M.2640 is a miniature, single-board computer produced by the BBC as part of their PG Mini series. It is based around a 16-bit Acorn RISC Machine (ARM) processor and includes 128 KB of RAM and 32 KB of ROM, as well as a 16MHz oscillator to help keep time for the computer. It has a range of peripherals, including an Audio Input/Output (AIO) port, a General Purpose Input/Output (GPIO) port, and a synchronous serial communications port (SSC) port. It has an expansion port that can be used to connect other devices, such as controllers, displays, and storage devices, as well as its own built-in expansion connectors. The device was designed to be modular, making its maintenance and upgrade process simple.