By DAVID KOENIG, AP Business Writer Mon Jul 10, 7:49 AM ET DALLAS - Achieving a long-sought goal of the $48 billion memory chip industry, Freescale Semiconductor Inc. announced the commercial availability of a chip that combines traditional memory's endurance with a hard drive's ability to keep data while powered down. ADVERTISEMENT The chips, called magnetoresistive random-access memory or MRAM, maintain information by relying on magnetic properties rather than an electrical charge. Unlike flash memory, which also can keep data without power, MRAM is fast to read and write bits, and doesn't degrade over time. Freescale, which was spun off of Motorola Inc. in July 2004, said Monday it has been producing the 4-megabit MRAM chips at an Arizona factory for two months to build inventory. A number of chip makers have been pursuing the technology for a decade or more, including IBM Corp.