Glossary of Western Digital Hard Disk Drive (Letter I)

I/O
Input/Output. An operation, program, or device that that transfers data to or from a computer or other device.

IcePack™
3.5-inch mounting frame with a built-in heat sink that keeps the 2.5-inch WD VelociRaptor extra cool when installed in a 3.5-inch drive bay.

IDE
Integrated drive electronics. A technology in which interface controller electronics are incorporated into the design of the hard drive rather than into a separate controller. See also PATA.

index pulse signal
A digital pulse signal indicating the beginning of a disk revolution. An embedded servo pattern or other prerecorded information is present on the disk following the index.

initialization
See low-level formatting.

initiator
A device in control of a SCSI bus that sends commands to a target. Most SCSI devices have a fixed role as either initiator or target; however, some devices can assume both roles.

input
Incoming data that a computer processes, such as user-issued commands.

IntelliPark™
Delivers lower power consumption by automatically unloading the heads during idle to reduce aerodynamic drag.

IntelliPower™
A fine-tuned balance of spin speed, transfer rate, and caching algorithms designed to deliver both significant power savings and solid performance.

IntelliSeek™
WD AV feature that optimizes seek speeds to lower power consumption, noise, and vibration.

interface
A hardware or software protocol to manage the exchange of data between a device and a computer; the most common ones are PATA (also known as EIDE), SATA, and SCSI.

interface controller
A chip or circuit that translates computer data and commands into a form usable by a hard drive and that controls data transfers between buffer and host. See also disk controller and disk drive controller.

interleave
The arrangement of sectors on a track.

interrupt
A signal sent by a subsystem to the CPU when a process either was completed or could not be completed.

IP
Internet Protocol. A system that controls how data messages are separated into packets, routed from the sender, and reassembled at the destination.

IP address
A 32-bit, binary number that uniquely identifies a computer connected to the Internet.

ISA
Industry Standard Architecture. The standard 16-bit AT bus for the PC/AT system. ISA was the only industry standard bus for PCs until the recent release of Peripheral Component Interconnect (PCI).