GLOSSARY
frequency response
A measure of how effectively a circuit or device transmits the different frequencies applied to it. In disk and tape drives this refers to the read/write channel. In disk drives, it can also refer to the dynamic mechanical characteristics of a positioning system.
G
gigabyte (GB)
One billion bytes (one thousand megabytes) or 10E9.
H
hard error
An error that is not able to be overcome by repeated readings and repositioning means.
hard sectored
A technique where a digital signal indicates the beginning of a sector on a track. This is contrasted to soft sectoring, where the controller determines the beginning of a sector by the reading of format information from the disk.
head
The electromagnetic device that write (records), reads (plays back), and erases data on a magnetic media. It contains a read core(s) and/or a write core(s) and/or erase core(s) which is/are used to produce or receive magnetic flux. Sometimes the term is all inclusive to mean the carriage assembly which includes the slider and flexure.
head crash
The inadvertent touching of a disk by a head flying over the disk (may destroy a portion of the media and/or the head).
head disk assembly (HDA)
The mechanical portion of a rigid, fixed disk drive. It usually includes disks, heads, spindle motor, and actuator.
head loading zone
The
head positioner
Also known as actuator, a mechanism that moves the arms that carry read/write heads to the cylinder being accessed.
I
index
Similar to a directory, but used to establish a physical to logical cross reference. Used to update the physical disk address (tracks and sectors) of files and to expedite accesses.
inside diameter
The smallest radial position used for the recording and playback of flux reversals on a magnetic disk surface.
initialization
Applying input patterns or instructions to a device so that all operational parameters are at a known value.
input
Data entering the computer to be processed; also user commands.
input/output (I/O)
The process of entering data into or removing data from a computer system or a peripheral device.
intelligent peripheral
A peripheral device that contains a processor or microprocessor to enable it to interpret and execute commands.
interface
The data transmitters, data receivers, logic, and wiring that link one piece of computer equipment to another, such as a disk drive to a controller or a controller to a system bus.
interface standard
The interface specifications agreed to by various manufacturers to promote
interleave
An ordering of physical sectors to be skipped between logical sectors on your hard disk.
I/O processor
Intelligent processor or controller that handles the input/ output operations of a computer.
interrupt
A signal, usually from a subsystem to a central processing unit, to signify that an operation has been completed or cannot be completed.
J
jumper
A small piece of plastic that slides over pairs of pins that protrude from the circuit board on the hard drive to make an electrical connection and activate a specific option.
K
kilobyte (KB)
A unit of measure of approximately 1,000 bytes. (However, because computer memory is partitioned into sizes that are a power of two, a kilobyte is really 1,024 bytes.)
L
landing zone or Lzone
The cylinder number/location to where the read/write head(s) move upon power down.
late bit
A bit that is in the late half of the data window.
GL – 4
