PANOS is a discontinued computer operating system developed by Acorn Computers in the 1980s and released in 1985, which ran on the 32016 Second Processor for the BBC Micro and the Acorn Cambridge Workstation. These systems had essentially the same architecture, based on a 32-bit NS32016 CPU; the ACW having a BBC Micro-based "I/O processor". Access to the I/O processor was through a NS32016 firmware kernel called Pandora.