Screw (simple machine) of the last of the simple machines to be invented. It first appeared in ancient Greece and Egypt, and by the first century BC was used in the form of the screw press and the Archimedes' screw, but when it was invented is unknown. Greek philosopher Archytas of Tarrentum (428 – 347 BC) was said by the Greeks to have invented the screw. Although the Greek philosopher Archimedes is credited by the Greeks with inventing the Archimedes screw water pump around 234 BC. records indicate it was first used in ancient Egypt. Archimedes was first to study the screw as
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