Vocabulary A-E

A

Adapter
A device that serves as an interface between the system unit and a device attached to it, such as a SCSI Adapter.   Often synonymous with expansion card, card, or board.  Can also refer to a special type of connector.

Anti-Virus
Software that detects, repairs, cleans, or removes virus-infected files from a computer.

Application
A more technical term for program.

ABIOS
Acronym for Advanced Basic Input/Output System, a set of input/output service routines built into the IBM PS/2 microcomputers that use the Micro Channel Architecture. These routines are designed to support multitasking and protected mode – a means of reserving a portion of memory exclusively for a particular program, thus protecting it and its resources from interference by other executing programs.

B

Bank
The collection of memory chips or modules that make up a block of memory.  This can be 1, 2 or 4 chips.  Memory in a PC must always be added or removed in full-bank increments.

BIOS
The part of the operating system that provides the lowest level interface to peripheral devices.  The BIOS is stored in the ROM on the computer’s motherboard.

Boot
To start up your computer.  Because the computer gets itself up and going from an inert state, it could be said to lift itself up “by its own bootstraps” — this is where the term ‘boot’ originates.

Boot Disk
The magnetic disk (usually a hard disk) from which an operating system kernel is loaded (or “bootstrapped”).  MS-DOS and Microsoft ® Windows® can be configured (in the BIOS) to try to boot off either floppy disk or hard disk, in either order (and on some modern systems even from CD or other removable media).  A special floppy boot disk (often called a System Rescue Disk) can be created that will allow your computer to boot even if it cannot boot from the hard disk.

Boot Record
Once the BIOS determines which disk to boot from, it loads the first sector of that disk into memory and executes it.   Besides this loader program, the Boot Record contains the partition table for that disk.  If the Boot Record is damaged, it can be a very serious situation!

Boot Sector
See Boot Record.

Bootstrap
To load and initialize the operating system on a computer.  Often abbreviated to boot.

Bus
A set of conductors (wires or connectors in an integrated circuit) connecting the various functional units in a computer.  There are busses both within the CPU and connecting it to external memory and peripheral devices.  The bus width (i.e., the number of parallel connectors) is one factor limiting a computer’s performance.

C

Card
A circuit board that usually is designed to plug into a connector or slot.  See also adapter.

Cache
(Internet Browser) – The files and graphics saved locally from web sites you have previously visited.

Click
To click an item means to point to it with the screen pointer, and then press quickly and release the left mouse button at once.

Cluster
Windows allocates space to files in units called clusters.  Each cluster contains from 1 to 64 sectors, depending on the type and size of the disk.  A cluster is the smallest unit of disk space that can be allocated for use by files/A hard disk term that refers to a group of sectors, the smallest storage unit recognized by DOS. On most modern hard disks, four 512-byte sectors make up a cluster, and one or more clusters make up a track.

CMOS
A part of the motherboard that maintains system variables in static RAM.  It also supplies a real-time clock that keeps track of the date, day and time.  CMOS Setup is typically accessible by entering a specific sequence of keystrokes during the POST at system start-up.

Cold Boot
Starting or restarting a computer by  turning on the power supply.  See also warm boot.

Context Menu
Also called a context-sensitive menu, or a shortcut menu, a context menu includes the commands that are commonly associated with an object on the screen.  To activate an itme’s context menu, point to it with the screen pointer, then press and release the right mouse button once.

Cookies
(Internet Browser) – Holds information on the times and dates you have visited web sites. Other information can also be saved to your hard disk in these text files, including information about online purchases, validation information about you for members-only web sites, and more.

CPU
Stands for Central Processing Unit, a programmable logic device that performs all the instruction, logic, and mathematical processing in a computer.

Crash
A sudden, usually drastic failure.  Can be said of the operating system or a particular program when there is a software failure.  Also, a disk drive can crash because of hardware failure.

Cross-linked files
Two files that both refer to the same data.

D

Data Recovery:

Defragment
As modern file systems are used and files are deleted and created, the total free space becomes split into smaller non-contiguous blocks.  Eventually new files being created, and old files being extended, cannot be stored each in a single contiguous block but become scattered across the file system.  This degrades performance as multiple seek operations are required to access a single fragmented file.

Defragmenting consolidates each existing file and the free space into a contiguous group of sectors.  Access speed will be improved due to reduced seeking.  A nearly-full disk system will fragment more quickly.   A disk should be defragmented before fragmenting reaches 10%.

Directory
This is an index into the files on your disk.  It acts as a hierarchy, and you will see them represented in Windows looking like manila folders.

DMA
Stands for direct access memory.  DMA is a fast way of transferring data within a computer.  Most devices require a dedicated DMA channel (so the number of DMA channels that are available may limit the number of peripherals that can be installed).

DRAM
Dynamic Random Access Memory (see also SDRAM).  A type of memory used in a PC for the main memory (such as your “32 Mbytes of RAM”.)  “Dynamic” refers to the memory’s memory of storage – basically storing the charge on a capacitor.  Specialized types of DRAM (such as EDO memory) have been developed to work with today’s faster processors.

Driver
A program designed to interface a particular piece of hardware to an operating system or other software.

DOS
Disk Operating System.  Usually used as an abbreviation for MS-DOS, a micro-computer operating system developed by Microsoft.

E

EIDE
Stands for enhanced integrated drive electronics.  A specific type of attachment interface specification that allows for high-performance, large-capacity drives.  See also IDE.

Encrypted data
Data converted into cyphertext. Encryption is the safest way to ensure data confidentiality.

Executable
A binary file containing a program in machine language which is ready to be executed (run).  MS-DOS and Windows machines use the filename extension “.exe” for these files.

Extract
To extract is to return a compressed file to its original state.  Typically in order to view the contents of a compressed file, you must extract it first.

Expansion Card
An integrated circuit card that plugs into an expansion slot on a motherboard to provide access to additional peripherals or features not built into the motherboard.  See also adapter.