Upgrading and Repairing PCs, Sixteenth Edition

Chapter 9. Magnetic Storage Principles

Magnetic Storage

Permanent or semipermanent computer data storage works by either optical or magnetic principles—or, in some cases, a combination of the two. In the case of magnetic storage, a stream of binary computer data bits (0s and 1s) is stored by magnetizing tiny pieces of metal embedded on the surface of a disk or tape in a pattern that represents the data. Later, this magnetic pattern can be read and converted back into the exact same stream of bits you started with. This is the principle of magnetic storage and the subject of this chapter.

Magnetic storage is often difficult for people to understand because magnetic fields can’t be seen by the human eye. This chapter explains the principles, concepts, ...