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PostPosted: Sun Oct 09, 2005 1:22 pm 
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Hey as I am quite the n00b, this question may be oversimplified, but Ive been messing with rom hacking recently and ive been looking a lot at cory arcangels stuff. hes released his source so i think its a valuable tool for learning. i noticed that he took out the character data from smb to use in his hack, which he did by taking the lower 8k from the ROM, the question is when can you or cant you do this? I want to do a hack of megaman 1, but it uses mapper#2, which ive seen described as 128k PRG / 0k CHR. Now, I have to admit, i dont really get how the CHR could be 0k in the first place (does that mean the CHR chip is literally blank) but the thing is is it still possible to extract the CHR data from MM? its not the bottom 8k (right?) but is there another way?

thanks so much for any help


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PostPosted: Sun Oct 09, 2005 2:38 pm 
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Megaman uses the UNROM board, it uses a RAM chip for CHR. So all the CHR data is in the PRG. If it's uncompressed you could use a normal tile editor to view the rom and find them, but if it's stored with compression it'd be a little trickier to extract it.

If nothing else, you could use an emulator like NESten that lets you dump the $0000-$1FFF CHR region, that'll give you a copy of the tiles that are loaded currently.


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PostPosted: Sun Oct 09, 2005 8:04 pm 
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so in other words the graphics are just littered throughout the whole thing? if i could get them isolated and consolidate them into one CHR, would that work for a rom with mapper 0? (obviously id have to lose some of em, but its for a hack anyway)


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PostPosted: Mon Oct 10, 2005 7:44 am 
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If the program just uploads a bunch of CHR into RAM and then never modifies it during the part of the game that your hack represents, that should work. But some games that use CHR RAM continuously rewrite it so that they can perform tile animation.


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