Multi-memory controllers or memory management controllers (MMC) are different kinds of special chips designed by various video game developers for use in Nintendo Entertainment System (NES) cartridges. These chips extend the capabilities of the original console and make it possible to create NES games with features the original console cannot offer alone. The basic NES hardware supports only 40k of ROM total, up to 32k PRG and 8k CHR, thus only a single tile and sprite table are possible. This limit was rapidly reached within the Famicom's first two years on the market and game developers began requesting a way to expand the console's capabilities.
In the emulation community, these chips are also known as mappers.
