Acmlm's Board - I2 Archive - Rom Hacking - Now what?
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HyperLamer
Posts: 5097/8210 |
You should just be able to stick in a bank change instruction though...? |
BGNG
Posts: 48/276 |
Otherwise, I believe that the last bank of PRG-ROM is loaded into the upper memory bank by default, so if the file is simply enlarged, that'd be a bunch of 00's, or the... erm.... BRK opcode? |
Fx3
Posts: 54/80 |
For some unknown reason, a game might write values higher than the actual number of PRG-ROM banks. This way, if you "expand" the game, you WILL HAVE problems. Internal hacking is required in order to trap that invalid value and fix it.
Remember - there's no MAGIC WAND on romhacking. |
Rockman
Posts: 224/250 |
What I did, was for every $4000 bytes I added at the end of the ROM, I increased 0x04 by 1. I never had any problems with SMB3. But with other ROMs, I have. Every game is different. If you need more information, take a look at this. Good luck. |
beneficii
Posts: 146/567 |
Originally posted by Ringodoggie I changed the byte in the NES header to expand PRG-ROM space for my SMB3 hack, and expanded the file size, but a grey screen appears every time I try to play, like a blank ROM.
Doesn't mapper 4 have certain fixed sizes for the ROM?
Also, did you make sure to put the last $4000 bytes of the PRG-ROM in the original game also the last $4000 in your expanded ROM? In mapper 4, the last $4000 bytes of the PRG-ROM are hardwired to certain addresses, depending on your settings. |
Lenophis
Posts: 493/830 |
Originally posted by Kefka Once you add space to a rom, don't you need to rearrange/program everything to make sure it runs properly? I've never expanded though, so perhaps I am just naive.
I believe the master code must be in the last bank of the rom. It's been a while though... =\ |
Kefka
Posts: 3220/3392 |
Once you add space to a rom, don't you need to rearrange/program everything to make sure it runs properly? I've never expanded though, so perhaps I am just naive. |
Ringodoggie
Posts: 207/281 |
I changed the byte in the NES header to expand PRG-ROM space for my SMB3 hack, and expanded the file size, but a grey screen appears every time I try to play, like a blank ROM. |
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