Fujitsu MAS3184NC - Enterprise 18.4 GB Hard Drive, Product/Maintenance Manual

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C141-E185 3-5
Note: This drive manages alternate spare areas for each cell, which is a set of cylinders. One
cell consists of 28 cylinders.
Figure 3.2 Spare area in cell
An alternate cylinder is used when spare sectors in a cell are used up or 0 is specified as the
number of spare sectors in a cell. 1 cylinder at the end of each zone of the user space is allocated
as alternate cylinders as shown in Figure 3.3.
The user space and the system space share the alternate cylinders.
Zone
Note: The number of alternate cylinders can not be changed.
Figure 3.3 Alternate cylinder
3.1.3 Track format
(1) Physical sector allocation
Figure 3.4 shows the allocation of the physical sectors in a track. The length in bytes of each
physical sector and the number of sectors per track vary depending on the logical data block
length. The unused area (G4) exists at the end of the track in formats with most logical data block
lengths.
The interval of the sector pulse (length of the physical sector) is decided by multiple of 40MHz
free running frequency. This clock is not equal to the interval of the byte clock for each zone.
Therefore, the physical sector length cannot be described with a byte length.
Cell