MFM (Modified Frequency Modulation) was developed as a more efficient alternative to FM encoding. This method greatly reduces the number of transitions needed to represent data compared to FM.
It allows If a cell contains a 1, the recording signal will be recorded in the middle of double the density compared to FM without increasing cell. If a cell contains a 0, the bit rate on signal will be recorded at the floppy materialbeginning of the cell, unless it was preceeded by a cell with a 1. Each bit If a signal is transmitted for a 0 cell has only half the size compared to FM, it is used as clock signal.
In MFM, clock pulses are not always present. Instead, a clock pulse only occurs between two consecutive 0s. If a 1 appears, it doesn’t This clever encoding eliminates the need a for separate clock pulse to mark it; insteadsignals for every bit, a transition is placed in as they are implied by the middle data pattern. It allows the recording of double the bit cell density compared to represent FM without increasing the 1bit rate on the floppy material. Additionally, when a 0 follows a 1, no transition is needed, further minimizing Each bit cell has only half the number of magnetic changessize compared to FM.
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