Apple's iPhone boss in sudden departure

Did Papermaster walk or was he pushed?

Mark Papermaster, Apple's head of mobile hardware who oversaw much of the design of the iPhone 4, has left the company unexpectedly.

His biography has already been removed from the Apple site, and the company confirmed to The New York Times that he is "leaving the company, and that Bob Mansfield, senior vice president of Macintosh hardware engineering, is assuming his responsibilities".

Papermaster oversaw iPhone and iPod development with special interest in Apple's A4 chip and displays. Speculation is rife that he has become the latest casualty in the so-called 'antennagate' scandal.

Mansfield, rather than Papermaster, was present at the hastily called iPhone press conference in July, indicating that he may already have been given his notice.

Papermaster spent 26 years at IBM and rose through the ranks to become a highly respected chip designer, developing the PowerPC chip adopted by Apple, before becoming vice president of IBM's Blade Development Unit.

IBM started legal proceedings when Apple poached Papermaster in 2008, as he had had full access to the company's intellectual property database and advanced chip designs.

IBM settled the case with an undertaking that a non-compete clause on information was legally enforced by the courts.