< storage > (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 Except for 1.44 MB floppy disks, this encoding is obsolete.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)