actuator arm: The arm in a disk drive that holds all of the read and write heads, and moves them in unison.

adapter card: A circuit board plugged into a slot in the motherboard to add features or peripherals to a system. Also called an expansion card.

address: A hexadecimal number designating the location of a device or of a piece of data.

address lines: The lines in a bus or cable that carry address information rather than data.

AGP: Accelerated Graphics Port, a high-speed bus just for video.

alphanumeric: Consisting of letters and numbers.

analog: Continuously changing, rather than jumping from one numerical value to the next. See digital.

application: A computer program to perform a specific task, as opposed to the operating system program that runs the computer itself.

ASCII: A digital code for print characters, including those on a standard keyboard. It stands for the American Standard Code for Information Inter-change,

ASPI: Advanced SCSI Programming Interface. The standard protocol used by most programs to access a SCSI device.

ATAPI: ATA Packet Interface, the ATA/IDE standard for CD-ROM, tape and removable drives.

Athlon: A high-speed CPU made by AMD.

average seek time: The average amount of time it takes a disk drive to locate a specific track and sector.

backup: A copy of a disk or selected files made for safekeeping, usually to removable media.

base memory: The first 1 MB of system RAM.

Basic Input / Output System: The hard-wired instructions that the CPU uses to boot up and to control I/O devices. Usually abbreviated as BIOS.

batch file: A file with an extension of .BAT, containing a list of commands or program routines that the computer will execute in sequence.

BAUD rate: A rate of data transfer, usually used to measure data rates over a phone line.

benchmark: A standard test or measurement used to compare the performance of similar components or systems.

binary: A number system using just two digits.

BIOS: Basic Input / Output System. The hard-wired instructions that the CPU uses to boot up and to control I/O devices.

bit: A single digit in the binary system, the smallest unit of computer information.

boot up: To start or restart a computer. From the phrase "picking yourself up by the bootstraps."

bus: A signal path that serves multiple devices or multiple points on a circuit board.

byte: A unit of digital information consisting of eight bits.

cache: A block of memory for temporary storage of data likely to be used again. The CPU and hard drive frequently use a cache.

CD: Compact Disc. A thin platter that has computer data or music recorded on it in optical form. See CD-ROM.

CD-R: A CD which can be written on by the user. A CD-RW can be written, erased and re-written.

CD-ROM: Compact Disc Read-only Memory. The term is often used for the CD platters as well as for the drive which reads them.

Celeron: A low-cost Pentium without cache.

central processing unit: The master chip in a computer that controls the execution of program instructions, arithmetic functions, and access to memory and peripherals. Abbreviated CPU, and also called the microprocessor.

CGA: Color Graphics Array. The first video standard for color monitors and video adapters.

chip: A slang term for an integrated circuit.

chipset: The chip or chips on a motherboard containing various functions supporting the CPU.

circuit: Any combination of wiring and components that provides a path for the flow of electricity.

circuit board: A thin board, usually fiberglass, on which components are mounted. Also called a printed circuit board (or PCB) because the connections between the components are printed onto the board.

CMOS: A type of chip able to operate with a tiny trickle of electricity from a battery. The term also refers to the contents of a CMOS chip on the motherboard, which holds information about the system and its peripherals even while the system is turned off. CMOS stands for Complementary Metal Oxide Substrate.

COM1: The name of the first serial port in a system. Additional ports are labeled COM2, COM3 and COM4.

communication: The exchange of information between two points.

computer: An electronic device for the storage and processing of information.

configuration: The way the parts of a system or network are arranged or connected, or the act of arranging them.

conflict: See resource conflict.

controller: A circuit that manages the operation of some part of a computer and its communication with the rest of the computer.

co-processor: See math co-processor.

CPU: See central processing unit.

cylinder: The same-numbered tracks of all the platters in a drive make up a cylinder. Cylinder 1 is all Track 1s, cylinder 2 is all Track 2s, etc.

data: Information, especially information in a form that can be used by a computer. It can include text, numbers, sounds and pictures. A single piece of information is called a Datum.

data processing: Using a computer to manage or store information.

decimal: Based on ten parts.

device: Any peripheral or part of a computer system that can send or receive data.

digit: A single unit or numeral in a counting system.

digital: Made of or using distinct digits or numerical values, rather than continuously variable values. Most often used to refer to information existing in electronic form as Ones and Zeroes.

digital camera: A camera that records pictures electronically rather than on film.

DIMM: Dual Inline Memory Module. Called Dual because it has separate signals to each side of the circuit board.

DIN: A type of connector for keyboards and mice, named for the German group originating the standard, Deutsche Industrie Norm.

DIP: Dual Inline Package. The configuration of two rows of pins used by many ICs. This configuration is also used to combine several switches into a single component.

disc: Same as Disk. This spelling is usually used with 'Compact Disc'.

disk: A thin platter coated with a magnetic material, and used in a disk drive to store information. Also can refer to the drive itself.

disk drive: A device used to store and retrieve information for a computer. It can be either a hard drive which has the platter permanently attached, or a floppy drive which has a removable platter.

diskette: The removable storage platter used in a floppy disk drive.

DMA: Channels for Direct Memory Access, which allow a device to move data to and from RAM without interrupting the CPU.

DOS: Disk Operating System. This is the operating system used by the original IBM PC and many since.

drive: A data storage device connected to a computer. Examples are a hard drive, floppy drive or tape drive.

drive parameters: The values for the number of cylinders, heads and sectors in a drive.

driver: Also device driver. A file containing the information an operating system or application needs to interact with a particular hardware device. These files will have an extension of .DRV (or .SYS in DOS)..

DVD: Digital Versatile Disk. A compact-disc format with much higher capacity than traditional CD-ROM.

DVD-RW: A DVD technology that allows the user to write to the disk.

EGA: Extended Graphics Array. A video standard allowing up to 64 colors.

electro-magnet: A magnet consisting of a coil of wire around a metal core. It is magnetic only when a current flows through the wire coil.

e-mail: Electronic Mail, messages sent over a computer network.

expanded memory system: The combination of a memory manager program and plug-in Expanded Memory Cards. Abbreviated EMS, which also stands for Expanded Memory Standard.

expansion card: A circuit board that plugs into a motherboard, used to add new peripherals to a computer system. Also called an adapter card.

expansion slot: A socket on the motherboard that accepts an expansion card.

extended memory: System RAM above 1MB.

extended memory specification: The rules for using an extended memory manager to access RAM above 1MB. The specification is known as XMS and was developed jointly by several companies.

FAT: File Allocation Table. A cluster map listing locations of the sequential parts of each file. There are two copies of the FAT for each partition, located just after the volume boot record.

FAT 16: The original FAT version allowing 1016 clusters per partition, with file names limited to 8 characters with a 3-character extension.

FAT 32: A later version allowing 255-character file names and 1028 clusters per partition.

factory-type format: The same as a low-level format

firmware: Computer instructions which are permanently imbedded in the circuitry, usually in a ROM chip.

fixed disk: Another name for a hard drive.

fixed media: The platters of a hard drive which, unlike a floppy diskette, cannot be removed.

flash BIOS: A ROM BIOS chip whose content can be changed by the system without removing the chip. The same type of chip used in an adapter card or peripheral is called Flash ROM.

floppy diskette: The removable storage platter of a floppy disk drive.

floppy drive: A disk drive with a removable storage platter.

format: The size and shape of something, or the way it is arranged. In computers it refers to the way data is organized or presented, especially on the platters of a disk.

FORMAT: The DOS command that creates the VBR, FAT, root directory and data areas for each partition. Also, either of two processes preparing the platter surfaces for data storage. See high level format and low level format.

GB: Abbreviation for gigabyte.

giga: A prefix meaning one billion. When measuring computer data, it means 230 or 1,073,741,824, which is the power of 2 closest to one billion.

gigabyte: 1024 megabytes, approximately 1.074 billion bytes.

hard drive: A disk drive with permanent storage platters.

hardware: The physical parts of an electronic device, such as nuts, bolts and components.

hard-wired: Unable to change. Usually refers to instructions in a ROM (Read Only Memory) chip or to logic created with physical connections rather than software.

head: A part mounted very close to the surface of a disk platter to read or write data.

hexadecimal: Made up of 16 parts. The hexadecimal numbering system uses the numbers 0 through 9 plus letters A through F to represent the 16 digits.

high-level format: The process of creating the FAT and other partition structures, done by the FORMAT command.

IC: Integrated Circuit. A part containing within itself many other circuits.

IDE: A common hard-drive interface, standing for Integrated Drive Electronics.

I/O: Input/Output. The flow of data to and from the CPU. Also refers to the peripherals sending the data, and the pathways they use.

I/O Port: A hex address used by a device to send and receive data.

input: Data received by a device or by the CPU.

integrated circuit: See IC.

Intel: A manufacturer of CPUs, motherboards and other components.

interface: The meeting point between a computer and something or (someone) outside of it. Common interfaces for peripherals are the serial and parallel ports. Common interfaces for people are the monitor screen and keyboard.

interleave: An offset between comparable sectors of adjacent tracks of a disk platter, needed because of the time it takes the heads to move from one track to the next. On some older drives, the interleave can be set by the user.

interrupt: A temporary break in the CPU's normal execution of program instructions, to allow it to handle a request from a peripheral.

IRQ: Interrupt ReQuest, the signal that a peripheral or program uses to interrupt the CPU.

ISA: The original PC bus architecture, and still included in many systems. It stands for Industry Standard Architecture.

joystick: An input device used for video games and for some graphics applications.

keyboard: An input device similar to a typewriter, for the entry of text, numbers and punctuation.

keyboard controller: A small processor on the motherboard that manages the entry of data from the keyboard.

kilo: A prefix meaning 1000. When used to measure computer data, it means 210 or 1024, which is the power of 2 closest to 1000.

kilobyte: 1024 bytes.

laser: A very pure and intense beam of light formed within a crystal, or the device that creates the light. LASER stands for Light Amplification by Stimulated Emission of Radiation.

legacy: Containing obsolete technology.

logical block addressing: A translation done by the disk controller of large-capacity drive so that the Head/Sector/Cylinder addresses will appear to be in the range recognized by the BIOS. Abbreviated LBA.

low-level format: The initial factory process of putting on new sector marks to prepare the platter surface for data storage. A low-level format destroys any previous data on the disk.

LPT-1: or LPT-2,3. The standard names for the parallel ports. LPT stands for Line PrinTer.

main-frame: A large computer designed to be used by many people at the same time.

male connector: A connector with pins that fit into the sockets of a female connector.

master: One of two drives attached to an IDE controller, the other being Slave.

master boot loader: The program in a disk's master boot record that contains instructions for loading in the operating system.

master boot record: The first sector on a disk, containing the partition table and master boot loader. Abbreviated MBR.

master file table: The file-tracking system used instead of a FAT in the Windows NT file system.

math coprocessor: Circuitry to handle floating-point arithmetic for the CPU. It may be incorporated in the CPU or it may be a separate chip. Also called the NPU or Numerical Processing Unit.

MBR: See master boot record.

MCA: Micro-Channel Architecture. A type of bus introduced by IBM in the late 1980s. It is no longer manufactured.

MB: Abbreviation for megabyte.

MBR: See Master Boot Record.

media: Methods of communication. In computers, it refers to the material or device used to store or transmit data.

medium: Singular of Media.

mega: A prefix meaning one million. For computer data, it means 220 or 1,048,576, which is the power of 2 closest to one million.

megabyte: 1,048,576 bytes.

memory: The part of a computer that holds data. This usually refers to RAM.

memory bank: The number of memory modules needed to have the same number of data bits as the bus. In a 64-bit Pentium system, each DIMM is one bank, but two 72-pin SIMMs are required for each bank.

microprocessor: A master control circuit. See central processing unit.

MicroScope: Trade name for a hardware diagnostic program that uses its own operating system to manipulate hardware directly without interference from the main operating system.

Microsoft: A software company, best known for the Windows operating system.

modem: A device that allows a computer to send and receive data over a voice phone line. Modem stands for Modulator / Demodulator.

modulate: To change a signal in a way that conveys information. For instance, a tone sent over a phone line can be changed in volume or frequency to represent Ones and Zeroes, thus sending digital data over an audio line.

module: A self-contained part of something that can function on its own.

monitor: A peripheral device with a screen for the visual display of information.

motherboard: The main circuit board, containing the CPU. All of the other functions and peripherals are connected in some way to the motherboard.

mouse: An input device that controls an on-screen pointer.

multimedia: Presenting data in more than one medium, such as combining text, graphics and sound.

NPU: Numeric Processing Unit. See math co-processor.

NTFS: The disk file structure used by Window NT and Windows 2000, which has a Master File Table instead of a FAT.

operating system: The master control program that runs the computer and allows it to execute applications.

optical: Using light.

OS: Operating system.

output: Data sent by a device or the CPU. Especially, the end result of a processing task, sent to the printer or to the monitor screen.

over-clocking: Setting the clock multiplier so that the CPU will run faster than its rated speed. Not a recommended practice.

parallel: Components or circuits connected to the same end points, so that each circuit provides an alternate path for electrical current from the same source. Compare to series.

parallel port: A connection for high-speed transfer of information, using multiple data lines.

parameters: See drive parameters.

parity: An extra bit added to data for error checking purposes, to make the quantity of Ones consistently either odd or even.

partition: A division of the hard drive, or the process of setting up divisions on the hard drive.

PC: Personal Computer. An IBM or IBM-compatible self-contained computer system, designed to be used by one person at a time.

PCB: See printed circuit board.

PCI: A high-speed bus for 486, Pentium and compatible systems. PCI stands for Peripheral Component Interconnect.

Pentium: A high-speed microprocessor chip made by Intel.

peripheral: Any of the devices which connect to the CPU and exchange information under the CPU's control. Peripherals include all of the computer's input and output devices.

pixel: Picture Element. A dot of light that is the smallest part of the visual image on a monitor. The number of pixels depends on the resolution setting of the monitor.

platter: The actual disk inside of a disk drive. Its surface is coated with a magnetic material that records data. Both sides of the platter are used, and a typical disk drive has several platters, stacked like pancakes.

plug-and-play: A standard that allows the system to automatically configure adapter-card resources.

port: A connection for moving data to and from the motherboard.

POST: An acronym for Power-On Self Test, a series of instructions executed by the BIOS during boot-up to confirm system functions before turning control over to the operating system. The codes put on the bus during POST can be used by POST reader cards to diagnose systems that fail to boot.

POST reader: A diagnostic card that is inserted into a bus slot to display the POST codes during boot-up. This is used to diagnose a system that won't boot up. The most comprehensive POST reader is Micro 2000's Universal Post-Probe.

printed circuit board: A thin board, usually fiberglass, on which components are mounted. So called because the connections between the components are printed onto the board. Abbreviated PCB.

printer: A device that puts computer data onto paper.

processing: Using a computer program to manage data, either sorting it, storing it or changing it in some way.

processor: The part of the computer that controls the execution of program instructions. See CPU.

program: A series of instructions for completion of a specific task or for performance of an activity.

RAM: Random Access Memory, the standard operating memory of the computer.

random access: Able to directly access any portion of data, without having to accept data in sequence.

read head: A head in a disk drive used to retrieve data from the platter.

read-only memory: Information hard-wired into chips. Used for the BIOS and in many I/O devices. Abbreviated as ROM.

real-time clock: The CMOS circuitry that keeps track of the year, day and time of day for the system. Abbreviated RTC.

refresh: A signal fed to RAM chips periodically, to keep them charged up so that data is not lost.

removable media: A cartridge or cassette that can be removed from the drive.

resolution: The sharpness of an image. Measured in a printer by Dots Per Inch, and in a monitor by the number of horizontal and vertical pixels.

resource conflict: The situation when two or more devices are trying to use the same system resources.

resources: See system resources.

riser card: A card that plugs into the motherboard to provide a perpendicular extension of the bus. Adapter cards are then plugged into the riser instead of the motherboard, allowing a lower profile to the case. Most often used for desktop systems that sit under the monitor.

ROM: See read only memory.

RTC: See real-time clock.

SCSI: A high-speed interface for hard drives, CD-ROM drives, scanners and other devices. SCSI comes from Small Computer System Interface.

sector: A division of a disk platter, shaped like a piece of pie.

seek: In a disk drive, the process of finding a specific location, by moving the actuator arm over the desired track and waiting until the correct sector comes under the heads.

sequential access: Data must be read in the order it appears. This method applies to tape, and to a lesser degree to disks.

serial port: A connection for data transfer, using a single data line.

silicon: The element used to make transistors and integrated circuits.

SIMM: Single In-line Memory Module, a small plug-in circuit board with one row of input signals.

software: Instructions for a computer, organized into sets called programs.

sound card: An expansion card with connections for speakers.

start bit: A zero bit marking the start of a serial port data byte.

stepping switch: A push-button switch on the Post-Probe that when pressed shows the code in the POST sequence immediately previous to the one currently displayed.

stop bits: One or more bits marking the end of a serial port data byte.

storage: Holding of program instructions and data for use by the computer. Temporary storage while the computer is running is provided by the RAM, and permanent storage is available on disk and tape.

SVGA: Super Video Graphics Array, the enhanced version of VGA used in most new PCs. Standard resolution is 800 x 600.

SXGA: A high-end video standard, with 1280 x 1024 resolution. It stands for Super Extended Graphics Array.

system: All of the parts that work together for a particular purpose. A computer system consists of the monitor, keyboard, all of the components in the CPU cabinet and any peripherals connected to it. An operating system is all of the routines and utilities needed for control of the computer, organized into one program.

system board: Same as motherboard.

system resources: Motherboard features which must be allocated among devices. These include IRQs, DMA channels, I/O ports and ROM addresses.

tape drive: A storage device that uses a long strip of magnetic tape.

track: The path in a magnetic surface that actually holds the recorded data. On a disk platter, the tracks are circles, one inside of the other. On a tape, the tracks are parallel stripes that run the length of the tape.

transistor: An electronic device used to control the flow of electricity.

UART: Universal Asynchronous Receiver/Transmitter, the control chip or circuitry for a serial port.

upper memory area: The 384KB of RAM between 640KB and 1MB, reserved in DOS for BIOS, video and adapter card ROMs.

USB: Universal Serial Bus, a port that allows the hot-plugging of multiple external plug-and-play devices.

utility: A software program or routine that aids in system management.

Universal Post-Probe: A POST reader card from Micro 2000 containing many advanced features, including the ability to read either ISA or PCI with the same card.

UXGA: A high-end video standard. It stands for Ultra Extended Graphics Array, and has a resolution of 1600 x 1200.

VGA: A video standard for unlimited color reproduction.

video: Having to do with the visual presentation of information, usually on a monitor screen.

video card: An adapter card used to manage the display on the monitor.

video controller: The circuitry driving the monitor display. This circuitry may be on the motherboard or on a video adapter card.

volume: A physical unit of data storage, such as a diskette, tape reel or one partition of a hard drive.

volume boot record: The first sector of a partition, containing the disk parameters of that volume.

warm boot: Restarting the boot-up without first turning off the power.

Windows: A widespread operating system from Microsoft, used on approximately 80% of all PCs.

write head: A small electromagnet in a disk drive that puts data onto the platter.

XGA: Extended Graphics Array, a video standard with a resolution of 1024 x 768 at 256 colors, or 640 x 480 with 16-bit color.

Zip Drive: A high-density removable-media drive. Each diskette holds either 100 or 250 megabytes.