Distribution Media Format
Encyclopedia
Distribution Media Format (DMF) is a format
for floppy disk
s that Microsoft
used to distribute software. It allowed the disk to contain 1680 KB of data on a 3½-inch disk, instead of the standard 1440 KB. As a side effect, utilities had to specially support the format in order to read and write the disks, which made copying
of products distributed on this media
more difficult. 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 DMF and standard 1440 KB 3½-inch diskettes:
DMF
in the form of a 1680 KB VFD image and XDF
images are supported by Windows Virtual PC
.
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
for floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...
s that Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
used to distribute software. It allowed the disk to contain 1680 KB of data on a 3½-inch disk, instead of the standard 1440 KB. As a side effect, utilities had to specially support the format in order to read and write the disks, which made copying
Copyright infringement of software
Copyright infringement of software=The copyright infringement of software refers to several practices which involve the unauthorized copying of computer software. Copyright infringement of this kind varies globally...
of products distributed on this media
Data storage device
thumb|200px|right|A reel-to-reel tape recorder .The magnetic tape is a data storage medium. The recorder is data storage equipment using a portable medium to store the data....
more difficult. 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 DMF and standard 1440 KB 3½-inch diskettes:
| 1440 KB | DMF | |
|---|---|---|
| Track Cylinder-head-sector Cylinder-head-sector, also known as CHS, was an early method for giving addresses to each physical block of data on a hard disk drive. In the case of floppy drives, for which the same exact diskette medium can be truly low-level formatted to different capacities, this is still true.Though CHS... s |
80 | 80 |
| Sector Disk sector In computer disk storage, a sector is a subdivision of a track on a magnetic disk or optical disc. Each sector stores a fixed amount of user data. Traditional formatting of these storage media provides space for 512 bytes or 2048 bytes of user-accessible data per sector... s per track |
18 | 21 |
| Cluster Cluster (file system) In computer file systems, a cluster or allocation unit is the unit of disk space allocation for files and directories. To reduce the overhead of managing on-disk data structures, the filesystem does not allocate individual disk sectors, but contiguous groups of sectors, called clusters.On a disk... size |
512 byte Byte The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer... s |
1024 or 2048 bytes |
| Root directory entries | 224 | 16 |
DMF
Distribution Media Format
Distribution Media Format is a format for floppy disks that Microsoft used to distribute software. It allowed the disk to contain 1680 KB of data on a 3½-inch disk, instead of the standard 1440 KB. As a side effect, utilities had to specially support the format in order to read and write the...
in the form of a 1680 KB VFD image and XDF
IBM Extended Density Format
The IBM eXtended Density Format is a way of formatting standard high-density 3.5" and 5.25" floppy disks to larger-than-standard capacities...
images are supported by Windows Virtual PC
Windows Virtual PC
Windows Virtual PC is a virtualization program for Microsoft Windows. In July 2006 Microsoft released the Windows-hosted version as a free product...
.
See also
- 2M2M (DOS)2M is a DOS program by the Spanish programmer Ciriaco García de Celis. It enables higher than normal capacity formatting of floppy disks. It saw active development from 1993 to 1995. The last version, v3.0, was released on March 6, 1995. It was written in C and assembler and compiled using Borland...
, a program that allows the formatting of high capacity floppy disks - fdformatFdformatFdformat is the name of two unrelated programs:* A command-line tool for Linux that "low-level formats" a floppy disk.* A DOS tool written in Pascal by Christoph H. Hochstätter that allows users to format floppy disks to a higher than usual density, enabling the user to store up to 300 kilobytes...
, a program that allows the formatting of high capacity floppy disks - XDFIBM Extended Density FormatThe IBM eXtended Density Format is a way of formatting standard high-density 3.5" and 5.25" floppy disks to larger-than-standard capacities...
, a high-density diskette format used by IBM