Magnetic Disk - Fujitsu M2361A Customer Engineering Manual

4.3.2 Magnetic disk
A magnetic disk has a diameter of 10.5 inches (268 mm) and is made of aluminum
on which magnetic material is coated. Special coating is provided on the
surface of this magnetic material in order to prevent wear caused by repeated
contact-start/stop operations.
cb
I
Glidin area
Inner head area
Outer head area
Data
surfaces
CYL 0 (18.611 BPI) CYL
841
CYL 0 CYL 841 (10.655 BPI)
"1~"'??"7"J~~~1
I
I
surface
Figure 4.3.3 Data and servo area locations
ThouSh the rotational angle of arm assemblies is constant for all tracks (2.27
x 10
4
radians per track), the track pitch for the inner and outer heads
varies as shown in Figure 4.3.4 depending on the mechanical arrangement of the
head-arm and the cores.
The track width of the inner head is made wider than that of the outer head to
avoid decrease of time margin for the read operation.
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