PC Hardware in a Nutshell, 3rd Edition

Chapter 6. Floppy Disk Drives

The following four chapters cover standard floppy disk drives, high-capacity “super” floppy disk drive replacements, removable hard drives, and tape drives, all of which are characterized as removable magnetic storage devices. These devices use media that can be swapped in and out of the drive, versus hard disk drives, whose media are a fixed part of the drives themselves. Although they are typically slower at accessing data than hard disks—sometimes much slower—removable magnetic storage devices are useful because you can store an unlimited amount of data on additional cartridges, albeit with only a subset of the data available online at any one time. Because media are separate items, you can transfer data between computers that are not networked, if those computers are equipped with a compatible drive. Removable media also allow storing data off-site as protection against fire, theft, or other catastrophes.

A major drawback of removable magnetic storage is inherent: magnetic storage is less reliable than optical storage. Over time, zero bits and one bits stored as magnetic domains tend to become an unreadable blur. A less obvious drawback of magnetic versus optical storage is the proprietary nature of most magnetic drives and media, and the continually changing standards. Try, for example, to read data written only five years ago to a proprietary DC600 tape drive. The original drive is dead, the manufacturer no longer exists, and the software used ...