1D One dimensional 1GL First General Language (machine language) 2D Two-dimensional 2GL Second Generation Language (assembly language) 3COM "3 Com Corporation (The 3 Coms are Computer, Communications and Compatability)" 3D Three-dimensional 3GL Third Generation Language (programming language) 4GL Fourth Generation Language (descriptive language) 6DOF Six Degrees Of Freedom A/D Analog to Digital A/P Accounts Payable A/R Accounts Receivable AA Auto Answer AAB All-to-All Broadcast AAD Analogue Alignment Diskette AAL Asynchronous Transfer Mode Adaption Layer AAP Applications Access Point [DEC] AAS Atomic absorbance spectroscopy All-to-All scatter AASP ASCII Asynchronous Support Package AAT Average Access Time Arbitrated Access Timer ABC Atanasoff-Berry Computer ABE Agent Building Environment ABEC Aracda Backup Executive Agent ABEND Abnormal End ABI Application Binary Interface ABIOS Advanced Basic Input / Output System ABIST Automatic Built-In Self-Test [IBM] ABLE Adaptive Battery Life Extender ABM Asynchronous balanced mode ABR Available Bit Rate ABRS Automated Book Request System [British Library] ABS Antilock braking system Air bearing slider (magnetic head) Acrylonitrile-butadiene-styrene (resin) Address Book Synchronisation [IBM] Absolute ABT Abort ABTS ASCII Block Terminal Services AC Autocheck Automatic Computer Alternating Current Access control ACAP Application Configuration Access Protocol ACC Accumulator ACD Automated Call Distribution Automatic Call Distributor ACDI Asynchronous Communications Device Interface ACE Advanced Computing Environment [SCO] Adverse Channel Enhancements [Microcom] Automatic Computing Engine ACEL AC electroluminescent ACF Access Control Field Advanced Communications Function ACH Automated Clearing House ACIA Asynchronous communications interface adaptor ACIAS Automated Calibration Interval Analysis System ACIS American Committee for Interoperable Systems ACK Acknowledge character acknowledgement ACL Automatic contrast level Access control list ACM Association for Computing Machinery Audio Compression Manager [Microsoft] ACMS Application Control Management System ACP Ancillary Control Program Auxillary Control Process Action control point ACPI Advanced Configuration Power Interface ACROSS Automated Cargo Release and Operations Service System ACRT Accelerated crucible rotation technique ACS Add compare select Automatic class selection Access Access Control Set Access Control System Asynchronous Communication Server ACSR Aluminium conductor steel reinforced ACT acoustic charge transport ACTS Automated Computer Time Service ACTT Advanced Communication and Timekeeping Technology [Seiko] ACU Automatic Calling Unit ACV Air cushion vehicle ADA Automatic Data Acquisitions ADB Apple Desktop Bus ADC Adaptive Data Compression (protocol) [Hayes] Add with Carry Analog to Digital Converter advanced data connector ADCCP Advanced Data Communication Control Procedures ADD Automatic Document Detection [WordPerfect] ADF Automatic Document Feeder Automatically Defined Function ADI AutoCad/AutoDesk Device Interface (driver) ADL Address Data Latch ADLAT Adaptive Lattice Filter ADLC Adaptive Lossless Data Compression [IBM] Asynchronous (Add-on) Data Link Control ADM Add-drop-midtiplexer (optical transmission) Adaptive delta modulation ADMACS Apple Document Mangagement And Conrol System ADMD Administrative Management Domain [X.400] ADO Active Data Objects ActiveX Data Objects ADP "Administrative (Automotive,automatic,automated) data processing Ammonium dihydrogen phosphate" ADPCM Adaptive Differential Pulse Code Modulation ADR Address ADS Application Development Solutions [AT&T] Application Development System Automatic Distribution System Automatic depressurisation system ADSC Address Status Changed Adobe Document Structuring Conventions ADSI Active Directory Services Interface ADSL Asynchronous (Asymmetric) Digital Subscriber Line ADSR "Attack, Decay, Sustain, Release" ADT Application Data Types ADU Automatic Dialing Unit AE Above or Equal acoustic emission AEB Analogue Expansion Bus [Dialogic] AES Auger electron spectra (-oscopy) AF Audio frequency auto-focus auxiliary carry flag AFA Accelerated File Access AFBC Atmospheric fluidised bed combustion AFC Automatic Font Change Automatic Frequency Control AFD Automatic File Distribution AFDW Active Framework for Data Warehousing [Microsoft] AFE Audio frequency energised AFII Association for Font Information Interchange AFIRM Automated Fingerprint Image Reporting and Match AFIS Automated Fingerprint Identification System AFL Abstract family of languages AFM Atomic force microscopy AFMR Antiferromagnetic resonance AFP Appletalk Filing Protocol [Macintosh] AFR Away from reactor (spent fuel storage) AFS Andrew File System (protocols) Air flow sensor AFTP Anonymous File Transfer Protocol AGB Asymptotic giant branch AGC Automatic gain control Audio graphic conference AGIS Apex Global Information Services AGN Active galactic nucleus (nuclei) AGP Advanced Graphics Port Accelerated Graphics Port AGR Advanced gas-cooled reactor AGRAS Antiglare-Antireflective-Antistatic AGS Alternating gradient synchrotron AGU Address-Generation Unit AGV Automatic guided vehicle AH Authentication Header AI Analog Input Artificial Intelligence AIA Applications Integration Architecture [DEC] AIC AIXwindows Interface Composer [IBM] AIF Audio Interchange Format AIIM Association for Information and Image Management AIMUX ATM Inverse Multiplexing AIN Advanced Intelligent Network [Bell Atlantic] AIS Automated Identification System [NCIC] Alarm indication signal AISB Association of Imaging Service Bureaus AISP Association of Information Systems Professionals AIT Advanced Intelligent Tape [Sony] AIX Advanced Interactive Executive [IBM] AL Artificial Life ALARA As low as reasonably achievable ALC Arithmetic and Logic Circuits Automatic Level Control ALD Atomic layer doped ALE Address Latch Enable Atomic layer epitaxy ALGOL Algorithmic Oriented Language (see IAL) ALIBI Adaptive Location of Internetworked Bases of Information ALINK Active Link [HTML] ALIVE Artificial Life Interactive Video Environment ALIWEB Archie Like Indexing in the Web [Internet] ALL Amplitude-locked loop ALN Asynchronous Learning Network ALR "Advanced Logic Research, Inc." ALT Alternate (mode) ALU Arithmetic Logic Unit ALV Autonomous land vehicle ALWR Advanced light water reactor AM Air mass number Amplitude modulation Active matrix AMA Automatic Message Accounting AMANDDA Automated Messaging and Directory Assistance AMD "Active Matrix Display Advanced Micro Devices, Inc." AMG Alternate metal virtual ground (EPROM) AMI "American Megatrends, Inc. Alternate mark inversion" AMMA Advanced Memory Management Architecture [Everex Systems] AMON ATM Monitoring AMP Arbitration on message priority (SMA/CD-AMP) AMPS Advanced Mobile Phone Service AMPTE Active Magnetospheric Particle Tracer Explorers AMR Automatic meter reading AMRF French for FDMA AMRT French for TDMA AMS Accelerator mass spectroscopy AMS Access Method Services ANA Automatic network analyser ANCOVA Analysis of Covariance ANDF Architecture-Neutral Distribution Format ANI Automatic Number Identification ANN Artificial Neural Network ANOVA Analysis Of Variance ANS Advanced Neutron Source ANSI American National Standards Institute AO Analog Output AOB Any other business AOCE Apple Open Collaboration Environment AODLF Acousto-optic dispersive light filter AOE Application Operating Environment [AT&T] AOI Automatic optical inspection AOL America Online AOS Add Or Subtract AP Adjunct Processor Application Processor APA Adaptive Packet Assembly All Points Addressable Arithmetic Processing Accelerator APACHE Accelerator for Physics and Chemistry of Heavy Elements APANA Australian Public Access Network Association APAR Authorized Program Analysis Report [IBM] APAREN Address Parity Enable [IBM] APC adaptive predictive coding automatic phase control APCM Adaptive pulse code modulation APCUG Association of PC User Groups APCVD Atmospheric pressure CVD APD Avalanche photodiode APFIM Atom probe field ion microscopy API Application Program (processor) Interface APIC Advanced Programmable Interrupt Controller (bus) [Intel] APIS Advanced Passenger Information System APK Amplitude phase keying APL A Programming Language (Mathematics) APM Advanced Power Management [IBM] APPC Advanced Program-to-Program Communications [IBM] APPI Advanced Peer-to-Peer Internetworking APPN Advanced Peer-to-Peer Networking [IBM] APPS Applications APR Acoustic paramagnetic resonance APRFR Army Pulsed Radiation Facility Reactor APRP Adaptive Pattern Recognition Processing APS Advanced Photo System Advanced Printing Service [IBM] Asynchronous Protocol Specification Appearance potential spectra (-oscopy) APSE ADA Programming Support Environment APT Address Pass Through Advanced Parallel Technology Automatically Programmed Tools APU Auxiliary power unit APW Augmented plane wave APWR Advanced pressurised water reactor ARA AppleTalk Remote Access ARAG Antireflective-Antiglare ARAS Antireflective-Antistatic ARC Advanced RISC Computing Attached Resources Computing ARCA Advanced RISC Computing Architecture ARCnet Attached Resource Computer Network ARI Autofahrer Rundfunk Information ARIES ATMResearch and Industrial Enterprise Study ARL Adjusted Ring Length ARLL Advanced Run Length Limited ARM Advanced RISC Machine (processor) Annotated Reference Manual Asynchronous Response Mode ARMA Association of Records Managers and Administrators Autoregressive Moving Average ARMAX Autoregressive moving average erogenous ARP Address Resolution Protocol [Novell] ARPA Advanced Research Projects Agency ARPANET Advanced Research Projects Agency NETwork ARPES Angle resolved photoemission spectra (-oscopy) ARPL Adjust Requested Privilege Level ARQ Automatic Repeat reQuest ARTA Apple Real Time Architecture ARTIC A Real-Time Interface Copressor [IBM] ARTS Asynchronous Remote Takeover Server ARTT Asynchronous Remote Takeover Terminal ARU Audio Response Unit ARUPS Angular resolved UPS ARX AutoCAD Runtime eXtension AS Autonomous System [Internet] AS/400 Application System/400 [IBM] AS/U Advanced Server for Unix AS3AP ANSI SQL Standard Scalable and Portable ASAP As Soon As Possible Automatic Switching And Processing Any service/any port ASCI Accelerated Strategic Computign Initiative ASCII American Standard Code for Information Interchange ASDM Asynchronous sigma-delta modulator ASE Amplified spontaneous emission ASG Advanced Systems Group ASIC Application-Specific Integrated Circuit ASID Address Space IDentifier ASIT Advanced Security and Identification Technology ASK Amplitude shift keying ASL Adaptive Speed Levelling ASLM Apple Shared Library Manager [Macintosh] ASMP Asymmetric Multprocessing ASN Abstract Syntax Notation Autonomous System Number ASP Authorized Service Provider Association of Shareware Professionals Advanced services platform Active server page ASPI Advanced SCSI Programming Interface [Adaptec] ASPS Advanced Signal Processing System ASR Anti-slip regulation (Antriebs-schlupf Regeleinrichtung) Automatic send/receive Address space register Automatic speech recognition AST "AST Research, Inc. (named from first initials of the founders: Albert Wong, Safi Qureshey, Thomas Yuen) Asynchronous system trap" ASYNC Asynchronous AT Advanced Technology Attention AT&T American Telephone & Telegraph ATA Advanced Technology Attachment ATAPI Advanced Technology Attachment Packet Interface ATC Air traffic control Adaptive transform coding ATCS Advanced Train Control System ATD Asynchronous time division Address transition detection (for RAM) ATDM Asynchronous time division multiplexing ATDP Attention Dial Pulse ATDT Attention Dial Tone ATE Automated Test Equipment ATF Advanced Toroidal Facility ATG Advanced Technology Group ATH Attention Hang-Up (Modem command) ATL Active Template Library ATM Asynchronous transfer mode Automatic teller machine Axilrod-Teller-Moto Address translation memory Adobe typeface manager ATPS AppleTalk Printing Services [Macintosh] ATR Attenuated total reflection Automatic target recognition Advanced terminal reactor Automatic terminal recognition ATS Administrative Terminal System Apple Terminal Services ATTN Attention ATTRIB Attribute (also ATR) ATV Advanced television ATWS Anticipated transients without scram ATZ Attention Restore configuration profile from nonvolatile RAM (Modem command) AUDIT Automated Data Input Terminal AUI Attachment Unit Interface AUP Acceptable Use Policy [Internet] AUTO Automatic AUTOEXEC Automatic Execution AUX Auxiliary AV Audio/Video Audiovisual Authenticity Verification Atria-ventricular AVA Audio Visual Authoring [IBM] AVC Automatic volume control Automatic voltage compression Audio visual connection [IBM] AVD Alternating Voice and Data AVG Average AVHRR Advanced very high resolution radiometer AVI Audio Visual Interleave [Microsoft] AVM Automatic vehicle-monitoring AVN Ameritech Virtual Network AVR Automatic Voice Recognition AWC Area wide centrex AWG American Wire Gage AWGN Additive white Gaussian noise AWK "(Unix language named after its authors... Al Aho, Peter Weinberger and Brian Kernighan)" AWP Amusement with prizes AWS Advanced Workstations and Systems (group) [IBM] Amusement with skill AWT Abstract Windowing Toolkit [Java] Abstract Windows Toolkit AX Architecture Extended Automatic Transmission B-CHANNEL Bearer Channel B/F Background/Foreground B2X Binary To Hexadecimal [REXX] B8ZS Binary 8-Zero Substitution BACP Bandwidth Allocation Control Protocol BAER Brainstem auditory evoked response BAK Binary Adaptation Kit [Microsoft] BAL Basic Assembly Language BALUN Balanced Unbalanced (device) BAM Boyan Action Module BARITT Barrier injection transit time BARTS Bell Atlantic Regional Timesharing BAS Bit rate assignment signal (sign) BASH Bourne Again Shell [Unix] BASIC Beginner's All-purpose Symbolic Instruction Code BASM Built-In Assembler BAT Block Address Translation BAW Bulk acoustic wave BBD Bucket-brigade device BBGKY Bogoliubov-Born-Green-Kirkwood-Yvon BBS Bulletin Board System BCC Body centred cubic Block check character Blind carbon copy BCCD Buried charge coupled device BCD Binary Coded Decimal BCDMA Broadband Code Division Multiple Access BCDMOS Bipolar-CMOS-DMOS BCH Bose-Chaudhuri-Hocquenghem BCL Batch Command Language BCN Beacon BCO Burst control oscillator BCP Best Current Practice Bulk Copy Program BCPL Basic Computer Programming Language BCR Byte Count Register BCS Bardeen-Cooper-Schrieffer Binary synchronous communications Bar code sorter BCT Body centred tetragonal BDA Bios Data Area BDC Backup Domain Controller BDE Borland Database Engine [Borland] BDK Beans Development Kit BDLC Burroughs data link control BDOS Basic Disk Operating System BDR Bus Device Request BE Below or Equal BEBC Big European Bubble Chamber BECN Backward Explicit Congestion Notification BEDO Burst Extended Data Out BEDT-TTF Bis(ethylenedithio)-tetrathiafulvalene (-inium) BEL Bell BELLCORE Bell Communications Research BEM Boundary element method BEOL Back end of the back line BEPC Beijing Electron Positron Collider BER Bit error rate BERT Bit Error Rate Test/Tester BEZS Bandwidth Efficent Zero Support BF Bad Flag BFF Binary File Format [IBM] BFL Buffered FET logic BFO Beat-frequency oscillator BFT Binary File Transfer BFTP Batch FTP BGA Ball Grid Array BGcolour Background Colour [HTML] BGE Branch if Greater or Equal BGO Bismuth germanate BGP Border Gateway Protocol BGT Branch if Greater Than BH Buried heterostructure BHI Branch if Higher BHIS Branch if Higher or Same BHT Blowdown heat transfer BI Binary Input BIBO Bounded input bounded output BIC Breakdown of insulator for conduction BICFET Bipolar inversion channel FET BICMOS Bipolar/CMOS BICMOS BIpolar Complementary Metal Oxide Semiconductor BiDi Bi-Directional BIFET Bipolar Field Effect Transistor BIL Band Interleaved by Line Buried Injection Logic BIM Beginning of Information Marker BIMOS Bipolar/metal-oxide-semiconductor BINAC Binary Automatic Computer BIND Berkeley Internet Name Domain BIOS Basic Input/Output System BIP Band Interleved By Pixel BIQUARTT Bipolar quantum resonant tunnelling transistor BIS Bremsstrahlung isochromat spectroscopy Business information system BISDN Broadband Integrated Services Digital Network BIST Built-In Self-Test BiSYNC (See BSYNC) BIT Binary Digit Built in test BITBLT BIT BLock Transfer BITNET Because It's Time Network BITNIC Bitnet Network Information Center BIU Bus Interface Unit BIX Byte Information Exchange (BBS) BKSP Backspace BL Backlit Bit Line Blue lighting BLAST Blocked Asynchronous Transmission (protocol) [Communications Research Group] BLD Bistable laser diode BLDC Brushless direct current (motor) BLE Branch if Less or Equal BLER Block Error BLK Block BLMC Buried Logic Macrocell BLOB Binary Large Object BLOS Branch if Lower Or Same BMC Bulk moulding compound BMI Branch if Minus BMIC BusMaster Interface Controller [Intel] BMIDE Bus Managed Integrated Drive Electronics BMP Basic Mapping Support Batch Message Processing Program BNC Bayonet Neill-Concelman (connector used with coaxial cable invented by Mr. Neill-Concelman) Baynet N-type Compact BNE Branch if Not Equal BNF Backus-Naur Form (also Backus-Normal Form) [developed by John Backus and Peter Naur] BNS Backbone Network Service BNZS Bit number zero sequence BO Binary Output BoB Break-out Box BOC Bell Operating Company Basic operator console BOD Bistable optical device biological oxygen demand BOF Beginning Of File BOM Beginning Of Message BOND Bandwidth On Demand BOOTP Bootstrap Protocol [Internet] BOPS Billion Operations Per Second BORPQU Borland Pro Quattro BORQU Borland Quattro BOS Basic Operating System BOT Beginning Of Table Beginning of Tape Robot BOX Buried oxide isolation BP Base Pointer Boiling point BPB BIOS Parameter Block BPDU Bridge Protocol Data Unit BPF Berkeley Packet Filter Band pass filter BPI Bits Per Inch BPL Branch if Plus Bits per line BPM Beam propogation method BPMES Buried p-layer metal Schottky (FET) BPP Bits Per Pixel BPS Bits Per Second Bytes Per Second BPSG Borophosphosilicate glass BPSK Binary phase shift keying BR Bad Register BRD W Germany BRET Breeder Reprocessing Engineering Test BRGC Binary Reflected Gray Code BRI Basic Rate Interface Brain Response Interface BS Broadcast satellite Backspace BSAM Basic Sequential Access Method BSC Binary (Bi-) Synchronous Communication BSCC Buried stacked capacitor cell (for DRAM) BSCS Bachelor of Science (Degree) in Computer Science BSD Berkely Software/Standard Distribution BSF Bit Scan Forward BSG Borosilicate glass BSI British Standards Institution BSO Bismuth silicate BSOD Blue Screen Of Death BSP Bulk Synchronous Parallelism BSQ Band SeQuential BSR Bit Scan Reverse BSS Block Started by Symbol BSV BASIC Bsave Graphics (file name extension) BSY Busy BSYNC Binary Synchronous Communications (protocol) BT Bit Test BTAM Basic Telecommunications Access Method [IBM] BTB Branch Target Buffer BTC Bit Test and Complement BTL Balanced transformerless BTOA Binary To ASCII BTP Batch Transfer Program BTR Bit Test and Reset BTRS Buried twin ridge substrate BTS Bit Test and Set Base transceiver station BTSC Broadcast Television Systems Committee Btx Bildschirmtext BU Branch Unit BUBL Bulletin Board for Libraries [Janet] BUF Buffer BUS Broadcast and Unknown Server BVH Base Video Handler BVP Boundary value problem BWIP Basalt Waste Isolation Project BWM Block-Write Mode BWO Backward wave oscillator BWR Boding water reactor BWT Backward wave tube BYTE Binary Element String C C Programming Language C&T Chips and Technologies C-SCANS Client-Systems Computer Access NetworkS C-V Capacitance-voltage C/D Control Data C/S Client/Server C2 Command and control C2D Character To Decimal [REXX] C2X Character To Hexadecimal [REXX] C3 Cleaved coupled cavity Command control communications C31 Command control communications and intelligence C3L Complementary constant current logic C4 Command control communications and computers Controlled collapse chip connection CA Computer Animation Collision avoidance CAA Computer aided analysis CAAB/AM Companded single sideband amplitude modulation CAC Connection Admission Control CACP Central Arbitration Control Point CAD Computer Aided Design Computer Aided Drafting CADAT Computer aided design and testing CADD Computer Aided Design and Drafting CADE Client/server Application Development Environment CAE Client Application Enabler Common Applications Environment Computer Aided Engineering CAEX Computer Aided Exploration CAG Column Address Generator CAI Common air interface Computer assisted instruction CAL Calendar Computer Aided Learning CALCO Combined action lateral control operation CAM Common Access Method Computer Aided Manufacturing (machining) Contents Addressable Memory CAMAC Computer automated measurement and control CAN Controller Area Network Cancel CANDU Canadian deuterium uranium CANTAT Canadian transatlantic telephony cable CAP Carrierless Amplitude and Phase-Modulation Central Arbitration Point Communication Application Platform Computer Aided Publishing CAPC Carrier automatic phase control CAPD Computing To Assist Persons With Disabilities [Johns Hopkins University] CAPP Computer aided process (production) planning CAPS Capitals (Upper Case Letters) Cassette Programming System CAR Computer aided retrieval CARL Colorado Alliance of Research Libraries [Internet] CARS Coherent anti-Stokes Raman scattering (spectra) CAS Column Address Select (strobe) Communications Application Specification Computer Aided Styling CASE Computer aided software engineering Common applications service elements CASL Crosstalk Application Scripting Language [DCA] CASS Computer Assisted Search Service CASSIS Classified and Search Support Information System CAT "Computer Aided Testing Computer Aided (assisted, axial) Tomography Computer Aided Transcription Concatenate" CAT SCAN Computerized Axial Tomography Scan CATS Computer Assisted Training System CATT Controlled avalanche transit transistor CATV Cable television Community Antenna Television (this was the original name for what is now known as Cable TV) CAU Controlled Access Unit CAV Constant Angular Velocity CB Component Broker Citizens' Band CBC Closed Brayton cycle (in engine) Cipher Block Chaining CBCR Channel Byte Count Register CBDS Connectionless broadband data service CBE Chemical beam epitaxy CBED Convergent beam electron diffraction CBEMA Computer and Business Equipment Manufacturers Association CBGA Ceramic Ball Grid Array CBI Computer Based Instruction CBL Computer Based Learning CBMS Computer-Based Mail System CBOOA Cyanobenzylidene octyloxyaniline CBR Constant Bit Rate CBT Computer Based Training CBW Convert Byte to Word CBX Computer-Controlled Branch Exchange CC Cluster Controller Carbon copy CCB Command Control Block CCBA Coupled channel Born approximation CCCS Current controlled current source CCD Charged-Coupled Device CCF Cold cathode fluorescent (light bulb) CCFL Counter current flow limiting (LOCA phenomenon) CCFT Cold Cathode Fluorescent Tube CCH Second generation current conveyor CCI Common Client Interface CCIR International Radio Consultative Committee CCIS Common channel integrated (inter-office) signalling CCITT Comite Consultatif International Telegraphique et Telephonique/ Consultative Committee for International Telegraph and Telephone CCL Connection/Cursor Control Language Capacitor coupled logic Colour centre laser CCP Console Command Processor Communications control program CCS Common Command Set Common Communications Services Common Communications Support Continuous Composite Servo Common channel signalling Computer communications software CCSD Cellular Circuit-Switched Data CCTF Cylindrical Core Test Facility CCTR Culham Conceptual Tokamak Reactor CCTV Closed circuit television CCU Computer controlled unit Communications control unit Camera control unit CCVS Current controlled voltage source CCW Count control word CD Carrier Detect Change Directory Collision Detection Colour Display Compact Disc Critical dimension Carrier detect Circular dichroic CD+G Compact Disk plus Graphics CD-DA Compact Disk -Digital Audio CD-E Compact Disk - Erasable CD-MO Compact Disk - Magneto Optical CD-RDx Compact Disk - Read Only Memory Data Exchange Standard CD-ROM Compact disc ROM CD-RTOS Compact Disk - Real Time Operating System CD-RW Compact Disk Re-Writable CD-V Compact disc - video CD-WO Compact Disc - Write Once CD-XA Compact Disc - Extended Architecture CD_CHRDY Card Channel Ready [IBM] CDA Compound Document Architecture [DEC] CDC Control Data Corporation CDDI Copper Distributed Data Interface CDDI Copper Distributed Data Interface CDE Common Desktop Environment Complex Data Entry CDF Channel Definition Format CDFR Commercial Demonstration Fast Reactor CDFS Compact Disc File System [Microsoft] CDI Collector diffusion isolation Capacitor discharge ignition Compact disc interactive CDIA Certified Document Imaging Architect CDL Computer Design Language CDLC Cellular data link control CDM Carrier domain magnetometer Code division multiplexing CDMA Code Division Multiple Access CDMF Commercial Data Masking Facility [IBM] CDOS Concurrent Disk Operating System CDP Common depth point CDPD Cellular Digital Packet Data CDR Call Detail Record Call Detail Recording Compact disc recordable CDRL Contract Data Requirements List CDS Current Directory Structure CDSA Common Data Security Architecture CDV Cell Delay Variation CDVT Cell Delay Variation Tolerance CDW Charge-density wave CE Cache Enable Chip Enable Collision Elimination Convert Enable Consumer electronics CEB Consumer Electronic Bus CECL Cascade-emitter coupled logic CEG Continuous Edge Graphics CEGB Central Electricity Generating Board CEI Conducted Electromagnetic Interference CELP Code excited linear predictive coding CEM Channel electron multiplier CEMS Constituent Electronic Mail System CEOP Conditional End Of Page CEPA coupled electron pair approximation CEPT Conference of European Postal and Telecommunications CERDIP Ceramic dual-in-line package CERN The European Particle Physics Laboratory (Conseil European pour la Recherche Nucleaire) CERT Computer Emergency Response Team CES Circuit Emulation Services CESAR CERN Electron Storage and Accumulation Ring CESR Conduction electron spin resonance CETI Contact with extraterrestrial intelligence CFAR Constant FALSE alarm rate CFB Cipher Feedback Configurable Function Block CFC Chlorofluorocarbon CFEK Coherent frequency exchange keying CFG Context free grammar CFL Context free language CFM Code Fragment Manager [Macintosh] Colour flow map CFR Computerized Facial Recognition CFS Caching/Common File System CFSK Coherent frequency shift keying CFV Call For Votes [Bitnet] CG Control Gate CGA Colour Graphics Adapter CGE Common Graphics Environment CGH Computer-generated holography (-grarn) CGI Common Gateway Interface Computer Generated Images Computer Graphics Interface CGM Computer Graphics Metafile CGTO Contracted Gaussian-type orbital CHAP Challenge-Handshake Authentication Protocol CHAR Character CHAT Conversational Hypertext Access Technology [Internet] CHCK Channel Check CHCP Change Code Page CHDIR Change Directory CHEMFET Chemical-sensitive FET CHF Coupled Hartree-Fock CHFN Change Finger [Unix] CHGRP Change Group CHI Communications hardware interface CHKDSK Check Disk CHMOD Change Mode CHO Chinese hamster ovary CHOWN Change Owner CHP Combined heat and power Chapter CHR Character CHRP Common Hardware Reference Platform CHS Cylinders / Heads / Sectors CI Component Interface Configuration interaction CIA Current Instruction Address CIAC Computer Incident Advisory Capability CICS Computer Information Control System CICS/VS Customer Information Control System/ Virtual Storage [IBM] CID Charge-Injection Device Configuration/Installation/Distribution CIDEP Chemically induced dynamical electron polarisation CIDNP Chemically induced dynamical nuclear polarisation CIDR Classless Inter-Domain Routing CIEH Charge iterated extended Huckel CIF Common Interchange/Intermediate/Inter-media Format Crystallographic Information File Customer Information Feed CIFS Common Internet File System CILE Call information logging equipment CIM Common Information Model CompuServe Information Manager Computer Integrated Manufacturing Constituent Interchange Model CIO Chief Information Offier CIOCS Communication Input/Output Control System CIP Command Interface Port CIR Committed Information Rate CIRC Circular Reference Cross-Interleaved Reed-Solomon Code CIS Card Information Structure Client Information System CompuServe Information Service Computer Information Systems Contact Image Sensor Customer Information System CISC Complex Instruction Set Computer Complex Instruction Set Code CIT Compact Ignition Tokarnak Computer Integrated Telephony CIVR Computer and Interactive Voice Response CIX Commercial Internet Exchange Compulink Information Exchange CJLI Command Job Language Interpreter CKD Count Key Data (device) CKSS Code key security system CLAR Channel Local Address Register CLASS Client Access to Systems and Services Cooperative Library Agency for Systems and Services Custom Local-Area Signaling Services CLB Configurable logic block CLC Clear Carry Flag Cell loss priority CLD Clear Direction Flag CLE Configurable logic element CLI Call-Level Interface Clear Interrupt Flag Client Library Interface Command Line Interface CLID Calling Line Indentification CLIST Command List CLK Clock CLNAP connectionless network access protocol CLNIP connectionless network interface protocol CLNP Connectionless Network Protocol CLOS Common Lisp Object System Command-to-line-of-sight CLP Cell Loss Priority Constraint Logic Programming CLS Connectionless service/server Clear screen CLSID CLasS Identifier CLTP Connectionless Transport Protocol CLTS Clear Task Switch Flag CLUI Command Line User Interface CLUT Colour Look-Up Table CLV Constant Linear Velocity CM Centimetre Control Mark Corrective Maintenance Commercial message Common mode CMA Concert Multi-thread Architecture Current mirror amplifier CMC Common Mail Calls Common Messaging Calls Communication Mangement Configuration Complement Carry Flag Computer-Mediated Communication [Internet] CMD Carrier modulation device Charge modulation device Circuit mode data CMF Creative Music Format CMI Computer managed instruction Coded mark inversion Cable microcell integrator CMI/HIC Cable Microcell Integrator \ Headend Interface Converter CMIP Common Management Information Protocol CMIS Common Management Information Services/System CML Conceptual Modelling Language Computer Managed Learning Current Mode Logic CMM Capability Maturity Model CMMS Computerized Maintenance Management Software CMMU Cache/Memory Management Unit [Motorola] CMOS Complementary Metal-Oxide Semiconductor CMOV Conditional Move CMP Compare Computer CMPS Compare word String CMRR Common mode rejection ratio CMS Code Management System Compiler Monitor System Conversation Monitor System CMVC Configuration Management Version Control [IBM] CMW Compartmented Mode Workstation CMY Cyan-Magenta-Yellow (colour model) CMYK Cyan-Magenta-Yellow-Black (colour model) CN Common Name CNA Certified NetWare Administrator [Novell] CNAPS Co-Processing Node Architecture for Parallel Systems CNC Computer Numeric Control CNDO Complete neglect of differential overlap CNE Certified NetWare Engineer CNG Calling (tone) CNI Certified Novell Instructor [Novell] CNIDR Clearinghouse for Network Information and Discovery and Retrieval [Internet] CNN Composite Network Node CNR Carrier to noise ratio CNSS Core Nodal Switching Subsystem [Internet] CNV Conventional (pertaining to Memory) CNVT Convert CNX Certified Network Expert CO Central Office Command Output Convert Out CO-GND Central office ground Common ground point COAST Cache On A STick COB Chip-On-Board COBOL Common Business-oriented Language (See HLL) CODASYL Conference on Data System Languages (Group that designed COBOL) CODE Client-Server Open Development Environment CODEC Coder/Decoder Compression/Decompression COEM Commercial Original Equipment Manufacturer COF Chip on flexible printed circuit. COFF Common Object File Format [Unix] COG Chip-on-glass COGO Coordinate Geometry (Programming Language) COL Collision Computer Oriented Language COLD Computer Output to Laser Disk COLL Collision COM Common Object Model [Microsoft] Computer output to microform (fiche or film) Component object model COM1 First serial Port (asynchronous port) COM2 Second serial Port COM3 Third serial Port COM4 Fourth serial Port COMDEX COMmunications Development EXposition Computer dealers exposition COMET Cornell Macintosh Terminal Emulator COMFET Conductivity-modulated field effect transistor COMP Compare Communications COMSAT Communications Satellite Corporation CON Console (includes Keyboard and Screen) COND Condition CONFIG Configuration CONS Connection-Oriented Network Service Consulting CONTONE Continuous Tone COPS Concept Oriented Programming System CORBA Common Object Request Broker Architecture CORDIC Coordinate rotation digital computer CoREN Corporation for Research and Enterprise Network COS Compatible Operating System COSE Combined Office Standard Environment Common Open Software/Systems Environment COSMIC Computer Software Management and Information Center [NASA] COSMOS COmputer System for Mainframe OperationS COSS Common Object Services Specification COTS Commercial Off-The-Shelf COVA Computer code validation COW Character-Oriented Windows interface CP Copy Protected Charge/Parity CP-MAS Cross-polarisation MAS CP/M Control Program for Microcomputers [Digital Research] CPA Coherent potential approximation Critical path analysis Certified public accountant CPC Constant Point Calculation Compound parabolic concentrator CPCS Check Processing Control System [IBM] CPE Central Processing Element Customer Premises Equipment Customer Provided Equipment CPFSK Continuous phase FSK CPG Clock Pulse Generator CPI Characters Per Inch Clock Per Instruction Common Programming Interface [IBM] CPI-C Common Programming Interface for Communications [IBM] CPIO Copy In and Out [Unix] CPL Current Privilege Level Control panel layout CPM Continuous phase modulation Critical path method CPP Calling party pays CPR Cardio pulmonary resuscitation CPS Characters Per Second Cycles Per Second CPSK Coherent phase shift keying CPT "Command Pass Through Charge, parity, time" CPU Central Processing Unit CPW Coplanar waveguide CR Carriage return character Capacitor-resistor CR/LF Carriage Return/Line Feed CRA Call routing apparatus CRAM Card Random Access Memory Computational Random Access Memory Cyberspatial reality advancement movement CRBR Clinch River Breeder Reactor Project CRC Cyclic Redundancy Check CRD Capacitor-resistor diode CRDA Control rod drop accident CREN Computer Research Education Network Corporation for Research and Education Networking CREW Concurrent read exclusive write CRF Cable Retransmission Facility Cross Reference File CRI Colour Reproduction Indices CRMA Cyclic reservation multiple access CRNL Chalk River Nuclear Laboratories CRO Cathode ray oscilloscope CROM Control Read Only Memory CRSR Coherent resonant Stokes rotation CRT Cathode Ray Tube CRTC CRT Controller CRUS Create / Retrieve / Update / Delete CRV Code rule violation CS Coupled states Chip select (for memory) Communications satellite Clear to send Code segment CS/SS Card Service/Socket Service CSA Calendaring and Scheduling API [IBM] CSAR Channel System Address Register CSCW Computer Supported Cooperative Work CSD Circuit-Switched Data Computer Services Department Corrective Service Diskette [IBM] CSDS Packet Switched Data Service CSE Certified System Engineer CSFI Communication Subsystem For Interconnection CSG Constructive Solid Geometry Consulting Services Group [Lotus] CSI Command Sequence Introducer CompuServe Incorporated Current source inverter CSID Call Subscriber ID CSL Computer Sensitive Language CSLIP Compressed Serial Line Interface Protocol [Internet] CSM Communications Services Manager Continuous slowing down models CSMA Carrier-Sense Multiple Access CSMA/CA Carrier Sense Multiple Access/with Collision Avoidance CSMA/CD CSMA with collision detection CSMA/CR CSMA carrier resolution CSMS Customer Support Management System CSN Card-Select Number CSNET Computer Science Network CSO Central Services Organization CSP Certified Systems Professional Commercial Subroutine Package CompuCom Speed Protocol [CompuCom] Channel substrate planar CSPDN Circuit Switched Public Data Network CSRS Coherent Stokes-Raman spectra (-oscopy) CSS Cascading Style Sheets [Microsoft] Contact Start-Stop Continuous system simulator (Language) Cellular subscriber station CSSB/AM Companded single sideband amplitude modulation CSSM Client-Server Systems Management [IBM] CSTA Computer-Supported Telephony Applications CSU Channel Service Unit CSV Circuit-Switched Voice Comma-Separated Value/Variable Common Services Verbs (interface) [Microsoft] CT Computerised tomography Current transformer Computer telephony CT-2 Cecond generation cordless telephone CTA Circuit terminating equipment CTB Cipher Type Byte CTC Channel To Channel CTCP Client-To-Client Protocol CTD Cell Transfer Delay Charge transfer device CTE Coefficient of thermal expansion CTI Computer Telephony Integration CTL Complementary-transistor logic CTOS Computerized Tomography Operating System Convergent Technologies Operating System CTPA Coax-to-Twisted-Pair Adapter CTR Controlled thermonuclear reactor CTRL Control CTS Clear to Send (signal) CTSS Compatible Time Sharing System CTTC Copper To The Curb CTTH Copper To The Home CTTL Complementary transistor-transistor logic CTTY Console TeleTYpe CUA Common User Access [IBM] CUB Cursor Backward CUD Cursor Down CUE Custom Updates and Extras (card) [Egghead Software] CUF Cursor Forward CUG Closed user group CUI Character-Oriented User Interface Common User Interface [IBM] CUP Cursor Position CUPID Completely Universal Processor I/O Design [AST] CUSIP Committee for Uniform Security Identification Procedures [U.S. Treasury] CUT Control Unit Terminal CUTE Clarkston University Terminal Emulator CUU Cursor Up CVD Chemical vapour deposition CVDP Compact video disc player CVF Compressed Volume File CVGA Colour Video Graphics Array CVIA Computer Virus Industry Association CVR Continuously variable ratio CVSDM Continuously variable slope delta modulation CVT Continuously variable transmission Convert CVW CodeView for Windows CW Continuous Wave CWD Convert Word to Double Word Change Working Directory [Internet] CWIS Campus Wide Information Service/System [Internet] Community Wide Information Service/System [Internet] CYBORG CYBernetic ORGanism CYL Cylinder CYMK Cyan-Yellow-Magenta-Black (or Key) [colour model] cz Czochralski D-CHANNEL Data channel D/A Digital to Analogue D/R Direct or Reverse D/S Dhrystone Per Second D2C Decimal To Character [REXX] D2T2 Dye Diffusion Thermal Transfer (printing) D2X Decimal To Hexadecimal [REXX] DA Destination address DAA Data Access Arrangement Decimal Adjust for Addition DAB Digital audio broadcasting DAC Data Acquisition and Control Digital to Analogue Converter Dual Attachment Concentrator DAD Desktop Application Director [Borland] Digital Audio Disc DAI Distributed Artificial Intelligence DAL Data Access Language [Apple Computer] Disk Access Lockout DAM Data Acquisition and Monitoring DAMA Demand assigned multiple access DAMPS Digital AMPS DAO Data Access Object [Microsoft] DAP Data Access Protocol [DEC] Developer Assistance Program DAPIE Developers Application Programming Interface Extensions DARI Database Application Remote Interface [IBM] DARMS Digital Alternate Realization of Musical Symbols DART Digital Audio Reconstruction Technology Dual asynchronous receiver/transmitter DAS Decimal Adjust for Subtraction Dual-Attached Station DASD Direct Access Storage Device DASS Digital access signalling system DAT Digital Audio Tape Disk Array Technology DATAC Digital autonomous terminal access communication DATACOM Data Communications DATV Digitally assisted TV DAV Digital Audio-Video DAVIC Digital Audio-Visual Council DAW Dry active waste dB Decibel DB Data Base Data Buffer DB2 Database 2 dBA A-weighted Decibel DBCS Delivery Bar Code Sorter Double-Byte Character Set DBIS Dun & Bradstreet Information Services DBL DOS Batch Language DBM Data Base Manager DBMS Data Base Management System DBR Distributed Bragg reflector DBS Direct broadcasting by satellite DBS Data Base Server DBU Dual-line back-up unit DC Data Collection Data Communication Data Control Device Control Direct Current Dispersion compensated (optical fibre) DC-PBH Double-channel PBH DCA Digital Communications Associates Document Content Architecture [IBM] Direct chip attachment DCADC Digitally controlled asymmetrical delay circuit DCAF Distributed Console Access Facility [IBM] DCAM Direct Chip Attach Module DCB Device Control Block Disk Coprocessor Board [Novell] DCC Digital Command Control Digital Compact Cassette Direct Cable/Client Connection Display Combination Code DCD Data Carrier Detect DCE Data Circuit-Terminating Equipment Data/Digital Communications Equipment Distributed Computing Environment [OSF] Distributed Computing Equipment DCE Distributed Computing Environment DCED Distributed Computing Environment Daemon DCEL Direct current electroluminescent DCF Data Communication Facility [IBM] Data Compression Facility Data Count Field [IBM] Driver Configuration File [Lotus] DCFL Direct-coupled FET logic DCG Dichromated gelatin DCI Display Control Interface DCL Data Control Language Declaration DEC Command Language [DEC] Device Clear Digital Control Logic Digital Command Language [Digital] DCLC Drift cyclotron loss cone (instability) DCOM Distributed Component Object Model DCP Digital Light Processing [TI] DCS Data Collection System Data Control System Desktop colour Separation Distributed Control System Digital cross-connect system DCT Discrete Cosine Transform DCTL Direct-coupled transistor logic DCU Data-Cache Unit DD Day Digital Display Double Density DDA Distributed Data Access Domain-Defined Attribute Digital differential analyser DDB Device Dependent Bitmap Device Descriptor Block DDC Digital Data Channel [VESA] Display Data Channel Direct digital control DDC1 Display Data Channel One DDCMP Digital Data Communications Message Protocol [DEC] DDCS Distributed Database Connection Services [IBM] DDD Data Definition Language Direct Distance Dialing Double diffused drain DDE Direct Data Entry Dynamic Data Exchange [Microsoft] DDEML Dynamic Data Exchange Manager Library [Microsoft] DDF Display Data Channel Dynamic Data Formatting [IBM] DDI Device Driver Interface Direct Dial In DDK Device Driver Kit [Microsoft Windows] DDL Data Definition Language Data (-base) Description Language Diode-Diode Logic DDM Distributed Data Management DDN Defense (or Digital) Data Network DDNS Dynamic Domain Naming System DDP Distributed Data Processing DDR E Germany DDS Digital Dataphone Service [AT&T] Design Data Sheet Digital Data Storage Distributed Database Services DDX Digital Data Exchange DE Device End DEBI DMA Extended Bus Interface DEC Decrement Device Clear Digital Equipment Corporation DECENT Distribution of exact classical energy transfer DECNET Digital Equipment Corporation Networking (protocol) DECT Digital European Cordless Telephone (Telecommunication) DEDMS Diethoxydimethylsilane DEDPS Diethoxy diphynyl silane DEDPS Diethoxy diphynyl silane DEF Desktop Functional Equivalent [Compaq] DEFRAG Defragment DEK Data Encryption Key DEL Delete DELSTR Delete String [REXX] DEN Document Enabled Networking [Novell-Xerox] DES Data Encryption Standard Data Entry Sheet DESIRE Diffusion enhanced silylating resist DESY Deutsches Electron Synchrotron DET Device Execute Trigger DEV Device DF Data Field Destination Field Device Flag Double Flag Dirac-Fock DFB Distributed feedback DFC Data Flow Control DFE Decision feedback equaliser DFET Depletion FET DFM Design For Manufacturability [IBM] DFPLL Distributed feedback phase locked loop DFS Distributed File System DFSMS Data Facility Storage Management Subsystem [IBM] DFT Design For Testability Diagnostic Funtion Test Discrete Fourier Transform Distributed Function Terminal DFU Data File Utility DGIS Direct Graphics Interface Standard DH Double heterostructure DHCP Dynamic Host Configuration Protocol DHD Double heat-sink diode DHF Deformed helix ferroelectric (liq.crystal) Dirac-Hartree-Fock DHL Dynamic Head Loading DHT Discrete Hartley transform DI Data In Destination Index DIA Document Interchange Architecture [IBM] DIAL Differential-absorption lidar DIB Device Independent Bitmap Directory Information Base DIBOL DEC Business Oriented Language DID Direct Inward Dialing DIDS Distributed Intrusion Detection System DIET Desorption induced by electronic transitions DIF Data Interchange Format DIFFSENS Differential Sense DIFMOS Double Injection Floating-gate Metal Oxide Semiconductor DIIP Direct Interrupt Identification Port DIL Dual-in-line DIMM Dual In-Line Memory Module DIN Deutsche Industrie Norm (German equivalent of EIA) DIO Data Input-Output DIP Dialup Internet Protocol [Internet] Digital Imaging Processing Dual In-line Package Dual In-line Pin DIR Development inhibitor releasing Directory (file) DIS Dynamic Impedance Stabilization [CompuCom] DISA Data Interchange Standards Association DISP Displacement (offset) DIT Directory Information Tree DITE Divertor in Torus Experiment DIV Divide DIVE Direct Interface Video Extension [OS/2 Warp] DIW D-Inside Wire [AT&T] DKDP Deuterated potassium dihydrogen phosphate DL Download (also D/L) DL/1 Data Manipulation Language 1 [IBM] DLC Data Link Control (protocol) [IBM] Distributed Loop Carrier DLCI Data Link Connection Identifier DLD Display List Driver DLE Data Link Escape DLL Dynamic Link Library Delay locked loop DLM Distributed Lock Manager Dynamic Link Module DLP Digital Light Processing [TI] DLR DOS LAN Requester DLT Digital Linear Tape DLTS Deep level transient spectra (-oscopy) DM Delta modulation differential mode DM Distributed Memory DMA Direct Memory Access/Addressing DMAC DMA Controller DMACS Distributed Manufacturing Automation & Control Software DMC Digital mark correction DMD Digital Micromirror Device [TI] DME Distributed Management Environment DMF Distribution Media Format [Microsoft] DMI Desktop Mangement Interface DML Dimyristoyl-alpha-lecithin Data manipulation language DMM Digital Multimeter DMMS Dynamic Memory Management System DMO Dip move-out (seismology) DMOS Double-diffused metal-oxide-semiconductor DMOS Double-diffused Metal-Oxide Semiconductor DMOS Diffusion Metal Oxide Semiconductor Double-diffused Metal Oxide Semiconductor DMP Dot Matrix Printer DMPC Distributed Memory Parallel Computer DMQS Display Mode Query and Set [IBM] DMS Data Management Software Data(-base) Management System Diluted magnetic semiconductor DMSD Digital Multistandard Decoding DMSO Dimethylsulphoxide DMT Digital/Discrete Multi-Tone DMTF Desktop Management Task Force DMY Day Month Year DN Down DNA Deoxyribonucleic acid digital network architecture DNC Direct Numerical Control DNIC Data Network Identification Code DNIS Dialed Number Identification Service DNMR Double nuclear magnetic resonance DNS Domain Name System Domain Name Server DNTS Digital data exchange network testing system DO Data Out Distributed Objects DO-IT "Disabilities, Opportunities, Internetworking and Technology" DOBAMBC p-decyloxybenzylidene p'-amino 2-methyl butyl cinnamate DoD Department of Defense (USA) DOE Department of Energy (USA) Distributed objects everywhere Diffraction optical elements DOES Double heterostructure opto-electronic switch DOF Degree of freedom DOIP Dial Other Internet Providers [IBM] DOMF Distributed Object Management Facility DOPOS Doped poly:silicon DOPSK Differential offset phase shift keying DORIS Doppel-Ring-Speicher DOS Disk Operating System DOSEM DOS Emulation DOVETT Double velocity transit time DOW Day Of Week DP Data processing Dial pulse Degree of polymerisation DP/MF Dial pulse/multi-frequency DPA Demand Protocol Architecture [3Com] DPAM Demand Priority Access Method DPAREN Data Parity Enable [IBM] DPB Drive Parameter Block DPC Direct Program Control DPCM Differential pulse code modulation DPDA Deterministic pushdown automaton DPI Distributed Protocol Interface Dots Per Inch DPL Descriptor Privilege Level DPM Digital Panel Meter DPMA Data Processing Management Association DPMI DOS Protected Mode Interface [Microsoft] DPMS Display Power Management Support DPNSS Digital private network signalling system DPO Data Phase Optimization DPPC Dipalmitoyl phosphatidyl chloride DPPH Diphenylpicrylhydrazyl DPS Document Processing System DPSK Differential Phase Shift Keying DPtoTP Display Coordinates to Tablet Coordinates (converting) DQDB Distributed Queue Dual Bus DQL Data Query Language DQPSK Differential quadrature PSK DR Data Received DR-DOS Digital Research-Disk Operating System DR.BOND Dial-up Router Bandwith On Demand [NEC] DRAM Dynamic Random Access Memory DRAW Direct Read After Write DRDA Distributed Relational Database Architecture [IBM] DRDW Direct Read During Write DRI Digital Research Incorporated DRO Data Request Output Destructive Read-Out Dielectric resonator oscillator DRS Document Registration System Data and reporting system DRV Drive DS Data Segment Data Send Data Server Double Sided DS-SSMA Direct sequence SSMA DS1 Digital signal 1 DSA Digital subtraction angiography Directory System Agent DSAM Doppler shift attenuation method DSAP Destination Service Access Point DSB Double sideband DSC Differential scanning calorimetry District switching centre DSDD "Double Sided, Double Density (diskette)" DSE Data Storage Equipment DSEA Display Station Emulation Adapter DSECT Dummy Control Section DSHD "Double Sided, High Density (diskette)" DSI Digital speech interpolation DSIS Distributed Support Information Standard DSL Digital Subscriber Line Dynamic Simulation Language DSLAM Digital Subscriber Line Access Multiplexer DSM demand side management DSMA Digital Sense Multiple Access DSN-SC Double sideband suppressed carrier DSO Digital storage oscilloscope DSOM Distributed System Object Model DSP Digital Signal Processing/Processor Directory Synchronization Protocol [Lotus] DSQD "Double Sided, Quad Density (diskette)" DSR Data Set Ready Device Status Register Device Status Report Digital satellite radio DSS Decision Support System Digital Signature Standard Digital subscriber signalling DSSI Digital Standard Systems Interconnect [DEC] DSSS Direct-Sequencing Spread Spectrum DSTN Double Supertwisted Nematic DSU Data Service Unit Digital Service Unit DSV Digital sum value DSVD Digital Simultaneous Voice and Data DSW Data Status Word Device Status Word DTA Disk Transfer Area Differential Thermal Analysis DTC Distributed Transaction Co-ordinator Desktop Conferencing DTD Document Type Definition DTE Data Terminal Equipment Dumb Terminal Emulator DTF Distributed Test Facility DTL Dialog Tag Language [IBM] Diode-Transistor Logic DTMF Data Tone Multiple Frequency Dual Tone Multifrequency DTP Desktop Publishing Distributed Transaction Process DTPP Demonstration Tokamak Power Plant DTR Data Terminal Ready Data Transfer Rate Diffusion Transfer DTU Dual topological unitarisation DTV Desktop Video DTVC Desktop Video Conferencing DU Disk Usage DUA Directory User Agent DUAT Direct User Access Terminal DUN Dial-Up Networking [Microsoft] DUNCE Dial Up Network Connection Enhancement DUT Device under test DV-X alpha discrete variational X alpha method DVC Desktop Video Conferencing DVD Digital Versatile Disk Digital Video Disk DVE Digital Video Effect DVI Digital Video Interactive DVM Digital voltmeter DVMRP Distance Vector Multicast Routing Protocol [Internet] DVTR Digital video tape recorder DWBA Distorted wave Born approximation DWG Drawing DWIA Distorted wave impulse approximation DWMT Discrete Wavelet Multitone DWPF Defence Waste Processing Facility DXC Data Exchange Control DXF Drawing Exchange Format E-FORM Electronic Form E-MAIL Electronic Mail E-ZINE Electronic Magazine E2PROM electrically erasable PROM EA Effective Address Extended Attribute [OS/2] EAR External Access Register EARN European Academic Research Network EAROM Electrically Alterable Read Only Memory EARS Electronic Access to Reference Services EAS extensive air shower electronic article surveillance EATA Enhanced AT Bus Attachment EAX electronic automatic exchange EB exponential Born EBBA 4-ethoxybenzylidene-4'n-butylaniline EBC EISA Bus Controller EBCDIC Extended Binary Coded Decimal Interchange Code [IBM] EBCT Electron Beam Computed Tomography EBI Equivalent Background Input Extended Background Investigation EBIC electron beam induced current(t) EBR experimental breeder reactor EBT Elmo Bumpy Torus EBT Electronic Benefits Transfer EBU European Broadcasting Union EBX electronic branch exchange EC Electronic Commerce Error Control ECAL Enjoy Computing And Learn ECAT Electronic Card Assembly and Test [IBM] ECB Electronic Codebook Event Control Block Electrically controlled birefringence ECC Error Check Code Error Checking and Correction Error Correction Code Emergency core cooling ECCM electronic counter-counter measures ECCS emergency core cooling system ECD Enhanced colour Display Enhanced Compact Disk ECELR Epithermal Critical Experiment Laboratory Reactor ECG Electrocardiography (-gram) ECHO European Commission Host Organization [Internet] ECI External Call Interface ECL Emitter Coupled Logic ECLD External cavity laser diode ECM Electronic countermeasures Electrochemical machining Electronic Control Module ECMA European Computer Manufacturers Association ECMWF European Centre for Medium Range Weather Forecasts ECNE Enterprise Certified NetWare Engineer [Novell] ECOG electrocortiography (-gram) ECP Enhanced/Extended Capabilities Port [Microsoft] ECR electron cyclotron resonance ECRH electron cyclotron resonance beating ECTL Electronic Communal Temporal Lobe ECU EISA Configuration Utility Electronic control unit ED Erase Display Ending Delimiter EDA Electronic Design Automation Embedded Document Architecture [Go Corporation] Ethylene diatnine EDAX energy dispersive X-ray analysis EDC Electronic Digital Computer Enhanced Data Correction Error Detection and Correction EDDC Extended Distance Data Cable EDF Electricite de France EDGAR "Electronic Data Gathering, Analysis and Retrieval" EDI Electronic Data Interchange Electronic Document Interchange [DEC] EDIF electronic data interchange format EDIFACT EDI for Administration Commerce and Transport EDL Edit Decision List EDLC Ethernet Data Link Control EDLIN Editor (Line Text) EDM Electronic Document Management Electric discharge machining EDMS Electronic Document Management System EDO Extended Data Out EDORAM Extended Data Out Random Access Memory EDOS Enhanced DOS for Windows EDP Electronic Data Processing EDPM Electronic Data Processing Machine EDRAM Erasable Dynamic Random Access Memory EDS Electronic Data Systems (corporation) EDSAC * Electronic Delay Storage Automatic Computer EDSI Enhanced Small Device Interface EDTA ethylene diamine tetra-acetic acid EDTV extended definition television EDU error detecting unit EDVAC * Electronic Discrete Variable Automatic Computer (First stored-program digital computer) EDW electron density wave EDX energy dispersive X-ray EE Extended Edition [IBM] EEC Extended Error Correction EEG Electroencephalography (-gram) EEL Epsilon Extension Language EELS Electron energy loss spectra (-oscopy) EEM Extended Memory Management EEMS Enhanced Expanded Memory Specification EEPLD Electrically erasable PLD EEPROM Electrically Erasable Programmable Read-Only Memory EES Escrow Encryption Standard EFA Extended File Attribute EFF Electronic Frontier Foundation EFG Edge-defined film fed growth EFI Electromechanical Frequency Interference Electronics For Imaging EFL Emitter-follower logic Emitter-function logic EFM Extended Flygare method EFT Electronic Fund Transfer EFTS Electronic Funds Transfer System EGA Enhanced Graphics Adapter EGG Electrogastrography (-gram) EGP Exterior Gateway Protocol EGR Exhaust gas recirculation EGREP Extended Global Regular Expression Print [Unix] EHD Electrohydrodynamics EHDTV Enhanced high definition television EHF Extremely high frequency EHLLAPI Emulator High Level Language Application Programming Interface [IBM] EHP Electron-hole potential method EHT Extended Huckel theory extra high tension EHV Extra high voltage EIA Electronic Industries Association EIDE Enhanced Integrated Drive Electronics EIR equipment identity register EIRP equivalent isotropically radiated power EIS Executive Information System EISA Extended Industry Standard Architecture EKG clectrokymography (-gram) EL Electroluminescent (display) Erase Line "El,E2" "electric dipole, quadrupole" ELAN Emulated Local Area Network ELC Embedded Linking and Control ELDOR electron electron double resonance ELF Executable and Linking Format Extremely Low Frequency ELO epitaxial lateral overgrowth ELR earthed loop ELS Entry Level System EM Electronic Mail Emphasized End of Medium Expanded Memory Electromagnetic EMA Electronic Mail Association Enterprise Management Architecture EMACS Editing Macros [Unix] EMB Extended Memory Block [LIM/AST] EMBARC Electronic Mail Broadcast to a Roaming Computer [Motorola] EMC Electromagnetic Compatibility Enhanced Memory Chip E-Mail Connection Extended Math Coprocessor European Muon Collaboration EMF electromotive force EMG electromyography (-gram) EMI Electromagnetic Interference EMM Expanded Memory Manager EMP electromagnetic pulse EMR Electro-Magnetic Radiation Enhanced Metafile Record EMS Electronic Mail System Electronic Message Service Expanded Memory Specification [LIM] Energy management system Extended Memory Service EMTP electromagnetic transients program EMWAC European Microsoft Windows NT Academic Centre ENDEC Encoder/Decoder ENDOR electron nuclear double resonance ENDS Ends Segment ENEL Ente Nazionale per I'Energia Elettrica Otalian National Electric Energy Agency) ENG electronic newsgathering ENIAC * Electronic Numerical Integrator Analyzer and Computer (First fully electronic digital computer) ENQ enquiry ENQ Enquiry ENSO El Nino - Southern Oscillation ENSS Exterior Nodal Switching Subsystem [Internet] EO electro-optical EOA End Of Address EOB End Of Block EOC End Of Conversion EOF End Of File Enterprise Objects Framework [Next Computer] EOG Electro-optic grating EOG electro-oculography (-gram) EOI End Of Interrupt End Or Identify EOJ End Of Job EOL End Of Line End Of List EOM End Of Message EOQ economic order quantity EOR Exclusive OR (Also XOR) EOS Earth Observing System [NASA] End Of String Electrical overstress EOSDIS Earth Observing System Data and Information System [NASA] EOT end of transmission EOT End Of Table End Of Tape (marker) End Of Text End Of Transmission EP Electrophotographic Engine EPA Environmental Protection Agency (USA) EPDM ethylene propylene diene monomer EPI electrical patents index echo planar imaging EPL Effective Privilege Level EPLD Electrically Programmable Logic Device EPM Enhanced Editor for Presentation Manager [IBM] Enterprise Process Management [IBM] EPMA electron probe microanalysts EPOS electronic point of sale EPP Enhanced Parallel Port EPR Einstein Podolsky Rosen electron paramagnetic resonance ethylene propylene rubber EPRI Electric Power Research Institute EPROM Electrically Programmable Read Only Memory Erasable Programmable Read Only Memory EPSF Encapsulated PostScript Files EPSS experimental packet switching service ER Entity Relationship ER/RC Extended Result/Response Code ERA Extended Registry Attributes ERAS Electronic Routing and Approval System [Hughes Aircraft] ERBE Earth Radiation Budget Experiment ERG electroretinography (-gram) ERIC Educational Resources Information Center [Internet] ERLL Enhanced Run Length Limited EROM Erasable Read Only Memory EROS Earth Resources Observation System [U.S. Geological Survey] ERR Error ES Extra Segment ESA Enterprise Systems Architecture [IBM] European Space Agency ESC EISA System Component Escape ESC/P Epson Standard Code for Printers ESCA electron spectroscopy for chemical analysis ESCAR Experimental Superconducting Accelerating Ring ESCM Extended Services Communications Manager [IBM] ESCON Enterprise System Connection (Architecture) [IBM] ESD Electronic Software Distribution Electrostatic Discharge Electron stimulated desorption ESD1A electron stimulated desorption ion angular distributions ESDI Enhanced Small/System Device Interface ESEM environmental scanning electron microscope (-oscopy) ESF engineering safety features ESH electric strip heater ESI Enhanced Serial Interface (specification) [Hayes] ESM electronic support measures ESMR Enhanced Specialized Mobile Radio ESN Electronic Security Number ESOC European Space Operations Centre ESP Emulation Sensing Processor Encapsulating Security Payload (header) Enhanced Serial Port [Hayes] Enhanced Service Provider Estimated Selling Price Electrostatic precipitators ESPI electronic speckle pattern interferometry ESPRIT estimation of signal parameters by rotational invariance techniques European Strategic Programme for Research in Information Technology ESR Event Service Routine Electron Spin Resonance ESS Electronic Switching System ESU Electro-Static Unit ET Enhancement Technology ETACS Extended Total Access Communication System [IBM] ETANN Electrically Trainable Analog Neural Network (chip) [Intel] ETB End of Transmission Block ETC Electronic Toll Collection Enhanced Throughput Cellular (modem protocol) [AT&T] Electro-thermal (integrated) circuit ETOM Electron-Trapping Optical Memory ETPL Endorsed Tempest Products List ETS Econometric Time Series ETSI European Telecommunications Standards Institute ETV enhanced TV ETX end of text ETX End Of Text EU Execution Unit EUC End User Computing Extended Unix Code [IBM] EUI End-User Interface EULA End User License Agreement EUV extreme ultraviolet EVA extra vehicular activity EVE Extensible VAX Editor EVF electronic view-finder EVGA Extended Video Graphics Array Extended Video Graphics Adapter EW electronic warfare EWAN Emulator Without A Good Name [Internet] EWS Employee Written Software [IBM] EX-OR exclusive-OR EXAFS extended X-ray absorption fine structure ExCA Exchangeable Card Architecture [Intel] EXE2BIN Program used to convert an (.EXE) file to binary format (.COM) file EXM Enterprise Messaging Exchange [Lotus] EXP Exponent EXT External EXTRN External Reference F/T Full Time FA factory automation FAB Computer-Chip Fabrication Plant FAC File Access Code FAG flat aperture grill FAMOS Floating Gate Avalanche MOS FANS Future Air Navigation System FAP File Access Protocol FAPI Family Application Program Interface FAQ Frequently Asked Questions FARNET Federation of American Research Networks [Internet] FASIC Function and Algorithm-Specific Integrated Circuit FAT File Allocation Table FAX Facsimile FBC fluidised bed combustion FBR fast breeder reactor FBT fly-back transformer FC frame control FC/AL Fiber Channel/Arbitrated Loop FC/EL Fiber Channel/Enhanced Loop FCB File Control Block FCC face centred cubic Federal Communications Commission (USA) FCC: File Carbon Copy FCCSET "Federal Coordinating Council for Science, Engineering and Technology" FCFS first come first served FCI Flux Changes per Inch Fuel-cladding interaction FCR FIFO Control Register FCS Fiber Channel Standard Frame Check Sequence FCT field controlled thyristor FD Floppy Disk Floppy Drive Full Duplex FDC Floppy Disk Controller FDD Floppy Disk Drive FDDI Fiber Digital Device Interface Fiber Distributed Data Interface FDISK Fixed Disk FDM Frequency-Division Multiplexing FDMA Frequency Division Multiple Access FDNC frequency dependent negative conductance FDNR frequency dependent negative resistance FDP fast digital processor FDS frequency division separator FDX Full Duplex FEA finite element analysis FEC forward error correction/control FECL feedback ECL FECN Forward Explicit Congestion Notification FED Fusion Engineering Device (USA) Field-emitter display FEDC Fusion Engineering Device Centre (USA) FEFO "First-Ended, First-Out" FEK frequency exchange keying FEL free electron laser FEM field emission microscopy finite element method FEOL Front end of the line FEP fluorinated ethylene-propylene copolymer front end processor FEPI Front End Programming Interface FER Fusion Experimental Reactor (Japan) FeRAM Ferro-electric RAM FESDK Far East Software Development Kit [Microsoft] FET Field Effect Transistor FF Flip-Flop Form Feed FFDC First Failure Data Capture [IBM] FFHR fusion-fission hybrid reactor FFS Fast File System FFST First Failure Support Technology [IBM] FFT Fast Fourier Transform Final Form Text [IBM] FFTF Fast Flux Test Facility FG Floating Gate FGD flue gas desulphurisation FGREP Fixed Global Regular Expression Print [Unix] FH-SSMA frequency hopped SSNIA FHNC Fermi hypemetted chain FHSS Frequency-Hopping Spread Spectrum FI frequence intermediaire (French for IF) FIB focused ion beam FIBAE focused ion beam assisted etching FIC fast idle control FIF Fractal Image Format FIFO First In First Out FILO "First-In, Last-Out" FIM field ion microscopy FIMOS floating gate ionisation injection metal-oxide-semiconductor FIP File Processor Buffering FIPOS full isolation by porous oxidised silicon FIPS Federal Information Processing Standard FIR Far (Fast) Infrared Finite Impulse Response FIRST Forum of Incident Response and Security Teams FISO fast in slow out FITL fibre in the loop FIU Fingerprint Identification Unit [Sony] FIX Federal Internet Exchange FK Fluessigkristal (liquid crystal) FLA Four Letter Acronym FLC Ferro-electric Liquid Crystal FLD Field FLIR forward looking infrared FLL FoxPro Link Library [Microsoft Fox Pro] FLOP Floating-Point Operation FLOPS Floating Point Operations Per Second FLOTOX floating gate tunnel oxide FM frequency modulation frequency multiplexer FMCW frequency modulated carrier wave FMECA failure modes effects and criticality analysis FMIT Fusion Materials Irradiation Test Facility FMR ferromagnetic resonance FMS Flexible manufacturing system Flight (forms) management system FMSR Fast Mixed Spectrum Reactor FMT Format FMV Full Motion Video FNT Font FOCUS Forum of Control Data Users FOD Fax On Demand FOG First Osborne Group Fibre optic gyro FOIRL Fiber Optic Inter Repeater Link [IEEE] FOLDOC Free On-Line Dictionary Of Computing FOP Fibre optical plate FORTH (Programming Language)(See HLL) FORTRAN Formula Translator (Programming Language)(See HLL) FOSE Federal Office Systems Exposition FOSI Format Option Specification Instance FOSSIL Fido/Opus/Seadog Standard Interface Layer FOV field-of-view FPC Fusion power core Flexible printed circuit (board) Floating point calculation FPCE Floating-Point C Extension (specification) FPGA Field Programmable Gate-Array FPLA Field Programmable Logic-Array FPM Fast Page Mode FPP Fixed Path Protocol Floating Point Processor FPR Floating-Point Register FPS Favorite Picture Selection Frames Per Second FPT Forced Perfect Termination Finite perturabation theory FPU Floating Point Unit FQDN Fully Qualified Domain Name [Internet] FRAD Frame Relay Access Device Frame Relay Assembler/Disassembler FRAG Fragment Fragmentation FRAM Ferro-electric Random Access Memory FRC Functional Redundancy Checking FRE Forward and Reverse Engineering FRED Frame Editor Front-End to Dish FRED-FET fast recovery epitaxial diode FET FRMR field reversed mirror reactor FRP fibre-reinforced plastics FRPI Flux Reversals Per Inch FS File Separator Frame status FSCL feedback source coupled FET logic FSD File System Driver [OS/2] Forward scale deflection FSDE fission suppressed direct enrichment (breeder blanket) FSE Full Screen Editor Fast spin echo FSF Free Software Foundation [Internet] FSGO floating spherical Gaussian orbitals FSK Frequency Shift Keying FSN Full Service Network FSP File Service Protocol FSR Free System Resources Frequency standard reference FSRAM fan static RAM FST Flat Square Tube (monitor) FTAM "File Transfer, Access (Application) and Management File Transfer and Access Method" FTET heterojunction field effect transistor FTIR Fourier transform infrared frustrated total internal reflection FTM Flat Tension Mask [Zenith] FTP File Transfer Protocol [Internet] FTPD File Transfer Protocol Daemon FTR Fan Test Reactor FTS Federal Telecommunication System FTTC Fibre To The Curb FTTH fibre-to-the-home FTX Fault Tolerant Unix FUI File Update Information FUNC Function FVT Full Video Translation FWHM full width half maximum FWIR high flux isotope reactor FWITR FEgh Field Ignition Test Reactor FYI For Your Information FZ Floating zone G/L General Ledger G3 group 3 G4 group 4 GA General Availability GAAP Generally Accepted Accounting Principles GAL Generic Array Logic GAMBIT gate modulated bipolar transistor GANIL Grand Accelerateur National a Ions Lourds GAPI Gateway Application Programming Interface Gb "Gigabit (1,024 megabits)" GB "Gigabyte (1,024 megabytes)" GC gas chromatography GCC GNU C-Compiler [Unix] Gasification combined cycle GCFR gas cooled fast breeder reactor GCHWR gas cooled heavy water moderated reactor GCM general circulation model generator coordinate method GCR group code recording ghost cancel reference gas-cooled reactor GDA Global Data Area GDDM Graphics Data Display Manager GDG Generation Data Group [IBM] GDI Graphical Device Interface GDLC Generic Data Link Control [IBM] GDP Graphic Draw Primitive GDR giant dipole resonance GDT Geometric Dimensioning and Tolerancing Global Descriptor Table Graphics Development Toolkit GECOS General Electric Comprehensive Operating System GEIS General Electric Information Service (company) GEM Graphics Environment Manager (DRI Program) GENIE General Electric Network for Information Exchange GEO Geostationary Earth Orbit GEOS Graphic Environment Operating System [Geoworks] GET Get Execute Trigger GETR General Electric Test Reactor GGG gadolinium gallium garnet GGP Gateway-Gateway Protocol [Internet] GHF-NO-CI generalised Hartree-Fock/natural orbital/configuration interactions GHZ Gigahertz GI Graded index GIAO gauge-invariant atomic orbitals GIC generalised immittance converter graphite intercalation GIGO "Garbage In, Garbage Out" GII Global Information Infrastructure GILS Government Information Locator Service GIOP General Interoperable ORB Protocol GIS Geographic Information System Global Information Solutions [AT&T] Gas insulated system (substation or switchgear) GITL gas insulated transmission line GIX Global Internet Exchange [Internet] GKS Graphical Kernel System GL Graphics Language GLIS Global Land Information System [US Geological Survey] GLM General Linear Models GLOBE Global Learning by Observations to Benefit the Environment [Internet] GM Geiger Muller GMDH group method of data handling GMIDI General Musical Instrument Digital Interface GMP Global Mobile Professional GMR Giant Magneto-Resistive Giant monopole resonance GMS Global Management System Global Messaging Service [Novell] GMSK Gaussian filtered MSK GMT Greenwich Mean Time GND Ground (signal/system) GNN Global Network Navigator GNU Gnu's Not Unix (operating system) GO Gaussian orbitals GOLD gate-drain overlapped device GOSIP Government Open Systems Interconnection Profile GP Gas Plasma General Purpose Guinier-Preston GPED gas phase electron diffraction GPF General Protection Fault GPI Graphics Programming Interface General purpose interface GPIB General Purpose Information/Interface Bus GPM ground potential model GPR General Purpose Register [IBM] GPS Global Positioning Satellite/System GPSS General Purpose Systems Simulator (language) GQR giant quadrupole resonance GRADD Graphics Adapter Device Driver [IBM] GRE Graphics Engine GREP Global Regular Expression Print GRIN graded (gradient) refractive index GRIN-SCH graded index separate confinement heterostructure GS Group Separator GSC group switching centre GSGG gadolinium scandium gallium garnet GSI General Server Interface GSM Global Shared Memory Global System for Mobile-Communications (network) Groupe Speciale Mobile GSMBE gas source molecular beam epitaxy GSNW Gateway Service for NetWare [Microsoft] GSPC gas scintillation proportional chamber (counter) GSTN General Switched Telephone Network GTD geometrical theory of diffraction GTE General Telephone Electronics (corporation) GTHTGR gas turbine HTGR GTL Gunning Transceiver Logic GTO Guide To Operations [IBM] Gate turn-off Gaussian-type orbitals GUI Graphical User Interface GUID Globally Unique Identifier Global Universal Identifier GUIDE Graphical User Interface Design Editor GUT grand unified theory GVB generalised valence bond GVT Global Virtual Time GW-BASIC Gee Whiz BASIC H/V Horizontal/Vertical Hardware HA home automation HACMP High Availability Cluster Multi-Processing [IBM] HACT heterojunction acoustic charge transport HAL "Hard Array Logic Hardware Abstraction Layer House-Programmed Array Logic Heuristically Programmed Algorithmic (computer) [from 1968 movie ""2001: A Space Odyssey""]" HAM hydrogenic atoms in molecules HAP Host Access Protocol HARMEMS high aspect ratio micro-electro mechanical structure HASP Houston Automatic Spooling Priority (System) HBA Host Bus Adapter HCC heat conduction cooling HCDA hypothetical core disruptive accident HCI human-computer interaction HCMOS high speed complementary MOS HCP hexagonal close packed HCSS High Capacity Storage System HCU Home Computer User HD High Density Hard Drive HDA Head Disk Assembly HDB3 high-density bipolar code no. 3 HDCD High Definition Compatible Digital HDD High Double Density Hard Disk Drive HDF Hierarchical Data Format [NCSA] HDI Head to Disk Interference HDL hardware description language HDLC High-Level Data Link Control HDM Hardware Device Module HDMI high-density multichip interconnect HDPE high density polyethylene HDR Header HDS Hydro desulphurisation High definition system HDSC High Density Signal Carrier [DEC] HDSL High-data-rate Digital Subscriber Line HDSS Holographic Data Storage System HDT Host Digital Terminal HDTV High Definition Television HDVD High Definition Volumetric Display HDW Hardware HDX Half Duplex HEC header end control HEED high energy electron diffraction HEL Hardware Emulation Layer HeLa Henrietta Lacks HEMP high altitude electromagnetic pulse HEMT high electron mobility transistor HEPA high efficiency participate air HERC Hercules HET hot electron transistor HEU/Th highly enriched U/Th fuel HEX Hexadecimal HEXFET hexagonal MOSFET HF Hartree-Fock high frequency hyperfine HFB Hartree-Fock-Bogoliubov HFC Hybrid Fibre-Coaxial HFEF Hot Fuel Examination Facility HFETPD HFET photodetector HFO Hartree-Fock-Overhauser HFS Hierarchical File System [Macintosh] Hartree-Fock-Slater Hyperfine structure HFT High Function Terminal [IBM] HGA Hercules Graphics Adapter HGCP Hercules Graphics Card Plus HGMS high gradient magnetic separation HH Hour HHLAPI High-Level Language Application Programming Interface HI2L heterojunction integrated injection logic HIC hybrid integrated circuit HID high intensity discharge HIF Hyper-G Interchange Format HIFD High-Density Floppy Disk HIFET heterointerface field effect transistor HIGFET heterostructure insulated gate FET HIL Human Interface Link [HP] HIMEM High Memory HIP hot isostatic pressing HIPOS high pressure porous oxidised silicon HIPPI HIgh Performance Parallel Interface HIXE heavy ion induced X-ray emission HJBT heterojunction bipolar transistor HJFET heterojunction field effect transistor HLCO High Low Close Open HLL High Level Language HLLAPI High Level Language Application Programming Interface HLLW high level liquid waste HLQ High Level Qualifier HLR home location register HLS "Hue, Luminance, Saturation (colour model)" HLT Halt HLW high level waste HM hybrid modulation HMA High Memory Area [Microsoft] Hub Management Architecture HMD Head Mounted Display HMDS hexa methyl disilazane HMM Hidden Markov Model HMMP Hyper-Media Management Protocol HMO Huckel molecular orbitals HMOS High Density (Performance) Metal Oxide Semiconductor High Speed Metal Oxide Semiconductor HMP Host Monitoring Protocol HMTSEF hexamethylenetetraselenafulvalene (-inium) HMTTF hexamethyltetrathiofulvalene (-inium) HOAB heptyloxyazoxybenzene HOE holographic optical elements HOH Hash Of Hashes HOMO highest occupied molecular orbitals HOTT Hot Off The Tree (electronic newsletter) HP Hewlett-Packard (Company) HPC Handheld Personal Computer HPCC High Performance Computing and Communications HPCI high pressure coolant injection HPCS high-pressure core sprays HPDJ Hewlett-Packard Desk Jet HPF high pass filter HPFS High-Performance File System HPFS High Performance File System HPG Hewlett-Packard Graphics HPGL Hewlett-Packard Graphics Language HPIB Hewlett-Packard Interface Bus HPLC high performance liquid chromatography HPLJ Hewlett-Packard Laser Jet HPPA Hewlett-Packard Precision Architecture HPPI High Performance Parallel Interface HPR High Performance Routing [IBM] HPUX Hewlett-Packard Unix HPW High Performance Workstation [Sun] HREELS high resolution EELS HREM high resolution electron microscopy HRG High Resolution Graphics HRIS Human Resource Information System HRMS Human Resource Management System HRTF Head Related Transfer Function HRV heart rate variability HS High Speed HSA Head suspension assembly HSB "Hue, Saturation, Brightness (colour model)" HSC High Speed Channel HSI "Hue, Saturation, Intensity" HSLA high strength low alloy (steel) HSLN high speed local network HSM Hierarchical Storage Management HSP High Speed Printer HSSI High Speed Serial Interface HST High Speed Technology [U.S. Robotics] HSV Hue Saturation Value HT high tension horizontal tabulation HTCC high temperature co-fired ceramic HTETR High Temperature Engineering Test Reactor HTGR high temperature gas-cooled reactor HTGR SC/C HTGR steam cycle co-generation HTML HyperText Markup Language HTP hermetic thin package HTR high temperature reactor HTTP HyperText Transport Protocol HTTP-NG HTTP Next Generation HTTPD HyperText Transfer Protocol Daemon HUD Heads Up Display HUT Hopkins Ultraviolet Telescope HV high voltage HVAC "heating, ventilation and air conditioning high voltage alternating current" HVDC high voltage direct current HVEM high voltage electron microscopy HVIC high voltage integrated circuit HVP Horizontal & Vertical Position HWCP Hardware Code Page HWD Height-Width-Depth HWLWR heavy water moderated LWR HWR heavy water reactor HYTELNET Hypertext-browser for Telnet Accessible Sites Hz Hertz HZE high Z and energy HZP Hot Zero Power I-IEU highly enriched uranium (93% U235) I-V current-voltage I-WAY Information Highway I/0 input-output I/F Interface I/O Input/Output I2L integrated injection logic I3L isoplanar I2L IA5 international alphabet no. 5 IAB Internet Architecture Board [Internet] IAC Inter-Application Communication [Macintosh] IAEA International Atomic Energy Agency IAG Instruction Address Generation IAK Internet Access Kit [IBM] IAL * International Algebraic Language (ALGOL was first called IAL) IANA Internet Assigned Numbers Authority [Internet] IAP Internet Access Provider [Internet] IAR isobaric analogue resonance IAS isobaric analogue state IAT Import Address Table IAUP Internet User Account Provider [Internet] IB Interface Builder IBA interacting boson approximation IBC Instrument Bus Computer IBCN integrated broadband communication network iBCS Intel Binary Compatibility Specification IBFA interacting boson-fermion approximation IBM International Business Machines (Corporation) Interacting boson model IBM-GL IBM Graphics Language IBPBAC isobutyl-4- (4'-phenylbenzylidene-amino) cinnamate IC Input Circuit Integrated Circuit Interrupt Controller Internal combustion ICA Intra-application Communications Area Intelligent Console Architecture ICAP Internet Calendar Access Protocol [Lotus] ICAS Intel Communicating Applications Specifications ICB Internet Citizen's Band Ionised cluster beam ICCP Institute for the Certification of Computing Professionals ICDF intermediate coupling Dirac-Fock ICE Intrusion Countermeasure Electronics In-Circuit Emulator [Intel] ICES Interference-Causing Equipment Standard ICF inertial confinement fusion ICI Image Component Information ICL Interface Clear ICLID Incoming-Call Line Identification ICM Image colour Matching [Kodak] ICMP Internet Control Message Protocol [Novell] iCOMP Intel Comparative Microprocessor Performance [Intel] ICP Integrated Channel Processor Inductively coupled plasma Interconnection protocol ICPP Idaho Chemical Processing Plant ICR Intelligent Character Recognition ICRF ion cyclotron range of frequencies ICRH ion cyclotron resonance heating ICS Intuitive Command Structure ICU ISA Configuration Utility Instruction-Cache Unit ID Identification Identifier Internal diameter IDA Integrated Digital Access Intelligent Disk Array Intelligent Drive Array IDAPI Integrated Database Application Programming Interface IDC Integrated Database Connector Integrated Desktop Connector Internet Database Connector [Microsoft] IDD international direct dialling IDDE Integrated Development & Debugging Environment [Symantec] IDE Imbedded Drive Electronics Integrated Development Environment [Borland] Integrated Drive Electronics Intelligent Drive Electronics Interactive Design and Engineering Interface Design Enhancement Integrated device electronics IDEA "International Data Encryption Algorithm Internet Design, Engineering, and Analysis" IDF Intermediate Distribution Frame IDFL integral diode FET logic IDIV Integer Divide IDL Interface Definition Language IDMR InterDomain Multicast Routing IDMS Integrated Data Base Management System IDN integrated digital network IDNX Integrated Digital Network Exchange [IBM] IDP Integrated Data Processing IDR Intelligent Document Recognition IDT Interface Design Tool Interrupt Descriptor Table Interdigital transducer IDTV improved definition television IE Internet Explorer [Microsoft] IEC Interexchange carrier International Electrotechnical Commission IEEE Institute of Electrical and Electronics Engineers IEF Information Engineering Facility IEMSI Interactive Electronic Mail Standard Identification IEN Internet Engineering Notes IEPA independent electron pair approximation IES French for ISI IESG Internet Engineering Steering Group [Internet] IETF Internet Engineering Task Force [Internet] IETS inelastic electron tunnelling spectra (-oscopy) IF intermediate frequency IFA ionisation front accelerator IFC Internet Foundation Classes IFD Image File Directory IFE intelligent front end IFF Interchangeable File Format [Amiga] IFG Incoming Fax Gateway IFH Image File Header IFM instantaneous frequency measurement IFP Instruction Fetch Pipeline IFS Installable File System IFSM Information Systems Management IFTW Install From The Web IGA Integrated Graphics Array IGBT insulated gate bipolar transistor IGC Integrated Graphics Controller IGCC integrated gasification combined cycle IGES Initial Graphics Exchange Specification (Standard) IGFET insulated gate field effect transistor IGMP Internet Group Multicast (Management) Protocol [Internet] IGRP Interior Gateway Routing Protocol [Cisco] IGS Internet Go Server [Internet] IGT Insulated gate transistor IHD Integrated Help Desk [IBM] IHEP Institute of High Energy Physics IHV Independent Hardware Vendor II image intensifier IID Independently identically distributed Impurity induced disordering Interface identifier IIF Immediate Interface III Interstate Identification Index [NCIC] IIL integrated injection logic IIOP Internet Inter-Operability Protocol Internet Interoperable ORB Protocol IIR Immediate (Infinite) Impulse Response IIS Internet Information Server [Microsoft] Interference inter-symboles (French for ISI) IITF Information Infrastructure Task Force IJ insulator junction IKBS intelligent knowledge based system IKO Institute v. Kemph Ouder (Amsterdam) IKP Internet Keyed Payments [IBM] ILA Image Light Amplifier ILB inner lead bonding ILD injector laser diode ILS International Language Support Instrument landing system ILW intermediate level (radioactive) waste IMACS Image Management and Communication System IMAP Internet Message Access Protocol [Internet] IMAX Maximum Image IMD intermodulation distortion IMDS Image Data Stream (format) [IBM] IME Input Method Editor IMG Image IML Initial Microcode Load [IBM] IMP Information/Interface Message Processor IMPA Intelligent Multi-Port Adapter [DCA] IMPATT impact avalanche transit time IMR Internet Monthly Report [Internet] IMS Information Management System Intermediate Maintenance Standards IMSP Internet Message Support Protocol IMTC International Multimedia Teleconferencing Consortium IMTV Interactive Multimedia Television IMUL Integer Multiply IMUX Inverse Multiplexer IN Intelligent network Input INC Increment INDO incomplete neglect of differential overlap INDOR internuclear double resonance INEPT insensitive nuclei enhanced by polarisation transfer INFO information ING intense neutron generator INIT Initialization Initialize INM Integrated Network Management INMARSAT International Maritime Satellite INND Internet News Daemon INO iterative natural orbital INS Input String Integrated Network Server Inertial navigation system Information Network System INT Integer Internal Interrupt International (organization Domain name) [Internet] INTA Interrupt Acknowledge InterNIC Internet Network Information Center [Internet] INTO Interrupt if Overflow occurs INTOR International Tokamak Reactor IO Input/Output IOC-omega inclusion of the overlap charges in the omega IOCC Input/Output Channel Converter Input/Output Controller Chip IOCS Input/Output Control System IOCTL Input/Output Control IODE Integrated Development and Debugging Environment [Symantec] IOP Input/Output Processor IOPL Input/Output Privilege Level IOS Input/Output System IOSGA Input/Output Support Gate Array IP Instruction Pointer Internet Protocol Imaging plate Intelligent peripheral IPC Instructions Per Clock Interprocess Communication IPCP Internet Protocol Control Protocol IPDS IBM Personal Dictation System [IBM] Intelligent Printer Data Stream [IBM] IPFC Information Presentation Facility Compiler [IBM] IPI Intelligent Peripheral Interface IPL Initial Program Load/Loader Ion Projection Lithography IPL Information Programming Language IPM Interface message processor Intelligent power module Interpersonal message IPng "Internet Protocol, next generation" IPS Information Processing System IPSE Integrated programming support environment Integrated project support environment IPSS International packet switching system IPTC International Press Telecommunications Council IPU Integrated power unit IPX Internetwork Packet Exchange [Novell] IQL Interactive Query Language IR Infrared Inversion recovery IRBIC infrared beam induced current(s) (contrast) IRC Internet Relay Chat [Internet] IRD Integrated Receiver/Descrambler IRDA Infrared Data Association IRDO intermediate retention of differential overlap IRDS Information Resource Dictionary System IREB intense relativistic electron beam IRED infrared emitting diode IRET Interrupt Return IRF Intermediate Routing Function Inheritance Rights Filter [Novell] IRL Interactive Reader Language Inter-Repeater Link IRLAP Infrared Link Access Protocol IRLED Infrared Light Emitting Diode IRM Information Resource Management Inherent Rights Mask IRQ Interrupt Request IRS information retrieval system infrared spectroscopy IRTF Internet Research Task Force [Internet] IRX Information Retrieval Experiment IS Information System Interrupt Status ISA Industry Standard Architecture (Adapter) Instruction-Set Architecture ISABELLE intersecting storage and acceleration ISAKMP Internet Security Association and Key Management Protocol ISAM Indexed Sequential-Access Management/Method ISAPI Internet Server Application Programming Interface [Microsoft] Internet Server Advanced Programming Interface ISBN International Standard Book Number ISC idle speed control ISC Instruction Set Computer Inter-Systems Communication [IBM] ISCP Integrated service control point ISD Image Section Descriptor Instructional Systems Design International subscriber dialling ISDN Integrated Services Digital Network ISDSN integrated services digital satellite network ISFET ion-sensitive field effect transistor ISH Information Super Highway ISI Internally Specified Index Intersymbol interference ISIS Integrated Systems and Information Services ISKM Internet Starter Kit for the Macintosh ISL Interactive System Language Integrated Schottky logic Inter-satellite links ISM Intermediate Service Module Internet Service Manager [Microsoft] ISMA idle signal multiple access ISMF Interactive Storage Management Facility ISO International Standardisation Organisation ISO/OSI International Standards Organization/Open Systems Interconnection (model) ISOC Internet Society ISP Internet (Information) Service Provider [Internet] Interrupt Stack Pointer Interrupt Status Port In-system programmable ISPBX integrated services private automatic branch exchange ISPF Interactive System Programming Facility ISR Information Storage and Retrieval Interrupt Service Routine Interrupt Status Register Intersecting storage ring ISRC Inverted sidewall recessed channel ISS ion scattering spectroscopy ISSN International Standard Serial Number ISV Independent Software Vendor ISX impurity study experiment IT Information Technology ITA2 international telegraph alphabet no.2 ITB Information Technology Branch Intermediate Text Block ITC International Typeface Corporation Ionic thermocurrents ITDM intelligence TDM ITE Information Technology Equipment ITEP Institute of Theoretical and Experimental Physics (USSR) ITF Interactive Test Facility ITN Identification Tasking and Networking ITO indium tin oxide ITR In-core thermionic reactor Ignition Test Reactor Internet Talk Radio ITSEC Information Technology Security Evaluation Criteria ITU International Telecommunication Union ITU-TSS ITU-Telecommunication Standards Section ITUG International Telecommunications User Group ITV Interactive (Industrial) Television ITX Intermediate Text Block IU Indiana University (USA) Integer unit IUAP Internet User Account Provider [Internet] IUS/ITB Interchange Unit Separator/Intermediate Transmission Block IV&V Independent Verification & Validation IVIS Interactive Video Information System IVL Independent Vendor League Intel Verification Lab IVO improved virtual orbitals IVP initial value problem IVR Interactive Voice Response IVS Interactive Videodisk System IVT Interrupt Vector Table IWM Incremental Warehouse Methodology IXC Interchange Carrier JA Jump Address Jump if Above JAD Joint Application Design JAE Jump if Above or Equal JAERI Japan Atomic Energy Research Institute JANET Joint Academic Network JBE Jump if Below or Equal JC Jump if Carry set JCL Job Control Language JDBC Java DataBase Connectivity JDI Java Driver Interface JDK Java Development Kit JE Jump if Equal JEDEC Joint Electronic Devices Engineering Council JEIDA Japanese Electronics Industry Development Association JES Job Entry System JET joint European Torus JFC Java Foundation Classes JFET Junction Field Effect Transistor JFIF JPEG File Interchange Format JFS Journaled File System [IBM] JG Jump if Greater JGE Jump if Greater or Equal JGL Java Generic Library JINR joint Institute for Nuclear Research (USSR) JIPS JANET Internet Protocol Service JIS Japanese industry standard JIT Just-In-Time (compiler) JL Jump if Less JLE Jump if Less than or Equal to JMAPI Java Management Application Program Interface JMP Jump JNA Jump if Not Above JNAE Jump if Not Above or Equal JNB Jump if Not Below JNBE Jump if Not Below or Equal JNG Jump if Not Greater JNGE Jump if Not Greater or Equal JNLE Jump if Not Less or Equal JNO Jump if No Overflow JNP Jump if No Parity JNS Jump if No Sign JNZ Jump if Not Zero JOE Java Objects Everywhere JPE Jump if Parity Even JPEG Joint Photographic Experts Group JPL Jet Propulsion Laboratory JPO Jump if Parity Odd JS Jump if Sign JavaScript JSS Java-Script Style Sheet JT-60 Japanese Tokamak-60 JTIDS joint Tactical Information Distribution System JTMP joint transfer and manipulation protocol JTP Jolt Transaction Protocol JUGHEAD Jonzy's Universal Gopher Hierarchy Excavation and Display [Internet] JVM Java Virtual Machine JZ Jump if Zero K-12 Kindergarten through 12th Grade [US Education System] KAM Keep Alive Memory kb kilobyte Kb Kilobit KB "Keyboard Kilobyte (1,024 bytes)" KBD Keyboard (also KEYB) Kbps Kilobits Per Second KBps Kilobytes Per Second KBS knowledge based system KDP potassium dihydrogen phosphate KDT Key Definition Table KdV Korteweg-de Vries KEFIR Key Findings Reporter [GTE] KEK japan National Laboratory for FEgh Energy Physics KHz Kilohertz KIF Knowledge Interchange Format KIS Knowbot Information Service [Internet] KKR Korringi-Kohn-Rostoker KPI Kernel Programming Interface KQML Knowledge Query and Manipulation Language KRL knowledge representation language KRS Knowledge Retrieval System KSH Korn Shell (program) [Unix] KSPH Keystrokes Per Hour KSR Keyboard Send Receive KTP potassium titanium phosphate KTS key telephone service L2F Layer Two Forwarding L2TP Layer Two Tunnelling Protocol LAD lens assisted deflection LADDR Layered Device Driver Architecture [Microsoft] LALL Longest Allowed Lobe Length LAM line adapter module LAMPF Los Alamos Meson Physics Facility LAN Local Area Network LANACS Local Area Network Asynchronous Connection Server LANDP LAN Distributed Platform LANE Local Area Network Emulation LAP link access protocol LAPB Link Access Procedure Balanced (protocol) LAPD Link Access Protocol (Procedure) D-channel QSDM LAPM Link Access Procedure for Modems LAR Load Access Rights LASER Light Amplification by Stimulated Emission of Radiation LASTport Local Area Storage Transport (protocol) [DEC] LAT Local Access Terminal Local Area Transport [DEC] LATA Local Access and Transport Area LATI large angle tilt implant LAVC Local Area VAX Cluster LAWN Local Area Wireless Network LB Langmuir-Blodgett local bus Left Button (of 2 or 3 button Mouse) LBA Logical Block Address LBI linear induction motor LBIC light beam induced current(s) LBL Label LBLOCA large break LOCA LBP Laser Beam Printer LBR Librarian LBT Listen Before Talk LBX Local Bus Accelerator LC inductance-capacitance liquid crystal liquid chromatography line concentrator (telecomms.) LCA Lotus Communications Architecture [Lotus] LCAO linear combination of atomic orbitals LCBO linear combinations of (semi-localised) band orbitals LCC Leadless Chip Carrier LCCC leadless ceramic chip carrier LCD Liquid Crystal Display Lowest Common Denominator LCF Low Cost Fibre LCGO linear combination of Gaussian orbitals LCK Library Construction Kit [Microsoft FoxPro] LCP Large Cod Program least cost planning Link Control Protocol LCR least cost routing inductance capacitance resistance Line Control Register LCRO linear combination of Rydberg orbitals LCTF Large Cod Test Facility LCU Last Cluster Used LD laser diode loop disconnect LDA laser Doppler anemometry (-meter) LDA Logical Device Address LDAP Lightweight Directory Access Protocol [IBM] LDC Lotus Development Corporation LDD lightly doped drain LDM Long Distance Modem LDMOS lateral double-diffused MOS LDMS laser desorption mass spectrometry LDPE low density polyethylene LDT Local Descriptor Table LDV laser Doppler velocimetry (-meter) LE Less or Equal LEA Load Effective Address LEAF Law Enforcement Access Field LEAR Low Energy Antiproton Ring LEC liquid encapsulated Czochralski local exchange carrier Local Area Network Emulation Client LECS LAN Emulation Configuration Server LED Light Emitting Diode LEED low energy electron diffraction LEFD Large Experimental Fusion Device LEL "Link, Embed and Launch-to-edit [Lotus]" LEM Language Extension Module LEMP lightning electromagnetic pulse LEN Low Entry Networking LEO low-Earth-orbit LEP Large Electron Positron (CERN) LERG local exchange routing guide LES Local Area Network Emulation Server light-emitting switch LES/BUS LAN Emulation Server / Broadcast and Unknown Server LET linear energy transfer LEU low enrichment uranium (10% U235) LEU/Th low enrichment U/Th fuel LEX Lexicon LF low frequency line feed LFFET low frequency field effect transistor LFI Last File Indicator LFN Long File Name LFSR linear feedback shift register LFT Low Function Terminal [IBM] LFU Least Frequently Used LGC linear grating coefficients LGDT Load Global Descriptor Table LHPG laser heated pedestal growth LHRH lower hybrid resonance heating LHSV liquid hourly space velocity LIAS Library Information Access System LIC Line Interface Coupler [IBM] LICS Lotus International Character Set [LDC] LIDB line information data bus LIDT Load Interrupt Descriptor Table LIEP Large Internet Exchange Packet [Novell] LIF laser induced fluorescence LIF Low Insertion Force LIFO "Last In, First Out" LILO "Last In, Last Out" LIM Lotus/Intel/Microsoft LIMA Lotus/Intel/Microsoft/AST LIMDO Light Intensity Modulation Direct Overwrite LIME laser induced magnetically enhanced LIMM Light Intensity Modulation Method LIMS Library Information Management System LINAC linear accelerator LINC linear amplification with nonlinear components LINUX (Operating system named after Linus Torvalds) LIP Large Internet Packet LIPS Logical Inferences Per Second LISP List Processing (Language)(See HLL) LISTSERV List Server [Internet] LJFO last in first out LLC Logical Link Control LLCCC leadless ceramic chip carrier LLDT Load Local Descriptor Table LLF Low Level Format LLTR Large Leak Test Rig LLW low level (radioactive) waste LMB Left Mouse Button LMB Lower Memory Block LMBCS Lotus Multi-Byte Character Set [Lotus] LMC Large M2gellanic Cloud LMDS Local Multipoint Distribution Service LME liquid metal embrittlement LMFBR liquid metal fast breeder reactor LMI Local Management Interface LMIS liquid metal ion source LMN lead magnesium niobate LMOS lateral MOS LMR liquid metal reactor LMS Lotus Messaging Switch [Lotus] Least mean square LMSW Load Machine Status Word LMTO Linear combination of muffin tin orbitals LMU LAN Management Utilities [IBM] LAN Manager for Unix LN Load Number Logarithm (Natural) LN:DI Lotus Notes:Document Imaging LNA Low noise amplifier LNB Low noise block LNG Liquefied natural gas LNK Link LO Local oscillator Longitudinal optical LOAP Lightweight Directory Access Protocol LOC Lead on chip Loop On-Line Control LOCA Loss of coolant accident LOCE Loss of coolant experiment LOCIS Library of Congress Information System LOCOS local oxidation of silicon LOD Level Of Detail LODSB Load String Byte LOF loss of flow LOFT Loss of Flow Test Facility LOFW loss of feed water LOG Logarithm (Base 10) LOGO (Programming Language)(See HLL) LONA low noise amplifier LOOPE Loop while Equal LOOPNE Loop while Not Equal LOOPNZ Loop while Not Zero LOOPUS loop occupied permanently by unistationary satellites LOOPZ Loop while Zero LOOSP loss of onsite power LORE Line Oriented Editor LOS line of sight LP linear programming liquid phase LPC Local Procedure Call Linear predictive coding LPCS low pressure core spray LPCVD low pressure CVD LPD Line Printer Daemon (protocol) [Berkley] LPE liquid phase epitaxy LPFL low pinchoff-voltage FET logic LPI low probability of intercept lines per inch LPL Lotus Programming Language [Lotus 1-2-3] [LDC] LPM Lines Per Minute LPN Logical Page Number LPR Line Printer Remote LPS Low-Power Schottky LPSC low power self-contained cell LPT Line Printer LPT1 First Parallel Printer Port LPT2 Second Parallel Printer Port LPT3 Third Parallel Printer Port LQ Letter Quality LQG linear quadratic Gaussian LQM Link Quality Monitoring (protocol) LR Link Register LRC longitudinal redundancy check LRC Local Register Cache Longitudinal Redundancy Check LRL Least Recently Loaded LRM Language Reference Manual Least Recently-Used Master LRO long-range order LRU least recently used LRU Least Recently Used LSA LAN and SCSI Adapter [IBM] Line Sharing Adapter Local Security Authority [Microsoft] Least squares approximation Limited space charge accumulation LSAPI License Services Application Program Interface LSB lower sideband least significant bit LSC Least Significant Character LSD local spin density loop shut-down lysergic acid diethylatnide least significant digit LSI Large Scale Integration LSL Link Support Layer Load Segment Limit LSP line spectrum pair LSPB Large Scale Prototype Breeder LSSD level sensitive scan design LSSGR LATA switching system generic requirement LST List LSTF Large Scale Test Facility LT line termination LTCC low temperature co-fired ceramic LTE local thermodynamic equilibrium line terminating equipment LTR loop transfer recovery Left-To-Right Letter Load Task Register LU Logical Unit (Also LUN) LUA Logical Unit Application (interface) LUI Local User Input LUIS Library User Information Service LUMO lowest unoccupied molecular orbitals LUN Logical Unit Number LUT Lookup Table LV low voltage LV Logical Volume [IBM] LVDT linear variable differential transformer linearly variable differential transducer LVM Logical Volume Management [IBM] LW Lazy Write LWL Lichtwellenleiter (optical waveguide) LWR light water reactor LWT listen while talk LZW Lempel-Ziv-Welch (compression algorithm) "M1, M2" "magnetic dipole, quadrupole" M2FM modified modified frequency modulated mA Milliampere Mac Macintosh (Apple Macintosh Computer) MAC Media/Medium Access Control multiplexed analogue component MACH Multilayer Actuator Head [Epson] MACL Memory Access Control Logic MADE Manufacturing and Automated Design Engineering MADO Mulliken approximation for differential overlap MADYMO Mathematical Dynamic Modeling [TNO] MAG metal arc gas MAGFET magnetic field sensitive FET MAGLEV magnetic levitation MAh Milliampere-Hour MAHO mobile assisted hand-off MAI Multiple Applications Interface message area identification MAN metropolitan area network Multiple Applications Interface manual MANPAGE Manual Page [Unix] MAP Maintenance Analysis Procedures Manufacturing Automation Protocol Memory Allocation Map Modular Arithmetic Processor MAPI Mail/Messaging Applications Programming Interface [Microsoft] MAPICS "Manufacturing, Accounting and Production Information Control System [IBM]" MARS Mirror Advanced Reactor Study MARVEL Machine-Assisted Realization of the Virtual Electronic Library [Library of Congress] MAS magic angle spinning MASM Macro Assembler [Microsoft] MASS Maximum Availability and Support Subsystem [Parallan] MAT machine assisted translation Maintenance Access Terminal MATE modular automatic test equipment MAU Media Access Unit Multistation Access Unit MAVDM Multiple Application VDM MAX Maximum MB "Megabyte (1,024 kilobytes) Middle Button (of 3 button Mouse)" MBASIC Microsoft BASIC [Microsoft] MBBA 4-methoxybenzylidene-4'n-butylaniline MBCS Multi-Byte Character Set [IBM] MBE molecular beam epitaxy MBONE Multicast Backbone [Internet] MBPS Megabytes Per Second MBPT many body perturbation theory MBR Master Boot Record MBX Mailbox MC mobility controller MC-PGA Metallized Ceramic - Pin Grid Array MC-QFP Metallized Ceramic - Quad Flat Pack MCA multi-channel access micro-channel architecture/adapter MCAD Mechanical Computer Aided Design MCB Memory Control Block MCCB moulded-case circuit breakers MCCI molten core-concrete interaction MCD magnetic circular dichroism MCFC molten carbonate fuel cell MCFR magnetic confinement fusion reactor MCGA Multicolour Graphics Array MCI "MCI Communications Corp. (name from initials of original company - Microwave Communications, Inc.) Media Control Interface [Microsoft]" MCL Microsoft Compatibility Labs [Microsoft] MCM Multi-Chip Module MCNE Master Certified Novell Engineer [Novell] MCP multi-chip package microchannel plate MCPESCF multiconfiguration paired excitation SCF MCPS Microsoft Certified Product Specialist [Microsoft] MCR Modem Control Register MCSCF multiconfiguration SCF MCT MOS controlled thyristor MCU Microcontroller Unit Multi-Chip Unit [DEC] Multipoint Control Unit MCVD modified chemical vapour deposition MCVF multi-channel voice frequency MCX alpha multiconfiguration X alpha MCZDO multi-centre zero differential overlap MD Make Directory Mini Disk [Sony] Monochrome Display MDA Monochrome Display Adapter Multidimensional Analysis MDCT modified discrete cosine transform MDDBMS Multidimensional Data Base Management System MDF main distribution frame MDI Memory Display Interface Multiple Document Interface MDIC Manchester Decoder and Interface Chip [AT&T] MDK Multimedia Developers Kit [Microsoft] MDLP Mobile Data Link Protocol MDR Minimum Design Requirement MDS multidimensional scaling MDY Month Day Year MEB Memory Expansion Board MEC molecular electron correlation(s) MEDO multiple expansion of diatomic overlap MEG magnetoencephalography (-gram) MEL/Th Medium Enrichment U/Th fuel MEM Memory MES Manufacturing Execution System MESFET metal-semiconductor FET MESI "Modified, Exclusive, Shared and Invalid (protocol)" MET Memory Enhancement Technology [Hewlett-Packard] MEU Medium Enrichment Uranium (20% U235) MF medium frequency multiple frequency MFC Microsoft Foundation Class [Microsoft] MFET mechanical FET MFFS Microsoft Flash File System [Microsoft] MFLOPS Million Floating Point Operations Per Second MFM Modified Frequency Modulation MFP MultiFunction Peripherals mean free path MFPI Multifunction Peripheral Interface MFR mirror fusion reactor MFS Macintosh File System [Macintosh] Magnetic Tape Field Search Memory File System Modified Filing System [Revelation Technologies] MFSK multiple frequency shift keying MFT Master File Table Multiprogramming with a Fixed number of Tasks MFTF Mirror Fusion Test Facility MGA Monochrome Graphics Adapter MGE Modular GIS Environment MGET Multiple Get [Unix] MGR Manager MH modified Huffman MHD magnetohydrodynamics MHS Message Handling Service Message Handling System MHz MegaHertz MI Management Interface MI/MIC Mode Indicate/Mode Indicate Common MIB Management Information Base MIC microwave integrated circuit monolithic integrated circuit Memory In Cassette MICR magnetic ink character recognition MICRO One-millionth MICS Macro Interpretive Commands MID magnetically insulated diode MIDI Musical Instrument Digital Interface MIDP microwave induced delayed phosphorescence MIEHM modified iterative extended Huckel method MIF Management Information Format MIG Metal In Gap Metal inert gas MIL Machine Interface Layer [Go Corporation] MIL-STD Military Standard MIM metal-insulator-metal MIMB1 metal-insulator-metal-insulator-metal MIMD Multiple Instruction (Input) Multiple Data Stream (processor) MIME Multipurpose Internet Mail Extension [Internet] MIMIC millimetre-wave monolithic integrated circuit MIMO multiple input multiple output MIN mobile identification number multiprocessor interconnection network MIND mass impregnated non-draining MINDO modified incomplete NDO MINUET Minnesota Internet Users Essential Tools [Internet] MIP Multim In Parvum MIPS Million Instructions Per Second MIS management information system metal-insulator-semiconductor multimedia information sources [internet] MISC Miscellaneous MISFET metal-insulator-semiconductor FET MISO multiple input single output MIST MIS transistor MIT Massachusetts Institute of Technology (USA) MITATT mixed tunnelling avalanche transit time MIX Member Information Exchange MKDIR Make Directory ML Machine Language Meta Language MLAPI Multilingual Application Programming Interface MLB multilayer board MLC Multilayer Ceramic Multilevel Cell (program) [Internet] MLE Multi-Line Editor maximum likelihood estimation MLID Multi-Link Interface Driver MLM Mailing List Manager [Internet] MLP multiple layer perceptron MLR Multichannel Linear Recording MLS microwave landing system MLSE multi-state maximum likelihood sequence estimator MLT mechanical loop testing MLTF multilayer thick film MLW medium level (radioactive) waste mm millimetre MM Minutes Month MMA Microcomputer Managers Association MMC Matched Memory Cycle Microcomputer Marketing Council MMCD MultiMedia Compact Disk MMCX Multimedia Communication Exchange [Lucent Technologies] MMF magnetomotive force MMI Man-Machine Interface MMIC monolithic microwave integrated circuit MMIS Materials Manager Information System MMPM Multi Media Presentation Manager MMR modified modified READ MMU Memory Management Unit MMX Matrix Manipulation Extensions [Intel] Multimedia Extensions MNDO modified neglect of differential overlap MNOS Metal Nitride Oxide Semiconductor MNP Microcom Networking Protocol [Microcom] MO magneto optical (disc) molecular orbitals MOB Memory-Order Buffer MOBO Mother Board MOCIC molecular orbital constraint of interaction coordinates MOCVD metal-organic chemical vapour deposition MOD Module Modulus MODEM Modulator/Demodulator MODFET modulation doped field effect transistor MODPOT modulator potential MOHLL Machine Oriented High Level Language MOLAP Multidimensional On-Line Analytical Processing MOM Microsoft Office Manager [Microsoft] Message Oriented Middleware MOMBE metal-organic MBE MONOS metal oxide nitride oxide semiconductor MOO "MUD, Object Oriented [Internet]" MOP Maintenance Operations Protocol MOS Metal Oxide Semiconductor Magneto-Optic Storage MOSFET Metal Oxide Semiconductor Field Effect Transistor MOSIS Metal Oxide Semiconductor Implementation System MOSPF Multicast Open Shortest Path First MOSS MIME Object Security Services MOST Metal Oxide Semiconductor Transistor MOTD Message Of The Day MOV Metal Oxide Varistor Move MOVPE metal-organic vapour phase epitaxy MOVS Move String MOX mixed oxide fuel MP Massively Parallel (processing) Multiple Processors MPC Multimedia Personal Computer Multipath Channel MPCS Mission Planning and Control Station (Software) MPE Multiple Programming Executive [HP] MPEG Moving Picture Experts Group MPG miles per gallon MPH moving plasmoid heater MPI Message Passing Interface Multiprecision Integer MPM Message Passing Library [IBM] MPMD Multiple Processor/Multiple Data MPOA Multi-Protocol over Asynchronous-Transfer-Mode MPP Massively Parallel Processing Message Posting Protocol Message Processing Program MPQP Multi-Protocol Quad Port [IBM] MPR Multipart Repeater Multi Protocol Router [Novell] MPS Multiprocessor Specification MPSK multiple phase shift keying MPTN Multi-Protocol Transport Network MPTS Multi-Protocol Transport Services MPU Microprocessor Unit MPX multiplexer MQI Message Queue Interface MQORC modified quadrature overlapped raised cosine MQW multiple quantum well MR Magnetoresistive Modem Ready magnetic resonance Modified read MRAC model reference adaptive control MRCF Microsoft Realtime Compression Format MRCI Microsoft Realtime Compression Interface MRD multiple-reference double excitation MRE Magnetic resistance element MRG magnetic resonance gyro MRI Magnetic Resonance Imaging MRINDO modified Rydberg INDO MRM Most Recently used Master MRO Multi-Region Operation MRP manufacturing resources planning materials requirements planning MRPL Main Ring Path Length MRS Media Recognition System monitored retrievable storage (radioactive waste) MRSI magnetic resonance spectroscopic imaging MRT Mean Repair Time MRU Maximum Receive Unit MS Memory System Message Store Microsecond Microsoft Corporation Millisecond management science mass spectrometry MS-DOS Microsoft - Disk Operating System [Microsoft] MSACM Microsoft Audio Compression Manager [Microsoft] MSAU Multi-Station Access Unit MSAV Microsoft Anti Virus [Microsoft] MSB Most Significant Bit MSBF Mean Swaps Between Failures MSC Mobile (main) switching centre MSCDEX Microsoft Compact Disc Extensions [Microsoft] MSD Mass Storage Device Most Significant Digit Microsoft System Diagnostics [Microsoft] MSDR Multiplexed Streaming Data Request MSDS Microsoft Developer Support [Microsoft] MSE mean square error MSFR Minimum Security Function Requirements [IBM] MSG Message MSI Medium Scale Integration MSK minimum shift keying MSL Map Specification Library Mirrored Server Link MSN Microsoft Network [Microsoft] MSO Multiple-Systems Operator MSR molten salt reactor MSRP Manufacturer Suggested Retail Price MSS Mass Storage System Multiprotocol Switched Services [IBM] MSSW magnetostatic surface wave MSU Michigan State University MSW Machine Status Word Magnetostatic waves MSX alpha - multiple scattering X alpha MT machine translation MTA message transfer agent MTA Message Transfer Agent Multiple Terminal Access MTBB Mean Time Between Breakdowns MTBF Mean Time Between Failures MTBJ Mean Time Between Jams MTF Microsoft Tape Format [Microsoft] Modulation Transfer Function MTI moving target indicator MTL merged-transistor logic MTS Message Transfer Service/System Multichannel Television Sound Microsoft Transaction Server MTSO mobile telephone switching office MTT Multi-Transaction Timer MTTD Mean Time To Diagnose MTTF Mean Time To Failure MTTR Mean Time To Repair MTU Maximum Transmission Unit MTX alpha - muffin-tin X alpha MUA Mail User Agent muCF muon catalysed fusion MUD Multi-User Dialogue/Dimension/Domain/Dungeon [Internet] MUF material unaccounted for maximum usable frequency MUL Multiply MUMPS Massachusetts General Hospital Utility Multi-Programming System (Programming Language) MURGR modular HTGR MUSE Multi-User Shared Environment multiple sub-Nyquist sampling encoding MUSIC multiple signal characterisation muSR muon spin rotation (resonance) MUST multiple scattering technique (LIDAR) MUT Monitor Under Test MUX Multiplexer MV Millivolt Medium voltage MVB Multimedia Viewer Book MVC Multimedia Viewer Compiler MVDM Multiple Virtual DOS Machines MVGA Monochrome Video Graphics Array MVIP Multi-Vendor Integration Protocol MVP Multimedia Video Processor MVS Multiple Virtual Storage MVT Multiprogramming with a Variable number of Tasks MWPC multiwire proportional chamber MX Mail Exchanger [Internet] MXS Microsoft Exchange Server [Microsoft] MZR Multiple Zone Recording N-ISDN Narrowband ISDN National ISDN N/I Non-Interlaced NAA neutron activation analysis NAC Network Adapter Card NACD National Association of Computer Dealers NACS National Advisory Committee on Semiconductors NAE Not Above or Equal NAK Negative (no) Acknowledgment NAL National Accelerator Laboratory NAM Number Assignment Module non-absorbing mirror NAMPS Narrow-Band Analog Mobile Phone Service [Motorola] NAND NOT-AND (logic) NANO One thousand-millionth NANP north American numbering plan NAP Network Access Point NAPLPS North American Presentation Level Protocol Syntax (graphics) NAS Network Application Support [DEC] NASA National Aeronautics and Space Administration NASDAQ National Association of Securities Dealers Automatic Quotation NASI NetWare Asynchronous Services Interface [Novell] NASICON sodium zirconium silicate phosphate NASIRC NASA Automated Systems Internet Response Capability NASKER NASA Ames Kernel (benchmark) NATO North Atlantic Treaty Organisation NAU Network Addressable Unit NAWS Negotiate About Window Size NBE Not Below or Equal NBETF Neutral Beam Engineering Test Facility NBEUI Network BIOS Extended User Interface NBFM narrowband frequency modulation NBI Nothing But Initials Neutral beam injection NBPS neutral beam power systems NBS National Bureau of Standards (USA) Numeric Backspace NC Network Computer No Carry Numerical Control Normally closed NCA Network Communications Adapter NCAR National Center for Atmospheric Research (USA) NCBR nitrine cooled breeder reactor NCC Network Control Center NCGA National Computer Graphics Association NCIC National Crime Information Center NCMET non-closed shell many electron theory NCMOS N-channel Complementary Metal Oxide Semiconductor NCMT * Numerical Control for Machine Tools NCOP network code of practice NCOS Network Computer Operating System NCP NetWare Core Protocol Not Copy Protected Network Control Processor/Program/Protocol NCR National Cash Register (Company) NCSA National Center for Supercomputing Applications NCSC National Computer Security Center NCSI Network Communications Services Interface [Network Products Corp.] NCU network control unit ND neutral density ((filter) NDB Non-Directional Beacon NDDK Network Device Development Kid [Microsoft] NDDO neglect of diatomic differential overlap NDE nondestructive evaluation NDEF Not to be Defined NDIR non dispersive infrared NDIS Network Device/Driver Interface Specification NDN Non-Delivery Notice NDO neglect of differential overlap NDP Numeric Data Processor NDR Network Data Representation Negative differential resistance NDRO Non-Destructive Read Out NDS NetWare (network) Directory Service [Novell] NDT nondestructive testing NEA negative electron affinity NEC Nippon Electric Company NED NASA Extragalactic Database [NASA] NEG Negative Negate NEMO non-empirical molecular orbitals NEP Network Entry Point NES National Education Supercomputer NEST Novell Embedded Systems Technology [Novell] NET Next European Tokamak NetBEUI NetBIOS Extended User Interface [IBM] NetBIOS Network Basic Input/Output System [IBM] NETMON Network Monitor NEVE non-empirical valence-electron NEWS NetWare Early Warning System [Frye Computer] Network Extensible Window System NEXAFS near-edge X-ray absorption fine structure NEXT Near-End Crosstalk NF negative feedback noise figure noise factor NFB non-fuse breaker NFF No Fault Found NFS Network File System [Sun] NG No Good NGE Not Greater or Equal NGS nuclear generating station NHC National Hurricane Center NHR National Handwriting Recognition NHS National Health Service NIA Next Instruction Address NIC negative impedance converter NIC Network Information Center [Internet] Network Interface Card Numeric Intensive Computing NICAD Nickel-Cadmium NICAM near-instantaneously companded audio multiplexer NICOLAS Network Information Center on-line Aid System [NASA] NID New Interactive Display [NEC] Next ID NIFTP network-independent file transfer protocol NII National Information Infrastructure NIM Network Installation Management [IBM] NIMH Nickel-Metal Hydride NIO Native Input/Output NIPS Network I/Os Per Second NIR Network Information Retrieval [UNIX] Near infra-red NISO National Information Standards Organization NISP Networked Information Services Project NIST National Institute of Standards and Technology (USA) NITC National Information Technology Center NITS network-independent transport system NIU Network Interface Unit NJ normal junction NJE Network Job Entry (protocol) [IBM] NL New Line NLE Not Less or Equal NLM NetWare Loadable Module [Netware] NLP Natural-Language Processing NLQ Near Letter Quality NLSFUNC National Language Support Function NLV National Language Version [IBM] NMI Non-Maskable Interrupt NMM NetWare Management Map [NetWare] NMOS Negative-channel Metal Oxide Semiconductor NMP Network Management Protocol [AT&T] NMR nuclear magnetic resonance NMR-ON NMR on oriented nuclei NMS Network Management System [Novell] NMU network management unit NN Network Node No News [Internet] NNI Network-Network Interface Network note interface NNNDO neglect of non-neighbour differential overlap NNTP Network News Transfer Protocol [Internet] NO normally open NOAA National Oceanic and Atmospheric Administration (USA) NOC Network Operations Center NOP No Operation NOPAC Network OPAC NOR NOT-OR (logic) NORE nominal overall reference equivalent NOS Network Operating System NOVA nonoverlapping super-self-aligned NP no pin NPA Network Printer Alliance NPI Network Printer Interface NPL National Physical Laboratory (UK) Non procedural language NPP nuclear power plant NPS Novell Productivity Specialist [Novell] NPTN National Public Telecomputing Network NPU Natural Processing Unit NPX Numeric Processor Extension NQR nuclear quadrupole resonance NQS Network Queing System [Cray] NRC Nuclear Regulatory Commission (USA) National Research Council (Canada) NRD nonradiative dielectric NREN National Research and Education Network NRM natural remanent magnetisation normal response mode NRZ Non Return to Zero NRZI Non Return to Zero Inverted NS Nanosecond National Semiconductor (as in Ns16550 UART) Network Supervisor Non Stop NSA POLY National Security Agency Polygraph NSAP Network Services Access Point NSAPI Netscape Server API [Netscape] NSERC National Sciences and Engineering Research Council (Canada) NSF National Science Foundation NSFNET National Science Foundation Network NSI NASA Science Internet NSLOOKUP Name Server Lookup [Unix] NSLS National Synchrotron Light Source NSM Netscape Server Manager [Netscape] NSP Native Signal Processing [Intel] Network Service Provider NSRR Nuclear Safety Research Reactor NSSC NASA Standard Spacecraft Computer NSSS nuclear steam supply system NSTC National Science and Technology Council NSTL National Software Testing Labs NT New Technology [Microsoft] Network termination NT1 network terminal no. 1 NTAS NT Advanced Server [Microsoft] NTC negative temperature coefficient NTD neutron transmutation doping NTE network terminating equipment NTF No Trouble Found NTFS New Technology File System [Microsoft] NTIA National Telecommunications and Information Administration NTIS National Technical Information Service NTL nonthreshold logic NTLM NT Lan Manager NTO natural transition orbitals NTRAS NT Remote Access Services [Microsoft] NTS notch tensile strength NTSA NetWare Telephony Services Architecture [Novell] NTSC National Television Standards Committee NTU network terminating unit NUA network user address NUI Network User Identification Network User Interface Notebook User Interface [Go Corporation] NUL Null (dummy device) (no device) NUMA Non-Uniform Memory Access NV No Overflow NVM Non-Volatile Memory NVOD Near-Video On Demand NVP Nominal Velocity of Propagation NVRAM Non-Volatile Random Access Memory NVT Network Virtual Terminal Novell Virtual Terminal [Novell] NWPA Nuclear Waste Policy Act (USA) NWS NetWare Web Server [Netware] NYM Anonymous OA office automation OAB One-to-All Broadcast OAD Open Architecture Driver [Bernoulli] OAG Official Airline Guide Online Air Guide OAI Open Applications Interface OAM "operations, administration and maintenance" OAS One-to-All Scatter OBD On Board Diagnostics Optical breakdown OBEX Object Exchange [Borland] OBIC optical beam induced current(s) OBJ Object OC Optical Carrier OCE Open Collaborative Environment [Apple] OCF Objects Components Framework [Borland] OCL Operation Control Language Operator Control Language OCR optical character recognition organic cooled reactor OCRWM Office of Civilian Radioactive Waste Management (USA) OCS On-Card Sequencer OCU office channel unit OCX OLE Custom Control OD outside diameter ODA Office Document Architecture ODAPI Open Database Application Programming Interface [Borland] ODBC Object-Oriented Database Connectivity Open Data Base Connectivity [Microsoft] ODBMS Object-Oriented Database Management System ODE ordinary differential equation ODI Open Datalink Interface [Novell] Open Device Interconnect [NetWare] ODM Object Data Manager [IBM] ODMA Open Document Management API ODMR optical detection of magnetic resonance ODP Open Distributed Processing ODS Open Data Services [Microsoft] ODSI Open Directory Service Interface [Microsoft] ODT Open Desktop OE opto-electronic OEIC optoelectronic integrated circuit OEM Original Equipment Manufacturer OEP Operand Execution Pipeline OER oxygen enhancement ratio OF Overflow Flag OFB Output Feedback (mode) OFDM orthogonal frequency division mulitplex OFMT Output Format for Numbers OFS Object File System [Microsoft] Output Field Separator OH ohmic heating Off hook OHP overhead projector OHTE Ohmically Heated Toroidal Experiment OI Optical isolator OIDL Object Interface Definition Language OIS Office Information Systems OLAP OnLine Analytical Processing OLE Object Linking and Embedding [Microsoft] OLI Optical Line Interface [AT&T] OLMC Output Logic Macrocell OLSP On-Line Service Provider OLTP OnLine Transaction Processing OM Object Manager OMA Object Management Architecture [Microsoft] OMCVD organometallic CVD OME Open Messaging Environment (protocol) OMF Object Module Format [Microsoft] Open Media Framework Open Message Format OMG Object Management Group OMI Open Messaging Interface [Lotus] OMNS Open Network Management System OMR Optical Mark Recognition OMT overhead message train OMVPE organometallic vapour phase epitaxy ONA open network architecture ONC Open Network Computing [Sun] ONDS Open Network Distribution Services [IBM] ONE Open Network Environment [Netscape] ONO oxide-nitride-oxide ONU Optical Network Unit OO Object Orientation OODB Object-Oriented Database OODMS Object-Oriented Database Management System (also see ODBMS) OOK on-off keying OOL Object-Oriented Language OOOS Object-Oriented Operating System OOP Object Oriented Programming OOPL Object-Oriented Programming Language OOPS Object Oriented Programming and Systems OOS Object-Oriented Systems Off-line Operating Simulator OOT Object-Oriented Technology OOUI Object Oriented User Interface OP Operation Optical Output OPAC Online Public Access Catalog [Internet] OPC Organic photoconductive conductor Optical Photoconductor OPCODE Operational Code OPD Operand OPFT orbital polarised Hartree-Fock OPI Open Prepress Interface OPL Organizer Programming Language OPM Operations Per Minute OPS Operations OPT Open Protocol Technology OPUS Octal Program Updating System OPW orthogonal plane wave OQPSK offset quadrature phase shift keying operations research ORACLE On-Line Inquiry and Report Generator (UNIX DB program) ORB Object Request Broker [Microsoft] ORD optical rotatory dispersion ORELA Oak Ridge Electron Linear Accelerator (USA) ORI Online Retrieval Interface ORM Object Role Modeling ORMOSIL Organic-inorganic complex matrix ORNL Oak Ridge National Laboratory (USA) ORS Output Record Separator OS Operating System OS/2 Operating System/2 [IBM] OS/E Operating System/Environment OSA Open Scripting/System Architecture OSF Open Software Foundation OSI Open Systems Interconnection OSM OS Specific Module Off-screen model OSP On-Screen Programming Optical Storage Processor OSPF Open Shortest Path First OSQL Object Structured Query Language OSR operating system run OT Object Technology OTA Operation-Triggered Architecture Operational transconductance amplifier OTDR Optical Time Domain Reflectometer OTEC ocean thermal energy conversion OTF Open Token Foundation Optical transfer function OTH over the horizon OTM Object Transaction Monitor OTP One-Time Programmable OTS Orbital Test Satellite OTSG once-through steam generator OURS Open Users Recommended Solutions OUTS Output String OV Overflow OWL Object/Open Windows Library [Borland] OWM one word memory OZI Okubo-Zweig-Ijzuha (quark model) P&S Publish and Subscribe P-MAIL Paper Mail P-SRAM Pseudo-Static Random Access Memory P/S parallel/series P/T Part Time PAA Paraazoxyanisole Phased aerial array PAB Personal Address Book PABX Private Automatic Branch Exchange PAC perturbed angular correlation PACE Priority Access Control Enabled [3Com] PACS Picture Archiving and Communication System PACS-L Public Access Computer Systems List [Internet] PAD Packet Assembler/Disassembler PADS Pen Application Development System [Slate Corporation] PAF platelet activating factor PAHR post accident heat removal PAIH Public-Access Internet Host [Internet] PAIS Public-Access Internet Site [Internet] PAL Paradox Applications Language [Borland] Phase Alternating Line Programmable Array Logic Programming Assembly Language PALC Plasma-Addressed Liquid Crystal (display) PALS Principles of the Alphabet Literacy System PAM programmable active memory pulse amplitude modulation PAP Packet-level Procedure Password Authentication Protocol Printer Access Protocol paraazoxyphenctole PAR Personal Animation Recorder Parallel PARA Paragraph PARC Palo Alto Research Center [XEROX] PARS private advanced radio service PASCAL (Programming Language named for Blaise Pascal) PAT priority access timer PAX Portable Archive Exchange [Unix] Private automatic exchange PB pushbutton PBE Prompt By Example PBF power bursts facility PBFA Particle Beam Fusion Accelerator PBGA Plastic Ball Grid Array PBH planar buried heterostructure PBL Planetary boundary layer PBLG poly-gamma-benzyl-L-glutamate PBR pebble bed reactor PBS personal base station PBT permeable base transistor PBX Private Branch Exchange PC personal computer polycarbonate printed circuit programmable controller Program counter PC-DOS Personal Computer - Disk Operating System [IBM] PC-I/O Program Controlled I/O PCAC partially conserved axial currents PCACIAS Personal Computer Automated Calibration Interval Analysis System PCB polychlorinated biphenyl. printed circuit board Program control block PCBC Plain Cipher Block Chaining PCD Photo Compact Disk PCEB PCI to EISA Bridge [Intel] PCES phase change energy storage PCI Program Controlled Interruption Personal Computer Interface Peripheral Component Interconnect/Interface pellet-cladding interaction PCIC PC-Card Interrupt Controller PCILO perturbative configuration interaction using localised orbitals PCILOCC PCILO for crystal calculation PCL Printer Command Language [HP] Process Control Language PCM Personal Computer Manufacturer Printer Cartridge Metric [HP] Pulse Code Modulation phase change material PCMC "PCI, Cache, Memory Controller [Intel]" PCMCIA Personal Computer Memory Card International Association PCMIM Personal Computer Media Interface Module PCN Personal Computer (Communications) Network PCNFS Personal Computer Network File System PCO Point of Control and Observation PCRV prestressed concrete reactor vessel PCS Patchable Control Store Personal Communication Services/System Personal Conferencing Specification Planning Control Sheet Print Contrast Signal Process Control Systems Program Counter Store PCT Private Communications Technology PCV primary containment vessel PCX plasma confinement experiment PD Phase-Change Dual Public Domain Partial discharge PDA Personal Digital Assistant PDC Primary Domain Controller PDD Physical Device Driver PDE partial differential equation PDF Package Definition File Portable Document Format Portable Document File Processor Defined Function Program Development Facility Probability density function PDF Portable Document File PDHB polarisation-dependent hole-burning PDIAL Public Dialup Internet Access List [Internet] PDL Page Description Language Program Description Language + Program Design Language PDM Product Data Management PDN Public Data Network PDO Portable Distributed Objects [Next] PDP "Plasma Display Panel Programmable Data Processor (DEC Computer System Designation, i.e. PDP-8, PDP-11)" PDS Packet Driver Specification Partitioned Data Set Planetary Data System Portable Document Software Processor Direct Slot [Macintosh] PDSS Post Development and Software Support PDT Performance Diagnostic Tool [IBM] Programmable Drive Table PDU Plug Distribution Unit PDX Poloidal Divertor Experiment PE Parity Even Processing Element Protect Enable phase encoded polyethylene PEA Pocket Ethernet Adapter PEC photoelectrochemical cell PECL pseudo emitter coupled logic PECVD plasma enhanced chamical vapour deposition PEEK polyaryletheretherketone polyetheretherketone PEEL programmable electrically erasable logic PEK polyetherketone PEL Picture Element [IBM] PEM Privacy-Enhanced Mail [Internet] Photoelectro-magnetic PEMA polyethylmethaerylate PEN SDK Pen Computing Software Development Kit PEO polyethylene oxide PEP "Packetized Ensemble Protocol [Telebit] Positron Electron Photon (Stanford, USA)" PERL Practical Extraction and Report Language [Unix] PERT Program Evaluation and Review Technique PES Positioning Error Signal Processor Enhancement Socket Processor Upgrade Socket photoelectron spectra (-oscopy) PET Print Enhancement Technology [Compaq] polyethylene terephthalate positron emission tomography PETRA Positron Electron Tandem Ringbeschleuniger Anlage PF poloidal field power factor positive feedback PFBC pressurised fluidised bed combustion PFC phase-frequency characteristics PFE Programmer's File Editor PFM pulse frequency modulation PFR Power-Fail Restart Prototype Fast Reactor PFU programmable function unit PGA Pin Grid Array Professional Graphics Adapter [IBM] PGC Program Group Control [Microsoft] PGDN Page Down PGM Program PGP Pretty Good Privacy (name of encryption program) PGUP Page Up PHIGS Programmers' Hierarchial Interactive Graphics Standards PHS Personal Handyphone System PHWR pressurised heavy water reactor PI Program Interruption "PI, PD" proportional + integral + differential (derivative) PIA Peripheral Interface Adapter PIC Personal Intelligent Communicator Priority Interrupt Controller Program Interrupt Controller PICS Platform for Internet Content Selection PICT Picture PID "Process Identification Number Proportional, Integral, Derivative (Differential)" PIER Procedures for Internet/Enterprise Renumbering PIF Picture Interchange Format File Program Information File PII Program Integrated Information PILOT Programmed Inquiry Learning Or Teaching PilotACE Pilot Automatic Computing Engine PIM Personal Information Manager Protocol Independent Multicast Primary Interface Module PIN Personal Identification Number Process Identification Number [Unix] PINE Pine Is Not Elm (original usage) Program for Internet News & Email (present usage) PING Packet INternet Groper PIO Parallel Input/Output Processor Input/Output Programmed Input/Output peripheral input-output PIP Picture In Picture Problem Isolation Procedure Programmable Interconnect Point PIPECO photoion photoelectron coincidence PIPO "Parallel In, Parallel Out" PISO parallel in serial out PIT Programmable Interval Timer PIXE photon induced X-ray emission PIXEL Picture Element PKC Public Key Cryptography PL Plus PL/1 * Programming Language One PL/M Programming Language for Micros PLA phase locked array programmable logic array PLA Programmable Logic-Array PLATO Programmed Logic for Automatic Teaching Operations PLBR Prototype Large Breeder Reactor PLC Programmable Logic Controller PLCC plastic leadless chip carrier plastic leaded chip carrier PLD Programmable Logic Device PLDS Pilot Land Data System [NASA] PLIMPATT planar IMPATT PLL Phase Locked Loop PLS Primary Link Station PLT Princeton Large Torus Plus Process inherent ultimately safe PLV Production Level Video PLZT lead lanthanum zirconate titanate PM Presentation Manager [IBM] Preventative Maintenance Process Manager Polarisation maintaining (optical fibre) Permanent magnet Phase modulation Pulse modulation PMBX Private manual branch exchange PMD Packet Mode Data PMDR Phosphorescence microwave double resonance PMMA Polymethylmethacrylate PMMU Paged Memory Management Unit PMN lead magnesium niobate PMOS Positive-channel Metal Oxide Semiconductor PMR Proton magnetic resonance Private mobile radio Problem Management Report [IBM] PMS Policy Management System pre-main-sequence PMT Photomultiplier tube PN Planetary nebula(e) pseudo noise Processing node PNA Programmable Network Access PNDO Partial neglect of differential overlap PNG Portable Network Graphics PNM Positive-negative-metal PNO-CI Pair natural orbital configuration interaction PNP Plug aNd Play PNS Pulsed Neutron Source PO Parity Odd POC Point Of Contact POCSAG Post Office Code Standard Advisory Group POE Power Open Environment POH Power-On Hours POL Problem Oriented Language pair orthogonalised Lowdin POP Point Of Presence [MCI] Pop from Stack Post Office Protocol POPA Pop All Registers POPAE protons on protons and electrons POPF Pop Flags POPOP phenyl-oxazolyl-phenyl- oxazolyl-phenyl POR Power-On-Reset PORV power operated relief valve POS Point Of Sale Positive Programmable Object Select POSIX Portable Operating System Interface for Unix POST Power On Self Test POSTNET Postal Numeric Encoding Technique POTS Plain Old Telephone Service POWER Performance Optimization with Enhanced RISC [IBM] PowerPC Performance Optimization with Enhanced RISC-Performance Computing PP Parallel Port PPB parts per billion PPDM pulse pause difference modulation PPDP/S Pariser-Parr-Del Bene-Pople/Segal calculations PPDS Personal Printer Data Stream [IBM] PPGA Plastic Pin Grid Array PPI plan position indicator PPM parts per million pulse position modulation Pages per minute ppp Pariser-Parr-Pople polyparaphenylene Point-to-Point Protocol [Internet] PPS Packets Per Second Power Personal Systems [IBM] plant protection system pulses per second PPTP Point-to-Point Tunneling Protocol [Microsoft] PQFP Plastic Quad Flat Package PRA probabilistic risk assessment PRACSA Public Remote Access Computer Standards Association PRAM Parallel Random Access Memory Programmable Random Access Memory PRDDO partial retention of diatomic differential overlap PRE Preformatted [HTML] PReP Power PC Reference Platform [IBM/Motorola] PREPP Process Experimental Pilot Plant PRF pulse recurrence (repetition) frequency PRIDE positive resist images by dry etching PRINTF Print with Formatting [C Programming Language] PRISM Photo-Refractive Information Storage Material PRMD Private Mangement Domain [X.400] PRML Partial-Response Maximum-Likelihood PRN Printer PROC Procedure PROFS Professional Office System [IBM] PROG Program Programmer PROLOG Programming In Logic (Programming Language)(See HLL) PROM Pockels readout optical modulator programmable read-only memory PRTSC Print Screen PS polystyrene proton synchrotron (CERN) Proportional spacing PS/2 Programming System 2 [IBM] PSC Personal Super Computer Print Server Command Product Service Center PSD power shut-down power spectral density PSDN Packet-Switched Data Network PSDS Packet-Switched Data Service PSERVER Print Server [NetWare] PSF Permanent Swap File PSG Phosphosilicate glass Phosphorosilica glass PSID PostScript Image Data PSK phase shift keying PSM Printing Systems Manager PSN Packet Switching Network PSP Personal Software Products (group) [IBM] Program Segment Prefix PSPDN Packet-Switched Public Data Network PSRAM Pseudo-Static Random Access Memory PSRT PostScript Round Table [GEnie] PSS packet switching service Packet SwitchStream (UK) PST point source transmittance PSTN Public Switched Telephone Network PSU Power Supply Unit PSW Program Status Word PT Page Table PTC positive temperature coefficient PTD Parallel Transfer Disk Drive PTF Problem Temporary/Trouble Fix [IBM] Polymer thick film PTFE polytetrafluorocthylene PTH plated through hole PTM pulse tirne modulation PTO power take off public telecommunications operator PTP Peer-To-Peer PTT Post Telephone and Telegraph Administration push to talk PTY programme type (call signs for radio) PUB Public (directory) [Internet] Publish PUN Physical Unit Number PUP PARC Universal Packet (protocol) PUS Processor Upgrade Socket PUSHA Push All Registers PUSHF Push Flags PV photovoltaic PVA polyvinyl alcohol PVAC polyvinylacetate PVC Permanent Virtual Circuit Polyvinyl Chloride PVD physical vapour deposition PVDF polyvinylidene fluoride PVER pattern visual evoked response PVF polyvinylidene fluoride PVK polyvinylcarbazole PVM Parallel Virtual Machine Pass-through Virtual Machine (protocol) [IBM] PVP Parallel Vector Processing PVS Parallel Visualization Server PW printed wiring board Password PWA partial wave analysis PWB Printed Wire Board Programmer's Workbench [Microsoft] PWD Print Working Directory [Unix] PWDA plane wave Dorn approximation PWIA Plane wave impulse approximation PWM pulse width modulation PWR pressurised water reactor Power PWSCS Programmable Workstation Communication Services [IBM] PZT lead zirconate titanate piezoelectric translator photographic zenith tube QA Quality Assurance QAM Quadrature Amplitude Modulation QASK quadrature amplitude shift keying QBE Query By Example QBF Query by Form QBIC Query By Image Content [IBM] QBO quasi-biennial oscillation QC Quality Control QCD quantum chromodynamics QCIF quadratic common intermedia format QD Querty/Dvorak QDM quad driver module QDMBPT quasi-degenerate MBPT QDOS Quick and Dirty Operating System QDPSK quadrature differential PSK QED quantum electrodynamics QEMM Quarterdeck Expanded Memory Manager [Quarterdeck Corp.] QF quality factor QFA Quick File Access QFP Quad Flat Pack QFSK quadrature frequency shift keying QHD quantum hadrodynamics QIC Quality Information Using Cycle Time [Hewlett-Packard] Quarter-Inch Cartridge QMF quadrature mirror filter QORC quadrature overlapped raised cosine QOSRC quadrature overlapped squared raised cosine QPG Quantum Phase Gate QPM quark-parton model QPO quasi-periodic oscillation QPR quadrature partial response QPRS quadrature partial response signalling QPSK Quadrature Phase Shift Keying QSAM quadrature sideband amplitude modulation QSO quasi-stellar object (quasar) QTC Quicktime Conferencing [Macintosh] QUADFET quantum diffraction FET QWITT quantum well injection transit time R&D Research and Development R-O Read Only R/T Receive/Transmit R/W Read/Write RA Return Authorization RAA random access array RACE Research and Development in Advanced Communications Technologies in Europe RACF Resource Access Control Facility RAD ribbon-against-drop radio analysis diagram rapid access device Rapid Application Development RADAR "Rights, Availabilities, Distribution Analysis and Reporting [Disney]" RADB Routing Arbiter Data Base RADSL Rate Adaptive Digital Subscriber Line RAG Row Address Generator RAID Redundant Arrays of Independent Disks Redundant Arrays of Independent Drives Redundant Arrays of Inexpensive Disks RAIS Redundant Arrays of Inexpensive Systems RALU Register Arithmetic Logic Unit RAM "radar absorbing material random access memory reliability, availability and maintainability" RAMAC RAID Architecture with Multilevel Adaptive Cache RAMDAC Random Access Memory Digital-to-Analog Converter [Sierra] RAMP Remote Access Maintenance Protocol [Internet] RAND Random RAP Rapid Application Prototyping RARE rapid acquisition with relaxation enhancement RARP Reverse Address Resolution Protocol RAS "Random Access Storage Reader Admission System [British Library] Reliability, Availability and Serviceability Remote Access Service Row Address Select (Strobe)" RASAPI Remote Access Service Application Programming Interface [Microsoft] RAVE Rendering Acceleration Virtual Engine [Apple Computer] RB Right Button (of 2 or 3 button Mouse) RBBS Remote Bulletin Board System RBCS Remote Bar Code System RBE relative biological effectiveness RBMK "light water cooled, graphite moderated reactor" RBOC Regional Bell Operating Company RBS Rutherford backscattering RBT remote branch terminal RCC remote centre compliance (sensor) RCCB residual current circuit breaker RCD residual current device RCIC reactor core isolation cooling RCL Rotate Carry Left RCP Remote Control Panel Remote Copy [Internet] Restore Cursor Position RCR Rotate Carry Right RCS Records Communications Switching System Revision Control System [Unix] radar cross-section rapid cycling synchrotron reactor coolant systems RCT resistively coupled transistor (e.g. in LCD) RCTL resistor-capacitor-transistor logic RD Receive Data Remove Directory RDA Remote Database Access RDB Receive Data Buffer Relational Database RDBMS Relational Database Mangement System RDCLK Received Timing Clock RDDMS relational database management system RDO Remote Data Object RDP Reliable Datagram Protocol RDRAM Rambus Dynamic Random Access Memory RDS Radio Data System RDSR Receiver Data Service Request RDSS radio determination satellite service RDTO Receive Data Transfer Offset [IBM] RE resistance-capacitance reinforced concrete REA rod ejection accident READ relative element address designation RECAP reverse casting by planarisation REELS reflection electron energy loss spectra (-oscopy) REG Register REGAL Rigid Epoxy Glass Acrylic Laminate RELSECT Relative Sector REM Remark Remote Ring Error Monitor Rare earth metal REMPI resonance enhanced multiphoton ionisation REN Rename REP Repeat REPE Repeat while Equal REPNE Repeat while Not Equal REPNZ Repeat while Not Zero REPZ Repeat while Zero REQ Request REREG Re-Register RES Remote Execution Service Reset Resolution RESLJRF reduced surface field RET Resolution Enhancement Technology [HP] Return REX Relocatable Executable REXEC Remote Execution REXX Restructured Extended Executor (language) [IBM] RF Radio Frequency RFC Request For Comments [Internet] radio frequency compatibility RFD Request for Discussion [Internet] RFI Radio Frequency Interference RFP Request for Proposal RFPR reversed field pinch reactor RFQ Request for Quotation RFS Remote File Sharing Remote File System Ready for sending RFT Revisable Form Text Rich Text Format RFU Reserved For Future Use RFX Reversed Field (Pinch) Experiment RG renormalisation group RGB Red-Green-Blue (colour model) RHC reheat cod RHEED reflection high energy electron diffraction RHET resonant hot electron transistor restricted Hartree-Fock RI Referential Integrity Ring Indicate RIA reactivity initiated accident radio immunoassay RIBE reactive ion beam etching RICH ring imaging Cherenkov detector RIE reactive ion etching RIF French for FIR RIFF Resource Interschange File Format [Microsoft] RII French for IIR RIM Remote Installation and Maintenance [Microsoft] reaction injection moulding RIME RelayNet International Message Exchange RINDO Rydberg incomplete NDO RIP Raster Image Processor Remote Imaging Protocol Routing Information Protocol [Novell] RIPEM Riordan's Internet Privacy Enhanced Mail RIPS Raster Image Processing System RISC Reduced Instruction Set Computer RIT Raw Input Thread [Microsoft] RJE Remote Job Entry RKKY Rudermann-Kittel-Kasuya-Yosida RLC resistance-inductance-capacitance RLD Received Line Detect RLE Run Length Encoded RLL Run Length Limited RLN Remote LAN Node [DCA] RLOGIN Remote Login RLS recursive least squares RLSD Received Line Signal Detected RLSI * Ridiculously Large-Scale Integration RM Reset Mode RMA Return Material Authorization Return to Manufacturer Authorization RMB Right Mouse Button RMDIR Remove Directory RMI Remote Method Invocation RMLSAT International Telecommunications Satellite Consortium RMON Remote Monitor/Monitoring RMP Remote Maintenance Processor [IBM] RMS Record Management Services Root Mean Square RMTP Reliable Multicast Tranport Protocol RMW Read-Modify-Write RN Read News [Internet] RNA ribonucleic acid RND Random RNG Random Number Generator RNIS French for ISDN RNP Regional Network Provider RNS residue number system ROB Reorder Buffer [Intel] ROL Rotate Left ROLAP Relational OnLine Analytical Processing ROM Read Only Memory ROOM Real-Time Object-Oriented Modeling ROP Raster Operation RISC Operation ROR Rotate Right ROS Read-Only Storage [IBM] raster output scanning (scanner) ROT Running Object Table RPA random phase approximation RPAE random phase approximation with exchange RPC Remote Procedure Call RPG Report Program Generator (Programming Language) RPL Resident Programming Language Requested Privilege Level Remote program load RPM relaxation potential model revolutions per minute RPN Real Page Number Reverse Polish Notation Residual package number RPPROM Reprogrammable PROM RPQ Request for Price Quotation RPRINTER Remote Printer [NetWare] RPT Repeat RPV reactor pressure vessel remote piloted vehicle RQBE Relational Query By Example [Fox Pro] RR Real Reality RS Radio Shack Recommended Standard (as in RS-232) [EIA] Record Separator Request to Send Reed-Solomon RSA129 "(129 digit cryptographic security number named after its inventors: Drs. Ronald L. Rivest, Adi Shamir and Leonard M. Adelman)" RSAC Recreational Software Advisory Council RSCS Remote Spooling Communications System RSD Route Server Daemon RSH Remote Shell RSL Request-and-Status Link RSP Required Space Character RST Reset Restart RSTS Resource Sharing Time Sharing [Digital] RSVP Resourse reSerVation Protocol RSX Real Time Resource Sharing Executive RT Real Time RISC Technology Run Time resynchronisation timer RTA rapid thermal annealing RTAM Remote Terminal Access Method RTC Real Time Clock reseau telephonique commute RTD resonant tunnelling diode RTDM Real-Time Data Migration RTEL Reverse Telnet [Internet] RTF Rich Text Format RTFET resonant tunnelling FET RTG radioisotope thermoelectric generators RTL Register Transfer Language/Level Resistor Transistor Logic Right-To-Left Run Time Library RTM Response Time Monitor Runtime Manager [Borland] RTMP Routing Table Maintenance Protocol RTOS Real Time Operating System RTP Rapid Transport Protocol Real-Time (Transport) Protocol rapid thermal processing RTS Remote Takeover System Request (Ready) To Send RTSP Real-Time Streaming Protocol RTTI Runtime Type Information RTTY radio teletypewriter remote Teletype terminal RTV Real Time Video RVA Relative Virtual Address RVB resonating valence bond RVI Reverse Interrupt RWM Read-Write Memory RX Receiver RXD Receive Data RZ return to zero RZT lead S-CDMA Synchronous Code-Division Multiple Access S-HTTP Secure Hypertext Transfer Protocol S-MIME Secure MIME S-VHS Super VHS S/H Sample and Hold S/N Signal-to-Noise (Ratio) S/P series/parallel S/TK Sectors Per Track S/W Software SA Selective Availability submerged arc source address SAA Systems Application Architecture [IBM] SAC Single Attachment Concentrator SACCI symmetry adapted cluster configuration interaction SADL Synchronous Data Link Control [Racal-Vadic] SAG self aligned gate SAINT self-aligned implantation for N+-layer technology Symbolic Automatic Integrator SAL Shift Arithmetic Left SALICIDE self-aligned silicidation SAM Serial Access Memory Sequential Access Method Security Accounts Manager [Microsoft] Single Application Mode [Microsoft] scanning acoustic microscope scanning Auger microscopy SAM-APD separate absorption and multiplication avalanche photodiode SAMC simulated ab initio molecular orbitals SAMO stacked gate avalanche injection metal-oxide-semiconductor SAN System (Small) Area Network SANE Standard Apple Numeric Environment SANS small-angle neutron scattering SAP Second Audio Program Service Access Point [DEC] Service Advertising Protocol Symbolic Assembly Program SAPI Speech Application Program Interface [Microsoft] SAR synthetic aperture radar SAR Segmentation and Reassembly Shift Arithmetic Right Successive Approximation Register Synthetic Aperature Radar SARSAT search and rescue satellite aided tracking SAS Sales Accounting System Single Attached Station Single Audio System Statistical Analysis System SASI Shugert Associates System Interface (SCSI originated from SASI) SATAN Security Administrator Tool for Analyzing Networks SAVDM Single Application VDM SAW surface acoustic waves SAXS small-angle X-ray scattering SB Sound Blaster [Creative Labs] Sound Board SBA Scene Balance Algorithms [Kodak] SBB Subtract With Borrow SBBS stimulated backward Brillouin scattering SBC Single-Board Computer Sub-band coding SBCS Single-Byte Character Set SBD Schottky barrier diode (transistor) SBF short pitch bistable ferroelectric (LCD) SBFL Schottky barrier FET logic SBH strip buried heterostructure SBI Sound Blaster Instrument SBLOCA small break LOCA SBN strontium barium niobate SBR styrene-butadiene rubber SBS stimulated Brillouin scattering styrene-butadiene-styrene SC switched capacitor suppressed carrier SCADA Supervisory Control and Data Aquisition SCAM SCSI Configuration Automatically SCARA selective compliance assembly robot arm SCAS Scan String SCB Subsystem Control Block [IBM] SCC Serial Communications Controllers Serial Controller Chip Synchronous Channel Check [IBM] Stress corrosion cracking SCCS Source Code Control System SCD Standard colour Display SCE short channel effect service creation environment SCF System Control Facility self-consistent field SCFL source-coupled FET logic SCH separate confinement heterostructure SCIF Slab Core Test Facility SCL space charge limited SCLM Softwre Configuration and Library Management [IBM] SCM ScreenCam Format [Lotus] Software Configuration Management Station Class Mark subcarrier multiplex(ing) SCN service circuit node SCO Santa Cruz Operation (Software Company) SCOPE Simple Communications Programming Enironment [Hayes] SCP Save Cursor Position Subsystem Control Port System Control Program Service control point SCPC single channel per carrier SCPT self-consistent perturbation theory SCR Silicon Controlled Rectifier SCRA single-line call-routing apparatus SCRN Screen (video display) SCRS Scalable Cluster of RISC Systems SCSA Signal Computing System Architecture [Dialogic] SCSI Small Computer Standard Interface Small Computer System Interface SCVF single-channel voice frequency SD Send Data Super Density Starting delimiter SD-ROM Super Density ROM SD_STB Streaming Data Strobe [IBM] SDA Software Disk Array Source Data Automation System Display Architecture [Digital] SDB Symbolic Debugger [Unix] SDD Software Description Database [Internet] SDF Space Delimited File Space Delimited Format SDFL Schottky-diode FET logic SDH Synchronous Digital Hieararchy SDI Selective Dissemination of Information Single Document Interface Software Development Interface [Mosaic] Strategic Defense Initiative (USA) SDK Software Developer's Kit [Microsoft] SDLC Synchronous Data Link Control (protocol) SDM space division multiplexing sigma-delta modulator System Development Multitasking SDMA space division multiple access SDMS SCSI Device Management System [NCR] SDN Software Defined Network [AT&T] SDNS Secure Data Network Service SDO shielded diatomic orbitals SDR Streaming Data Request SDRAM Synchronous Dynamic Random Access Memory SDS Sysops Distribution System SDSL Single-line Digital Subscriber Line SDTAS side-wall doped trench and stacked capacitor SDV Switched Digital Video [AT&T] SDX Storage Data Xceleration SEA Standard Extended Attribute [OS/2] SEAC "* Name of first computer to use transistors, built by (National Bureau of) Standards Eastern Automatic Calculator (Also see SWAC)" SEAL Segmentation and Reassembly Layer (protocol) Screening External Access Link [Digital-DEC] SEAM scanning electron acoustic microscopy SEC Single Edge Contact Single Error Correction SECAM Sequentiel Couleur Avec Memoire (Sequential colour With Memory) SED Stream Editor Stream-Oriented Editor stochastic electrodynamics SEED self-electrooptic effect device SEG Segment SEH Structured Exception Handling SEHF spin extended Hartree-Fock SEL Select SEM Scanning Electron Microscope Standard Electronic Module SEP somatosensory evoked potential SEPOX selective poly:silicon oxidation SEPP Secure Encryption Payment Protocol single-ended push-pull SER Serial SERS surface enhanced Raman scattering SET Secure Electronic Transaction Softwave Engineering Technology SETEXT Structure Enhanced Text [Internet] SETI search for extraterrestrial intelligence SEU Smallest Executable Unit Single event upset SEXAFS surface extended X-ray absorption fine stricture SF Sign Flag SFAT still frame audio tape SFE solar-flare effect SFL substrate fed logic SFQL Structured Full-text Query Language SFS System File Server SFT System Fault Tolerance SFX Sound Effect(s) SGDT Store Global Descriptor Table SGEMP system generated electromagnetic pulse SGEN Signal Generator System Generator SGHWR steam generating heavy water reactor SGI "Silicon Graphics, Inc." SGM Shaded Graphics Modeling SGML Standard Generalised Markup Language SGMP sol gel microsphere pelletisation SGR Set Graphics Rendition SGRAM Synchronous Graphics Random Access Memory SGT surrounding gate transistor SHA Secure Hash Algorithm [NSA] SHAR Shell Archive SHED Segmented Hypergraphic Editor SHF superhigh frequency SHG Segmented Hypergraphics second harmonic generation SHL Shift Logical Left SHR Shift Logical Right SHV superhigh voltage SI Shift-In Source Index System Information semi-insulating Systeme Internationale SI/SO Serial In/Serial Out Shift In/Shift Out SIC Standard Industrial Code SICOS sidewall base contact structure SID Security Identifier Serial Input Data Station Identification [AT&T] Symbolic Interactive Debugger SIDF System Independent Data Format SIDH System Identification for Home Systems SIDT Store Interrupt Descriptor Table SIFT Stanford Information Filtering Tool SIG Special Interest Group SIGCAT Special Interest Group on CD-ROM Applications and Technology SIL single-in-line SILO scaled interface local oxidation SIM subscriber identity module Simulator SIMD Single Instruction Multiple Data-stream (processor) SIMM Single In-line Memory Module SIMOX separation by implantation of oxygen SIMS secondary ion mass spectra (-oscopy) SIMTEL Simulation and Teleprocessing SIMULA Simulation (language) SIN Swiss Institute of Nuclear Research SINDO scaled incomplete NDO SIO Serial Input/Output (communications driver) SIP Single In-line Package SIPC Simply Interactive Personal Computer [Microsoft] SIPO "Serial In, Parallel Out" SIPOS semi-insulating polycrystalline silicon SIPOX semi-insulating poly:silicon oxidation SIPP Single In-line Pin Package SIR Serial Infrared [Hewlett-Packard] SIRDS Single-Image Random Dot Stereogram SIS semiconductor-insulator-semiconductor superconductor-insulator- superconductor SISAM spectrometer with interference-selective amplitude modulation SISFET semiconductor-insulator-semiconductor FET SISO single input single output SIT Special Information Tones static induction transistor SIThy static induction thyristor SIU System Interface Unit SKIP Simple Key management for Internet Protocols SKU# Stock Keeping Unit Number SLA storage logic array SLAC Stanford Linear Accelerator SLAM scanning laser acoustic microscopy SLC Stanford Linear Collider SLDT Store Local Descriptor Table SLED Single Large Expensive Disk SLIC System Level Integration Circuit subscriber line interface circuit SLIP Serial Line Internet (Interface) Protocol SLM Spatial Light Modulator SLMR Silly Little Modem Reader SLOSH "Sea, Lake and Overland Surge from Hurricane (program)" SLSF Sodium Loop Safety Facility SLSI Super Large-Scale Integration SLSS Systems Library Subscription Service [IBM] SLU Spoken Language Understanding SM Set Mode Shared Memory SMA surface mount(ed) assembly sub miniature series A SMART Self-Monitoring Analysis and Reporting Technology SMATV satellite master antenna television SMB Server Message Block (protocol) [MII] SMC Small Magellanic Cloud surface mount(ed) component sheet moulding compound SMD Surface Mounted Device SMDR station message detail recording SMDS Switched Multimedia/Multi-Megabit Data Service SMES superconductive magnetic energy storage SMF Single Mode Fibre System Manager Facility [Compaq] SMI System Management Interrupt [Intel] SMIF Standard Mechanical Interface SMIME Secure Multipurpose Internet Mail Extensions SMIT System Management Interface Tool [IBM] SMK Software Migration Kit [Microsoft] SML Standard Meta Language SMM System Mangement Mode [Intel] SMOBC Solder Mask Over Bare Copper SMOS stacked-gate injection MOS SMP Simple Management Protocol Symbolic Manipulation Program Symmetrical Multi-Processing Symmetric Multiprocessor Service Message Blocks SMPC Shared Memory Parallel Computer SMPS Switched Mode Power Supply SMQORC staggered modified quadrature overlapped raised cosine SMRAM System Management Random Access Memory SMS Small Messaging System Storage Management Services [NetWare] Storage Management Subsystem/System Systems Management Server [Microsoft] service management system SMS Systems Management Server SMSW Store Machine Status Word SMT Station Management (protocol) Surface-Mount Technology SMTA single-line multi-extension telephone apparatus SMTP Simple Mail Transport Protocol SMU System Management Utility SN Serial Number Supernova (c) SN-R signal to noise ratio supernova remnant SNA Systems Network Architecture [IBM] SND Sound SNDCF subnetwork-dependent convergence facility SNEWS Secure News Server [Internet] SNICF subnetwork-independent convergence facility SNM special nuclear material SNMP Simple Network Management Protocol SNOBOL String Oriented Symbolic Language (Progamming Language) SNP Serial Number/Password [Omen Technology] SNR Signal-to-Noise Ratio SNS spallation neutron source superconducting normal superconducting SO-DIMM Small Outline DIMM SOA Start Of Authority Safe operating area SOC System On a Chip SOCKS Socket Secure (server) [Internet] SOE Standard Operating Environment SOG spin-on-glass strongly orthogonal geminal sea of gates SOH Start of Header SOHO Small Office/Home Office SOI silicon on insulator SOIC small outline integrated circuit SOJ small outline J-bend (semiconductor package) SOL Simulation Oriented Language SOM Start of Message System Object Model [IBM] SONET Synchronous Optical Network SONOS silicon oxide nitride oxide semiconductor SOP Standard Operating Procedures state of polarisation SOR successive over-relaxation synchrotron orbital radiation SORD superconducting optically reconfigurable device SOS Silicon On Sapphire Sophisticated Operating System Standards and Open Systems SOT small outline transistor SOTA State Of The Art SOX Sound Exchange SP Service Pack [IBM] Stack Pointer System Product SPA Software Publishers Association separated pair approximation SPACE service provisioning and creation environment SPAN Space Physics Analysis Network SPARC Scaleable Processor ARChitecture SPC Small Peripheral Controller Statistical Process Control stored program control SPCL Spectrum Cellular Corporation SPCP single parity check product (code) SPCS Stored Program Controlled Switch SPDT single pole double throw SPDU session protocol data unit SPE solid phase epitaxy SPEAR Stanford Positron Electron Asymmetric Ring SPEC Systems Performance Evaluation Cooperative SPECT single photon emission computerised tomography SPEF spin polarised Hartree-Fock SPF Shortest Path First System Programming Facility SPI Security Parameters Index Service Provider Interface SCSI Parallel Interface SPICE simulation program with integrated circuit emphasis SPID Service Profile/Provider Identifier SPIKE Science Planning Intelligent Knowledge-Based Environment [STScI] SPIRES Stanford Public Information Retrieval System [Stanford University] SPL Spooler System Programming Language [HP] super push-pull logic sound pressure level SPLC subscriber per line controller SPLEED spin polarised low energy electron diffraction SPM System Performance Monitor [IBM] Self phase modulation SPOOL Simultaneous Peripheral Operations On Line SPOT Shared Product Object Tree [IBM] SPP Sequenced Packet Protocol SPPS Scalable Power Parallel System [IBM] SPR Special Purpose Register Statistical Pattern Recognition SPREAD "* Systems Programming, Research, Engineering and Development [IBM]" SPS Super Proton Synchrotron (CERN) Standby Power System SPSS Statistical Package for the Social Sciences SPST single pole single throw SPT Sectors Per Track SPX Sequenced Packet Exchange [Novell] SQ Squeezed (files) SQAM superposed quadrature amplitude modulation SQC statistical quality control SQE Signal Quality Error (test) SQL Structured Query Language SQL/DS Structured Query Language/Data System [IBM] SQPR staggered quadrature partial response SQPSK staggered quadrature PSK SQRT Square Root SQUID superconducting quantum interference device SQW single quantum well SR Shift Register SRAM Shadow Random Access Memory Static Random Access Memory SRAPI Speech Recognition API SRB Source-Route Bridge SRD Screen Reader System SRDRAM Self-Refreshed DRAM SRE Standards for Robot Exclusion SREMP source region electromagnetic pulse SRGB Sustained RGB (values) SRM Security Reference Monitor SRMCASE symmetry-restricted multi-configuration annihilation of single excitations SRO Sharable and Read Only Short range order SRP Suggested Retail Price SRPI Server-Requester Programming Interface SRQ Service Request SRR Serially Reusable Resource SRS Sound Retrieval System Stimulated Raman Scattering SRV safety release valve SS Stack Segment Single Sided Seconds Stainless steel SS-QAM stepped square QAM SS-TDMA satellite switched TDMA SS7 Signalling System No.7 SSA Serial Storage Architecture SSADM structured systems analysis and design methodology SSAP Source Service Access Point SSB single sideband SSB-SC single sideband suppressed carrier SSBW surface skimming bulk wave SSC sudden storm-commencement Superconducting Super Collider SSCP Systems Service Control Point [IBM] SSCR spectrum shift controlled reactor SSD Solid State Disk solid-state detector SSEC * Selective Sequence Electronic Calculator [IBM] SSFL Schottky-barrier coupled Schottky-barrier gate FET logic SSGA System Suppport Gate Array SSI Server Side Includes Single System Image Small Scale Integration SSL Secure Sockets Layer SSMA spread spectrum multiple access SSNTD solid-state nuclear track detector SSPI Security Service Provider Interface SST Spread-Spectrum Technology Systems Services and Technology sea surface temperature supersonic transport super self-aligned technology STA Spanning Tree Algorithm STAR Self Defining Text Archival STB Strobe STBR stirred tank biological reactor STC Set Carry Flag stacked capacitor STD Set Direction Flag Standard salinity-temperature-depth subscriber trunk dialling STDA StreetTalk Directory Assistance [Banyan] STDAUX Standard Auxillary STDERR Standard Error STDIN Standard Input STDIO.H Standard Input/Output Header [C Programming Language] STDM Statistical Time Division Multiplexer STDOUT Standard Output STDPRN Standard Printer STEC solar thermal energy conversion STEM scanning transmission electron microscope STI Set Interrupt Flag scientific and technical information STL Schottky transistor logic scattering of throughgoing light Standard Template Library STM scanning tunnelling microscopy synchronous transfer mode STN super twisted nematic (LCD) switched telephone network STO Slater-type orbitals STOL short take-off and landing STOS Store String STP Secure Transfer Protocol Shielded Twisted Pair (cable) Signal Transfer Point Synchronized Transaction Processing Slater-transfer Preuss STR Store Task Register Synchronous Transmitter Receiver STRAM self-timed RAM STRESS Structural Engineering System Solver (Programming Language) STRUDL Structural Design Language (Programming Language) STS space-time-space STScI Space Telescope Science Institute STT Secure Transaction Technology [Microsoft] STX Start of Text SUB Subroutine Substitute Subtract SUN "Sun Microsystems, Inc." SURMAC surface magnetic confinement SUSY GUT supersynunetric grand unified theory SVC static VAr compensator switched virtual circuit SVF Simple Vector Format SVGA Super Video Graphics Adapter (Array) SVM System Virtual Machine [Microsoft] SVN Switched Virtual Network [IBM] SVP-MP service processor-microprocessor SVR Server SVR# System V Release Number [AT&T] SW short wave SWAC "* Mobile version of SEAC, built for deployment to White Sands, and named Standards Western Automatic Calculator" SWAIS Simple Wide Area Information Server [Internet] SWAMI sidewall masked insulation SWAT stress wave analysis technique SWISH Simple Web Indexing System for Humans SWP spatial walk-off polariser SWR sodium water reactor standing wave ratio SXAPS soft X-ray appearance potential spectra (-oscopy) SYLK Symbolic Link SYN synchronous idle SYNC Synchronous SYS System SYSADMIN System Administrator SYSGEN System Generator SYSLOG System Log SYSMOD System Modification SYSOP SYStem OPerator SYSREQ System Request SZ Send ZModem [Unix] T/B Top and Bottom T/R Transmit/Receive TA terminal adaptor TAB Tape automated bonding TAC Time amplitude converter TACS Total Access Communications System TAD Telephone Answering Device TAN Trunk access node TAP Telelocator Alphanumeric Protocol TAPCIS The Access Program for the CompuServe Information Service TAPI Telephony Applications Programming Interface TAS Telephone Access Server TASI Time assignment speech interpolation TASM Turbo Assembler [Borland] TAT Transatlantic telephone cable Turn around time TAXI Transparent Asynchronous Tranceiver/Receiver Interface TB "Terabyte (1,024 gigabytes)" TBBA Terephthal-butylaniline TBBS The Bread Board System (BBS) TBC Time base (error) correction (e.g. VTR) TBDF Transborder data flow TBGA Tape Ball Grid Array TBR Timed break TBU Tape Backup Unit TC Test Control Transmission Control TCAP Transaction capabilities applications protocol TCAS Traffic alert and collision avoidance system TCE Temperature coefficient of expansion TCL Tool Command Language TCM Trellis-Coded Modulation TCNE tetracyanoethylene TCNQ tetracyanoquinodimethane TCP tape carrier package TCP/IP Transmission Control Protocol/Internet Protocol TCR temperature coefficient of resistance TCT Thermal cycle test TCU trunk coupling unit TCXO temperature compensated crystal oscillator TD Transmit Data TDAC time division aliasing cancellation TDD Telecommunications Device for the Deaf Time division duplex TDDB time dependent dielectric breakdown TDE Terminal Display Editor Time dependent error TDF Technology Demonstration Facility transborder data flow TDFW time-dependent Hartree-Fock TDI Transport Device Interface TDM Technical Document Management Time Division Multiplexing TDMA Time Division Multiple Access TDMF time dependent mean field theory TDMS Terminal Display Management System TDP Telelocator Data Protocol TDPAC time differential PAC TDR Time Domain Reflectometry TDS thermal desorption spectra (-oscopy) TDSR Transmitter Data Service Request TDtoDP Tablet Coordinates to Display Coordinates (converting) TE transverse electric terminal equipment Thermo-electric TE/2 Terminal Emulator/2 [Oberon] TEA transversely excited atmosphere TEB Thread Environment Block TEC Tokyo Electronics Corporation TED Transferred electron device Tiny editor TEGFET two-dimensional electron gas FET TEI Terminal Endpoint Identifier TELCO telephone company TEM transmission electron microscopy transverse electromagnetic TEMEX telemetric (data) exchange TEML Turbo Editor Macro Language [Borland] TEMP Temporary TEOS Tetra-ethyl-ortho-silicate TER Thermal Eclipse Reading [Sony] TERMPWR Terminator Power TEXT Texas Experimental Tokarnak TF toroidal field TFCX Toroidal Fusion Core Experiment TFDD Text File Device Driver TFEL Thin-Film Electroluminescent TFT Thin-Film Transistor (screens) TFTP Trivial File Transfer Protocol TFTR Tokamak Fusion Test Reactor TGA thermogravitnetric analysis TGFB triglycine fluoroberyllate TGMIS twin gate MOS image sensor TGS triglycine sulphate TGSE triglycine selenate THD Total Harmonic Distortion THF tremendously high frequency THOMAS The (U.S.) House (of Representatives) Open Multimedia Access System THOR Tandy High-Performance Optical Recording THORP Thermal Oxide Reprocessing Plant THORS Thermal-Hydraidic Out-of-Reactor Safety Facility THR Transmit Holding Register THTF Thermal Hydraulic Test Facility TI "Texas Instruments, Inc." TIA Telecommunications Industry Association The Internet Adapter [Internet] TID Target ID TIES Time Independent Escape Sequence TIFF Tagged Image File Format TIG tungsten inert gas TIGA Texas Instruments Graphics Architecture TIGER Topologically Integrated Geographic Encoding and Referencing TIIAP Telecommunications and Information Infrastructure Assistance Program [NII] TIL two interdigitation level TIM Technical Information Memo [Compaq] TIMI Technology Independent Machine Interface [IBM] TIP Terminal Interface Processor TIR total internal reflection TJF test jack frame TJS transverse junction stripe TK/TK Track to Track TLA Three-Letter Acronym TLB Translation Look-aside Buffer TLC thin layer chromatography TLD thermoluminescent dosimeter (-ry) TLDN temporary local directory number TLI Transport Layer Interface TLU Table Lookup TM Transverse magnetic Trademark TMC test module cod TMHR tandem mirror hybrid reactor TMI Three Mile Island TMMC tetramethylammonium manganese chloride TMP Temporary TMR tandem mirror reactor TMSPM 3-(trimethoxysilyl)-propylacrylate TMTSF tetramethyltetraselenafulvalene (-inium) TMTTF tetramethyltetrathiafulvalene (-inium) TMX-U Tandem Mirror Experiment-Upgrade TN Twisted Nematic TNC Terminal Node Controller TNO The Netherlands Organization TNS The Next Step ToC Table Of Contents TOD Time Of Day TOF time-of-flight TOP technical & office protocol transient overpower accident TP Transaction Processing TPAD time differential perturbed angular distribution TPC Transaction-Processing Performance Council Time projection chamber TPD temperature programmed desorption TPF Transactions Processing Facility [IBM] TPI Tracks Per Inch TPL Table Producing Language Transaction Processing Language TPM Transactions Per Minute TPORT Twisted Pair Port Transceiver [AT&T] TPS Transactions Per Second Transaction Processing System TPTF Two Phase Flow Test Facility TPW Turbo Pascal for Windows TQFP Thin Quad Flat Pack TQM Total Quality Management TR Terminal Ready TR-APATT trapped plasma avalanche triggered transit TR3 time resolved resonant Raman (spectra (-oscopy)) TRADIC Transistorized Airborne Digital Computer (Name of first computer to be entirely transistorized) TREAT Transient Reactor Test Facility TRM thermoremanent magnetisation TRN Threaded Read News [Internet] Token Ring Network TRON The Real-Time Operating System Nucleus TRRR time resolved resonant Raman (spectra (-scopy)) TRU transuranic (waste) TS Top Secret TS/SI Top Secret/Sensitive Information TSA Target Service Agent Technical Support Alliance TSAPI Telephony Services Application Program Interface [AT&T Novell] TSB Termination Status Block TSC thermally stimulated current TSD thermally stimulated desorption TSE The Semware Editor Terminal-switched exchange TSEE thermally stimulated exo-electron emission TSEF tetraselenafulvalene (-inium) TSET tetraselenatetracene TSIC thermally stimulated ionic currents TSO Time Sharing Option TSR Terminate and Stay Resident TSS Task State Segment Time Sharing System TST time-space-time TSTA Tritium Systems Test Facility TSTN Triple Supertwisted Nematic TSV Tab Separated Values TT Typewriter Text TTA Transport-Triggered Architecture TTCN Tree and Tabular Combined Notation TTF tetrathiafulvalene (-inium) True type font TTL Transistor-Transistor Logic TTMP transit time magnetic pumping TTP Thermal-Transfer Printing TTS Text-To-Speech Transaction Tracking System TTT temperature-time-transformation tetrathiatetracene TTY Teletype (terminal) TUCA transient undercooling accident TUCOP transient undercooled overpower accident TUI Text-Based User Interface [WordPerfect] TUMS Table Update and Management System [Stanford University] TV television TVF Table of contents Verbosely from File [UNIX] TVFS Toronto Virtual File System [IBM] TVI Television Interference TVOL Television On-Line TVRO TV receive only TW Travelling wave TWA Travelling wave amplifier TWAIN Technology Without Any Interesting Name (connection between application and scanner software) TWT Travelling wave tube TWX Teletypewriter Exchange Service TXD Transmit Data TXE Electronic exchange TXK Crossbar exchange TXT Text TXT2STF Text To Structured File [Lotus Agenda] TZ Time Zone [Unix] UA User Agent User Area User access UAE Unrecoverable Application Error UART Universal Asynchronous Receiver Transmitter UCHF Uncoupled Hartree-Fock UCL Universal Communications Language UCN Ultra cold neutrons UCS Unicode Conversion Support Universal Character Set User Coordinate System UCT Universal Coordinated Time UDC User Defined Commands UDE Universal Data Exchange UDF Universal Disk Format User Defined Functions Universal Data Format UDG User Defined Gateway UDP User Datagram Protocol UDT Uniform Data Transfer UFS Unix File System UG User Group UHF ultra high frequency unrestricted Hartree-Fock UHV ultra high voltage UI Unix International User Interface Universal interface UID User Identifier UIMS User Interface Management System UIQS underground hydroelectric pumped storage UJT unijunction transistor UKAEA United Kingdom Atomic Energy Authority UL Underwriters Laboratories Unordered List Upload ULA Uncommitted Logic Array ULF ultra low frequency ULL Unix Linkable Library ULN Universal Link Negotiation ULSI Ultra Large Scale Integration UMA Unified Memory Architecture UMB Upper Memory Block [LIM/AST] UMD unitised microwave devices UNC Universal Naming Convention Uuencoded Netnews Collator [Unix] UNCOL Universal Computed Oriented Language UNI User-Network Interface UNICOM Universal Integrated Communication (System) UNICOS Universal Compiler FORTRAN compatible UNII Unlicensed National Information Infrastructure UNIVAC Universal Automatic Computer UNIX Uniplexed Information and Computer Systems (AT&T Bell Laboratories Operating System) UNMA Unified Network Management Architecture UP unterputz (flush-mounted) Uniprocessor UPC Universal Product Code UPG Upgrade UPL User Program Language UPM Unix Programmer's Manual User Profile Management [IBM] UPROM unerasable PROM UPS ultraviolet photoelectron spectra (-oscopy) uninterruptible power supply (system) URC Uniform Resource Characteristics Uniform Resource Citation UREP Unix RSCS Emulation Protocol (protocol) URI Uniform Resource Identifier (Indicator) URL Uniform Resource Locator URN Uniform Resource Name/Number URTJ Uncorrelated Root Mean Square Timing Jitter US Unit Separator Ultrasonic USA-RT universal synchronous/asynchronous receiver transmitter USART Universal Synchronous-Asynchronous Reciever/Transmitter USB Universal Serial Bus [Intel] Upper side band USENET User's Network [Internet] USERID User Identification USOC Universal Service Ordering Code USQ Unsqueezed (files) USR US Robotics (corporation) USRT Universal Synchronous Receiver/Transmitter USSA User Supported Software Association (United Kingdom) UT User Terminal UTC Coordinated Universal Time UTI Universal Text Interchange/Interface UTP Unshielded Twisted-Pair (cable) UTX Universal Transaction eXchange UU Uuencode/Uudecode UUCP Unix-To-Unix Copy Program UUD UUDecoding [Unix] UUE UUEncoding [Unix] UUI User-To-User Information [AT&T] UUID Universal Unique Identifier UUT unit under test UV Ultraviolet V&V Verification and Validation VA Virtual Address VAB voice answer back VAD Value Added Dealer Vapour phase axial deposition VADD Value Added Disk Driver VADS value added data service VADSL Very-High-Rate Asymmetric Digital Subscriber Line VAL Value Voice Application Language VAM Virtual Access Method VAN Value Added Network VANS Value added network services VAP Value Added Process VAR Value Added Reseller Value Added Retailer Variable VAST Variable Array Storage Technology VAV variable air volume (heating system) VAX Virtual Address eXtension VAX/VMS Virtual Address Extension/Virtual Memory System [DEC] VB Variable Block Visual Basic [Microsoft] Valence bond VBA Visual Basic for Applications [Microsoft] VBB video band buffer VBE VESA BIOS Extension VBE/AI Vesa Bios Extension/Audio Interface VBI vertical blanking interval vBNS Very High Speed Backbone Network Service [MCI NSF] VBR Variable Bit Rate VBRUN Visual Basic Runtime VCC Virtual Channel Connection VCCD vertical CCD VCCS voltage controlled current source VCD Virtual Communications Driver VCL Visual Component Library VCM voice coil motor VCNR voltage controlled negative resistance VCO voltage controlled oscillator VCOS Visual Caching Operating System [AT&T] VCPI Virtual Control Program Interface VCR Video Cassette Recorder VCSEL vertical cavity surface emitting laser VCVS voltage controlled voltage source VCXO voltage controlled crystal oscillator VDD Virtual Device Driver VDDM Virtual Device Driver Manager VDE Video Display Editor Visual Development Environment VDISK Virtual Disk VDM Virtual DOS Machine [IBM] Vector dominance model Vienna Development Methodology VDMAD Virtual Direct Memory Access Device [Microsoft] VDMOS vertical double diffused MOS VDS Virtual DMA Services VDSL Very-High-Data-Rate Digital Subscriber Line VDT visual display terminal VDT Video Dial Tone Video Display Terminal VDU Video Display Unit Visual Display Unit VDW van der Waals VEGA "Video-7 Enhanced Graphics Adapter [Video-7, Inc.]" VEMM Virtual Expanded Memory Manager VEMMI Versatile Multimedia Interface VER Verify Version visual evoked response VERONICA Very Easy Rodent-Oriented Net-Wide Index to Computer Archives [Internet] VERR Verify Read Access VERW Verify Write Access VESA Video Electronics Standards Association VET very high frequency VF Virtual Floppy VFAT Virtual File Allocation Table [Microsoft] VFC Version.First Class (communications standard) VFD Vacuum Fluorescent Display VFO variable frequency oscillator VFTIC very high performance integrated circuit VFW Video For Windows [Microsoft] VGA Video Graphics Adapter (Array) VGC Video Graphics Controller VHDL VHSIC Hardware Description Language VHMISFET Vertical heterostructure MISFET VHS Very High Speed Video Home System Virtual Host Storage VHSIC Very High Speed Integrated Circuit VHV very high voltage VI Visual Interactive (editor) [UNIX] VIA Virtual Interface Architecture VIE Virtual Information Environment VIF Virtual Interface Virtual Interrupt Flag video intermediate frequency VIL vertical injection logic VIM Vendor Independent Mail Vendor Independent Messaging Video Interface Module VINES Virtual Networking System [Banyan] VIO Video Input/Output Virtual Input/Output ViP Visual Programming [Lotus] VIP Variable Information Processing Video Information Provider Virtual Interrupt Pending VIsual Programmer VIPER Verifiable Integrated Processor for Enhanced Reliability VIS Video Information System [Tandy] Visual Instruction Set [Sun] Voice Information System VITC vertical interval time control VJ HEADER Van Jacobsen Header (compression) [Unix] VJFET vertical junction FET VL-BUS Vesa Local-Bus [VESA] VLAN Virtual Local Area Network VLB VESA Local Bus VLBI very long base line interferometry VLD Variable-Length Decoder VLF Very Low Frequency VLIC Very Large Integrated Circuit VLINK Visited Link [HTML] VLIW Very Large (Long) Instruction Word VLM Virtual Loadable Module VLR visitor location register VLSI Very Large Scale Integration VLSIPS Very Large Scale Immobilized Polymer Synthesis VLT Variable List Table VM Virtual Memory Virtual Machine VMA Virtual Memory Address VMB Virtual Machine Boot VME Versa Module Eurocard Virtual Memory Environment versa module Europe (bus) VMM Virtual Machine/Memory Manager VMOS vertical channel metal-oxide-semiconductor VMOS Vertical Metal Oxide Semiconductor VMP Virtual Modem Protocol VMS Virtual Memory System Voice Message System VMSP Virtual Machine System Product VMT Virtual Memory Technique VN Virtual Network VNA Virtual Network Architecture VOC Creative Voice (format) [Sound Blaster] VOD Video On Demand VOL Volume VOM Volt-Ohm-Milliammeter VOR VI-IF omnidirectional range Visions Of Reality VOS Verbal/Voice/Virtual Operating System VP Virtual Path VPD Virtual Printer Device Vital Product Data [IBM] VPDN Virtual Private Data Network VPDS Virtual Private Data Service [MCI] VPE Video Port Extensions [Microsoft] Visual Programming Environment Vapour phase epitaxy VPL Virtual Programming Language VPM Video Port Manager VPN Virtual Page Number Virtual Private Network VPS Voice Processing System VPSC "Vault, Process, Structure, Configuration" VPT Virtual Print Technology [Dataproducts] VR Virtual Reality Voltage Regulated/Regulator VRAM video random access memory VRAM Video Random Access Memory VRC visual record computer virtual redundancy check VRE Voltage Regulated Extended VRM Voltage Regulator Module VRML Virtual Reality Modelling Language (originally named Virtual Reality Markup Language) VROOMM Virtual Real-time Object Oriented Memory Manager [Borland] VRS video response system VRT Voltage Regulation Technology [Intel] VRU Voice Response Unit VS Virtual Storage VSAM Virtual Storage Access Method VSAT Very Small Aperture Terminal VSB vestigial sideband VSCF "variable speed, constant frequency" VSE Virtual Storage Extended VSELP vector summed exciting linear predictive code VSEPR valence shell electron pair repulsion VSF Vertical Scanning Frequency VSI Virtual Socket Interface Voltage source inverter VSIO Virtual Serial Input Output VSLI Very Large Scale Integration VSM Virtual Shared Memory Virtual Storage Management Visual System Management [IBM] VSN Volume Serial Number VSOS Virtual Storage Operating System VSP vertical seismic profiling VSS variable structure systems VSWR voltage standing wave ratio VSYNC Vertical Sync VT Vertical Tab VTAM Virtual Telecommunications Access Method [IBM] VTOL vertical take-off and landing VTR video tape recorder voltage transformation ratio VU volume units VUI Video User Interface VUP VAX Unit of Performance VUV vacuum ultraviolet VVER water moderated water cooled reactor VVVF variable voltage variable frequency VWB Visual WorkBench [Microsoft] VxD Virtual Extended Driver [Microsoft] VXIbus VMEbus extension for instrumentation W/O Without W3 (see WWW) W3A World Wide Web Applets W3C World Wide Web Consortium W4 What-Works-With-What WAAS Wide Area Augmentation System WABI Windows Application Binary Interface [SunSoft] WAIS Wide Area Information Search (Server) WAITS Wide Area Information Transfer System WAN Wide Area Network WARC World Administrative Radio Conference WAS Web Application Server WATS Wide Area Telecommunications Service WAXS wide-angle X-ray scattering WBEM Web-Based Enterprise Management WC Word Count WCS World Coordinate System WDF wave digital filter WDL Windows Driver Library [Microsoft] WDM Win32 Driver Model Wavelength division multiplex(ing) WDRAM Windows Dynamic Random Access Memory WebNFS Web Network File System [Sun] WECS wind energy conversion system WELL Whole Earth 'Lectronic Link (BBS) WEPP Stored Waste Examination Pilot Plant WF wait flag WFW Windows For Workgroups [Microsoft] WGS Work Group System WHAM Waveform Hold and Modify [Microsoft] WHC Workstation Host Connection WIMP "Weakly interacting massive particle windows, icons, mice, pull-down menus" WINE Windows Emulator WINForum Wireless Information Networks Forum WINS Windows-Internet Naming Service [Microsoft] WINSOCK Windows Open Systems Architecture [Microsoft] Windows Sockets WINWORD Word For Windows [Microsoft] WIP work-in-progress WIPP Waste Isolation Pilot Plant WISE WordPerfect Information System Environment WIT Web Interactive Talk [Internet] WKB Wentzel-Kramers-Brillouin WL Word Line WMC Workflow Management Coalition WMF Windows Meta File WNIC Wide-Area Network Interface Co-Processor WNIM Wide-Area Network Interface Module WOM Web Object Management WORM Write Once Read Many WOS Workstation Operating System WOSA Windows Open Services/Systems Architecture [Microsoft] WP WordPerfect Word Processing Write Protected WPBX wireless private branch exchange WPHD Write-Protect Hard Disk WPM Words Per Minute WPOS Workplace Operating System WPS Windows Printing System [Microsoft] Workplace Shell [OS2] WPVM Windows Parallel Virtual Machine WR Wolf-Rayet WRAM Windows Random Access Memory WRB Web Request Broker WRBD Web Request Broker Dispatcher WRK Windows Resource Kit [Microsoft] WS WordStar Workstation WSAPI Web Site Application Program Interface [O'Reilly] WSI wafer scale integration WT Write Through WW wire wound WWER water moderated water cooled reactors WWIS World Wide Information System [Internet] WWW World-Wide Web [Internet] WYSBYGI What You See Before You Get It WYSIWYG What You See Is What You Get WZW Wess-Zwnino-Witten X2B Hexadecimal to Binary [REXX] X2C Hexadecimal to Character [REXX] X2D Hexadecimal to Decimal [REXX] XA Extended Architecture Extended Attribute XANES X-ray absorption near edge structure XAPIA X.400 Application Program Interface Association XCHG Exchange XCMD External Command XCOPY Extended Copy XDF Extended Density Format [IBM] XDR Extended/External Data Representation XFCN External Function XGA Extended Graphics Array (Adapter) [IBM] XID Exchange Identifier XIOS Extended Input/Output System XLAT Translate XLM Excel Macro Language [Microsoft] XLPE cross-linked polyethylene XMIT Transmit XML eXtensible Markup Language XMM Extended Memory Manager [LIM/AST] XMS Extended Memory Specification [LIM/AST] XNS Xerox Network System (protocol) [Xerox] XOFF Transmitter Off XON Transmitter On XOR Exclusive OR (Also EOR) XPD cross-polarisation discrimination XPIC cross polarisation interference controller XPRM Xerox Print Resources Manager [Xerox] XPS X-ray photoelectron spectra XRD X-ray diffraction XRT Extensions for Real-Time XSMD Extended Storage Module Drive (interface) XSSI Extended Server Side Includes XTAL Crystal XTCLK External Transmit Clock XUV X-ray ultraviolet YAG yttrium aluminium garnet YAHOO Yet Another Hierarchically Officious Oracle [Internet] YAM Yet Another Modem [Omen Technology] YC luminance chrominance YIG yttrium iron garnet YTD Year To Date YTO YIG tuned oscillator Z-CAV Zoned Constant Angular Velocity ZAW Zero Administration for Windows [Microsoft] ZBR Zone-Bit Recording [IBM] ZDL Zero Delay Lockout ZDS Zenith Data Systems ZEBRA Zero Energy Breeder Reactor Assembly ZGS zero gradient synchrotron ZIF Zero-Insertion Force (socket) ZIP Zigzag In-Line Package Zone Improvement Plan (ZIPcode) ZPPR zero power plutonium reactor ZPV Zoomed Port Video [Toshiba] ZSL Zero Slot LAN ZTP Z toroidal pinch See http://homepage.ntlworld.com/bernadette.hancock/acronyms.txt for more, mainly NG, acronyms from another source.