I write a little newsletter once a month. This month I wrote about hacking ZX Spectrum games using a Multiface One.
The Multiface was similar to Datel's Action Replay cartridge for the Commodore 64. A push of the magic red button and you've got access to a monitor and hex editor. The creator's Genie software added a disassembler into the mix. I wrote the walkthrough with emulation in mind, but the same techniques will work on the real deal, they'll just take longer to load.
But this did get me thinking, has anyone done anything like this for the C64 and Action Replay? I know RetroLab covered bypassing protection in F/A 18 Interceptor on the Amiga 500, but I'd like to learn more about the C64 as I never really touched it growing up.