His script has no copyrighted contents, nor routines which deal with protection circumvention (encryption/decryption of the ROM) so I don't see why DMCA would b

His script has no copyrighted contents, nor routines which deal with protection circumvention (encryption/decryption of the ROM) so I don't see why DMCA would be concerned with the post as written. Now, if the post were to say "the cartridge was protected, so I used hardware X to dump it, and software Y to decrypt it, here are instructions" that'd be circumvention description and thus subject to DMCA. (disclaimer: I am not a lawyer)