||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.
||Software that detects, repairs, cleans, or removes virus-infected files from a
||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
||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.
||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.
||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. Go into Windows/Control Panel/Add-Remove Programs to make this disk.
||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! There are some good disk utility programs available that can actually
recover your hard drive and it's data if the boot record should become damaged.
||See Boot Record.
||To load and initialize the operating system on a computer. Often
abbreviated to boot.
||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.
||A circuit board that usually is designed to plug into a connector or slot.
See also adapter.
||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. Windows Scan Disk can
maintain your hard drive and locate lost clusters, either recycling them as free space or making
them into files so you can review the data.
||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
||Starting or restarting a computer by turning on the power supply. See
also warm boot.
||Stands for Central Processing Unit, a programmable logic device that performs all
the instruction, logic, and mathematical processing in a computer.
||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. There are "crash detection" programs available, although few can really
fully protect your system from crashing... most can only recover in a limited way.
||Two files that both refer to the same data.
||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%. Windows has a good built in defragment program as part of its built in utility
package. You need to do it regularly. Once a month is recommended.
||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.
||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).
||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.
||A program designed to interface a particular piece of hardware to an operating
system or other software.
||Disk Operating System. Usually used as an abbreviation for MS-DOS, a
micro-computer operating system developed by Microsoft.
||Stands for enhanced integrated drive electronics. A specific type of
attachment interface specification that allows for high-performance, large-capacity drives.
See also IDE.
||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
||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
||See File Allocation Table.
||See File Allocation Table.
||The disk-partitioning program used in DOS and several other operating systems to
create the master boot record and allocate partitions for the operating system's use.
||A collection of data grouped into one unit on a disk.
|File Allocation Table
||(FAT or FAT32) DOS uses the FAT to manage the disk data area. The FAT
tells DOS which portions of the disk belong to each file. The FAT links together all of the
clusters belonging to each file, no matter where they are on disk. The FAT is a critical
file: you should be sure to back it up regularly.
FAT32 is a newer type of FAT that was designed to handle large hard disks. The older FAT
(FAT16) can only support partitions up to two gigabytes in size. FAT32 can handle partitions
that are thousands of gigabytes.
||A system for organizing directories and files, generally in terms of how it is
implemented in the disk operating system.
||Software contained in a read-only memory (ROM) device.
||The DOS format program that performs high-level formatting on a hard disk, and
both high- and low-level formatting on a floppy disk.
||The state of having a file scattered around a disk in pieces rather than existing
in one contiguous area of the disk. Fragmented files are slower to read than unfragmented
||See Video Adapter
||A small electromagnetic device inside a drive that reads, writes, and erases data
on the drive's media.
||A mass of metal attached to a chip carrier or socket for the purpose of
||Stands for integrated drive electronics. Describes a hard disk with the
disk controller integrated within it. See also EIDE.
||I/O stands for input/output. I/O is the communication between a
computer and its user, its storage devices, other computers (via a network) or the outside world.
The I/O port is the logical channel or channel endpoint in an I/O communication system.
||Stands for interrupt request. IRQ is the name of the hardware
interrupt signals that PC peripherals (such as serial or parallel ports) use to get the
processor's attention. Since interrupts usually cannot be shared, devices are assigned
unique IRQ addresses that enable them to communicate with the processor. Peripherals that
use interrupts include LAN adapters, sound boards, scanner interfaces, and SCSI adapters.
||A small, plastic-covered metal clip that slips over two pins protruding from a
circuit board. When in place, the jumper connects the pins electronically and closes the
circuit, turning it "on".
||An essential part of the operating system, responsible for resource allocation,
low-level hardware interfaces, security, and more.
|Lost Cluster Chain
||This is a cluster on disk that is not registered as free, but does not have any
known data in it.
||The "heart" of your PC -- it handles system resources (IRQ lines, DMA channels,
I/O locations), as well as core components like the CPU, and all system memory. It accepts
expansion devices such as sound and network cards, and modems.
||Windows NT File System.
||A logical section of a disk. Each partition normally has its own file
||A 64-byte data structure that defines the way a PC's hard disk is divided into
logical sectors known as partitions. The partition table describes to the operating system how the
hard disk is divided. Each partition on a disk has a corresponding entry in the partition
table. The partition table is always stored in the first physical sector of a disk drive.
||A location of a file. The path consists of directory or folder names,
beginning with the highest-level directory or disk name and ending with the lowest-level directory
||Any part of a computer other than the CPU or working memory (RAM and ROM).
For example, disks, keyboards, monitors, mice, printers, scanners, tape drives, microphones,
speakers, and other such devices are peripherals.
||(PnP) A hardware and software specification developed by Intel that allows
a PnP system and a PnP adapter to configure automatically . PnP cards generally have no
switches or jumpers, but are configured via the PnP system's BIOS or with supplied software for
||Stands for power-on self test. Each time a PC initializes, the BIOS
executes a series of tests collectively known as the POST. The test checks each of the
primary areas of the system, including the motherboard, video system, drive system, and keyboard,
and ensures that all components can be used safely. If a fault is detected, the POST reports
it as an audible series of beeps or a hexadecimal code written to an I/O port.
||Random Access Memory (see also DRAM, SDRAM). A data storage device for
which the order of access to different locations does not affect the speed of access. This
is in contrast to magnetic disk or magnetic tape where it is much quicker to access data
sequentially because accessing a non-sequential location requires physical movement of the storage
medium rather than just electronic switching. The most common form of RAM in use today is
built from semi-conductor integrated circuits, which can either be static (SRAM) or dynamic
||See System Registry
||Read-Only Memory. A type of data storage device which is manufactured with
fixed contents. The term is most often applied to semiconductor integrated circuit memories.
ROM is inherently non-volatile storage - it retains its contents even when the power is switched
off, in contrast to RAM. It is used in part for storage of the lowest level bootstrap
software (firmware) in a computer.
||Stands for small computer system interface. A standard that allows multiple
devices to be connected in daisy-chain fashion.
||Stands for synchronous dynamic random Access memory (see also DRAM). SDRAM
incorporates new features that make it faster than standard DRAM and EDO memory.
||The tracks on a disk are divided into sectors. Clusters contains from 1 to
||A physical connector on a motherboard to hold an expansion card, SIMM, DIMM, or a
processor card in place.
||A receptacle, usually on a motherboard, that processors or chips can be inserted
||The system configuration files used by Windows 95, 98 and NT to store settings
about user preferences, installed software, hardware and drivers, and other settings required for
Windows to run correctly. The system updates the registry every time you add new hardware or
a new program to your system. When the registry becomes "broken," it can cause serious
|System Rescue Disk
||See Boot Disk.
||Most commonly found in relation to a SCSI chain, this functions to prevent the
reflection or echoing of signals that reach the ends of the SCSI bus. Usually terminators
are hardware circuits or jumpers.
||An expansion card or chip set built into a motherboard that provides the
capability to display text and graphics on the computer's monitor. If the adapter is part of
an expansion card, it also includes the physical connector for the monitor cable. If it is a
chip set on the motherboard, the video connector will be on the motherboard also.
||A virus is a program written to cause mischief or damage to a computer system.
A mild virus might only be a slight nuisance, or even amusing. However, most viruses do
damage, whether to your files, your registry, or even your hardware. Viruses are hard to
detect, easy to propagate, and difficult to remove. Your computer can pick up a virus when
you copy a seemingly normal file from a diskette or download it from the Internet.
||Rebooting a system by means of a software command as opposed to turning the power
off and on. See also cold boot.
||Y2K (Year 2000) is the common name for all the difficulties the turn of the
century may bring to computer users. Back in the seventies and eighties the turn of the
century looked so remote and memory and disk space were so expensive that most programs stored
only the last two digits of the years. Those which will still be in use will produce
surprising results after 2000: they may believe that 1 January 2000 is 1 January 1900, they may
calculate the day of the week wrong, etc. In addition, serious problems may occur when the
internal clocks in your system fail to roll-over.