HD Doctor Blog

Glossary Hard Disk Drive Terminology: From Letter A to Letter Z. If you enjoy it, just add it to your favorite!

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Zoned Recording
Increases the number of sectors on the outer tracks of the drive since the circumference of the outside tracks is greater. This type of recording affords more disk capacity because there can be more sectors on the larger outer tracks than would be possible if the number of sectors per track were constant for the whole drive.

Year 2000 Problem, or Y2K
The risk that computers will be disabled or perform incorrectly if they read the two-digit abbreviation “00″ to mean the year 1900 instead of the year 2000, as intended. The problem is said to have originated when early computer programmers abbreviated year dates to save storage space that was scarce and costly at the time. Western Digital hard drives are designed to be “Year 2000-compliant,” and the company’ suppliers are required to demonstrate that their WD-linked communications and products are compliant as well.

WD Caviar®
The trade name for Western Digital’s line of hard drives for desktop personal computers.

WD Enterprise
The trade name for Western Digital’s line of enterprise hard drives.

Winchester Disk
Former code name for an early IBM hard disk model, sometimes still used to refer to the technology and design of most traditional hard drives.

Windows
Microsoft’s series of operating systems for personal computers. Currently popular versions are Windows 95 and Windows 98.

Word
Two bytes that are processed together in a single operation.

Workstation
A personal computer with exceptional capacity and performance capabilities for use mainly in engineering, design and audiovisual applications demanding immediate access to data and the ability to manipulate it in technically sophisticated…

Value-added Reseller (VAR)
Often referred to as a “Var” or “Reseller.” The independent professionals who market computer systems and components and who add value by performing assembly, upgrades, training and other services.

Viterbi Detection
An algorithm used in read channel technology that detects an entire sequence of data bits at a time and determines the most likely sequence of data bits by comparing actual sequence of data bit samples with sequences of possible data bit sample to accurately detect that data written to disk.

Voice Coil
An actuator motor; the force of the magnetic rotary voice coil produces a movement of the head that is proportionate to the force exerted by the coil.

Ultra SCSI
Provides 20 MB/s transfers over an 8-bit bus or 40 MB/s transfers over a 16-bit Wide SCSI bus. Also known as Fast-20 SCSI, this feature is most commonly found in SCSI-3 drives.

Ultra DMA/33
A high-speed host data transfer feature that transfers data at 33.3 MB per second.

Un-correctable Error
An error that cannot be overcome using Error Detection and Correction.

Unformatted Capacity
The total number of usable bytes on a disk, including the space that is required to record location, boundary definitions, and servo data. (See also formatted capacity.)

Unrecoverable Error
A read error that cannot be overcome by an ECC scheme or by rereading the data when host retries are enabled.

Untagged…

Tagged Queuing
The ability of the drive to receive multiple I/O processes from each initiator.

Task File
The set of I/O Host Interface Registers used to transfer status, commands, and data between the host and the drive for the EIDE interface.

Thin Client Architecture
A computer system in which data is stored centrally, with only limited storage capacity at the various points of use.

Thin Film
A type of coating deposited on a flat surface through a photolithographic process. Thin film is used on disk platters and read/write heads, as well as on the write element of MR heads.

Thin-Film Inductive Head (TFI)
A head technology that uses a thin-film inductive element to read and write data bits on…