Distribution Media Format (DMF) is a format for floppy disks that Microsoft used to distribute software. It allowed the disk to contain 1680 KiB of data on a 3-inch disk, instead of the standard 1440 KiB. As a side effect, utilities had to specifically support the format in order to read and write the disks, which made copying of products distributed on this data storage medium more difficult. An Apple Macintosh computer running Disk Copy 6.3.3 on Mac OS 7.6 or later can copy and make DMF disks. The first Microsoft software product that uses DMF for distribution were the "c" revisions of Office 4.x. It also was the first software product to use CAB files, then called "Diamond".
Comparison of standard 1440 KiB and DMF 3-inch diskettes: Feature Standard DMF Tracks 80 80 Sectors per track 18 21 Cluster size, in bytes 512 1024 or 2048 Root directory entries 224 16
DMF, in the form of a 1680 KiB Virtual Floppy Disk (VFD) image, and IBM Extended Density Format (XDF) images are supported by Windows Virtual PC.
See also
fdformat, a DOS program that allows the formatting of high-capacity floppy disks IBM Extended Density Format (XDF), a high-density diskette format used by IBM
References
External links About DMF