Letter A

Abstract         An abstract class is a base class in a hierarchy that cannot
                 be made an instance of due to a virtual function as a member.

AC-3             Dolby Digital Surround Sound system.

Access           A file based database application, part of Microsoft Office.

Acorn Computers  Company that produced the Electron, BBC A/B/Master and Archimedes (RISC)
                 computers. They also developed the ARM processor used in Apple products.

ACPI             Advanced Configuration Power Interface. Power management for computer
                 hardware incl. power on/off, sleep, hibernation etc. 
							 
ActiveX          Microsoft language to provide dynamic HTML content.

ADA              A programming language developed by the DoD to replace its
                 450 programming languages used in embedded systems. Ada is
                 name after Ada Lovelace, the very first programmer.

ADF              Amiga Disk Format. Image of an Amiga floppy disk. Used for 
                 emulators such as Fellow, DOSUAE and Winuae.

Adobe            Company that produces popular graphics and design applications.

ADSL             Asymmetric Digital Subscriber Line. High speed network 
                 over dedicated digital lines. Average speeds at 8Mbps
                 downstream and 768Kbps upstream. See ThinkBroadband Web site.

Adware           Programs or popups used to advertise products or collect 
                 private information on browser use for use by advertisers
                 See Spyware.


AES              Advanced Encryption Standard or Rjindael using 128, 192 or 256 key bit lengths.
                  
AGA              Advaced Graphics Architechure used on Amiga 1200 and 4000 models.

Agnus            A Chip used in early Amigas for Chip memory management, the Copper and the Blitter.

AHCI             Advanced Host Controller Interface. Used by SATA drives to provide
                 higher speeds, hot swapping and native command queuing which is
                 not offered in IDE modes. Turning it off or switching to IDE
                 emulation will allow earlier versions of Windows to be installed.
                 
AIT              Advanced Intelligent Tape is magentic tape format based on DAT format but was
                 four times the capacity. Ideal for backup storage.

ALGOL            ALGOrithmic Language used mainly for Scientific computations, not
                 widely used as COBOL or Fortran. See ALGOL.
								 
AGP              Advanced or Accelerated Graphics Port. Very fast expansion 
                 port for graphics card in PCs and new Power Macs.

Air              Adobe Air is a plugin to develop rich web applications.

Alice            Memory Chip in 1200 or 4000 for AGA for 2MB Chip ram. Replaces Agnus chip.

Alpha            Software in early stages of development with many features not
                 available and bugs not removed yet. Probably unstable as well.
				 
Alpha            A 64 bit Processor developed by DEC, also known as Alpha AXP with RISC
                 architecture. Used by OS such as OpenVMS, Tru64 Unix, Windows NT, Linux, BSD etc 
                 
AMD              Advanced Micro Devices. Manufacturer of x86 compatible processors 
                 such as the K6-2, K6-3 and Athlon and also the AMD Radeon graphics chipsets.

AMD64            AMD's 64 bit expansion of their x86 processors to add 64 bit capability.


AMD-V            AMD's hardware virtualisation technology to support Hyper-V, VMWare, VirtualBox etc.


Amiga            Range of 16/32 bit computers produced by Commodore in mid 1980s.
                 More information on AmigaOS Wiki.

AMR              Audio, Modem Riser. New slot for software based modems and audio
                 cards. Usually looks like a very short brown slot near PCI slots.

Amstrad          Alan M. Sugar Trading company. Took over Sinclair's Spectrum and released new
                 versions including Spectrum 128. Also released Amstrad CPC and PC computers.

Android          Name of open source operating system for SmartPhones and tablet devices
                 developed by Google. See Android.com.
                 								 
ANSI             American National Standards Institute. See ANSI website.

AOL              America On Line. Propietary Internet provider using their
                 own software to provide a `portal` to the internet.

Apache           Open Source community that runs Apache HTTP Web Server used widely on 
                 Unix,Linux and Mac Systems. The TomCat version includes Java scripting.
                 Apache also runs OpenOffice, Netbeans, Cloudstack and other projects.

API              Application Programmer's Interface. The frontend of programs
                 and functions need to write applications for a given system.
                 DirectX is the API for games and multimedia applications.
								 								 
APM              Advanced Power Management. Software control over power saving
                 features of the PC.
								 
App			  Application that runs on a device from a Phone to a Computer.

Apple            Apple Inc. is the developer and producer of the Apple Mac computer, iPod,
                 iPhone and iPad products. macOS and IOS are its main operating systems.

AppStore         Application online store to make it easier to locate and install applications
                 available for computer or a mobile phone. 

APU			  Accelerated Processing Unit which combines a general CPU and graphics GPU
                 and other components such as memory controller and video decoder.

Arc              An older compression method. Superceeded by ZIP and LHA.

ARP              Address Resolution Protocol. Converts Ethernet MAC addresses
                 to IP addresses. Allows Broadcasting on LANs.

ASCII            American Standard Code for Information Interchange. Code for
                 displaying letters, numbers and symbols on computers.

ASIO             Audio System Input/Output. Provides direct access to audio
                 hardware to reduce latency.

ASP              Active Server Pages. Dynamic programming language for HTML
                 which can be written in Visual Studio or the older Visual Interdev.

ASP              Application Service Provider. Rather like an ISP but provides
                 application software for business over a network or internet.

ASPX			  Active Server Page framework based on Microsoft's .NET framework.
				  See ASP.NET docs.
                 
ASR              Automatic System Recovery. Feature of Windows Me/2001 which 
                 will protect system files from being overwritten by invalid or
                 older system files.
                  								 
Assembler        Program to produce machine code from Assembly language programs.

Assembly         Assembly language. Programmers use a symbolic language to produce
                 one-to-one instructions as the machine code equivalent. Used for
                 speed and low-level functions.

AT               Advanced Technology. For 80x86 based processors or higher.

ATAPI            AT Attachment Packet Interface. Standard used for IDE devices 
                 such as CD ROM drives. (ATA)

Atari            Games company that used produce consoles such as the Atari VCS, Atari 400, 800, 
                 the Atari ST and an upcoming AtariBox console.

Athlon           High speed processor by AMD. Compatible with Intel's x86 processors.

Athlon64         AMD's new 64 bit processor to replace older 32 bit processors. Similar
                 to Intel's Itanium but retains some 32 bit compatibility.

ATX              A standard motherboard (and case) size with Power Management.

AVX              Advanced Vector Extensions provides 256 integer commands and Fused Multiply add (FMA).

AWARD            Name of a common BIOS chip manufacturer. (Now part of Phoenix).

AWS			  Amazon Web Services. Provide cloud-based computing services for companies.

Azure			  Microsoft's cloud-based computing services for companies.