We thought the world’s oldest known computer — the Antikythera Mechanism — was 2000 years old. Now we know it was antique even before it sank beneath the waves in a wrecked Roman ship.

The New York Times has reported a new study of the ancient astronomical calendar/calculator shows it may date from about 200BC — some 150 years older than the ship in which it sank during a storm off an island between Greece and Crete in about 60BC.

It’s a fact which further ties the amazing bronze object with some of history’s greatest minds — Greek mathematicians and astronomers like Archimedes and Hipparchus.

Some 82 corroded fragments of the complex cogged mechanism have been recovered from the ocean floor since the wreck was first found in 1901. A new expedition in September this year recruited deep-diving exoskeleton to find more evidence of its mysterious workings. Its activities were stymied by bad weather. They will try again next year.

But a new analysis of what we have has uncovered one more clue.

The dial on the back, built to predict the timing of solar eclipses, appears to include an event which happened on May 12, 205BC.

This was just seven years after the eccentric inventor Archimedes was killed by a Roman soldier when his city was conquered.

Previous dating techniques had focused on analyzing the style of Greek writing on its face plate and radiocarbon analysis of its metal. All were combined with the context of the wreck within which it was found.

The new calendar setting puts one analysis of the text in new light — that it came from Syracuse, where Archimedes lived in 212BC.

The suggestion isn’t that Archimedes’ hands formed the Antikythera mechanism. But his maths, and perhaps even prototypes, probably did.

But a separate inscription among the discoloured bronze appears to be written in the style of the island of Rhodes, further challenging the Archimedes link. Instead, it ties it with the astronomer Hipparchus who died in Rhodes in 120BC

This disparity has caused some to speculate that there were actually two separate astrolabes — astronomical calculators — aboard the treasure-laden ship when it sank.

Despite the dispute over its age and location of creation, the device remains an object of fascination as its mechanics are centuries ahead of its time.