I am very new to working with NES roms. I am trying to programmatically pull the graphics out of the Ultima3, Ultima4, and Ultima5 roms, but aside from Ultima3, I'm not having much luck. I think I might be dealing with some sort of compression on the sprite images. Each rom shows 12 PRG banks in the header, but no CHR banks. I wrote a program that essentially dumps 8x8 sprites to an output file which worked well for Ultima3, but Ultima4 seems to have data between each animation set (typically 8 to 16 sprites). Even after adjusting for this meta data, sprites often degrade to data noise a few sprites in. Oddly, the first few sprites seem just fine so I know I'm offsetting into the ROM correctly to begin with. I've downloaded several tools for exporting tiles, but none of them seem to be able to cope with these roms. I think the majority of them depend on CHR banks containing sprite data.
As you can see the first animation I rip out (composite of 16 8x8 sprites) looks perfect, but the next animation starts out fine, and ends up garbage.
sample.png [ 1.42 KiB | Viewed 1094 times ]
I'm up for trying anything - either a tool that can do this for me or writing my own program to do it.
Thanks!
As you can see the first animation I rip out (composite of 16 8x8 sprites) looks perfect, but the next animation starts out fine, and ends up garbage.
Attachment:
sample.png [ 1.42 KiB | Viewed 1094 times ]
I'm up for trying anything - either a tool that can do this for me or writing my own program to do it.
Thanks!