An original Apple 1 computer from 1976 - one of only six still in working order - has sold at auction in Germany for more than 500,000 euros ($650,000).

The Apple 1 was one of the first 50 built by Apple co-founders Steve Jobs and Steve Wozniak in Jobs' parents' garage.

The computer - consisting only of a motherboard, signed by Mr Wozniak - went to an anonymous buyer from Asia.

Last year, an Apple 1 sold for 490,000 euros (£418,000; $633,000).

Only about 200 Apple 1s were ever made. About 46 remain in existence, but only six of those are still in working order.

Bob Luther, author of The First Apple, called the Apple 1 the "holy grail of collectable technology".

The one sold at auction in the German city of Cologne on Saturday was purchased together with an original monitor, tape-player, keyboard. The documentation was signed by Steve Jobs