The Risc PC (codenamed Medusa) was Acorn Computer's next generation RISC OS/Acorn RISC Machine computer, launched in 1994, which superseded the Acorn Archimedes.
Like the Archimedes, the Risc PC continued the practice of having the RISC OS operating system in a ROM module. Risc PC augmented the ROM-based core OS with a disk-based directory structure containing configuration information, and some applications which had previously been kept in ROM.