IBM unveils high-capacity hard drive.

Ultrastar can hold 73 gigabytes and goes on sale next year IBM Corp. introduced its highest capacity computer hard drive, offering enough storage space to hold the equivalent of a floor of books at a major metropolitan library. The Ultrastar 72ZX, holding 73 gigabytes, goes on sale early next year and is aimed at businesses that store lots of data and images, such as the recording and credit-card industries. IBM_s storage system division, based in San Jose, Calif., also unveiled on Friday two 36-gigabyte hard drives that will be available in limited quantities this quarter.The new IBM drives are designed to perform reliably without using lots of power in powerful "server" computers, which run networks of smaller machines. The 73-gigabyte model can store 7.04 billion data bits per square inch. It is roughly the size of a paperback novel and can hold as much information as a floor of books at the New York Public Library "with room to spare," the company said. IBM, based in Armonk, N.Y., invented the first hard drive in 1956.