreviations (usually without understanding what the middle letter should be)!

 

[ThisIsDaAccount]

Would simply inserting them into SNES VC work then?

 

[Renzo22]

hey this is the first time i ask something (in my terrible english probably), i have a DSTWO in my new 3ds, and i play gba games there, is there a diference in playing in a flashcard or in VC?

 

[Ryccardo]

hey this is the first time i ask something (in my terrible english probably), i have a DSTWO in my new 3ds, and i play gba games there, is there a diference in playing in a flashcard or in VC?

VC cias you normally hear of = hardware virtualization
Dstwo = software emulation (on the flashcard's CPU; as far as the console knows, it's a DS game)
This topic's interest = software emulation in 3DS mode

Each option has different compatibility vs quality tradeoffs for each game

--------------------- MERGED ---------------------------

Would simply inserting them into SNES VC work then?

If the SNES emulator supports GBA, sure: while the source for the Nintendo emulator may be only one, it's compiled with different options (the multiplayer emulator for Pokemon gen 1 doesn't support platforms other than GB/C, for one)

 

[Renzo22]

VC cias you normally hear of = hardware virtualization
Dstwo = software emulation (on the flashcard's CPU; as far as the console knows, it's a DS game)
This topic's interest = software emulation in 3DS mode

Each option has different compatibility vs quality tradeoffs for each game

thanks!

 

[CatmanFan]

If the SNES emulator supports GBA, sure: while the source for the Nintendo emulator may be only one, it's compiled with different options (the multiplayer emulator for Pokemon gen 1 doesn't support platforms other than GB/C, for one)

I don't think SNES emulator supports GBA, being designed exclusively for SNES; I've also looked in the ROMFS of a particular SNES CIA and it doesn't have the "agb.bin" file as in NES/GB/GBC VC. Hopefully it will be possible to inject New GBA VC, if there will ever be such a thing as New GBA VC as Nintendo hasn't announced GBA games on New 3DS yet.