Mod chip

A modchip is a device used to circumvent the digital rights management of many popular game consoles, including the Xbox and PlayStation. Almost all modern disc-based console gaming systems, with the notable exception of the Sega Dreamcast have hardware-based schemes that ensure the only officially sanctioned games may be used with the system, also making simple bitwise copying of games impossible. For example, Microsoft must cryptographically "sign" every Xbox game with their 2048-bit private key for it to work in an unmodded Xbox. Modchips circumvent this protection by effectively routing around the security check. Many mod chips require some experience to install, especially since they use soldering, though recently solderless mod chips have made headway.

Xbox modchips now allow a user to completely circumvent the BIOS on-board the video game console's mainboard. This allows a console to run code, such as user-created applications or games not licensed or published by Microsoft. One of the main uses in the modding community of this ability is to provide a non-Microsoft BIOS that does not contain any copyrighted code that will run the Linux Operating System from a DVD or the Xbox hard drive.

Modchips were made illegal in the US by the Digital Millennium Copyright Act (DMCA). This angered many people because they couldn't play homemade games. In early 2003, iSONEWS.com was taken over for selling modchips.