The
iwm driver interfaces to the built-in and external floppy disk drives on the Macintosh. It supports double-density media, written in Apple's proprietary GCR format. Currently, there is no disklabel support for the floppy drives. Instead, the
iwm driver sets up a fake in-core disklabel, using the minor device number to select from the supported disk formats.
The following formats are supported:
Partition
Size
sides
tracks
sectors/track
a
800Kb
2
80
10 (default)
(The above table describes the logical mapping as implemented by the driver; the physical layout of GCR floppies has 8..12 sectors per track.)