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FIGURE 4-2
FM RECORDING MAGNETIZATION PROFILES
As
the
disk
spins,
the
magnetic
fields
of
the stored data pass
successively under the head.
The changing fields induce, in the head,
an
A.
C.
voltage
signal
which
is
then amplified and filtered,
differentiated, and digitized (Figure 4-3).
The
comparator and the digitizer circuitry generate a one microsecond
Read Data pulse, corresponding to each peak of the Read signal.
Then,
the composite read data signal is sent to the user system via the Read
Data interface line.
UN.... OUTPUT 1'110101 PlLTIJI
OUTl'UT
1'110101 DII'PIIIINnATO"
liDO DATA INTIJIL"ACI
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fIGURE 4-3
READ TIMING DIAGRAM
4-2
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