Macintosh Bible, 8th Edition, The

Hard Disks (JC)

Hard disks are truly precision instruments that rely on principles of aerodynamics, electricity, and magnetism to operate. What follows are the gruesome anatomical details of hard-disk innards. While the following descriptions may seem somewhat technical, they will help you understand exactly what is happening as you use your Mac and prepare you for our “Hard-Disk Buyers' Guide,” later in this chapter.

Hard-Disk Anatomy

The numerous moving parts inside a hard disk work together for the sole purpose of reading and writing data. The main components—the platters, spindle, and actuator assembly—are contained inside a sealed housing to protect them from dust and other airborne contaminants (Figure 5.1).

Figure 5.1. Inside a hard disk ...