A-Z of Hardware

Abstract: This paper “A-Z of Hardware” is a repository for various essential terms that are related to computer and hardware. “A-Z of Hardware” contains a collection of ‘523’ hardware terms and provides easy-to-understand definitions in plain language. The paper contains hardware terms which has been collected from various sources and contains terms updated up to April 1, 2005. This paper is primarily made as a ready reference for essential hardware terms which are grouped in alphabetical order for easy browsing of the user. The user can browse through the document by clicking on the alphabetical bookmarks which will take to the terms starting with the respective alphabet and can come back to the first page by clicking on the ‘Back to Top’ link at the top-left corner of every page. The definitions are given against the respective terms in a table format. Click On Below Alphabets To Browse Alphabetically Through The Document: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Term Definition A A-weighted decibels Advanced Technology Attachment (ATA) A-weighted decibels, abbreviated dBA, or dBa, or dB(a), are an expression of the relative loudness of sounds in air as perceived by the human ear. ATA (Advanced Technology Attachment) is the official name that American National Standards Institute group X3T10 uses for what the computer industry calls Integrated Drive Electronics (IDE). Pixie dust is the name that IBM is using for its antiferromagneticallycoupled (AFC) media technology, which can increase the data capacity of hard drives to up to four times the density possible with current drives. The "pixie dust" used is a 3-atom thick magnetic coating composed of the element ruthenium sandwiched between two magnetic layers. AIBO (pronounced eye-bow) is an entertainment robot designed by Sony. AIBO means "companion" in Japanese. It is also an abbreviation for "artificial intelligence bot" ("bot" is short for "robot") in English. Sony created AIBO to be a robotic pet and promotes AIBO as having the capability to interact with its human owner in many of the same ways a living pet would - without the high maintenance. AIT (advanced intelligent tape) is a magnetic tape and drive system used for computer data storage and archiving. The tapes measure eight millimeters (8 mm) across. A helical scanning technique, similar to that used in Mammoth drives, optimizes the data transfer rate and the storage capacity. AMTOR (amateur teleprinting over radio) is a digital communications method used by radio amateurs, in which the frequency of errors is reduced by handshaking or character repetition. There are two modes in AMTOR, known as automatic repeat request (ARQ) or Mode A, and forward error correction (FEC) or Mode B. Appliance computing is an Internet-based computing architecture where software applications reside on a Web server rather than on the enduser's workstation. The workstation, or appliance, is a thin client; it does not have a CD-ROM or floppy drive. The appliance typically has only an operating system and a connectivity program, such as a Web browser, which allows the appliance to connect to the server in order to access applications the end-user needs. The purpose of appliance computing is to make remote management easier and more cost effective. AFC AIBO AIT AMTOR appliance computing BACK TO TOP An ASIC (application-specific integrated circuit) is a microchip designed for a special application, such as a particular kind of transmission protocol or a hand-held computer. You might contrast it with general integrated circuits, such as the microprocessor and the random access memory chips in your PC. ASICs are used in a wide-range of applications, including auto emission control, environmental monitoring, and personal digital assistants (PDAs). The AS/400 - formally renamed the "IBM iSeries," but still commonly known as AS/400 - is a midrange server designed for small businesses and departments in large enterprises and now redesigned so that it will work well in distributed networks with Web applications. Science-fiction author Isaac Asimov is often given credit for being the first person to use the term robotics in a short story composed in the 1940s. In the story, Asimov suggested three principles to guide the behavior of robots and smart machines. 1. Robots must never harm human beings or, through inaction, allow a human being to come to harm. 2. Robots must follow instructions from humans without violating rule 1. 3. Robots must protect themselves without violating the other rules. ASPI (Advanced SCSI Programming Interface) specifies how an application program can communicate with a SCSI (Small Computer System Interface) device through a common SCSI device driver. ASPI provides a set of functions that are common to any SCSI device. In computers, an ASSP (application-specific standard product) is a semiconductor device integrated circuit (IC) product that is dedicated to a specific application market and sold to more than one user (and thus, "standard"). Automated test equipment (ATE) is computer-controlled equipment that tests electronic devices for functionality and performance. ATE also conducts stress testing with minimal human interaction. ATE includes the control hardware, sensors, and software that collects and analyzes the test results. ATE is considered cost efficient for high-volume testing. ATX is an industry-wide specification for a desktop computer's motherboard. ATX improves the motherboard design by taking the small AT motherboard (sometimes known as the "Baby AT" or BAT) that was an earlier industry standard and rotating by 90 degrees the layout of the microprocessor and expansion slots. Directional sound is a technology that concentrates acoustic energy into a narrow beam so that it can be projected to a discrete area, much as a spotlight focuses light. Focused in this manner, sound waves behave in a manner somewhat resembling the coherence of light waves in a laser. application-specific integrated circuit (ASIC) AS/400 Asimov's Three Laws of Robotics ASPI ASSP ATE ATX audio spotlight BACK TO TOP autoloader A stackloader (also known as an autoloader) is a tape storage device that automatically loads tape cartridges using a robotic mechanism. A stackloader can load cartridges sequentially or in some specified order. A robot is a machine designed to execute one or more tasks repeatedly, with speed and precision. There are as many different types of robots as there are tasks for them to perform. autonomous robot B back-pressure sensor A back-pressure sensor is a transducer that detects and measures the instantaneous torque that a robot motor applies. The sensor produces a variable signal, usually a voltage, that changes in a linear manner as the torque varies. In a personal computer with an Intel processor chipset that includes a Dual Independent Bus (DIB), the frontside bus is the data path and physical interface between the processor and the main memory (RAM). The backside bus is the data path and physical interface between the processor and the L1 and L2 memory. Both the frontside bus and the backside bus can be in use at the same time, meaning that the processor gets more done in a given number of pulses per second. A barcode reader, also called a price scanner or point-of-sale (POS) scanner, is a hand-held or stationary input device used to capture and read information contained in a bar code. A barcode reader consists of a scanner, a decoder (either built-in or external), and a cable used to connect the reader with a computer. In disaster recovery, a bare metal restore is the process of reformatting a computer from scratch after a catastrophic failure. Typically the process involves reinstalling the operating system and software applications and then, if possible, restoring data and settings. Composite video, also called baseband video or RCA video, is the analog waveform that conveys the image data in a conventional National Television Standards Committee (NTSC) television signal. Composite video contains chrominance (hue and saturation) and luminance (brightness) information, along with synchronization and blanking pulses, all together in a single signal. BEDO DRAM (Burst Extended Data Output DRAM) is a type of dynamic random access memory (DRAM) that can send data back to the computer from one read operation at the same time it is reading in the address of the next data to be sent. In addition, after reading the address, it is able to send the data back in three successive clock cycles without clock coordination (that is, the three successive outputs seem to be sent from the RAM in a sudden burst. backside bus (BSB) bar code reader bare metal restore baseband video BEDO DRAM (Burst Extended Data Output DRAM) BACK TO TOP Betamax Betamax is a videocassette recording (VCR) technology that uses magnetic tape 1/2 inch (1.27 cm) in width. It was originally developed in Japan by Sony. Big-endian and little-endian are terms that describe the order in which a sequence of bytes are stored in computer memory. Big-endian is an order in which the "big end" (most significant value in the sequence) is stored first (at the lowest storage address). Little-endian is an order in which the "little end" (least significant value in the sequence) is stored first. A bit (short for binary digit) is the smallest unit of data in a computer. A bit has a single binary value, either 0 or 1. Although computers usually provide instructions that can test and manipulate bits, they generally are designed to store data and execute instructions in bit multiples called bytes. An injectable ID chip, also called a biochip transponder, is an electronic device that is inserted under the skin of an animal to provide the animal with a unique identification number. Injectable ID chips, which are less painful, faster to implement, and more cost-effective than ear-tags, brands, or tattoos, have been used to identify livestock animals such as pigs, sheep, cows, and horses for over a decade. Biomechatronics is the interdisciplinary study of biology, mechanics, and electronics. Biomechatronics focuses on the interactivity of biological organs (including the brain) with electromechanical devices and systems. A blade server is a thin, modular electronic circuit board, containing one, two, or more microprocessors and memory, that is intended for a single, dedicated application (such as serving Web pages) and that can be easily inserted into a space-saving rack with many similar servers. Brain-machine interface (BMI) is a collaboration in which a brain accepts and controls a mechanical device as a natural part of its representation of the body. Broadband over Power Line (BPL) is a technology that allows Internet data to be transmitted over utility power lines. (BPL is also sometimes called Power-line Communications or PLC.) A Braille display is a device, typically attachable to a computer keyboard, that allows a blind person to read the contents of a display one text line at a time in the form of a line of Braille characters. Each Braille character consists of six or eight movable pins in a rectangular array. The pins can rise and fall depending on the electrical signals they receive. A brick server is a compact computer server module without a chassis that can come in various processor, RAM, I/O, and storage configurations and is designed to fit into rack locations similar to those for blade servers. big-endian and little-endian bit biochip transponder biomechatronics blade server BMI (brain-machine interface) BPL (Broadband over Power Line) Braille display brick server BACK TO TOP buckytube In nanotechnology or the building of extremely small machines and computers, a nanotube is a long, cylindrical carbon structure consisting of hexagonal graphite molecules attached at the edges. nanotubes are sometimes called buckytubes. A bus network is an arrangement in a local area network (LAN) in which each node (workstation or other device) is connected to a main cable or link called the bus. bus network C In a shared memory multiprocessor with a separate cache memory for each processor, it is possible to have many copies of any one instruction operand: one copy in the main memory and one in each cache memory. When one copy of an operand is changed, the other copies of the operand must be changed also. Cache coherence is the discipline that ensures that changes in the values of shared operands are propagated throughout the system in a timely fashion. Cache memory is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. As the microprocessor processes data, it looks first in the cache memory and if it finds the data there (from a previous reading of data), it does not have to do the more time-consuming reading of data from larger memory. A camcorder is a portable electronic recording device that is capable of recording live-motion video and audio for later replay through VCRs, TVs, and, in some models, a personal computer. Capacity on demand (COD) is a purchasing option that allows companies to receive equipment with more computer processing, storage, or other capacity than the company needs at the time of purchase, and have that extra capacity remain unused and unpaid for until the company actually requires it. A tape cartridge is a protectively-encased tape that is portable. A charge-coupled device (CCD) is a light-sensitive integrated circuit that stores and displays the data for an image in such a way that each pixel (picture element) in the image is converted into an electical charge the intensity of which is related to a color in the color spectrum. A compact disc [sometimes spelled disk] (CD) is a small, portable, round medium made of molded polymer (close in size to the floppy disk) for electronically recording, storing, and playing back audio, video, text, and other information in digital form. CD-R (for compact disc, recordable) is a type of write once, read many (worm) compact disc (CD) format that allows one-time recording on a disc. CD-RW (for compact disc, rewriteable) is a compact disc (CD) format that allows repeated recording on a disc. cache coherence cache memory camcorder capacity on demand cartridge CCD CD CD-R CD-RW BACK TO TOP central processing unit (CPU) CPU (central processing unit) is an older term for processor and microprocessor, the central unit in a computer containing the logic circuitry that performs the instructions of a computer's programs. Centrino is a technology package from Intel that provides built-in wireless support for laptop computers while making it possible to run a laptop all day (up to seven hours) without a battery recharge. A CompactFlash (CF) card is a popular memory card developed by SanDisk in 1994 that uses flash memory to store data on a very small card. A CompactFlash card makes data easy to add to a wide variety of computing devices, including digital cameras and music players, desktop computers, personal digital assistants (PDAs), digital audio recorders, and photo printers. Custom factory integration (CFI) is an arrangement that a computer equipment vendor makes with a customer in which programs and files are pre-installed and the equipment is configured and tested at the factory prior to delivery. A channel extender is a device used with IBM's S/390 line of computers to increase the maximum communication distances between the S/390 channel-connected mainframe computers, or between an S/390 and peripheral devices such as workstations, printers, and storage devices. A chassis (pronounced TCHA-see or CHA-see) is the physical frame or structure of an automobile, an airplane, a desktop computer, or other multi-component device. "Chip" is short for microchip, the incredibly complex yet tiny modules that store computer memory or provide logic circuitry for microprocessors. A chipset is a group of integrated circuits (microchips) that can be used together to serve a single function and are therefore manufactured and sold as a unit. Megachips per second (Mcps) is a measure of the speed with which encoding elements, called chips (not to be confused with microchips), are generated in Direct Sequence Spread Spectrum (DSSS) signals. This speed is also known as the chipping rate. Chiral fiber is a specialized optical fiber medium with its core twisted into a helical shape. There are approximately 6,000 complete twists per linear centimeter of core, which has a rectangular cross section rather than the circular cross section typical of conventional fiber optic media. Circuit bending is the practice of modifying existing electronics items, most often toys, to create other items, usually musical instruments. The circular mil is a unit of area used especially when denoting the cross-sectional size of a wire or cable. It is the equivalent area of a circle whose diameter is 0.001 (10-3) inch, or approximately 0.7854 millionths of a square inch (or 2.5 x 10-7 times pi). Centrino CF card CFI channel extender chassis chip chip set chipping rate chiral fiber circuit bending circular mil BACK TO TOP In IBM's AS/400 and iSeries line of computers, CIW (Computer Intensive Workload) is a measure that can be used to compare the workload-handling capability of different computer models when running application programs in which most of the computer processor work is done within the applications. Clustering is the use of multiple computers, typically PCs or UNIX workstations, multiple storage devices, and redundant interconnections, to form what appears to users as a single highly available system. CMOS (complementary metal-oxide semiconductor) is the semiconductor technology used in the transistors that are manufactured into most of today's computer microchips. Communication and Networking Riser (CNR), which was developed by Intel, is an open industry standard for a scalable riser card, which is a hardware device that plugs into a motherboard and holds chips for functions like modems and audio devices. Coarse wavelength division multiplexing (CWDM) is a method of combining multiple signals on laser beams at various wavelengths for transmission along fiber optic cables, such that the number of channels is fewer than in dense wavelength division multiplexing (DWDM) but more than in standard wavelength division multiplexing (WDM). A cobot or "collaborative robot" is a robot designed to assist human beings as a guide or assistor in a specific task. Combinatorial logic is a concept in which two or more input states define one or more output states, where the resulting state or states are related by defined rules that are independent of previous states. Each of the inputs and output(s) can attain either of two states: logic 0 (low) or logic 1 (high). In a data center, compaction is the reduction or consolidation of hardware to make better use of physical floor space. In storage area management (SAM), compaction is the automatic removal of expired data from a storage area network (SAN) to condense the existing archive and make room for new data. S-Video (Super-Video, sometimes referred to as Y/C Video, or component video) is a video signal transmission in which the luminance signal and the chrominance signal are transmitted separately to achieve superior picture clarity. Computer forensics, also called cyberforensics, is the application of computer investigation and analysis techniques to gather evidence suitable for presentation in a court of law. CIW cluster computing CMOS CNR coarse wavelength division multiplexing cobot combinatorial logic compaction composite video computer forensics BACK TO TOP conventional memory core router DOS memory, sometimes referred to as conventional memory, refers to the memory-addressing scheme used in the original IBM and compatible PCs. A core router is a router that forwards packets to computer hosts within a network (but not between networks). A crossbar latch, also called a molecular crossbar latch, is a nanoscale device with properties similar to those of a conventional silicon transistor, but physically much smaller, having a diameter of approximately 2 nanometers (nm, where 1 nm = 10-9 m). Cycle time is the time, usually measured in nanoseconds, between the start of one random access memory (RAM) access to the time when the next access can be started. crossbar latch cycle time D D-VHS D-VHS (Digital Video Home System) is a digital enhancement of the Video Home System (VHS) videocassette recording (VCR) technology that was developed by Japan Victor Company (JVC) in 1976. Disk-to-disk-to-tape (D2D2T) is an approach to computer storage backup and archiving in which data is initially copied to backup storage on a disk storage system and then periodically copied again to a tape storage system (or possibly to an optical storage system). Digital audio broadcasting (DAB), also known as digital radio and highdefinition radio, is audio broadcasting in which analog audio is converted into a digital signal and transmitted on an assigned channel in the AM or (more usually) FM frequency range. DASD, pronounced DAZ-dee (Direct access storage device), is a general term for magnetic disk storage devices that has historically been used in the mainframe and minicomputer (mid-range computer) environments. A datacard is any removable computer component, approximately the size of a credit card, that contains data, or that contains nonvolatile memory to which data can be written and from which data can be recovered. The term is a synonym for smart card. A daughterboard (or daughter board, daughter card, or daughtercard) is a circuit board that plugs into and extends the circuitry of another circuit board. DB-xx is the designation for a series of port connectors for attaching devices to computers. DB-xx connectors include DB-9, DB-15, DB-25, DB-50, and DB-68. DB-15 is a female connector used as a joystick port on IBM-compatible computers and as the video connector on Macintosh computers. There is also a high-density DB-15 female connector for the Video Graphics Array (VGA) or Super Video Graphics Array (SVGA) video adapter on IBM-compatible computers. D2D2T DAB DASD datacard daughterboard DB-xx DB-15 BACK TO TOP DB-25 is a male connector used for attaching external modems and RS232 serial peripherals on older IBM-compatible computers. The DB-25 female connector is the parallel port connector for most personal computers. DB-25 was first used with the original IBM personal computer (PC) and has had a long life. DB-50 is a female connector used as the SCSI-2 connector for 8-bit Narrow SCSI devices on older Sun and Data General computers. However, DB-50 is not recognized by the SCSI specifications. DB-68 is a high-density connector used as a SCSI-3 connector for 16-bit Wide SCSI and Fast SCSI devices. DB-9 is a connector used for RS-232 connections and for several video interfaces on IBM-compatible computers. DDR SDRAM (double data rate SDRAM) is synchronous dynamic RAM (SDRAM) that can theoretically improve memory clock speed to at least 200 MHz Digital Data Storage (DDS) is a format for storing and backing up computer data on tape that evolved from the Digital Audio Tape (DAT) technology. DAT was created for CD-quality audio recording. Stores up to 2 gigabytes of uncompressed data on a 120-minute cartridge. Stores up to 8 GB of data in compressed format on a 120-minute cartridge. DDS-2 is ideal for small network servers. Stores up to 24 GB of data on a 125-minute cartridge. The DDS-3 drive is ideal for medium-sized servers. DDS-3 uses PRML (Partial Response Maximum Likelihood). PRML eliminates electronic noise for a cleaner data recording. The newest DDS drive, DDS-4 stores up to 40 GB of data on a 125minute cartridge. Small to mid-size businesses benefit from the DDS-4 drive. dBd (decibels related to dipole antenna) is a measure of the gain of an antenna system relative to a dipole antenna at radio frequency. A defragmenter is a software utility that rearranges the fragments or discontiguous parts of each file stored on a computer hard disk so that the small, empty storage spaces adjacent to fragments can be used, effectively creating new storage space and possibly making file access faster. A dendrimer (from Greek dendra for tree) is an artificially manufactured or synthesized molecule built up from branched units called monomers. Such processes involve working on the scale of nanometers (a nanometer is 10-9 or a billionth of a meter or a millionth of a millimeter). DB-25 DB-50 DB-68 DB-9 DDR SDRAM DDS DDS-1 DDS-2 DDS-3 DDS-4 decibels related to dipole antenna defragmenter dendrimer BACK TO TOP diagonal-parity RAID Double-parity RAID (redundant array of independent disks), also called diagonal-parity RAID, Advanced Data Guarding (RAID_ADG), or RAID-6, is a method of protecting against multiple storage drive failures by creating two sets of parity data on an array of hard disks. Digital audio broadcasting (DAB), also known as digital radio and highdefinition radio, is audio broadcasting in which analog audio is converted into a digital signal and transmitted on an assigned channel in the AM or (more usually) FM frequency range. Digital film is any storage medium (such as a memory card, diskette, or recordable CD) used in a digital camera to capture and store images. D-VHS (Digital Video Home System) is a digital enhancement of the Video Home System (VHS) videocassette recording (VCR) technology that was developed by Japan Victor Company (JVC) in 1976. A digital pen is a battery-operated writing instrument that allows the user to digitally capture a handwritten note or drawing. A digital projector, also called a digital projection display system, is a specialized computer display that projects an enlarged image on a movie screen. DTTV (digital terrestrial television, sometimes also abbreviated DTT) is digital television (DTV) broadcast entirely over earthbound circuits. Digital video is part of digital versatile disc (DVD), a new optical disc technology that is expected to rapidly replace the CD-ROM over the next few years. DVD is an optical disc technology with a 4.7 gigabyte storage capacity on a single-sided, one-layered disk, which is enough for a 133-minute movie. DVI (Digital Video Interface) is a specification created by the Digital Display Working Group (DDWG) to accommodate analog and digital monitors with a single connector. In computer storage, direct access is the ability to obtain data from a storage device by going directly to where it is physically located on the device rather than by having to sequentially look for the data at one physical location after another. RDRAM (Rambus Dynamic Random Access Memory) is a memory subsystem that promises to transfer up to 1.6 billion bytes per second. Direct sequence spread spectrum, also known as direct sequence code division multiple access (DS-CDMA), is one of two approaches to spread spectrum modulation for digital signal transmission over the airwaves. Directional sound is a technology that concentrates acoustic energy into a narrow beam so that it can be projected to a discrete area, much as a spotlight focuses light. digital audio broadcasting digital film Digital Home Video System digital pen digital projector digital terrestrial television (DTTV) digital versatile disk digital video disk Digital Video Interface direct access Direct Rambus direct sequence spread spectrum directional sound BACK TO TOP dish antenna A dish antenna, also known simply as a dish, is common in microwave systems. This type of antenna can be used for satellite communication and broadcast reception, space communications, radio astronomy, and radar. A disk cache is a mechanism for improving the time it takes to read from or write to a hard disk. Today, the disk cache is usually included as part of the hard disk. A disk cache can also be a specified portion of random access memory (RAM). Disk duplexing is a variation of disk mirroring in which each of multiple storage disks has its own SCSI controller. Disk mirroring (also known as RAID-1) is the practice of duplicating data in separate volumes on two hard disks to make storage more fault-tolerant. A jump drive - also known as a USB drive, flash drive, keychain drive, or disk-on-key - is a plug-and-play portable storage device that uses flash memory and is lightweight enough to attach to a key chain. A diskette is a random access, removable data storage medium that can be used with personal computers. DLT (digital linear tape) is a form of magnetic tape and drive system used for computer data storage and archiving. A special compression algorithm, known as Digital Lempel Ziv 1 (DLZ1), facilitates storage and retrieval of data at high speeds and in large quantities. DoCoMo, also known as NTT DoCoMo, is a Japanese communications corporation that has introduced a line of cell phone sets that contain the equivalent of a digital smart card. A document reader is a device that converts an electronic file or printed matter to a form suitable for use by people with visual impairment. The output can be in the form of enhanced video, speech, or Braille. DOT4 is a protocol that allows a device that is part of a multifunction peripheral (MFP) to send and receive multiple data packets simultaneously across a single physical channel to other devices on the MFP. A doubler is an electronic device that doubles the frequency of an input signal. An HD (high-definition) downconverter is a device that converts highdefinition television (HDTV) video to standard-definition video that can be viewed on conventional television (TV) receivers or computer monitors, or recorded on DVD. Dynamic random access memory (DRAM) is the most common kind of random access memory (RAM) for personal computers and workstations. A dropout is a small loss of data in an audio or video file on tape or disk. disk cache disk duplexing disk-on-key diskette DLT DoCoMo document reader DOT4 doubler down converter DRAM dropout BACK TO TOP DS-CDMA Direct sequence spread spectrum, also known as direct sequence code division multiple access (DS-CDMA), is one of two approaches to spread spectrum modulation for digital signal transmission over the airwaves. An HD (high-definition) upconverter, also known as a digital television (DTV) upconverter, is a device that converts the digital data on a DVD to a format that can be viewed directly on a high-definition television (HDTV) receiver without intermediate conversion to an analog signal. Duty cycle is the proportion of time during which a component, device, or system is operated. The duty cycle can be expressed as a ratio or as a percentage. Suppose a disk drive operates for 1 second, then is shut off for 99 seconds, then is run for 1 second again, and so on. DVD-RAM is a DVD (optical disc) technology for high-capacity data storage for computers. Like ordinary random access memory (RAM), it can be repeatedly read, written to, and erased. In voice over IP (VoIP), a jitter buffer is a shared data area where voice packets can be collected, stored, and sent to the voice processor in evenly spaced intervals. DTV up converter duty cycle DVD-RAM dynamic jitter buffer E E and M Ear and mouth (E&M) is a technology in voice over IP (VoIP) that uses a traditional telephone handset with an earphone (or earpiece) for listening to incoming audio and a microphone (or mouthpiece) for transmitting audio. E Ink is an electronic device that is similar to a computer display, but with qualities that enable it to be used for applications such as eBooks, electronic newspapers, portable signs, and foldable, rollable displays. An e-bomb (electromagnetic bomb) is a weapon that uses an intense electromagnetic field to create a brief pulse of energy that affects electronic circuitry without harming humans or buildings. The HP e3000 is a line of midrange business servers that carries on the well-known series of 3000 computers from Hewlett-Packard (HP). The e3000 uses HP's MPE/iX operating system, which can run applications written for the first 3000 systems that date as far back as the early 1970s and also run POSIX-conforming (Unix-based) applications as well. An erbium amplifier, also called optical amplifier or an erbium-doped fiber amplifier or EDFA, is an optical or IR repeater that amplifies a modulated laser beam directly, without opto-electronic and electrooptical conversion. E Ink e-bomb e3000 EDFA BACK TO TOP EDO RAM EDO (extended data output) RAM is a type of random access memory (RAM) chip that improves the time to read from memory on faster microprocessors such as the Intel Pentium. EDO RAM was initially optimized for the 66 MHz Pentium. In robotics, an end effector is a device or tool connected to the end of a robot arm. The structure of an end effector, and the nature of the programming and hardware that drives it, depends on the intended task An erbium amplifier, also called optical amplifier or an erbium-doped fiber amplifier or EDFA, is an optical or IR repeater that amplifies a modulated laser beam directly, without opto-electronic and electrooptical conversion. An exabyte (EB) is a large unit of computer data storage, two to the sixtieth power bytes. The prefix exa means one billion billion, or one quintillion, which is a decimal term. Extended desktop is a feature in a computer that allows a user to extend viewing capabilities by using two or more monitors at the same time. To connect more than one monitor to a computer, the user must have a computer with more than one monitor port. External storage is all addressable data storage that is not currently in the computer's main storage or memory. Synonyms are auxiliary storage and secondary storage. An eye-in-hand system is a robot end effector equipped with a closerange camera. end effector erbium amplifier exabyte extended desktop external storage eye-in-hand system F failover Failover is a backup operational mode in which the functions of a system component (such as a processor, server, network, or database, for example) are assumed by secondary system components when the primary component becomes unavailable through either failure or scheduled down time. Fan-in is a term that defines the maximum number of digital inputs that a single logic gate can accept. Fan-out is a term that defines the maximum number of digital inputs that the output of a single logic gate can feed. Fault-tolerant describes a computer system or component designed so that, in the event that a component fails, a backup component or procedure can immediately take its place with no loss of service. Fault tolerance can be provided with software, or embedded in hardware, or provided by some combination. A fax server (or faxserver) is a system installed in a local area network (LAN) server that allows computer users who are attached to the LAN to send and receive fax messages. fan in fan out fault tolerance fax server BACK TO TOP FC-PGA FC-PGA (flip chip-pin grid array) is a microchip design developed by Intel for its faster microprocessors in which the hottest part of the chip is located on the side that is away from the motherboard. Forward error correction (FEC) is a method of obtaining error control in data transmission in which the source (transmitter) sends redundant data and the destination (receiver) recognizes only the portion of the data that contains no apparent errors. FeliCa is a technology developed by Sony in which a microchip, embedded in a card or electronic device, combines processing, storage, and communications functions. The name derives from the word "felicity," suggesting convenience. A field-programmable gate array (FPGA) is an integrated circuit (IC) that can be programmed in the field after manufacture. FPGAs are similar in principle to, but have vastly wider potential application than, programmable read-only memory (PROM) chips. In electronic hardware, particularly computer systems, a fieldreplaceable unit (FRU) is a circuit board or part that can be quickly and easily removed and replaced by the user or by a technician without having to send the entire product or system to a repair facility. Firmware is programming that is inserted into programmable read-only memory (programmable ROM), thus becoming a permanent part of a computing device. Flash memory (sometimes called "flash RAM") is a type of constantlypowered nonvolatile memory that can be erased and reprogrammed in units of memory called blocks. A memory card (sometimes called a flash memory card or a storage card) is a small storage medium used to store data such as text, pictures, audio, and video, for use on small, portable or remote computing devices. In display technology, FOLED (flexible organic light emitting device) is an organic light emitting device (OLED) built on a flexible base material, such as clear plastic film or reflective metal foil, instead of the usual glass base. A flexible transistor is one which, unlike present, rigidly-structured transistors, can be successfully used in packages that can be curled up, wrapped, or bent, a quality that will enable users to - for example - have a display screen that can be rolled up. In October 1999, IBM announced that they had developed a very thin, flexible and inexpensive type of transistor that could actually be sprayed onto plastic. FEC FeliCa field-programmable gate array field-replaceable unit firmware flash memory flash memory card flexible organic LED flexible transistor BACK TO TOP flip chip-pin grid array FC-PGA (flip chip-pin grid array) is a microchip design developed by Intel for its faster microprocessors in which the hottest part of the chip is located on the side that is away from the motherboard. Forward error correction (FEC) is a method of obtaining error control in data transmission in which the source (transmitter) sends redundant data and the destination (receiver) recognizes only the portion of the data that contains no apparent errors. A field-programmable gate array (FPGA) is an integrated circuit (IC) that can be programmed in the field after manufacture. FPGAs are similar in principle to, but have vastly wider potential application than, programmable read-only memory (PROM) chips. Prior to newer forms of dynamic random access memory (DRAM), FPM DRAM (Fast Page Mode DRAM) was the most common kind of DRAM in personal computers. Full HDTV, also referred to as ultra-HD, true HDTV, and 1080p, is a television (TV) display technology that surpasses the video quality and sharpness of the original high-definition television (HDTV) technology, providing an image resolution of 1920 by 1080 pixels. forward error correction FPGA FPM DRAM full HDTV G fullerene GaAsFET A fullerene is a pure carbon molecule composed of at least 60 atoms of carbon. A gallium arsenide field-effect transistor (GaAsFET) is a specialized type of field-effect transistor (FET) that is used in amplifier circuits at very-high, ultra-high, and microwave radio frequencies. Galileo is the informal name for the European Global Navigation Satellite System (GNSS), a system that will offer users anywhere in the world "near pinpoint" geographic positioning when it becomes fully operational by 2008. A gigabyte (pronounced GIG-a-bite with hard G's) is a measure of computer data storage capacity and is "roughly" a billion bytes. A gigabyte is two to the 30th power, or 1,073,741,824 in decimal notation. A gigabit interface converter (GBIC) is a transceiver that converts electric currents (digital highs and lows) to optical signals, and optical signals to digital electric currents. Glassfet is jargon for vacuum tube. Vacuum tubes, consisting of electrodes enclosed in glass envelopes from which most of the air has been pumped out, are no longer used in computers, having been replaced by transistors in the 1960s and by integrated circuits in the 1970s. Graph theory is the study of points and lines. In particular, it involves the ways in which sets of points, called vertices, can be connected by lines or arcs, called edges. Galileo GB GBIC glassfet graph theory BACK TO TOP A graphics accelerator (a chipset attached to a video board) is a computer microelectronics component to which a computer program can offload the sending and refreshing of images to the display monitor and the computation of special effects common to 2-D and 3-D images. A grasping plan is an algorithm used by a robot arm and gripper to get hold of a specific object. The details of such a program depend on the type of robot arm and gripper, on the size of the robot's work area, and on the type of object(s) to be grasped. Gravity, also called gravitation, is a force that exists among all material objects in the universe. A gremlin is an imaginary creature that causes trouble in devices and systems of all kinds. During the Second World War, the term was used by British airmen to refer to ongoing trouble with aircraft in spite of mechanics' best efforts. Gremlins sometimes appear today in computer systems and networks. Grid storage is a general term for any approach to storing data that employs multiple self-contained storage nodes interconnected so that any node can communicate with any other node without the data having to pass through a centralized switch. A ground is a direct electrical connection to the earth, a connection to a particular point in an electrical or electronic circuit, or an indirect connection that operates as the result of capacitance between wireless equipment and the earth or a large mass of conductive material. graphics accelerator grasping plan gravity gremlin grid storage ground H HA In information technology, high availability refers to a system or component that is continuously operational for a desirably long length of time. availability can be measured relative to "100% operational" or "never failing." A hard disk is part of a unit, often called a "disk drive," "hard drive," or "hard disk drive," that stores and provides relatively quick access to large amounts of data on an electromagnetically charged surface or set of surfaces. A hard drive shredder is a mechanical device that physically destroys old hard drives in such a way that the data they contain cannot be recovered. At a minimum, this involves severing every track on every platter in a drive. Hardware clustering (sometimes called operating system clustering) is a hardware-based method of turning multiple servers into a cluster (a group of servers that acts like a single system). hard disk hard drive shredder hardware clustering BACK TO TOP hardware load-balancing device A hardware load-balancing device (HLD), also known as a layer 4-7 router, is a physical unit that directs computers to individual servers in a network, based on factors such as server processor utilization, the number of connections to a server, or the overall server performance. An HD (high-definition) downconverter is a device that converts highdefinition television (HDTV) video to standard-definition video that can be viewed on conventional television (TV) receivers or computer monitors, or recorded on DVD. An HD (high-definition) upconverter, also known as a digital television (DTV) upconverter, is a device that converts the digital data on a DVD to a format that can be viewed directly on a high-definition television (HDTV) receiver without intermediate conversion to an analog signal. An HD (high-definition) downconverter is a device that converts highdefinition television (HDTV) video to standard-definition video that can be viewed on conventional television (TV) receivers or computer monitors, or recorded on DVD. An HD (high-definition) downconverter is a device that converts highdefinition television (HDTV) video to standard-definition video that can be viewed on conventional television (TV) receivers or computer monitors, or recorded on DVD. A heatsink is a device that is attached to a microprocessor chip to keep it from overheating by absorbing its heat and dissipating it into the air. Generally, a microprocessor's temperature should not run in excess of 50-55 degrees Celsius while under a full load. HVAC stands for heating, ventilation, and air conditioning. In computing and especially in enterprise data centers, HVAC systems control the ambient environment (temperature, humidity, air flow, and air filtering) and must be planned for and operated along with other data center components such as computing hardware, cabling, data storage, fire protection, physical security systems and power. HSM (Hierarchical Storage Management) is policy-based management of file backup and archiving in a way that uses storage devices economically and without the user needing to be aware of when files are being retrieved from backup storage media. HDCD (High Definition Compatible Digital) is a digital encoding and decoding process for compact disc and DVD audio recording. HiP7 and HiP8 are abbreviations for two versions of HiPerMOS, a complementary-metal-oxide-semiconductor (CMOS) microchip technology invented by Motorola. Holographic storage is computer storage that uses laser beams to store computer-generated data in three dimensions. HD down converter HD up converter HD-SDI downconverter HDCD heat sink heating, ventilation, and air conditioning Hierarchical Storage Management High Definition Compatible Digital HiP7 and HiP8 holographic storage BACK TO TOP Horizontal scalability is the ability to connect multiple hardware or software entities, such as servers, so that they work as a single logical unit. In the case of servers, for example, you could increase the speed or availability of the logical unit by adding more servers, typically using clustering and load balancing. A hot swap is the replacement of a hard drive, CD-ROM drive, power supply, or other device with a similar device while the computer system using it remains in operation. The replacement can be because of a device failure or, for storage devices, to substitute other data. The HP 9000 is a line of Unix-based business servers from HewlettPackard (HP) with server models that span enterprise applications from the "entry-level" (branch or department-level computers, Web hosting servers, and so forth) through the midrange with needs for handling advanced enterprise resource planning (ERP) and analytical customer resource management (CRM) up to its high-end servers for very computing-intensive applications. The $100 PC is a product that several computer companies and thinkers have suggested is needed to help bridge the digital divide and bring information service to people in places such as China, India, and Africa who otherwise couldn't afford them. HVAC stands for heating, ventilation, and air conditioning. In computing and especially in enterprise data centers, HVAC systems control the ambient environment (temperature, humidity, air flow, and air filtering) and must be planned for and operated along with other data center components such as computing hardware, cabling, data storage, fire protection, physical security systems and power. Hyper-Threading is a technology used by some Intel microprocessors that allows a single microprocessor to act like two separate processors to the operating system and the application programs that use it. It is a feature of Intel's IA-32 processor architecture. horizontal scalability hot swap HP 9000 hundred dollar PC HVAC Hyper-Threading I I2S i5 i5 server I2S (Inter-IC Sound) is a serial bus (path) design for digital audio devices and technologies such as compact disc (CD) players, digital sound processors, and digital TV (DTV) sound. i5 is the latest hardware evolution of one of IBM's most widely-installed product lines, the AS/400, aimed at small and mid-sized businesses. i5 is the latest hardware evolution of one of IBM's most widely-installed product lines, the AS/400, aimed at small and mid-sized businesses. BACK TO TOP An iButton is a microchip similar to those used in a smart card but housed in a round stainless steel button of 17.35mm x 3.1mm - 5.89mm in size (depending on the function). The iButton was invented and is still manufactured exclusively by Dallas Semiconductor mainly for applications in harsh and demanding environments. Intelligent character recognition (ICR) is the computer translation of manually entered text characters into machine-readable characters. In practice, characters are entered in a rough printed form from an I/O device, and the image of the captured data entry is then analyzed and translated into the machine-readable characters. IDE (Integrated Drive Electronics) is a standard electronic interface used between a computer motherboard's data paths or bus and the computer's disk storage devices. The IDE interface is based on the IBM PC Industry Standard Architecture (ISA) 16-bit bus standard, but it is also used in computers that use other bus standards. DOT4 is a protocol that allows a device that is part of a multifunction peripheral (MFP) to send and receive multiple data packets simultaneously across a single physical channel to other devices on the MFP.The DOT4 protocol is specified in IEEE 1284.4, an enhancement of the original IEEE 1284 protocol for parallel ports on personal computers (PC). An imagesetter is a high resolution output device that can transfer electronic text and graphics directly to film, plates, or photo-sensitive paper. Insect robots work in fleets ranging in number from a few to thousands, with all fleet members under the supervision of a single controller. The term insect arises from the similarity of the system to a colony of insects, where the individuals are simple but the fleet as a whole can be sophisticated. An instruction is an order given to a computer processor by a computer program. An IP (intellectual property) core is a block of logic or data that is used in making a field programmable gate array (FPGA) or applicationspecific integrated circuit (ASIC) for a product. Intelligent character recognition (ICR) is the computer translation of manually entered text characters into machine-readable characters. An intelligent device is any type of equipment, instrument, or machine that has its own computing capability. iButton ICR IDE (Integrated Drive Electronics) IEEE 1284.4 image setter insect robot instruction intellectual property core intelligent character recognition intelligent device BACK TO TOP intelligent switch An intelligent switch is a high-level storage area network (SAN) routing switch that provides features such as storage virtualization, quality of service (QoS), remote mirroring, data sharing, protocol conversion, and advanced security. An IRQ (interrupt request) value is an assigned location where the computer can expect a particular device to interrupt it when the device sends the computer signals about its operation. The inverse-square law is a principle that expresses the way radiant energy propagates through space. The rule states that the power intensity per unit area from a point source, if the rays strike the surface at a right angle, varies inversely according to the square of the distance from the source. An IP PBX is a private branch exchange (telephone switching system within an enterprise) that switches calls between VoIP (voice over Internet Protocol or IP) users on local lines while allowing all users to share a certain number of external phone lines. interrupt request inverse-square law IP PBX J Java Ring A Java Ring is a finger ring that contains a small microprocessor with built-in capabilities for the user, a sort of smart card that is wearable on a finger. JBOD (for "just a bunch of disks," or sometimes "just a bunch of drives") is a derogatory term - the official term is "spanning" - used to refer to a computer's hard disks that haven't been configured according to the RAID (for "redundant array of independent disks") system to increase fault tolerance and improve data access performance. JEDEC (Joint Electron Device Engineering Council) SDRAM is an industry standard synchronous DRAM. It has a dual-bank architecture and several burst mode accesses that can be preset. In voice over IP (VoIP), a jitter buffer is a shared data area where voice packets can be collected, stored, and sent to the voice processor in evenly spaced intervals. Variations in packet arrival time, called jitter, can occur because of network congestion, timing drift, or route changes. In computers, a joystick is a cursor control device used in computer games and assistive technology. A jump drive - also known as a USB drive, flash drive, keychain drive, or disk-on-key - is a plug-and-play portable storage device that uses flash memory and is lightweight enough to attach to a key chain. JBOD JEDEC SDRAM jitter buffer joy stick jump drive K key chain drive A jump drive - also known as a USB drive, flash drive, keychain drive, or disk-on-key - is a plug-and-play portable storage device that uses flash memory and is lightweight enough to attach to a key chain. BACK TO TOP key logger A keystroke logger, sometimes called a system monitor, is a hardware device or small program that monitors each keystroke a user types on a specific computer's keyboard. Commonly used by a company within its private automatic branch exchange (PABX) telephone system, a keyphone (abbreviated as K/P, sometimes called a key station) is a telephone with the extra buttons and the intelligence to allow incoming calls to be transferred to other extensions. As a measure of computer memory or storage, a kilobyte (KB or Kbyte*) is approximately a thousand bytes (actually, 2 to the 10th power, or decimal 1,024 bytes). Key phone kilobyte L L1 L1 is "level-1" cache memory, usually built onto the microprocessor chip itself. L1 and L2 are levels of cache memory in a computer. If the computer processor can find the data it needs for its next operation in cache memory, it will save time compared to having to get it from random access memory. L2 (that is, level-2) cache memory is on a separate chip (possibly on an expansion card) that can be accessed more quickly than the larger "main" memory. A popular L2 cache memory size is 1,024 kilobytes (one megabyte). Lambda switching (sometimes called photonic switching, or wavelength switching) is the technology used in optical networking to switch individual wavelengths of light onto separate paths for specific routing of information. The acronym laser stands for "light amplification by stimulated emission of radiation." Lasers work as a result of resonant effects. The output of a laser is a coherent electromagnetic field. In a coherent beam of electromagnetic energy, all the waves have the same frequency and phase. A hardware load-balancing device (HLD), also known as a layer 4-7 router, is a physical unit that directs computers to individual servers in a network, based on factors such as server processor utilization, the number of connections to a server, or the overall server performance. LCD (liquid crystal display) is the technology used for displays in notebook and other smaller computers. Like light-emitting diode (LED) and gas-plasma technologies, LCDs allow displays to be much thinner than cathode ray tube (CRT) technology. Level of support indicates a specific extent of technical assistance in the total range of assistance that is provided by an information technology product (such as a software product) to its customers. L1 and L2 L2 lambda switching laser layer 4-7 router LCD level of support BACK TO TOP light-emitting polymer Polymer LED (light-emitting diode) - sometimes called light-emitting polymer or polyLED - is a technology based on the use of polymer as the semiconductor material in LEDs. A line doubler is an electronic device that converts analog or digital television (TV) video signals into a format suitable for display on a computer monitor. Linear Tape-Open (LTO) is an open-format tape storage technology developed by Hewlett-Packard (HP), International Business Machines (IBM), and Certance. Little-endian is an order in which the "little end" (least significant value in the sequence) is stored first Load balancing is dividing the amount of work that a computer has to do between two or more computers so that more work gets done in the same amount of time and, in general, all users get served faster. The logical AND symbol is used in Boolean algebra to indicate a conjunction between two statements. A conjunction is true if, but only if, both of its components are true. The most commonly used symbol is an asterisk (*). A logical partition (LPAR) is the division of a computer's processors, memory, and storage into multiple sets of resources so that each set of resources can be operated independently with its own operating system instance and applications. Long-haul optics refers to the transmission of visible light signals over optical fiber cable for great distances, especially without or with minimal use of repeaters. line doubler Linear Tape-Open little-endian load balance logical AND symbol logical partition long-haul optics M M2M M2M is an abbreviation for machine-to-machine, or technology that supports wired or wireless communication between machines. In the Open Systems Interconnection (OSI) model of communication, the Media Access Control layer is one of two sublayers of the Data Link Control layer and is concerned with sharing the physical connection to the network among several computers. The Mac mini from Apple is a low-cost and very compact personal computer that runs the Mac OS X operating system and is sold without a display, keyboard, or mouse. Magnetic resonance imaging (MRI) is a method of obtaining images of the interiors of objects, especially living things such as humans and animals. It does not use ionizing radiation such as X-rays. MAC layer Mac mini magnetic resonance imaging BACK TO TOP A magnetic stripe reader, also called a magstripe reader, is a hardware device that reads the information encoded in the magnetic stripe located on the back of a plastic badge. Magnetic stripe readers can be read by a computer program through a serial port, USB connection, or keyboard wedge, and are generally categorized by the way they read a badge. MRAM (magnetoresistive random access memory) is a method of storing data bits using magnetic charges instead of the electrical charges used by DRAM (dynamic random access memory). A magnetic stripe reader, also called a magstripe reader, is a hardware device that reads the information encoded in the magnetic stripe located on the back of a plastic badge. Main storage is the main area in a computer in which data is stored for quick access by the computer's processor. This term originated in the days of the mainframe computer to distinguish the more immediately accessible data storage from auxiliary storage. Mainframe is an industry term for a large computer, typically manufactured by a large company such as IBM for the commercial applications of Fortune 1000 businesses and other large-scale computing purposes. Historically, a mainframe is associated with centralized rather than distributed computing. Mammoth is a magnetic tape and drive system used for computer data storage and archiving. The tapes measure eight millimeters (8 mm) across. A helical scanning technique is used to optimize the data transfer and storage rates. MPP (massively parallel processing) is the coordinated processing of a program by multiple processors that work on different parts of the program, with each processor using its own operating system and memory. As a measure of computer processor storage and real and virtual memory, a megabyte (abbreviated MB) is 2 to the 20th power bytes, or 1,048,576 bytes in decimal notation. Megachips per second (Mcps) is a measure of the speed with which encoding elements, called chips (not to be confused with microchips), are generated in Direct Sequence Spread Spectrum (DSSS) signals. This speed is also known as the chipping rate. A speed of 1 Mcps is equivalent to 1,000,000, or 106, chips per second. MDI/MDIX is a type of Ethernet port connection using twisted pair cabling. The MDI (for medium dependent interface) is the component of the media attachment unit (MAU) that provides the physical and electrical connection to the cabling medium. Mean-swap-between-failure (MSBF) is a measure used by at least one company to express the reliability of an automated tape library system in which a robot is used to automatically swap tape cartridges when needed. magnetic stripe reader magnetoresistive RAM magstripe reader main storage mainframe Mammoth massively parallel processing MB Mcps MDI/MDIX mean-swap-between-failure BACK TO TOP Media Access Control layer In the Open Systems Interconnection (OSI) model of communication, the Media Access Control layer is one of two sublayers of the Data Link Control layer and is concerned with sharing the physical connection to the network among several computers. Megabytes per second (MBps) describes a unit of data transfer to and from a computer storage device. A megabyte is 2 to the 20th power bytes, or 1,048,576 bytes in decimal notation. Megachips per second (Mcps) is a measure of the speed with which encoding elements, called chips (not to be confused with microchips), are generated in Direct Sequence Spread Spectrum (DSSS) signals. This speed is also known as the chipping rate. A megaflop is a measure of a computer's speed and can be expressed as: * A million floating point operations per second * 10 to the 6th power floating-point operations per second * 2 to the 20th power FLOPS The megahertz, abbreviated MHz, is a unit of alternating current (AC) or electromagnetic (EM) wave frequency equal to one million hertz (1,000,000 Hz). A megapixel (that is, a million pixels) is a unit of image sensing capacity in a digital camera. (A pixel - a word invented from "picture element" is the basic unit of programmable color on a computer display or in a computer image.) In general, the more megapixels in a camera, the better the resolution when printing an image in a given size. Memory is the electronic holding place for instructions and data that your computer's microprocessor can reach quickly. A memory card (sometimes called a flash memory card or a storage card) is a small storage medium used to store data such as text, pictures, audio, and video, for use on small, portable or remote computing devices. Most of the current products use flash memory, although other technologies are being developed. A mesh network is a local area network (LAN) that employs one of two connection arrangements, full mesh topology or partial mesh topology. Mezzanine is a term used to describe the stacking of computer component cards into a single card that then plugs into the computer bus or data path. MFSK (multiple frequency shift keying), also called multi-frequency shift keying, is a method of signal modulation in which discrete audio tone bursts of various frequencies convey digital data. A micro fuel cell is a power source for electronic devices that converts chemical energy into electrical energy. Fuel cells operate by oxidizing combustible fuel, such as hydrogen or alcohol. megabytes per second megachips per second megaflop megahertz megapixel memory memory card mesh network mezzanine MFSK micro fuel cell BACK TO TOP A micrometer (sometimes expressed using the obsolete term, micron), is one-millionth of a meter and can also be expressed as: 10-6 meter One thousandth of a millimeter One 25-thousandth of an inch The micron, officially obsolete as a term of measurement, is sometimes used by microchip and wiring manufacturers in place of micrometer, one-millionth of a meter. A microrobot is a miniaturized, sophisticated machine designed to perform a specific task or tasks repeatedly and with precision. Microrobots typically have dimensions ranging from a fraction of a millimeter up to several millimeters. In general, midrange refers to computers that are more powerful and capable than personal computers but less powerful and capable than mainframe computers. MIMO (multiple input, multiple output) is an antenna technology for wireless communications in which multiple antennas are used at both the source (transmitter) and the destination (receiver) Mini-ITX is a compact motherboard configuration designed to support relatively low-cost computers in small spaces such as in automobiles, set-top boxes, and network devices. The Mini-ITX can also be used in making thin client computers. A minicomputer, a term no longer much used, is a computer of a size intermediate between a microcomputer and a mainframe. Smart Display is a wireless touch screen display device in development at Microsoft. The Smart Display is basically a portable PC monitor that can be carried from room to room in your house, connecting wirelessly to your computer for web-surfing and other activities that require little or no keyboard activity. The Smart Display development project was codenamed "Mira." MISO (multiple input, single output) is an antenna technology for wireless communications in which multiple antennas are used at the source (transmitter). A MultiMediaCard (MMC) is a tiny memory card that uses flash memory to make storage portable among various devices, such as car navigation systems, cellular phones, eBooks, PDAs, smartphones, and digital cameras, music players, and video camcorders, and personal computers. DoCoMo, which offers a product line that uses the FeliCa chip, refers to such a device as a mobile wallet. micrometer micron microrobot midrange MIMO Mini-ITX minicomputer Mira MISO MMC mobile wallet BACK TO TOP molecular cross latch A crossbar latch, also called a molecular crossbar latch, is a nanoscale device with properties similar to those of a conventional silicon transistor, but physically much smaller, having a diameter of approximately 2 nanometers (nm, where 1 nm = 10-9 m). The original Moore's Law derives from a speech given by Gordon Moore, later a founder of Intel, in 1965, in which he observed that the number of microcomponents that could be placed in an integrated circuit (microchip) of the lowest manufacturing cost was doubling every year and that this trend would likely continue into the future. MOSFET (metal-oxide semiconductor field-effect transistor, pronounced MAWS-feht) is a special type of field-effect transistor (FET) that works by electronically varying the width of a channel along which charge carriers (electrons or holes) flow. A motherboard tattoo is a unique code that can be written in the basic input/output system (BIOS) of a computer to ensure that system restore or diagnostic compact discs (CDs) will work only on the machine or line of machines with which the CDs are sold. A motion plan is a multi-step process that can be used by a robot to precisely position itself to perform a specified task. MTBF (mean time between failures) is a measure of how reliable a hardware product or component is. For most components, the measure is typically in thousands or even tens of thousands of hours between failures. Zoned-bit recording (ZBR) is a method of physically optimizing the utilization of a hard drive by placing more sectors in the outer tracks than in the inner tracks. This technique is also known as zone-bit recording, zone recording, zone-density recording, or multiple-zone recording. Multiprocessing is the coordinated processing of programs by more than one computer processor. Multiprogramming is a rudimentary form of parallel processing in which several programs are run at the same time on a uniprocessor. A myoelectric signal, also called a motor action potential, is an electrical impulse that produces contraction of muscle fibers in the body. Moore's Law MOSFET motherboard tattoo motion plan MTBF multiple-zone recording multiprocessing multiprogramming myoelectric signal N nanite nanochip nanocomputer A nanomachine, also called a nanite, is a mechanical or electromechanical device whose dimensions are measured in nanometers (millionths of a millimeter, or units of 10-9 meter). A nanochip is an integrated circuit (IC) that is so small, in physical terms, that individual particles of matter play major roles. A nanocomputer is a computer whose physical dimensions are microscopic. The field of nanocomputing is part of the emerging field of nanotechnology. BACK TO TOP nanofabrication Nanofabrication is the design and manufacture of devices with dimensions measured in nanometers. One nanometer is 10-9 meter, or a millionth of a millimeter. Nanofabrication is the design and manufacture of devices with dimensions measured in nanometers. One nanometer is 10-9 meter, or a millionth of a millimeter. A nanomachine, also called a nanite, is a mechanical or electromechanical device whose dimensions are measured in nanometers (millionths of a millimeter, or units of 10-9 meter). A nanorobot is a specialized nanomachine designed to perform a specific task or tasks repeatedly and with precision. Nanorobots have dimensions on the order of nanometers (a nanometer is a millionth of a millimeter, or 10-9 meter). A nanotransistor is a transistor - the component that acts as an electronic signal switch or amplifier - that is near the scale of a billionth of a meter (or nanometer) in size. In nanotechnology or the building of extremely small machines and computers, a nanotube is a long, cylindrical carbon structure consisting of hexagonal graphite molecules attached at the edges. A nanotube antenna is a device consisting of a carbon nanotube (a long, cylindrical carbon structure consisting of hexagonal graphite molecules attached at the edges) configured to transmit or receive electromagnetic fields (EM fields) at extremely short wavelengths. Network-attached storage (NAS) is hard disk storage that is set up with its own network address rather than being attached to the department computer that is serving applications to a network's workstation users. Near-line storage is the on-site storage of data on removable media. The removable storage idea dates back to the mainframe computer and, in the age of the smaller computer, remains popular among individuals, small businesses, and the large enterprise. A nematic liquid crystal is a transparent or translucent liquid that causes the polarization (that is, the focusing in a plane) of light waves to change as the waves pass through the liquid. IBM's Netfinity is an Intel-based enterprise server line that is based on IBM's X-architecture. A network interface unit (NIU) (sometimes called a network interface device) is a device that serves as a commmon interface for various other devices within a local area network (LAN), or as an interface to allow networked computers to connect to an outside network. nanolithography nanomachine nanorobot nanotransistor nanotube nanotube antenna NAS near-line storage nematic liquid crystal Netfinity network interface unit BACK TO TOP network load balancing Load balancing is dividing the amount of work that a computer has to do between two or more computers so that more work gets done in the same amount of time and, in general, all users get served faster. IBM's 370 mainframes, most RISC-based computers, and Motorola microprocessors use the big-endian approach. TCP/IP also uses the bigendian approach (and thus big-endian is sometimes called network order). NRZ (non-return-to-zero) refers to a form of digital data transmission in which the binary low and high states, represented by numerals 0 and 1, are transmitted by specific and constant DC (direct-current) voltages. Nonvolatile (sometimes written as "non-volatile") storage (NVS) - also known as nonvolatile memory or nonvolatile random access memory (NVRAM) - is a form of static random access memory whose contents are saved when a computer is turned off or loses its external power source. Nonvolatile memory is a general term for all forms of solid state (no moving parts) memory that do not need to have their memory contents periodically refreshed. Northbridge is an Intel chipset that communicates with the computer processor and controls interaction with memory, the Peripheral Component Interconnect (PCI) bus, Level 2 cache, and all Accelerated Graphics Port (AGP) activities. NUMA (non-uniform memory access) is a method of configuring a cluster of microprocessor in a multiprocessing system so that they can share memory locally, improving performance and the ability of the system to be expanded. network order non-return-to-zero non-volatile storage nonvolatile memory Northbridge NUMA O on-screen keyboard A soft keyboard (sometimes called an onscreen keyboard or software keyboard) is a system that replaces the hardware keyboard on a computing device with an on-screen image map. Hardware clustering (sometimes called operating system clustering) is a hardware-based method of turning multiple servers into a cluster (a group of servers that acts like a single system). An erbium amplifier, also called optical amplifier or an erbium-doped fiber amplifier or EDFA, is an optical or IR repeater that amplifies a modulated laser beam directly, without opto-electronic and electrooptical conversion. An optical computer (also called a photonic computer) is a device that uses the photons in visible light or infrared (IR) beams, rather than electric current, to perform digital computations. operating system clustering optical amplifier optical computer BACK TO TOP optical disc An optical disc is an electronic data storage medium that can be written to and read using a low-powered laser beam. Optical storage is any storage method in which data is written and read with a laser for archival or backup purposes. Typically, data is written to optical media, such as CDs and DVDs. Organic thin-film transistor (OTFT) technology involves the use of organic semiconducting compounds in electronic components, notably computer displays. Oscillation, in general, is a periodic fluctuation between two things; in the broadest sense, oscillation can occur in anything from a person's decision-making process to tides and the pendulum of a clock. optical storage organic thin-film transistor oscillation P P-Ink Photonic ink (P-Ink) is a substance that can change color electronically. Unlike earlier prototype electronic inks, which could only display two color values (usually black and white), photonic ink can display any color value in the spectrum. The P/390 is basically an IBM mainframe system adapted to run on a personal computer. A P/390 comes on a single card that contains a System/390 instruction set, allowing operating systems such as OS/390, MVS, VM, and VSE, to be installed. In storage, a pagefile is a reserved portion of a hard disk that is used as an extension of random access memory (RAM) for data in RAM that hasn't been used recently. Parallel presence detect (PPD) is a method of using resistors to communicate a memory module's speed and density to the basic input/output system (BIOS) when a computer boots (starts or restarts). In computers, parallel processing is the processing of program instructions by dividing them among multiple processors with the objective of running a program in less time. PRAM (parameter RAM or parameter random access memory) is a special battery-powered form of random access memory in certain Macintosh computers where vital system information such as the date and time are stored. In personal computers, a partition is a logical division of a hard disk created so that you can have different operating systems on the same hard disk or to create the appearance of having separate hard drives for file management, multiple users, or other purposes P/390 pagefile parallel presence detect parallel processing parameter RAM partition BACK TO TOP patch panel A patch panel is a mounted hardware unit containing an assembly of port locations in a communications or other electronic or electrical system. PDA (personal digital assistant) is a term for any small mobile hand-held device that provides computing and information storage and retrieval capabilities for personal or business use, often for keeping schedule calendars and address book information handy. PDP-11 (Programmed Data Processor-11) is one of the most famous computers in computing history, one of a series manufactured by Digital Equipment Corporation (DEC) from the early 1960s through the mid1990s. PDP-11, which was sold in 1970 for $10,800, was the only 16-bit computer ever made by the company. Permittivity, also called electric permittivity, is a constant of proportionality that exists between electric displacement and electric field intensity. This constant is equal to approximately 8.85 x 10-12 farad per meter (F/m) in free space (a vacuum). In education, the Personal Response System (PRS) is an instructional technology tool composed of a proprietary software application that is installed on the facilitator's computer, a wireless receiver, and hand-held infrared transmitters that have been assigned to students to record their responses to multiple choice or yes/no questions. A personal video recorder (PVR) is an interactive TV recording device, in essence a sophisticated set-top box with recording capability (although it is not necessarily kept on top of the television set). A petabyte is a measure of memory or storage capacity and is 2 to the 50th power bytes or, in decimal, approximately a thousand terabytes. PFC (power factor correction; also known as power factor controller) is a feature included in some computer and other power supply boxes that reduces the amount of reactive power generated by a computer. A phased antenna system consists of two or more active antenna elements, arranged so the electromagnetic fields effectively add in some directions and cancel in other directions. PHOLED (phosphorescent organic light-emitting device) is a proprietary display technology developed by the Universal Display Corporation (UDC) that uses soluble phosphorescent small molecule materials to create organic light-emitting devices (OLEDs). An optical computer (also called a photonic computer) is a device that uses the photons in visible light or infrared (IR) beams, rather than electric current, to perform digital computations. PDA PDP-11 permittivity Personal Response System personal video recorder petabyte PFC phased antenna system PHOLED photonic computer BACK TO TOP photonic switching Lambda switching (sometimes called photonic switching, or wavelength switching) is the technology used in optical networking to switch individual wavelengths of light onto separate paths for specific routing of information. A photovoltaic cell (PV cell) is a specialized semiconductor diode that converts visible light into direct current (DC). Some PV cells can also convert infrared (IR) or ultraviolet (UV) radiation into DC electricity. In computers, a pipeline is the continuous and somewhat overlapped movement of instruction to the processor or in the arithmetic steps taken by the processor to perform an instruction. Pipelining is the use of a pipeline. Pixie dust is the name that IBM is using for its antiferromagneticallycoupled (AFC) media technology, which can increase the data capacity of hard drives to up to four times the density possible with current drives. The term "pizza box server" refers to the shape of a computer server enclosed in a rectangular and horizontally-arranged chassis and often installed in a rack with similar servers. PPGA (plastic pin grid array) is a microchip design from Intel that has the silicon core of the microchip facing down toward the computer motherboard. Broadband over Power Line (BPL) is a technology that allows Internet data to be transmitted over utility power lines. (BPL is also sometimes called Power-line Communications or PLC.) A PLUGE (picture line-up generation equipment) pattern is a test pattern used to calibrate the black level on a video display. Power over Ethernet (PoE) is a technology for wired Ethernet LANs (local area networks) that allows the electrical current, necessary for the operation of each device, to be carried by the data cables rather than by power cords. Polarization, also called wave polarization, is an expression of the orientation of the lines of electric flux in an electromagnetic field (EM field). Polarization can be constant -- that is, existing in a particular orientation at all times, or it can rotate with each wave cycle. In a computer, a polled interrupt is a specific type of I/O interrupt that notifies the part of the computer containing the I/O interface that a device is ready to be read or otherwise handled but does not indicate which device. Polymer LED (light-emitting diode) - sometimes called light-emitting polymer or polyLED - is a technology based on the use of polymer as the semiconductor material in LEDs. photovoltaic cell pipelining pixie dust pizza box server plastic pin grid array PLC PLUGE pattern PoE polarization polled interrupt polymer LED BACK TO TOP port redirector A serial port server, also called a serial server or port redirector, is a device that transfers data between a computer serial port (COM port) and an Ethernet local area network (LAN). A portable keyboard (or handheld keyboard) is one that is designed to be used with wireless devices, such as personal digital assistants (PDAs) and smartphones. Portable media center is a term for a handheld multimedia device that can play digital music, image, and movie files that have been downloaded from the Internet or stored on a personal computer. A barcode reader, also called a price scanner or point-of-sale (POS) scanner, is a hand-held or stationary input device used to capture and read information contained in a bar code. PFC (power factor correction; also known as power factor controller) is a feature included in some computer and other power supply boxes that reduces the amount of reactive power generated by a computer. Power-up (or the synonym "power-on") is a verb meaning to apply electrical power to a device - that is, to "turn it on" as most of us would say about turning on a light switch when entering a dark room. Broadband over Power Line (BPL) is a technology that allows Internet data to be transmitted over utility power lines. (BPL is also sometimes called Power-line Communications or PLC.) PPGA (plastic pin grid array) is a microchip design from Intel that has the silicon core of the microchip facing down toward the computer motherboard. Preboot Execution Environment (PXE) refers to various methods of getting an IBM-compatible computer, typically running Windows, to boot up without the need for a hard drive or boot diskette. Pressure sensing allows a robot to tell when it collides with something, or when something pushes against it. In computers, a printer is a device that accepts text and graphic output from a computer and transfers the information to paper, usually to standard size sheets of paper. A processor is the logic circuitry that responds to and processes the basic instructions that drive a computer. ProLiant, an "industry standard" computer server from Compaq, typifies the popularly-priced server that is designed to satisfy general computing needs at various levels in an enterprise. In software development, a prototype is a rudimentary working model of a product or information system, usually built for demonstration purposes or as part of the development process. portable keyboard portable media center POS scanner power factor controller power-up Power-Line Communications PPGA Preboot Execution Environment pressure sensing printer processor ProLiant prototype BACK TO TOP proximity sensing Proximity sensing is the ability of a robot to tell when it is near an object, or when something is near it. This sense keeps a robot from running into things. The PS/2 was IBM's second generation of personal computers. Announced in 1987 together with the initial release of the OS/2 operating system, the PS/2 series offered a number of improvements over IBM's original PC series. A PS/2 connector is a round connector with six PINs that some makes of personal computer use for the keyboard or mouse connection.v PS/2 PS/2 connector Q QAM QAM (quadrature amplitude modulation) is a method of combining two amplitude-modulated (AM) signals into a single channel, thereby doubling the effective bandwidth. A quantum dot is a particle of matter so small that the addition or removal of an electron changes its properties in some useful way. QXGA (Quantum Extended Graphics Array) is a display mode in which the resolution is 2048 pixels horizontally by 1536 pixels vertically (2048 x 1536). This results in 3,145,728 pixels in the image (sometimes referred to as 3.2 million pixels). The term quantum mirage refers to a phenomenon that may make it possible to transfer data without conventional electrical wiring. quantum dot Quantum Extended Graphics Array quantum mirage R R/390 rack-mounted RAID An R/390 is the P/390-PCI card installed on IBM's RS/6000 server. Rack-mounted describes a unit of electronic equipment that is housed in a metal framework called an equipment rack. RAID (redundant array of independent disks; originally redundant array of inexpensive disks) is a way of storing the same data in different places (thus, redundantly) on multiple hard disks. Double-parity RAID (redundant array of independent disks), also called diagonal-parity RAID, Advanced Data Guarding (RAID_ADG), or RAID-6, is a method of protecting against multiple storage drive failures by creating two sets of parity data on an array of hard disks. RAM (random access memory) is the place in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer's processor RAMAC (pronounced RAY-mac; IBM does not spell out the initials) is a multiple-disk storage subsystem from IBM that emphasizes faulttolerance and is intended for large enterprises. RAID-6 RAM RAMAC BACK TO TOP Rambus Rambus DRAM RAS Rambus Dynamic Random Access Memory (RDRAM) is a memory subsystem that promises to transfer up to 1.6 billion bytes per second. RDRAM (Rambus Dynamic Random Access Memory) is a memory subsystem that promises to transfer up to 1.6 billion bytes per second. In computer memory technology, RAS (row address strobe) is a signal sent to a dynamic random access memory (DRAM) that tells it that an associated address is a row address. Composite video, also called baseband video or RCA video, is the analog waveform that conveys the image data in a conventional National Television Standards Committee (NTSC) television signal. reagent is a chemical substance that is used to create a reaction in combination with some other substance. A real-time clock (RTC) is a battery-powered clock that is included in a microchip in a computer motherboard. A reconfigurable tactile display (RTD) is a control interface that provides physical touch input, but that can be configured by programming. Recordable DVD (sometimes called writable DVD) is a DVD technology that allows a PC user to write data one or more times to a DVD with the PC's DVD drive. Redundant describes computer or network system components, such as fans, hard disk drives, servers, operating systems, switches, and telecommunication links that are installed to back up primary resources in case they fail. Refurbish, in everyday language, is "to renew or to restore to a new condition and/or appearance". Reliability is an attribute of any computer-related component (software, or hardware, or a network, for example) that consistently performs according to its specifications. A replicator is an object or organism that can make copies of itself. RZ (return-to-zero) refers to a form of digital data transmission in which the binary low and high states, represented by numerals 0 and 1, are transmitted by voltage pulses having certain characteristics. Reverse engineering is taking apart an object to see how it works in order to duplicate or enhance the object. Recordable DVD (sometimes called writable DVD) is a DVD technology that allows a PC user to write data one or more times to a DVD with the PC's DVD drive. RCA video reagent real-time clock reconfigurable tactile display recordable DVD redundant refurbish reliability replicator return-to-zero reverse engineering rewritable DVD BACK TO TOP RIBLOE The Remote Insight Board -- Lights Out Edition (RIBLOE) is a Peripheral Component Interconnect (PCI) card intended for the remote management of Compaq servers. A ring network is a local area network (LAN) in which the nodes (workstations or other devices) are connected in a closed loop configuration. Adjacent pairs of nodes are directly connected. Other pairs of nodes are indirectly connected, the data passing through one or more intermediate nodes. A robot is a machine designed to execute one or more tasks repeatedly, with speed and precision. There are as many different types of robots as there are tasks for them to perform. Roomba is the name of an intelligent robotic vacuum produced by iRobot Corporation of Burlington, Mass., a company that also created the CoWorker telepresence robot and the PakBot device for the military. Intended to be an affordable device for the home, Roomba was developed by a team from MIT's Artificial Intelligence (AI) Lab. Robotics is a branch of engineering that involves the conception, design, manufacture, and operation of robots. Robust (pronounced RO-buhst) is an adjective commonly applied in marketing literature to information technology products in several ways. A rocker switch is an on/off switch that rocks (rather than trips) when pressed, which means one side of the switch is raised while the other side is depressed much like a rocking horse rocks back and forth. Roentgen is IBM's development name for a liquid crystal display (LCD) that has 2560 x 2048 pixels and is described as providing an image "as precise as the original paper document." A rollout is a staged series of activities that often accumulate meaning as they occur. ring network robot robotic vacuum robotics robust rocker switch Roentgen Rollout S S-Video S-Video (Super-Video, sometimes referred to as Y/C Video, or component video) is a video signal transmission in which the luminance signal and the chrominance signal are transmitted separately to achieve superior picture clarity. Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.) is an interface between a computer's start-up program or BIOS (basic input/output system) and the computer hard disk. S/390 is IBM's large server (or mainframe) line of computer systems, which are marketed to the world's Fortune 1000 and many mid-size companies as a "tried-and-true" system with a history that stretches back to the System/360 of the early 1960s. S.M.A.R.T. S/390 BACK TO TOP Storage area management (SAM) is a still-evolving set of procedures, services, and standards for comprehensively managing the infrastructure of a storage area network (SAN), including all components within all servers, the disk arrays, the tape libraries, the switches, the routers, and the programs. A storage area network (SAN) is a high-speed special-purpose network (or subnetwork) that interconnects different kinds of data storage devices with associated data servers on behalf of a larger network of users. A SAN file system (that is, a storage area network file system) is programming that enables the sharing of the same copies of files stored on common storage media among multiple servers that may have different operating systems. A SAN island is a storage area network (SAN) that exists as a discrete, isolated entity within a larger SAN. The components of a SAN island are usually all located in the same building, or even within a single room. Serial-attached SCSI (SAS) is a method used in accessing computer peripheral devices that employs a serial (one bit at a time) means of digital data transfer over thin cables. Self-Scanned Amorphous Silicon Integrated Display (SASID) is the trade name for an active-matrix liquid crystal display (AMLCD) technology developed by Sarnoff Corporation. Serial ATA (Serial Advanced Technology Attachment or SATA) is a new standard for connecting hard drives into computer systems. As its name implies, SATA is based on serial signaling technology, unlike current IDE (Integrated Drive Electronics) hard drives that use parallel signaling. ScanDisk is a Windows utility used to check your hard disk for errors and to correct problems that are found. A scanning tunneling microscope (STM) is a device that obtains images of the atoms on the surfaces of materials. A serial communications interface (SCI) is a device that enables the serial (one bit at a time) exchange of data between a microprocessor and peripherals such as printers, external drives, scanners, or mice. Seat management is a method of coordinating all the workstations in an enterprise network by overseeing the installation, operation, and maintenance of hardware and software at each workstation. Secondary storage is all addressable data storage that is not currently in the computer's main storage or memory Secondary storage is all addressable data storage that is not currently in the computer's main storage or memory SAM SAN SAN file system SAN island SAS SASID SATA ScanDisk scanning tunneling microscope SCI seat management secondary storage sector BACK TO TOP SED The surface-conduction electron-emitter display (SED) is a flat-panel, high-resolution display currently under development by Canon and Toshiba. Self-scanning checkout, also called "self-checkout" is an automated process that enables shoppers to scan, bag, and pay for their purchases without human assistance. In computers, sequential consistency is best defined by its inventor, Leslie Lamport, who declared that a multiprocessing system had sequential consistency if: "...the results of any execution is the same as if the operations of all the processors were executed in some sequential order, and the operations of each individual processor appear in this sequence in the order specified by its program." A SerDes or serializer/deserializer is an integrated circuit (IC or chip) transceiver that converts parallel data to serial data and vice-versa. self-scanning sequential consistency SerDes Serial ATA (Serial Advanced Technology Attachment or SATA) is a Serial Advanced Technology Attachment new standard for connecting hard drives into computer systems. In a computer, a serial peripheral interface (SPI) is an interface that enables the serial (one bit at a time) exchange of data between two devices, one called a master and the other called a slave. A serial port server, also called a serial server or port redirector, is a device that transfers data between a computer serial port (COM port) and an Ethernet local area network (LAN). When a computer is booted (started), serial presence detect (SPD) is information stored in an electrically erasable programmable read-only memory (EEPROM) chip on a synchronous dynamic random access memory (SDRAM) memory module that tells the basic input/output system (BIOS) the module's size, data width, speed, and voltage. A serial port server, also called a serial server or port redirector, is a device that transfers data between a computer serial port (COM port) and an Ethernet local area network (LAN). Serial-attached SCSI (SAS) is a method used in accessing computer peripheral devices that employs a serial (one bit at a time) means of digital data transfer over thin cables. A SerDes or serializer/deserializer is an integrated circuit (IC or chip) transceiver that converts parallel data to serial data and vice-versa. A server accelerator card (also known as an SSL card) is a Peripheral Component Interconnect (PCI) card used to generate encryption keys for secure transactions on e-commerce Web sites. A server farm is a group of computers acting as servers and housed together in a single location. A server farm is sometimes called a server cluster. serial peripheral interface serial port server serial presence detect serial server serial-attached SCSI serializer/deserializer server accelerator card server farm BACK TO TOP server virtualization Server virtualization is the masking of server resources (including the number and identity of individual physical servers, processors, and operating systems) from server users. Small form factor (SFF) refers to any of several physically compact connector designs that have been developed for use in fiber optic systems. Small form-factor pluggable (SFP) is a specification for a new generation of optical modular transceivers. SGI (Silicon Graphics) is a leading manufacturer of high-performance computing, data management, and visualization products. Shadow RAM is a copy of Basic Input/Output Operating System (BIOS) routines from read-only memory (ROM) into a special area of random access memory (RAM) so that they can be accessed more quickly. In computer programming, shared memory is a method by which program processes can exchange data more quickly than by reading and writing using the regular operating system services. Shotgun debugging is the debugging of a program, hardware, or system problem using the approach of trying several possible solutions at the same time in the hope that one of them will work. A SIMM (single in-line memory module) is a module containing one or several random access memory (RAM) chips on a small circuit board with PINs that connect to the computer motherboard. SIMO (single input, multiple output) is an antenna technology for wireless communications in which multiple antennas are used at the destination (receiver). SISO (single input, single output) refers to a wireless communications system in which one antenna is used at the source (transmitter) and one antenna is used at the destination (receiver). Small Particle Reagent (SPR), a suspension of molybdenedisulfide powder in a detergent solution, is used for fingerprint detection on wet, oily, or dirty surfaces which may be unsuitable for other methods. A smart home or building is a home or building, usually a new one, that is equipped with special structured wiring to enable occupants to remotely control or program an array of automated home electronic devices by entering a single command. A smart card is a plastic card about the size of a credit card, with an embedded microchip that can be loaded with data, used for telephone calling, electronic cash payments, and other applications, and then periodically refreshed for additional use. SFF SFP SGI shadow RAM shared memory shotgun debugging SIMM SIMO SISO Small Particle Reagent smart building smart card BACK TO TOP Smart Display is a wireless touch screen display device in development at Microsoft. The Smart Display is basically a portable PC monitor that can be carried from room to room in your house, connecting wirelessly to your computer for web-surfing and other activities that require little or no keyboard activity. A smart wristwatch is a wristwatch that not only tells time but, using a wireless connection to an information source, can show you the news, stock, sports scores, or weather; remind you of meetings on your Outlook calendar; provide instant messaging input from others; and update the time when you move to another time zone. SMP (symmetric multiprocessing) is the processing of programs by multiple processors that share a common operating system and memory. In symmetric (or "tightly coupled") multiprocessing, the processors share memory and the I/O bus or data path. A keystroke logger, sometimes called a system monitor, is a hardware device or small program that monitors each keystroke a user types on a specific computer's keyboard. System-on-a-chip (SoC) technology is the packaging of all the necessary electronic circuits and parts for a "system" (such as a cell phone or digital camera) on a single integrated circuit (IC), generally known as a microchip. A soft keyboard (sometimes called an onscreen keyboard or software keyboard) is a system that replaces the hardware keyboard on a computing device with an on-screen image map SOLED (stacked organic light-emitting device) is a display technology from the Universal Display Corporation (UDC) that uses a stack of transparent organic light-emitting devices (TOLEDs) to improve resolution and enhance full-color quality. Solid-state storage is a nonvolatile, removable storage medium that employs integrated circuits (ICs) rather than magnetic or optical media. Sonar is an acronym (like radar, now spelled with all lower-case letters) for sound navigation and ranging. A sound card (also referred to as an audio card) is a peripheral device that attaches to the ISA or PCI slot on a motherboard to enable the computer to input, process, and deliver sound. Southbridge is an Intel chipset that manages the basic forms of input/output (I/O) such as Universal Serial Bus (USB), serial, audio, Integrated Drive Electronics (IDE), and Industry Standard Architecture (ISA) I/O in a computer. Smart Display smart wristwatch SMP sniffer keystroke logger SoC soft keyboard SOLED solid-state storage sonar sound card Southbridge BACK TO TOP When a computer is booted (started), serial presence detect (SPD) is information stored in an electrically erasable programmable read-only memory (EEPROM) chip on a synchronous dynamic random access memory (SDRAM) memory module that tells the basic input/output system (BIOS) the module's size, data width, speed, and voltage. In computer processing, if a processor changes the value of an operand and then, at a subsequent time, fetches the operand and obtains the old rather than the new value of the operand, then it is said to have seen stale data. A standalone dump is the copying of the contents of computer main storage (random access memory) to another storage device, usually for the purpose of debugging a programming problem. Standby power is electrical power that a device consumes when not in present use, but plugged in to a source of power and ready to be used. A star network is a local area network (LAN) in which all nodes (workstations or other devices) are directly connected to a common central computer. Variations in packet arrival time, called jitter, can occur because of network congestion, timing drift, or route changes. The jitter buffer, which is located at the receiving end of the voice connection, intentionally delays the arriving packets so that the end user experiences a clear connection with very little sound distortion. A stepper motor is a special type of electric motor that moves in increments, or steps, rather than turning smoothly as a conventional motor does. Stepping is a number used by Intel to identify what level of design change a microprocessor was built to. Storage distance extension refers to any of several different technologies that allow data communication in Fibre Channel storage area networks (SANs) over long spans of fiber optic cable. Virtualization is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage virtualization is commonly used in a storage area network (SAN). Strange matter is matter consisting of atoms whose nuclei contain pairs of particles called strange quarks. In computer or memory technology, a strobe is a signal that is sent that validates data or other signals on adjacent parallel lines. A supercomputer is a computer that performs at or near the currently highest operational rate for computers. SPD stale data standalone dump standby power star network static jitter buffer stepper motor stepping storage distance extension storage virtualization strange matter strobe supercomputer BACK TO TOP supercomputer center superconducting quantum interference device In general, a supercomputer center is a site with a supercomputer that is shared by a number of other sites, usually research sites A superconducting quantum interference device (SQUID) is a mechanism used to measure extremely weak signals, such as subtle changes in the human body's electromagnetic energy field. DLT (digital linear tape) is a form of magnetic tape and drive system used for computer data storage and archiving. A variant of DLT technology, called SuperDLT, makes it possible to store upwards of 100 GB on a single cartridge. Superdome is a high-end 64-bit, Hewlett-Packard (HP) PA-8600 processor-based UNIX server designed for e-commerce customers using very large databases. SuperDLT Superdome T T-Rex The z990, also known by its code name T-Rex, is a 64-bit mainframe computer from IBM that contains up to 32 processors, together capable of executing approximately 9,000 million instructions per second (MIPS), nearly three times the processing power of IBM's z900. In computers, tape is an external storage medium, usually both readable and writable, consisting of a loop of flexible celluloid-like material that can store data in the form of electromagnetic charges that can be read and also erased. In computers, tape backup is the ability to periodically copy the contents of all or a designated amount of data from its usual storage device to a tape cartridge device so that, in the event of a hard disk crash or comparable failure, the data will not be lost. Tempest was the name of a classified (secret) U.S. government project to study (probably for the purpose of both exploiting and guarding against) the susceptibility of some computer and telecommunications devices to emit electromagnetic radiation (EMR) in a manner that can be used to reconstruct intelligible data. The terahertz, abbreviated THz, is a unit of electromagnetic (EM) wave frequency equal to one trillion hertz (1012 Hz). Texture sensing is the ability of a robot end effector to determine whether a surface is smooth or rough. A display screen made with TFT (thin-film transistor) technology is a liquid crystal display (LCD), common in notebook and laptop computers, that has a transistor for each pixel (that is, for each of the tiny elements that control the illumination of your display). tape tape backup Tempest terahertz texture sensing TFT BACK TO TOP thermal grease Thermal grease, also called thermal paste or thermal compound, is a substance used to promote better heat conduction between two surfaces and is commonly used between a microprocessor and a heatsink. In the computer industry, a thin server is a PC that contains just enough hardware and software to support a particular function that users can share in a network, such as access to files on a storage device, access to CD-ROM drives, printing, or Internet access. A display screen made with TFT (thin-film transistor) technology is a liquid crystal display (LCD), common in notebook and laptop computers, that has a transistor for each pixel (that is, for each of the tiny elements that control the illumination of your display). A thyristor is a four-layer semiconductor device, consisting of alternating P type and N type materials (PNPN). A thyristor usually has three electrodes: an anode, a cathode, and a gate (control electrode). The terahertz, abbreviated THz, is a unit of electromagnetic (EM) wave frequency equal to one trillion hertz (1012 Hz). Tiered storage is the assignment of different categories of data to different types of storage media in order to reduce total storage cost. A twisted nematic (TN) display is a common type of liquid-crystal display (LCD) that consists of a substance called a nematic liquid crystal that is confined between two plates of polarized glass. TOLED (transparent organic light-emitting device) is a display technology being developed by the Universal Display Corporation (UDC) that uses transparent electrodes and light emitting materials in an organic light-emitting device (OLED). Toslink is a connector format for fiber optic digital audio cables. A transponder is a wireless communications, monitoring, or control device that picks up and automatically responds to an incoming signal. The term is a contraction of the words transmitter and responder. A traveling-wave tube (TWT) is a specialized vacuum tube used in wireless communications, especially in satellite systems. Full HDTV, also referred to as ultra-HD, true HDTV, and 1080p, is a television (TV) display technology that surpasses the video quality and sharpness of the original high-definition television (HDTV) technology, providing an image resolution of 1920 by 1080 pixels. Turnkey is a product or service that is designed, supplied, built, or installed fully complete and ready to operate. The term implies that the end user just has to turn a key and start using the product or service. A two-spindle system, also called a twin-spindle system, is a computer design with two internal storage drives. thin server thin-film transistor thyristor THz tiered storage TN display TOLED Toslink transponder traveling-wave tube true HDTV turnkey two-spindle system BACK TO TOP U U UHDV A U is a standard unit of measure for designating the height in computer enclosures and rack cabinets. A U equals 1.75 inches. UHDV (ultra high definition video) is a technology that provides video image resolution containing 16 times as many pixels as HDTV (high definition television). Ultra DMA (UDMA, or, more accurately, Ultra DMA/33) is a protocol for transferring data between a hard disk drive through the computer's data paths (or bus) to the computer's random access memory (RAM). Full HDTV, also referred to as ultra-HD, true HDTV, and 1080p, is a television (TV) display technology that surpasses the video quality and sharpness of the original high-definition television (HDTV) technology, providing an image resolution of 1920 by 1080 pixels. Ultrasound is acoustic (sound) energy in the form of waves having a frequency above the human hearing range. The highest frequency that the human ear can detect is approximately 20 thousand cycles per second (20,000 Hz). In a network, the Universal Naming Convention (UNC) is a way to identify a shared file in a computer without having to specify (or know) the storage device it is on. An HD (high-definition) upconverter, also known as a digital television (DTV) upconverter, is a device that converts the digital data on a DVD to a format that can be viewed directly on a high-definition television (HDTV) receiver without intermediate conversion to an analog signal. An uninterruptible power supply (UPS) is a device that allows your computer to keep running for at least a short time when the primary power source is lost. A jump drive - also known as a USB drive, flash drive, keychain drive, or disk-on-key - is a plug-and-play portable storage device that uses flash memory and is lightweight enough to attach to a key chain. Ultra DMA ultra HDTV ultrasound UNC up converter UPS USB drive V VCD VCD (also called video CD, video compact disc or "disc") is a compact disk format based on CD-ROM XA that is specifically designed to hold MPEG-1 video data and to include interactive capabilities. A VCR (videocassette recorder) is an electromechanical device for recording and playing back full-motion audio-visual programming on cassettes containing magnetic tape. A vertical cavity surface emitting laser (VCSEL) is a specialized laser diode that promises to revolutionize fiber optic communications by improving efficiency and increasing data speed. The acronym VCSEL is pronounced 'vixel.' VCR VCSEL BACK TO TOP vectored interrupt In a computer, a vectored interrupt is an I/O interrupt that tells the part of the computer that handles I/O interrupts at the hardware level that a request for attention from an I/O device has been received and and also identifies the device that sent the request. VeriChip is an injectable identification chip that can be inserted under the skin of a human being to provide biometric verification. Vertical interval time code (abbreviated VITC and sometimes pronounced VIHT-see) is a timing signal that is part of a video recording. VLSI (very large-scale integration) is the current level of computer microchip miniaturization and refers to microchips containing in the hundreds of thousands of transistors. VHS (Video Home System) is a widely-adopted videocassette recording (VCR) technology that was developed by Japan Victor Company (JVC) and put on the market in 1976. Video RAM (VRAM) means in general all forms of random access memory (RAM) used to store image data for a computer display. A virtual keyboard is a computer keyboard that a user operates by typing (moving fingers) on or within a wireless- or optical-detectable surface or area rather than by depressing physical keys. Virtual (or logical) memory is a concept that, when implemented by a computer and its operating system, allows programmers to use a very large range of memory or storage addresses for stored data. Virtual tape is the use of a special storage device that manages lessfrequently needed data so that it appears to be stored entirely on tape cartridges when some parts of it may actually be located in faster, hard disk storage. The programming for a virtual tape system is sometimes called a virtual tape server (VTS). A VoIP phone is a telephone set designed specifically for use in a voice over IP (VoIP) system by converting standard telephone audio into a digital format that can be transmitted over the Internet, and by converting incoming digital phone signals from the Internet to standard telephone audio. VeriChip Vertical interval time code very large-scale integration VHS video RAM virtual keyboard virtual memory virtual tape virtual tape server VoIP phone W WAN interface card watchdog timer A WAN interface card, or WIC, is a specialized network interface card (NIC) that allows devices to connect to a wide area network. A watchdog timer (WDT) is a device or electronic card that performs a specific operation after a certain period of time if something goes wrong with an electronic system and the system does not recover on its own. BACK TO TOP wave polarization Polarization, also called wave polarization, is an expression of the orientation of the lines of electric flux in an electromagnetic field (EM field). Polarization can be constant -- that is, existing in a particular orientation at all times, or it can rotate with each wave cycle. Lambda switching (sometimes called photonic switching, or wavelength switching) is the technology used in optical networking to switch individual wavelengths of light onto separate paths for specific routing of information. A wearable robot is a machine that facilitates telepresence, a sophisticated form of interactive remote control. A Web server farm can be either (1) a Web site that has more than one server, or (2) an Internet service provider (ISP) that provides Web hosting services using multiple servers. A whiteboard is a non-electronic variation of the traditional "rewriteable" schoolroom blackboard, but is white instead of black and of a material that can be written on with colored markers (known as dry erase markers). Windows Hardware Quality Labs (WHQL) is a Microsoft procedure for certifying that the hardware for peripherals and other components is compatible (works as expected) with Microsoft Windows operating systems. Wiegand is the trade name for a technology used in card readers and sensors, particularly for access control applications. Wiegand devices were originally developed by HID Corporation. Window RAM (WRAM), unrelated to Microsoft Windows, is very highperformance video RAM that is dual-ported and has about 25% more bandwidth than VRAM but costs less. Wiegand is the trade name for a technology used in card readers and sensors, particularly for access control applications. Wiegand devices were originally developed by HID Corporation. In computer storage media, WORM (write once, read many) is a data storage technology that allows information to be written to a disc a single time and prevents the drive from erasing the data. A wrap plug, also known as a loopback plug, is a special plug that can be inserted into a port on a communications device to perform a diagnostic test called a loopback test. wavelength switching wearable robot Web server farm whiteboard WHQL Wiegand Window RAM WinFrame WORM wrap plug X X server An X server is a server of connections to X terminals in a distributed network that uses the X Window System. BACK TO TOP X terminal An X terminal is typically a diskless computer especially designed to provide a low-cost user interface for applications that run in a network X server as part of a distributed X Window System. Y Y/C Video S-Video (Super-Video, sometimes referred to as Y/C Video, or component video) is a video signal transmission in which the luminance signal and the chrominance signal are transmitted separately to achieve superior picture clarity. A Yagi antenna, also known as a Yagi-Uda array or simply a Yagi, is a unidirectional antenna commonly used in communications when a frequency is above 10 MHz. Yagi antenna Z z990 The z990, also known by its code name T-Rex, is a 64-bit mainframe computer from IBM that contains up to 32 processors, together capable of executing approximately 9,000 million instructions per second (MIPS), nearly three times the processing power of IBM's z900 Zoned-bit recording (ZBR) is a method of physically optimizing the utilization of a hard drive by placing more sectors in the outer tracks than in the inner tracks. This technique is also known as zone-bit recording, zone recording, zone-density recording, or multiple-zone recording. A Zip drive is a small, portable disk drive used primarily for backing up and archiving personal computer files. ZBR Zip disk