Although I threatened to take a sledgehammer to my recently failed hard disk drive, I decided to dissect it instead.  This unit was fitted with three magnetic platters each storing 8 trillion bits of information and six flying heads, one for each side of each platter. When I was born, IBM was selling the 350 Disk File, a drive with fifty 24-inch platters and a total capacity of 30 million bits.  It was the size of two refrigerators with only 1/800,000 of the capacity.  As sophisticated as this technology has become, we will soon look back and scoff at the idea of storage based on spinning magnetic disks.