I've had this module, Games::NES::ROM, sitting on my drive for a while, so i thought i'd push it to CPAN. It's a fun little module that loads up an NES ROM file and parses its contents. It's not a terribly difficult module to understand; read in a few bytes, shift some bits around, save the flags. But, it was interesting to learn about the anatomy of an NES ROM none the less.
The latest edition has a new method:
Given the CHR bank number and index offset of any given sprite, it will return a raw, 4 color, 8x8 image. With a little bit of extra hackery, I was able to generate a 16x32 table of the CHR bank from Super Mario Bros. 1 which, with a grayscale palette, looks like this.