Btu

system fails to respond, you can reboot (also called warm boot) your computer by pressing < Ctrl><Alt><Del>; otherwise, you must perform a cold boot by pressing the reset button or by turning the computer off and then back on.

bootable diskette

A diskette that can boot your computer to the operating system in the event that the computer will not boot from the hard-disk drive.

bpi

Abbreviation for bits per inch.

bps

Abbreviation for bits per second.

Abbreviation for British thermal unit.

bus

An information pathway between the components of a computer. Your computer contains an expansion bus that allows the processor to communicate with controllers for all the various peripheral devices connected to the computer. Your computer also contains an address bus and a data bus for communications between the processor and RAM.

byte

Eight contiguous bits of information, the basic data unit used by your computer.

Abbreviation for Celsius.

cache

A fast storage area that keeps a copy of data or instructions for quicker data retrieval. For example, your computer's BIOS may cache ROM code in faster RAM. Or, a disk-cache utility may reserve RAM in which to store frequently accessed information from your computer's disk drives; when a program makes a request to a disk drive for data that is in the cache, the disk-cache utility can retrieve the data from RAM faster than from the disk drive.

card-edge connector

You can divide a hard-disk drive into multiple physical sections called partitions with the fdisk command. Each partition can contain multiple logical drives.

After partitioning the hard-disk drive, you must format each logical drive with the format command.

PCI

Abbreviation for Peripheral Component Interconnect. A standard for local-bus implementation developed by Intel Corporation.

peripheral device

An internal or external device-such as a printer, a disk drive, or a keyboard-connected to a computer.

PGA

Abbreviation for pin grid array, a type of processor socket that allows you to remove the processor chip.

pixel

A single point on a video display. Pixels are arranged in rows and columns to create an image. A video resolution, such as 640 x 480, is expressed as the number of pixels across by the number of pixels up and down.

Plug and Play

An industry-standard specification that makes it easier to add hardware devices to personal computers. Plug and Play provides automatic installation and configuration, compatibility with existing hardware, and dynamic support of mobile computing environments.

POST

Acronym for power-on self-test. Before the operating system loads when you turn on your computer, the POST tests various system components such as RAM, the disk drives, and the keyboard.

ppm

Abbreviation for pages per minute.

PQFP

Abbreviation for plastic quad flat pack, a type of processor socket in which the processor chip is permanently mounted.

"processor"

The primary computational chip inside the computer that controls the interpretation and execution of arithmetic and logic