Action Replay
Action Replay devices originated in the early 1980s, with the original Action Replay being released for the Commodore 64. Action Replay devices have been released for every major gaming console and handheld except for the PlayStation 3. Using the Action Replay, players can input codes that change the way that games play. Codes for specific games typically include cheats such as infinite lives, infinite money, the ability to walk through walls or having duplicates of game items that would otherwise be rare.
DS vs. DSi
Despite originating from the same core product line, there are differences between the DS and the DSi. The Nintendo DS features the ability to play both Nintendo DS and Game Boy Advance games by having two different game ports on the console. The DSi has only a Nintendo DS game port but introduces new software and hardware features such as a built-in camera that can take pictures from one of two lenses on the console and the ability to load and play MP3s from an SD memory card.
Action Replay Compatibility
The original Action Replay devices manufactured for the Nintendo DS insert into the console's Game Boy Advance game port. Because the Nintendo DSi does not have a Game Boy Advance port, these Action Replay devices for the DS are unusable on the DSi. Because the Action Replay models for the Nintendo DS aren't compatible with the Nintendo DSi, a new version of Action Replay was released specifically for use with the DSi in October, 2009. As the Action Replay DSi is compatible with the Nintendo DS as well as the DSi, no further DS-specific releases were made.
Firmware Issues
In 2009, Nintendo released new firmware for the Nintendo DSi that introduced anti-hacking and anti-cheating features as a way to combat piracy and online cheating. The new firmware recognized the Action Replay DSi as a cheating device and caused the caused the console to shut down until the Action Replay device was removed. An update for the Action Replay DSi circumvents the anti-cheating features of the Nintendo DSi; the device emulates game data so that the Nintendo DSi will load it, although after it's loaded the Action Replay function is accessible.