Have you ever wondered why computers have to format disks or diskettes, and why it takes so long? The reason is because the disk drive must write the initial sectors and tracks on the platter(s) so that when it comes time to write real data, it will know where to put it. Older disks were hard-sectored, which meant that there were holes in the floppies or some kind of reflective line in a hard disk so that the disk drive knew where the sectors started. Nowadays, soft-sectoring is used instead, where the disk drive doesn't rely on any physical indication of the start of sectors, but instead writes a special bit-pattern on the surface to indicate the beginning of sectors. Similarly, the dead space is really just a special bit pattern.

The ability to soft-sector a disk and to use a special bit pattern to indicate "there's no data here" implies that disk drives do not write bare 1's and 0's on the platter. That is, if a disk drive were to write the ASCII character 'A', which is 65, or 01000001, it would not actually write 01000001 onto the surface. In fact, it wouldn't write "bits" at all, but rather align the magnetic fields of the iron-paint, so that it might look like NSNNNNNS, where N means "North" and S means "South."