Essential Guide to Computing: The Story of Information Technology, The

Disk Storage

The most common kinds of storage after memory are disks, either magnetic or optical. The advantage of either of these types of storage is that they offer enormous capacity for a very low cost.

Tech Talk

Areal density: The number of bits that a disk drive can hold in a given space is called areal density. The first generation of drives used in microcomputers had an areal density of 15 megabits per square inch; current drives have about 5,000-10,000 megabits per square inch (5-10 Gigabits).

Magnetic Storage

Magnetic storage, mostly in the form of hard disks, is increasing in density by some 80 percent a year, nearly equaling the rate of bloat in today's software. Advances come from new materials that coat both the surface of the disks ...