Upgrading and Repairing PCs, 21st Edition

Chapter 8. Magnetic Storage Principles

Magnetic Storage

Most permanent or semipermanent computer data is stored magnetically, meaning 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 same original stream of bits. This is the principle of magnetic storage and the subject of this chapter.

History of Magnetic Storage

Before magnetic storage, the primary computer storage medium was punch cards (paper cards with holes punched in them to indicate character or binary data), originally invented by Herman Hollerith for use in the 1890 Census.

The history of ...