 Bad Sector
An unwritable portion of an optical disk
caused by a media defect. A bad sector map plots these
locations and prevents writing to them.
Baseline
Reflectance (Reflectivity)
The reflectance of an unwritten, non-grooved
area of a disk through the protective layer.
Bilayer Disk
An optical disk in which the active elements
consist of two layers which participate in the creation
of a recorded mark when illuminated by high intensity
laser light.
Bifringence
The property of a material which causes
incident light waves of different polarisations to be
refracted differently by the material.
Bifringence,
Double-Pass
The bifringence that results after incidence
and reflection through the protective layer of an optical
disk.
BOOTstrap Protocol (BOOTP).
A TCP/IP protocol that enables a workstation to find its
IP address. Similar to rarp but operates on the entire
network. Requires a bootp daemon running on the system.
Buffered Seek
In the buffered seek mode, the hard disk
drive receives all signal pulses for a seek operation at
one time and executes them in one go. In the non-buffered
seek mode, the controller sends the signal pulse to the
drive, the drive will execute this signal pulse, and only
then, the next signal pulse may follow. This term is
important for ST506 and ESDI drives; with SCSI and ATA,
this mode is executed internally.
Burst Error
1. An interval of clustered error
occurrences in which successive bit errors are separated
by a specified maximum number of correct bits;
alternately, a stream of continuous bit errors or
erasures.
2. In error correction, the loss of many consecutive bits
of information, usually because of some flaw in the
medium such as a scratch or dirt. The distinction is with
continuous noise which corrupts data in a different way,
requiring a different kind of error correction. In option
memory, most data loss is due to burst errors. The design
of an error correction code depends on how often error
bursts are likely to occur and how long the longest burst
is likely to be.
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