A major competitor, Quantum Corporation of Milpitas, Calif., couldn't be more different.

Apple's announcement followed a report on Tuesday by the Quantum Corporation, a major supplier of disk drives to Apple.

Before joining Maxtor, he was a co-founder of the Quantum Corporation, also a disk drive producer, where he served as vice president for marketing.

In 2007, Williams' patent became the subject of legal action between Quantum Corporation and Riverbed Technology.

Quantum Corporation formed the Plus Development subsidiary in 1983.

Mr. Belluzzo is now chief executive of the Quantum Corporation, which makes data storage products.

In 1994, the technology was purchased by Quantum Corporation, who manufactures drives and licenses the technology and trademark.

He noted that shares in the Quantum Corporation, Apple's sole supplier, were up $1.125 today, to $19.50.

The Quantum Corporation, a leading disk drive manufacturer, said yesterday that William J. Miller would join the company as chief executive.

For example, one of the biggest short positions for the period was in the Quantum Corporation, a manufacturer of hard disk drives.