Modified Frequency Modulation
MFM
(MFM, Modified FM, or sometimes "Multiple
Frequency Modulation") A modification to the original
frequency modulation scheme for encoding data on magnetic
disks. MFM allows more than 1 symbol per flux transition (up
to 3), giving greater density of data. It is used with a data
rate of between 250-500 kbit/s on industry standard 3.5" and
5.25" low and high density diskettes, and up to 5 Mbit/s on
ST-506 hard disks. Except for 1.44 MB floppy disks, this
encoding is obsolete.
Other data encoding schemes include GCR, FM, RLL. See
also: PRML.
(2002-06-24)
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