Tandon Corp. unveiled a portable hard-disk drive.

The 2.5-pound device, believed to be the first of its kind, stores data for personal computers on a hard, 3.5-inch disk and can be removed for use in other similarly equipped computers. Executives with the Chatsworth-based computer products company said Xerox provided $6 million of the $10 million development costs in exchange for an option to buy the product at a discount later.