Disk Surface - Zenith Z-100 Series User Manual

Chapter 1 Operation Page 1-17
Refer to Figure 1-16. A disk's surface is divided into tracks and sectors. A track
is that portion of the disk that passes under the read/write head. It is divided
into sectors by either timing holes placed in the disk itself, or by software.
When timing holes determine the sectoring of a track, the disk is said to be a
"hard-sector" disk. When software determines the sectoring, the disk is a "soft-
sector" disk.
The amount of information each sector can hold determines the disk's density.
(Disks are sold as single- or double-density types.) If a disk is capable of
"double-density" usage, it can hold twice as much information as the standard
"single-density" disk. A double-density disk can be formatted for single-density
use, but a single-density disk should not be formatted for double-density use.