Archimedes' screw Archimedes' screw An Archimedes' screw, also known by the name the Archimedean screw or screw pump, is a machine used for transferring water from a low-lying body of water into irrigation ditches. Water is pumped by turning a screw-shaped surface inside a pipe. The screw pump is commonly attributed to Archimedes, on the occasion of his visit to Egypt. This tradition may reflect only that the apparatus was unknown to the Greeks before Hellenistic times and was introduced in Archimedes's lifetime by unknown engineers. Depictions of Greek and Roman water screws show them being powered by a human treading on
Acorn Archimedes family omitted either the Acorn or Archimedes part of the name; the first models were named "BBC Archimedes", yet the name "Acorn Archimedes" is commonly used to describe any of Acorn's contemporary designs based on the same architecture. Archimedes machines are no longer sold, but computers such as the Raspberry Pi can still run its operating system, RISC OS (at least later versions), as they use ARM chips that are (mostly) compatible. The Acorn Archimedes was the first RISC-based home computer. The first models were released in June 1987, as the 300 and 400 series. The 400 series included four