This is the most advanced version of Game Genie Code Convertor I could find.
Game Genie Code Convertor 4.0
A good source for understanding several Assembly commands:
http://einsteinsbreakfast.com/snes/docs/65816/ASM hacking.txt
ASM_hacking.txt
A good source for understanding 6502 Assembly:
http://www.defence-force.org/computing/oric/coding/annexe_2/
6502 Assembly
This is a backup of the File2File program, since it got deleted on the forums:
File2File101.zip
This is a version of Gens that can find PAR codes. Use the 'Cheat>Search GG Codes' menu to be able to find PAR addresses
Gens210-mk2-bin.zip
One of the programs that's harder to get ahold of is a program to permanantly apply Game Genie codes. UCON64 is a command line tool that can apply Game Genie codes to an SNES, NES, Gameboy, Genesis, or Game Gear ROM, which can be a helpful and hard-to-find feature.
UCON64 Homepage