PC Terminology

Confused about all the lingo that goes with a typical PC? Here's an attempt to define some of the terms you might have come across but not understood.

ADSL - Asymmetric digital subscriber line. A high performance internet connection which can operate over conventional phone lines. Data rates of 500 kilobits per second can be achieved, although bandwidth is shared with other users on the same ring.

AGP - Accelerated Graphics Port. A dedicated high-bandwidth interface used for attaching video/graphics cards to the processor on. a motherboard. x1, x2, x4 and x8 speeds exist.

AT - Advanced Technology (well it was, back in 1986!) The name given by IBM to their first 286 machines.

ATX - A follow-on to AT with a better power supply specification and some design improvements, including more suspend and sleep modes.

Athlon - The name given to AMD's competitor against the Intel Pentium line

CD ROM - Compact Disc Read On Memory. Defines the formats to be used for digital data storage on a compact disc. CD's can hold 650-700MB of data and 74-80 minutes of music. 90 and 99 minute CD-R's exist but may not be compatible with all CD-ROMs or CD players.

CD RW - Compact Disc (Read/Write) - A read/write version of a CD-ROM. Allows users to create their own CDs.

Celeron - The name given to the cut-down version of Intel's Pentium processor.

CPU - Central Processor Unit, a large chip which is the "brains" of the machine.

DDR - Dual Data Rate - a faster version of SDRAM memory. Used in most modern PCs.

DIMM - Dual In Line Memory Module

DRAM - Dynamic Random Access Memory

Duron - AMD's latest low-end processor, a follow on from K6 family. A baby brother to the Athlon family, with smaller cache and a slower front side bus.

DVD ROM - Digital Versatile Disc Read Only Memory. Defines the formats to be used for digital data storage on DVD discs. Commerical DVD's can hold between 4-20 GB of data.

DVD RW - A recordable DVD format. There are actually 2 formats - DVD-R and DVD+R. There are also re-writeable variants - DVD-RW and DVD+RW. DVD-R media tends to be cheaper and DVD+R is faster to write. Currently, capacity is 4.7GB.

EDO - extended Data Out - a type of DRAM. Now obsolete.

EISA - A follow-on to the ISA bus. Popular for a couple of years, but overshadowed by PCI.

EGA - Extended Graphics Array, forerunner to the VGA format.

Floppy Disk

Hard Disk

ISA - Industry Standard Architecture - This was the interface built into the original IBM PC, PC-XT and PC-AT. No longer implemented on motherboards, since newer generation interface cards tend to use the PCI interface.

IRQ - Interrupt - a means for an interface to "prod" the central processor.

Keyboard - input device. The original PC keyboard had 84 keys, this was increased to 102 for the PS/2 line and is now 105 for Keyboards which support Windows 95/98. Multimedia keyboards have even more keys to control additional functions. Wireless keyboards use infra-red or radio frequency in place of a cable when communicating with a PC.

LCD - Liquid Crystal Display - used as the display in most Laptops. Desktop LCD displays have come down in price and are a viable replacement for Cathode Ray Tube displays.

Memory - Generally, a reference to semiconductor memory such as SRAM/DRAM, but can also refer to hard disk capacity.

MicroChannel - IBM's follow-on interface for the PC-AT, invented in the 1980s and unveilled in the original PS/2 line up. Never gained popular support and eventually abandoned in favour of PCI.

Modem - Modulator/Demodulator - a device for transmitting and receiving data, usually over a telephone line. Modems started off supporting such as 1200/75 bits per second but today's modems support 56k bits per second.

Monitor -

Motherboard - These holdmost of the circuits in modern PC. Older formats such as AT and baby AT are obsolete and most modern boards are designed to ATX or micro ATX (mATX) form factors. A newer standard (ITX) is used in slim or small form factor PCs.

Mouse- an input device, connects to serial, PS/2 or USB interfaces.

Multimedia - a "catch all" for audio and CD features. A multimedia PC must have a sound card and a CD drive.

Parallel - as in parallel interface, a type of interface originally used for attaching printers. These days can also be used to attach external devices such as tape drives or CD ROMS or scanners.

PCI - Peripheral Connect Interface. Developed by Intel as a high performance follow on to the ISA architecture. Its success spelt the end for VL-Bus, EISA and Micro Channel. PCI slots are included in almost all modern PCs. PC operates with a 32-bit bus and a clock of 33MHz for a peak performance of 133MB/s.

PCI-X - The next generation of PCI interface, promising a substantial improvement in performance over PCI. Uses 64-bit transfers and a higher clock speed (up to 133MHz)

Pentium - The name chosed by Intel for their 486 follow-on. Intel started choosing names for their processors because numbers can't be copyrighted but names can.

RAM - Random Access Memory

RDRAM - RAMBUS memory - a new type of high performance memory, endorsed by Intel

SCSI - Small Systems Computer Interface.

SDRAM - Synchronous Dynamic Random Access Memory. The most popular form of PC memory. Now superceeded by DDR SDRAM which is a faster derivative.

Serial- RS232

SIMM - Single Inline Memory Module

Sound - Creative Labs' Soundblaster cards set the standards for PC Audio. Many manufacturers now make high quality sound cards for PCs.

SVGA - Super VGA. 800 x 600 resolution.

TFT - Thin Film Transistor. A type of transistor used in high performance CD displays. Each display element is controlled by a TFT, so a colour LCD contains over 2 million transistors.

USB - Universal Serial Bus

VGA - Video Graphics Array - a set of video resolutions and formats invented by IBM in the 1980's. Highest resolution 640 x 480. Superceeded by SVGA (800 x 600) and XGA (1024 x 768).

Video - started off with MGA (mono graphics) with the original IBM PC and moved to chunky CGA and EGA before VGA and its derivatives took hold.

XGA

ZIP