RISC OS /rɪskoʊˈɛs/ is a computer operating system originally designed by Acorn Computers Ltd in Cambridge, England. First released in 1987, it was specifically designed to run on the ARM chipset, which Acorn had designed concurrently for use in its new line of Archimedes personal computers. RISC OS takes its name from the RISC (reduced instruction set computing) architecture supported.Between 1987 and 1998, RISC OS was bundled with every ARM-based Acorn computer model.