The Antikythera Mechanism was found by chance, in a shipwreck, close to the small island of Antikythera (between Crete and Peloponnese) in April 1900, by sponge divers, who were stranded there, due to bad weather. The shipwreck was dated from between 86 and 67 B.C. (coins from Pergamon). The Mechanism was probably built in Rhodes and has been dated, by epigraphologists, around the second half of the 2nd century B.C. (100 – 150 B.C.). About this time the great Greek astronomer Hipparchos lived in Rhodes. He died there in 120 B.C. It was a portable (laptop-size), geared artefact which calculated and displayed, with high precision, the movement of the Sun and the Moon on the sky, the phase of the Moon for a given epoch and could predict eclipses. It had one dial on the front and two on the back. Its gears were driven by a manifold, with which the user could set a pointer to any particular epoch (at the front dial). While doing so, several pointers were synchronously driven by the gears, to show the above mentioned celestial phenomena on three accurately marked annuli. It contained an extensive user manual. The exact function of the gears has finally been decoded and a large portion of the manual has been read after 2000 years by a major new investigation, using state of the art equipment.