Fujitsu MHS2020AT, Product Manual

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C141-E171-03EN GL-1
Glossary
Actuator
Head positioning assembly. The actuator consists of a voice coil motor and head
arm. If positions the read-write (R-W) head.
AT bus
A bus between the host CPU and adapter board
ATA (AT Attachment) standard
The ATA standard is for a PC AT interface regulated to establish compatibility
between products manufactured by different vendors. Interfaces based on this
standard are called ATA interfaces.
BIOS standard for drives
The BIOS standard collectively refers to the parameters defined by the host,
which, for example, include the number of cylinders, the number of heads, and
the number of sectors per track in the drive. The physical specifications of the
drive do not always correspond to these parameters.
The BIOS of a PC AT cannot make full use of the physical specifications of these
drivers. To make the best use of these drives, a BIOS that can handle the standard
parameters of these drives is required.
Command
Commands are instructions to input data to and output data from a drive.
Commands are written in command registers.
Data block
A data block is the unit used to transfer data. A data block normally indicates a
single sector.
DE
Disk enclosure. The DE includes the disks, built-in spindle motor, actuator,
heads, and air filter. The DE is sealed to protect these components from dust.
Master (Device 0)
The master is the first drive that can operate on the AT bus. The master is daisy-
chained with the second drive which can operate in conformity with the ATA
standard.