Letter D

Data Numbers, characters, text, pictures and so on is known as Data
which can be processed by a computer.

Database A central store of data, can be an Access type database or SQL database
or any sort of database. Can contains numbers, strings, pictures etc.

DDR Double Data Rate. Runs at same speed SDRAM but read and write
twice in a clock pulse. There are three types: DDR (1.6GB/s),
DDR2 (2.1GB/s) and DDR3 (1600 Mbps).

Debian A popular distribution of the Linux operating system.

Debug Process in which to remove errors and mistakes (bugs) from a program.

Debugger Program to help developers locate and remove errors and mistakes (bugs)
from programs.

Defragmentation Files on a hard disk can become broken in smaller chunks over time and
thus wastes disk space and increases time to read files. Defragmenting a
hard disk combines these pieces of files into larger or single chunks
to reduce waste and speed up file access.

DSP Delivery Service Partner. A delivery standard like OEM but the manufacturer's name is not stamped
on the software or manual. It is used for smaller distributers, system builder hobbyists and
generic no-name builders.

Delphi Borland Delphi is Windows based programming language similar to Object Pascal.

Denise Name of chip used in OCS/ECS Amigas used to display graphics and sprites.

Desktop A computer designed to be placed on a table or desk, computer tends to
be large with seperate monitor, keyboard and mouse.

Device A program which controls a particular device or group of devices.
For example, the scsi.device controls Hard Disks mainly either
via IDE or SCSI interfaces.

DHCP Dynamic Host Configuration Protocol.
Provides IP addresses dynamically, commonly used on networks or
when using the (C)SLIP protocol when connecting to the internet.
Replaces the older BOOTP method.

DIMM Dual In-line Memory Module. 64 bit memory board to add memory
to modern computers. Tend to come in sizes of 16Mb, 32MB or
more and run at 10ns or faster.

Directory A directory is a container for files or other directories.

DirectX A programming interface for graphics, music and sound for
the Windows operating system. Latest version is version 12
which comes with Windows 10.

Disk/Disc Refers to data storage medium. Common types are floppy disks,
hard disks, compact discs, external SCSI, USB, and Firewire disks.

DLL Dynamic Link Library. A file of program functions that can
be shared between applications.

DLT Digital Linear Tape used for magentic tape computer storage by DEC.

DMA Direct Memory Access. Feature which allows other chips to
access memory direct instead of via the CPU.

DNS Domain Name Server. Converts between IP addresses and human
readable formats e.g. 110.56.76.12 to www.noname.com

Dolby Digital Type of high quality sound used on PCs and DVD decks. See Dolby.

DOS Disk Operating System library which provides functions for disk
and file management on the PC.

Download Process to copy files from a remote server, such as a web or
ftp server, to your local computer. (See Upload).

DPI Dots Per Inch. Resolution of dots printed on modern printers.
The more dots there are the sharper and clearer the picture.

DPMS Display Power Management Signalling. Power Management standard
for Monitors and displays.

Dragon An 8 -bit computer by Dragon Data Ltd. It has 6809 CPU, 32 or 64 KB RAM,
Extended Basic. Similar to TRS-80 computer.

DRAM Dynamic Random Access Memory. Type of memory used for main
memory on computers, tends to very cheap and quite fast. Loses its
contents when the computer is switched off.

Drawer A directory with drawer icon which may contain files or other
drawers.

DR-DOS Digital Research DOS operating system.

Dreamcast Sega's last game console which was discontinued later on due to
competition with Sony's Playstation 2 which had a cheap DVD player
included. Production ended in 2001, 3 years after launch.

DRM Digital Rights Management. A security system to limit distribution of
media such as Music and Video. Widely used by companies to allow
users to donwnload music and pay for them.

Driver A Program which interfaces a peripheral or device connected to the
Amiga with the Operating System and gains access to that device's
many features. Drivers include Printers, Scanners, Network, Storage,
Graphics, Sound and motherboard devices and so on.

DTD Document Type Definition for XML documents to describe XML tags.

DTP DeskTop Publishing. Refers to page makrup production. For example,
Publisher, Quark Express, InDesign.

Dual Core Most processor have a single core, now that max speed of 3.8GHz is reached
new processors have two cores or more processors on each chip for true
multi-processing. See Quad Core.

Duplex Method of communication. Half-duplex is only one way at a time, while
Full duplex allows traffic at the same time (e.g. Telephone).

Duron Low cost processor from AMD with smaller Level 2 cache than the Athon.

DV Digital Video. Mainly refers to video editing on the PC.Requires
either a Digital Camera or Camcorder and video editing software
to produce your own videos.

DVD Digital Versatile Disc.
Replaces the CD for video, produces very high quality pictures and sound.
Can contain around 4.6 GB of data.

DVD-HD Digital Versatile Disc - High Definition.
Supports very high resolutions such as 720, 1080i, 1080p and store upto 30GB of data for 8 hours of video.

DVD-R
DVD+R Digital Versatile Disc Recordable. DVD Recordable format upto 4-5Gb.

DVD-RW Digital Versatile Disc Re-Writable. Re-Writable version of DVD like
DVD+RW CD-RW.

DVD-RAM A read/writable DVD format used for data and for video recording.
Can save upto 9.4GB of data.

DVI Digital Video Interface. Alternative to the SVGA interface for
connection to TFT screens etc.

Dynamic IP Dynamic Internet Protocol. When dialing your provider to get onto
the Internet, sometimes they give you an IP address from a pool
of addresses. So you don't always use the same address.