Rumour: Apple testing ARM A5-powered MacBook Air

Apple has produced a prototype MacBook Air powered by and ARM-designed A5 CPU according to a report from a Japanese tech blog.

Macotakara says it has been told by an anonymous source that Apple already has MacBook Air test hardware up and running with the new Thunderbolt interface in place and powered by the same ARM-designed A5 chip seen in the company's iPad 2 tablet device.

The report is suspiciously vague about whether the prototype was running Apple's full-blown desktop operating system OS X or its mobile offering iOS, but with Apple working hard to converge the best bits of both into the forthcoming OS X Lion upgrade, the confusion is understandable.

Recent reports have suggested that Apple may be eying ARM as a possible replacement for Intel-manufacturered x86-architecture chips in its laptop computers, but complications with running legacy applications could mean the move is several years away - if on the horizon at all.

Apart from that, we're sure Apple's R&D departement is littered with experimental hardware which never sees the light of day, so we won't be expecting to see this one hit the shelves any time soon.