Lock-out chip

In a general sense, a lock-out chip is a chip within an electronic device to prevent other manufacturers from using a company's device to perform certain functions.

The most famous example is the lock-out chip found in the Famicom (NES), known also as the Neg-5 Chip, designed to prevent "unlicensed" manufacturers from creating games for the console. The presence of the chip forced unlicensed companies to raise the price of each cartridge (due to the fact a bypass chip had to be added to the cartridge), and allowed Nintendo a tiny foothold for a dubious lawsuit. Though Nintendo never really had a case against these manufacturers, taking them to court was usually enough to render the offending company bankrupt. The one exception is Color Dreams who's religious themed games under the subsidiary Wisdom Tree made Nintendo wary of creating a public backlash for "persecution".