I'm trying to translate games by Waixing or Nanjing, but I can't figure out how to read and change the Chinese text. No hex editor seems to be able to read them since they are 16 bit characters, plus I can't use a disassembler because the games all use illegal opcodes so it just errors out.

Anyone have any tips? Maybe a hex editor that actually supports Chinese ROMs? Or a disassembler that supports weird mappers?