Access time
The time it takes for a device to access data. The access time, quoted in milliseconds (ms) for hard disks and nanoseconds (ns) for memory, is usually an average as it can vary greatly. Together with the transfer rate, it is used to gauge the performance of hard disks and other devices. The lower the number, the better the performance.

Applications
An application, or package, is one or more programs used for a particular task. For example, word processing, invoicing or spread sheeting.

ASCII (American Standard Code for Information Interchange )
Usually a synonym for plain text without any formatting (like italics, bold or hidden text). Since computers naturally use binary rather than Roman characters, text has to be converted into binary in order for the processor to understand it; ASCII assigns binary values to Roman characters. RTFI a Microsoft standard, adds extra formatting features to plain ASCII.

Backwards compatible
Compatibility of hardware or software to older versions of the product or standard.

Baud rate
The number of electronic signals that can be sent along a communications channel every second. In common usage, it is often confused with bits per second. These days modem speeds are normally measured in bits per second. (See V and Bit).

BC Card
Formerly PCMCIA. A standard to allow PCs, particularly notebooks, to be expanded using credit card-sized cards.

BIOS (Basic Input/Output System.)
Software routines that let your computer address other devices like the keyboard, monitor and disk drives.

Bit
Binary digit, the basic binary unit for storing data. It can either be 0 or 1. A Kilobit (Kbit) is 2¹⁰ (1,024 bits); and a Megabit is 2²⁰, which is just over a million bits. These units are often used for data transmission. For data storage, megabytes are more generally used. A megabyte (Mb) is 1,024 kilobytes (Kb) and a Kb is 1,024 bytes. A gigabyte (Gb) is 1,024Mb, A byte (binary digit eight) is composed of eight bits.

Bug
(See Crash)

Boot
Short for bootstrap. Refers to the process when a computer loads its operating system into memory. Reboot means to restart your computer after a crash, either with a warm reboot (where you press Ctrl Alt Del) or a cold reboot, where you switch the computer off and back on again. Bus
A "data highway", which transports data from the processor to whatever component it wants to talk to. There are many different kinds of bus, including ISA, EISA, MCAI and local bus (PCI and VL-bus).

Cache
(See Memory)

COAST
Cache On A Stick.

CD-ROM
A CD-ROM is the same as a normal audio CD, except it can store data as well as sounds. A CD-ROM player can be attached to your computer to read information from the CD-ROM into the computer's memory in the same way that a domestic CD player reads information from the CD into your hi-fi. The advantage of distributing information on CD-ROM rather than other media is that each one can hold up to 680Mbof data: equivalent to about 485 high-density 3.5in floppy disks.

CPU
Central Processing Unit. Normally refers to the main processor or chip inside a PC, (See Processor.)

DRAM
(See Memory)

DOS
(Disk Operating System) Once the standard operating system for PCs, it is now being replaced by Windows 95 and Windows NT.

Drive controller card
An expansion card that interprets commands between the processor and the disk drives.

Drivers
Pieces of software that, "drive" a peripheral, They interpret between the computer and a device such as a CD-ROM. If you have a SCSI CD-ROM drive connected, you will be able to use it on a PC or a Mac just by loading up the relevant driver on each machine.

EIDE
(See IDE)

EISA
(Extended Industry Standard Architecture) A bus standard designed to compete with MCA. Now being replaced by PCI.

Electronic mail
(E-mail, email) Still the biggest single use of the Internet, When you sign up with an ISP you are given an email address. Usually you can incorporate your name, or part of it, into your email address to make it easy to remember.

Expansion card
Circuit boards, which fit inside PCs to provide extra functionality. For example, one might be an internal modem, providing the same functions as an external version (which is more common) but sitting inside the PC, Expansion cards are designed to be fitted and removed by people with little knowledge of PCs.

Floppy disk drive
Practically all PCs come with a floppy disk drive: 3.5in HD thigh densityi 1.44Mb floppy disks are now the standard. They come in hard plastic cases and have replaced the older, literally floppy, 5.25in disks.

Fonts
A font is an alphabet designed in a particular style. Fonts apply both to screen and printed letters, Truetype and Type 1 fonts are stored as shape descriptions, scalable to any size,

Hard disk
Sometimes called a fixed disk, hard disks are hermetically sealed rigid disks able to store data and programs. Disk capacities increase all the time.

Hardware
All electronic components of a computer system, including peripherals, circuit boards and input/output devices.

HTML
(Hypertext mark-up language) The standard language used in the creation of web pages, which can be read by web browsers.

IBM-compatible
Originally meant any PC compatible with DOS. Now tends to mean any PC with an Intel or compatible processor capable of running DOS or Windows.

IDE
(Integrated Drive Electronics) A control system designed to allow computer and device to communicate, Once the standard for PC hard disks, now being replaced by EIDE (enhanced IDE~ which offers improved performance and extra features.

Internet
Millions of computers interconnected in a global network.

ISP
(Internet Service Provider) ISPs provide access to the internet. You use your modem to dial the ISP's modem. The ISP has a high-bandwidth permanent connection to the Internet.

IRDA
(Infra-Red Data Association) The standard for exchanging data using infra-red, typically from PDAs or notebooks to a PC or printer.

ISA
(Industry Standard Architecture) This was the original bus architecture on 286 PCs. Also known as the AT bus The 286 was known as the AT) it remains in use today. Slow by modern standards, but so widely accepted that expansion cards are still made for it, (See EISA, PCI.)

ISDN
(Integrated Services Digital Network) Offers significant advantages over analogue telephone lines, It can handle multiple transfers on a single connection and is faster, In the UK, however costs of installation and rental remain high.

JPEG
(See MPEG)

Kbit
(kilobit), Kb (See Bit)

LAN
(Local Area Network) (See Network)

Local Bus
PCI (Peripheral Component interconnect), developed by Inter, is now the standard far local bus architecture, It is faster than the older VL-Bus (Video Electronic Standards Association local bus) it replaces.

Macintosh
(Mac) A personal computer made by Apple and which is incompatible with PCs. Developed as a rival standard, its operating system looks like Windows but pre-dates it.

Maths co-processor
A specialised chip that handles mathematical calculations (floating point operations) for the processor, Modern processors such as the Pentium have a co-processor built into them.

MPEG
(Moving Picture Expert Group) A standard for compressing video, available in several flavours: MPEG 1, MPEG 2, MPEG 4. JPEG (Joint Photographic Expert Group) is a standard for still image compression.

Network
A network is a group of computers linked together with cable. The most common form of network is a LAN (Local Area Network), where electronic mail and other files can be exchanged between users without swapping floppy disks. Printers and other resources can be shared; All the PCs on a LAN are connected to one server, which is a powerful PC with a large hard disk that can be shared by everyone.

OS
(Operating System) The operating system communicates with the hardware and provides services and utilities to applications while they run, such as saving and retrieving files.

PDA
(Personal digital Assistant) Small electronic organisers. The Psion 3a is a typical example.

PCI
(See Local bus)

Package
(See Applications)

Parallel Ports
Used by your PC to communicate with the outside world, usually via a printer. Information can travel in parallel along a series of lines, making it faster than serial ports which can only handle one piece of information at a time.

Pentium
Fast 32-bit processor with a built-in cache. Now the standard on PCs, it is been replaced by the Pentium MMX chip which has extra instructions and a 32Kb cache. The Pentium Pre is a higher-end workstation CPU with 256Kb cache meant for full 32-bit operating systems like Windows NT.

Pixel Picture element.
The smallest addressable dot displayed on a monitor.

PCMCIA
A standard to allow PCs, particularly notebooks, to be expanded using credit card-sized cards.

Processor
Chip which does most of a computer's work.

Qwerty
The name of a standard English-language keyboard, derived from the first six letters in the top row. French equivalent is AZERTY.

RAM
(Random access Memory) (See Memory)

ROM
(Read Only Memory) See Memory)

SCSI
Small Computer System Interface is a bus that comes as standard in a Macintosh and is beginning to rival EIDE on PCs.

Serial port
Serial ports (Com1 and com2) are used by your PC to communicate with the outside world. Mostly used by modems and similar devices which communicate quite slowly. Faster communications are achieved through the parallel port.

Shareware
A method of distributing software. It is freely available, but not free of charge. You are honour-bound to pay a small fee to the software's developer if you continue to use the program after a set period.

SIMM
(Single Inline Memory Module) The standard modules for memory expansion on PCs. Older 30-pin SIMMs have now been replaced by the 72-pin variety available in capacities up to 16Mb.

Tape streamer
Magnetic tape recorder for backing up data from a hard disk.

UART
(Universal Asynchronous Receiver Transmitter)
Pronounced "you-art", this is a chip that allows your PC to cope with high-speed communications. V.34 plus, V.34, V.32bis A series of CCITT standards which define modem operations and error correction. There are more than 20, but the key ones are: .V.32bis, the standard for 14.4Kbps (kilobits per secondj modems. V,34, the standard for 28.8Kbps modems (see Baud). V.34 Plus, the new standard for speeds up to 33.6Kbps.

VESA
(See Local Bus)

VGA
Video Graphics Array is the name given to a popular display. VGA graphics have 640 pixels horirontally and 480 vertically, and can display 16 colours. SuperVGA (SVGA) graphics can display 800 x 600 or 1,024 x 768 in as many colours as the memory in your graphics card will allow: up to -16.4 million, or true colour.

VL-Bus
(See Local Bus)

Windows
a GUI (Graphical User interface) developed by Microsoft. Windows is intended to make programs easier to use by giving them a standard, mouse-driven interface. · Windows 3,11 16-bit operating system.

Windows NT
Robust, fully 32-bit operating system from Microsoft. The latest, version 4.0, features a Windows 95 type interface.

Windows 98
Major improvement to Windows 95, with a interface that can be set to work like the internet. Less prone to crashes and easier to use, but requires more memory.

Winsock
Short for "sockets for Windows". The Winsock.dll is an extension for Windows which is necessary for connecting to TCP/IP networks.

WWW
World Wide Web
Service on the internet using special software called web browsers (Netscape and Internet Explorer are two best-known browsers) to give access to pages of information with text, pictures and multimedia.

WYSIWYG
"What You See Is What You Get": what you see on the screen is exactly what you will get when you print out your work.

ZIF
(Zero Insertion Force) Sockets used for CPU's. Lifting a handle enables you to remove the processor

ZIP
The common standard for compressing files so that they take up less space, Zipped files have the extension .zip and are compressed and decompressed using shareware utilities such as Winzip and PKZip.