S

SAA: System Application Architecture (computer)
IBM suite of standards that provide programming and communications interface and protocol standards, in greater or lesser degree, for all of their product lines.

SAM: Security Accounts Manager (computer/Windows)
Windows Networking protected subsystem that maintains the SAM database and provides an application programming interface (API) for accessing the database.

SAM Database (computer/Windows)
Database of security information including information such as user account names and passwords, and settings of security policies. For a Windows Networking workstation, it is managed with User Manager. For a Windows Networking Advanced Server domain, it is managed with User Manager for Domains.

Sample (A/V, communications, computer, M/M)
In audio terminology, a digital representation of a sound created by a combination of microphone, amplifier, and analog-to-digital converter. Samples are stored in the form of a PCM file or memory block. They are usually of relatively short length and are then digitally processed by looping or other forms of repetition to create sounds of longer duration. Digital signal processing is used to change the pitch and other characteristics of samples, so a single sample may be used to create a range of notes.

Sample Playback Synthesizer (A/V, computer, M/M)
Synthesizer capable of using digitally recorded, instrumental waveform samples to create voices. More sophisticated sampling synthesizers combine record as well as playback of sampled sounds.

Sampling Rate (communications, computer)
In digitizing operations, the frequency with which samples are converted. The higher the rate, the closer to real-world sound (analog) the digital form creates. In communications, for example, the higher the sample rate for digitized voice, the more accurate the digitization of the human voice occurs. At over 800 times per second, in today's digital transmission systems, a human voice regeneration - from a digital pattern -is un-distinguishable from the actual analog generation of the original sounds. In digital recording, it is the recording speed of a sound's successive digital samples. Sampling rate is another measure of a digital sound sample's resolution. Standard digital recording sample rates are 11.025 kHz, 22.05 kHz, and 44.1 kHz.

Sampling Voltmeter (communications)
Special class of voltmeter that uses sampling techniques and is particularly effective in measuring high-frequency signals or signals mixed with noise. High-frequency instruments can operate on signals with frequencies as high as 12 gigahertz (GHz); amplitudes as small as 1 millivolt (mv).

Safe Area (A/V)
In audio/visual production, a term to describe, in picture composition, the boundaries set up as a guide so that important action or titles will not be lost in the transmission process.

Sans Serif Font (computer/Windows)
Font in which the characters do not have finishing strokes: Arial is an example.

SAP (A/V, communications, M/M)
Secondary Audio Program - NTSC audio channel that is used for auxiliary transmission, such as foreign language broadcasting or teletext transmission. One of the most common applications is for bilingual transmissions.

Sapphire Substrate (computer/microelectronics)
Materials which provide a uniform dielectric constant, controlled orientation, thermal conductivity, and the single crystal surface desired for SOS (silicone on sapphire transistor), hybrid IC (integrated circuit), and other microcircuit systems. The material may be grown (in furnace heating) directly in ribbons, tubes, filaments, and sheets.

Satellite Link (communications)
Signal that travels from earth to a satellite and back down again.

Saticon (A/V)
Video tube trademark name; made in Japan and the United States, it utilizes silicon as its principal light-sensitive element and is distinguished by high resolution and low flare.

Saturation (A/V, communications, microelectronics)
Condition in which, after a sufficient increase in a causal force, further increase in the force produces no additional increase in the resultant effect. In an npn transistor when the collector voltage becomes more negative then the base voltage, the base-to-collector diode becomes forward-biased; the collector then emits and the transistor is saturated. In colorimetry, the purer a color is, the higher its saturation. Radiation from a color of low saturation contains frequencies throughout much of the visible spectrum.

Saturation Current (A/V, communications, microelectronics)
Term having a variety of specific applications but generally meaning the maximum current which can be obtained under certain conditions. In a simple two-element vacuum tube, it refers to either the space-charge-limited current on one hand, or the temperature-limited current on the other. In a gaseous-discharge device, the saturation current is the maximum current which can be obtained for a given mode of discharge. Attempts to increase the current result in a different type of discharge. Such a case would be the transition from a glow discharge to an arc discharge. A third case is that of a semiconductor. Here again, the saturation current is the maximum current which just precedes a change in conduction mode.

Scalable Font (computer/printer)
Font that can be generated in various sizes without distortion.

Scale (A/V)
Term used in audio/visual production to describe basic fees for television talent as prescribed by the talent union (i.e. NABET) (i.e. paying to scale, etc.).

Scan (A/V)
In audio/visual production, a feature of a videocassette recorder (also referred to as search) that enables the user to move quickly forward or backward through the video tape (video disc if a laser disc player is used) with visible images, but no sound.

Scanner (computer)
Device that reads text and images directly into the computer (hand-held, or flatbed types).

Scanning (A/V)
In audio/visual terms, the movement of the electron beam from left to right and from top to bottom onto the cathode-ray tube (television screen).

Scanning Area (A/V)
In audio/visual terms, the picture area that is scanned by the camera pickup unit, and, in more general terms, the picture area that is actually reproduced by the camera and relayed back to studio monitors; it is then further processed by the masking of the television screen and in general transmission loss, through the transmission system, to the home.

Scan Rate (A/V, computer)
Number of times a cathode-ray-tube screen is refreshed in a finite time period: the total number of lines that are illuminated on a video display screen in one time period.

Schedule Service (computer/Windows)
Supports and is required for use of the "at" command. The "at" command can schedule commands and programs to run on a computer at a specified time and date.

Scheduling Algorithms (computer)
Purpose of scheduling algorithms is to allocate computer resources to the programs that require them in a large multiuser system. Most computer systems consist of a finite set of resources, such as processor cycles, memory locations, and input/output devices, which many programs or applications may need to use. At each decision point, a scheduling algorithm decides which of several competing processes should next receive a resource.

Scoop (A/V)
In audio/visual production, a term describing a scoop-like television floodlight.

Scope (computer)
In programming terminology, a variable's extent of visibility (definition). The variable's scope depends upon where it is declared (Global, Public, Local, etc.).

Scratch-Pad Memory (computer/microelectronics)
RAM (Random Access Memory) used by microprocessors as a temporary, fast-access store for interim results, variable data, and working figures or information.

Scratch Files (computer)
Term sometimes used to describe temporary files of short duration (as in multi-level sorting applications, where several files are created and then deleted automatically before the final file is prepared). During the processing of substantial files of data, it often becomes necessary to create temporary files for later use by copying all or part of a data set to another memory location. Such a temporary file (or associated storage location) is a scratch file. Sometimes, scratch-file data is unchanged from what was originally read into the computer memory during a sorting application.

Screen (A/V, microelectronics)
In microelectronics fabrication, the tension-mesh material with an open pattern through which ink penetrates to place an image or the substrate. The screen is above and parallel to the substrate during screen printing. In A/V and computing terms, the video display terminal that presents information to the user, while working at the computer.

Screen (computer/printing)
Traditionally, the glass or film device through which a photograph is converted into a halftone: now used to mean the halftone pattern, itself. Also, the screen input/output device connected to the computer to visualize the input of information (video display).

Screen Buffer (computer)
Size reserved in memory for the command prompt display.

Screen Fonts (computer)
Fonts displayed on a computer screen. Soft-font manufacturers often provide screen fonts that closely match the soft fonts for the printer. This ensures that documents look the same on the screen as they do when printed.

Screen Printing (computer/microelectronics)
In microelectronic fabrication, the art of depositing conductive, resistive, and insulating materials on a dielectric base. This deposition can be made through selected open areas in screens with differing types of inks or pastes that are forced through open areas of the screen by squeegee motion, on the substrat. In some cases, masks instead of conventional mesh screens may be used.

Screen Ruling (computer/printing)
Number of lines per inch (or metric terms) on a halftone screen.

Screen Saver (computer)
Application programs that blank the screen after a period of time when the computer has not been used: it substitutes any number of graphic, scenic representations.

Screen Simulation (A/V)
In audio/visual production terms, a type of chroma keying in which the chroma key area is confined to a simulated television screen, typically behind a newscaster.

Scribing (computer/microelectronics)
In microelectronics fabrication, scratching a tooled line or laser path on a brittle substrate to allow a wafer to be cleft or broken along the line (analogous to glass cutting), producing IC chips (integrated circuit) when all the breaks are completed.

Scrim (A/V)
In audio/visual production, a spun-glass material that is put in front of a lighting instrument as an additional light diffuser. In theatrical terms a scrim can be a backdrop, semitransparent drape or screen that can be seen through close-up, but that may have a scene painted on the front that appears solid from a distance (from the audience).

Script Marking (A/V)
In audio/visual production, a term that is sometimes used to describe a director's written symbols on a script to indicate major cues.

Scroll (computer)
To continuously move forward, backward or sideways through the images on screen or within a window. Scrolling implies continuous and smooth movement, a line, character or pixel at a time, as if the data were on a paper scroll being rolled behind screen.

Scroll Bar (computer/Windows)
Bar that appears at the right and/or bottom edge of a window or list box whose contents are not completely visible. Each scroll bar contains two scroll arrows and a scroll box, which enable the user to scroll through the contents of the window or list box.

Scroll Buffer (computer/Windows)
In Terminal (Windows Icon), the buffer that holds typed or received information that does not fit on the screen.

SCSI (computer)
Small Computer System Interface ("scuzzy") - a peripheral interface for up to seven devices. Available on PCs by plugging in a SCSI controller board. SCSI provides a high-speed parallel data transfer of up to 4 MegaBytes per second and has the advantage of connecting multiple peripherals while taking up only one slot in the computer.

SDK (computer)
Abbreviation for Microsoft Software Development Kit for Windows. The SDK includes the files and documentation necessary for Windows programming in the C++ Language.

SDLC (communications, computer)
Synchronous Data Link Control - IBM's primary link protocol used in SNA (system network architecture) networks. It is a bit-oriented synchronous protocol that is a subset of the ISO/OSI HDLC protocol (high level data link control).

Sealed Module (computer)
Disk drive containing the disks, access arms, read/write heads all sealed-in together.

Search And Replace Function (computer)
Word processing function that finds and changes each instance of a repeated item.

SECAM (A/V)
Système Electronic Pour Couleur avec Mèmoire: SECAM is the French standard for television transmission (819 horizontal lines per frame displayed at 25 frames per second). SECAM is the standard for most of Eastern Europe, including the former USSR and in African countries where French is the most common second language.

Secondary Color (computer/printing)
Color that results from mixing two primary colors: orange is created from yellow and red; purple is created from red and blue; green is created from blue and yellow.

Secondary Emission (computer/microlectronics)
Emission of electrons from the surface of a solid into vacuum caused by bombardment with charged particles, in particular with electrons.

Secondary Storage (computer)
Additional storage, often on disk, for information and programs. Secondary storage is separate from the central processing unit (CPU) and memory (also called auxiliary).

Sector (computer)
Smallest unit of storage read or written by a disk. Hardware may vary the disk speed to fit more sectors into tracks located on the outer edges of the disk platter. The sector is the physical unit called for by an instruction (i.e. READ TRACK 17 SECTOR 23). DOS, for example, reads one or more sectors from a disk and writes their data to buffer memory. Data from the buffer is written to the disk as necessary (always when the file is closed).

Sector Method (computer)
Term used to describe a method of organizing information on a disk in which each track is divided into sectors that hold a specific number/amount of bytes of information.

Security Accounts Manager: SAM (computer/Windows)
Windows Networking protected subsystem that maintains the SAM database and provides an application programming interface (API) for accessing the database.

Security Identifier (computer/Windows)
Unique name that identifies a logged-on user to the security system. Security IDs (SIDs) can identify one user or a group of users.

Security Log (computer/Windows)
Records security events: helps track changes to the security system and identify any breaches to security. For example, depending on the Audit settings in User Manager, attempts to log on to the system may be recorded in the security log (see event).

Security Policies (computer/Windows)

For a Windows Networking workstation, the security policies consist of the Account, User Rights, and Audit policies, and are managed with User Manager. For a Windows Networking Advanced Server domain, the security policies consist of the Account, User Rights, Audit, and Trust Relationships policies, and are managed with User Manager for Domains.

Seek (computer)
To locate a specific byte, sector, cluster, record, or chunk within a disk file.

Seek Time (computer)
Time it takes to move read/write head to a particular track on a disk after the instruction has been executed. The majority of a disk's access time is made up of seek time.

SEG: Special Effects Generator (A/V)
In audio/visual production, an electronic image generator that can generate a wide variety of special effects such as wipe patterns (circle, diamond, horizontal, vertical).

Segue (A/V)
Pronounced "seg-guay", a combination of, or transition between, two sounds without intervening silence. Segue is sometimes applied to transitions between video images with or without special effects, such as dissolves or wipes.

Select (computer/Windows)
In Windows, to highlight an item by clicking it with the mouse or using key combinations. Selecting does not initiate an action. After selecting an item, the user must choose the action they want to affect (see Choose and Highlighted).

Selection Cursor (computer/Windows)
Pointer that shows where a user is, in a window, menu, or dialog box and what has been selected. The selection cursor can be a highlight or as a dotted rectangle around text.

Selective Focus (A/V)
In audio/visual terms, emphasizing an object in a shallow depth of field through focus, while keeping its foreground and background out of focus.

Selectivity (communications)
Ability of a radio receiver to separate a desired signal frequency from other signal frequencies, some of which may differ only slightly from the desired value. Selectivity is achieved by using tuned circuits that are sharply peaked and by increasing the number of tuned circuits. With a sharply peaked circuit, the output voltage falls off rapidly for frequencies increasingly lower or higher than that to which the circuit is tuned.

Self Electrooptic Effect Device: SEED (communications/photonics)
Bistable device based on a multiple quantum well structure in a PIN photodiode.

SEM (computer/microelectronics)
Standard Electronic Module: in microelectronics fabrication, a subassembly configuration format which meets a particular U.S. Navy set of specifications. SEM is also an abbreviation for a Scanning Electron Microscope.

Semaphore (computer)
Term used to describe synchronization primitives that may be used in a computer system to coordinate the activities of two or more programs or processes that are running at the same time and sharing information. They may be used for elementary interprocess communication, to guarantee exclusive access to shared data, to protect a section of code that must be executed without certain kinds of interruptions (such a code segment is called a critical region or critical section), or to allocate a set of scarce resources.

Semiconductor (communications, computer)
Solid state substance that can be electrically altered. Certain elements in nature, such as silicon, perform like semiconductors when they are chemically combined with other elements. A semiconductor is halfway between a conductor, a material that conducts electricity, and an insulator, a material that resists electricity. When charged with electricity or light, semiconductors change their state from nonconductive to conductive or vice versa. The most significant semiconductor may be the transistor, which simply acts like an on/off switch, allowing current to pass or not to pass through it.

Semiconductor Devices (communications, computer)
Devices in which the characteristic distinguishing electron conduction takes place within a semiconductor, ranging from the single unit transistor to multiple unit devices such as the semiconductor rectifier. Other devices are diodes, photocells, thermistors, thyristors.

Semiconductor Diode (computer/microelectronics)
Two-terminal device utilizing properties of semiconductors from which it is constructed. Silicon and germanium are the semiconductors most often used in diodes, however, other materials may be used for special purposes: cadmium sulphide and cadmium selenide in photoconductors; gallium phosphide, gallium arsenide-phosphide, and silicon carbide in light-emitting diodes; and gallium arsenide in microwave generators.

Semiconductor Integrated Circuit (communications, computer)
Physical realization of a number of electric elements inseparably associated on or within a continuous body of semiconductor material, to perform the function of a circuit.

Semiconductor Memory (computer/microelectronics)
Devices for storing digital information that are fabricated by using integrated circuit technology. Semiconductor memories are widely used to store programs and data in almost every digital system. Almost all of the memories are a form of random-access memory (RAM), where any storage location can be accessed in the same amount of time.

Semiconductor Rectifier (computer/microelectronics)
Electrical component which conducts current preferentially in one direction and inhibits the flow of current in the other direction by utilizing the properties of a semiconductor material such as silicon. A major use of the semiconductor rectifier is as a component in electrical equipment designed to convert electrical power from alternating current (ac) to direct current (dc). Such total equipment, consisting of not only the components but also circuit breakers, bus work, fuses, sharing reactors, control circuits, is often referred to as semiconductor rectifier equipment.

Semiscripted (A/V)
Term used in audio/visual production to describe a program or show for which the dialogue is indicated but not completely written out: the opening and closing are usually fully scripted, with the middle only left semiscripted.

Sensitivity (A/V, communications, computer)
Ability of the output of a device or system to respond to an input stimulus. Sensitivity is closely related to noise. Quite often the limiting factor in increasing the sensitivity of devices or systems is the inherent noise level. Examples of sensitivity are visual contrast sensitivity, which is the ability of the eye to distinguish between the luminance of adjacent areas; galvanometer sensitivity, expressed as the ratio of the scale deflection in millimeters per microampere input; and radio receiver sensitivity, which is actually expressed in terms of reciprocal sensitivity in the form of antenna voltage in microvolts necessary to cause a specified output. The sensitivity of a radio receiver is a measure of its ability to reproduce weak broadcast signals with satisfactory output volume. The sensitivity of a television camera determines its ability to deliver a usable picture signal under poor lighting conditions.

Sensor (communications, computer)
Device that detects a real world condition, such as motion, heat or light and converts the condition into an analog or digital representation of it. An optical sensor detects the intensity or brightness of light, or the intensity of red, green and blue for color systems.

Sequence Control Structure (computer)
Term used to describe a program in which one statement follows another in sequence.

Sequencer (A/V, computer)
Device or application that records and plays back musical compositions in MIDI message format. Computer-based sequencer applications enable MIDI scores to be composed and edited. Sequencers are often incorporated within high-end keyboard synthesizers. Stand-alone sequencers are also available. They can record a performance from a MIDI keyboard and then be transported to a computer site and played into a sequencing application for editing.

Sequencing (A/V)
Term used in audio/visual production to describe the control and structuring of a shot sequence (same as Picturiazation).

Sequential Access File (computer)
File having one record follow another in the sequence applying to the application. Most text files are sequential.

Sequential File Organization (computer)
Term used for the arrangement of records in ascending or descending order by a key.

Sequential File Processing (computer)
Term used for processing in which records are usually in order according to a key field.

Sequential Machines (communications computer)
Term sometimes used to describe a mathematical model of a certain type of sequential switching circuit, where the dependence of the output, on past inputs, implies that a sequential machine has intelligent or "learn-able" memory, based on past routines.

Serial (communications, computer)
Technique for handling binary information (data) which has more than one bit: the bits are acted upon one at a time (contrast with parallel).

Serial And Parallel Port (communications, computer)
One serial and one parallel connector for connecting peripheral devices to a personal computer. Although more than one of each may be necessary for a particular requirement, the serial port allows you to hook up a modem, mouse or printer, and the parallel port lets you hook up to a printer (generally, this is the configuration).

Serial Communications
Process of transmitting information as a stream of bits in a specified length, usually over one or two pairs of wires such as a telephone line. Modems and the COM ports of PCs are serial communications devices.

Serial I/O (communications, computer)
Transfer of information, data, bits, between a microprocessor and peripheral devices (I/O -input/output devices) bit by bit, sequentially, over a single conductor.

Serial Interface (computer)
Interface between a computer and a printer in which the computer sends single bits of information to the printer, one after the other. Serial, asynchronous, and RS-232 interfaces are all the same type of interfaces.

Serial Operation (communications, computer)
Organization of information, data manipulation within a computer circuitry where the bits of a byte (or a word) are transmitted one at a time along a single line. The serial mode of operation is slower than parallel operating, but utilizes less complex circuitry.

Serial Port (computer & communications)
An external connector on a computer that is used to connect a modem or other serial device. The typical serial port uses a DB-25 or DB-9 connector.

Serial Processing (computer)
Term used for processing where a program must finish running before another can begin.

Serial Transmission (communications)
Transmission of data one bit at a time, one bit following the next. Contrast with parallel transmission, which transmits one or more bytes (8, 16 etc.) at the same time. As an analogy, in a horse race, only having one (serial) starting gate, where each horse must start and run through before the next horse can start and run through; by contrast to having many (parallel) gates, where all the horses start and run through at the same time.

Series Circuit (computer/microelectronics)
Electric circuit in which the principal circuit elements have their terminals joined in sequence so that a common current flows through all the elements. It may consist of any number of passive and active elements, such as resistors, inductors, capacitors, electron tubes, and transistors.

Server (communications, computer/Windows)
Device or application providing data to a client or application using the data. The client may modify and return the data to the server. The data may be in the form of a file or a network file server, an object in an OLE server, or topic values of a DDE server. For Windows Networking, it refers to a computer that provides shared resources to network users. For Windows Networking Advanced Server domains, it refers to a computer that receives a copy of the domain's security policy and domain database, and authenticates network logons.

Server Manager (communications, computer/Windows)
In Windows Networking Advanced Server, an application used to view and administer domains, workgroups, and computers.

Server Message Block: SMB (communications, computer)
In Local Area Networking, a formatted message used to request and reply to requests for file and print services on the LAN.

Server On a LAN (communications, computer)
Server workstation on a Local Area Network assigned to be responsible for managing the Local Area Network and its services. In larger LANs there can be File Servers, Network Servers, Database Servers, Print Servers, and Application Servers.

Server Services (communications, computer/Windows)
Provides remote procedure call (RPC) support, and file, print, and named pipe sharing.

Service (computer/Windows)
Process that performs a specific system function and often provides an application program interface (API) for other processes to call. Windows Networking services are RPC-enabled, meaning that their API routines can be called from remote computers.

Service Access Point: SAP (communications, computer)
Means of identifying a user of the services of a protocol entity. A protocol entity provides one or more SAPs for use by various-level entities.

Service Bureaus (computer)
Term used in data processing that describes a company that sells computer processing time and related services, usually in conjunction with access to networks and highly sophisticated, often proprietary software applications (or specialized services).

Service Program (computer)
Term sometimes used to describe a pre-written program that performs routine file-handling tasks, such as file conversions and sort/mergers (also can be called a utility).

Service Routine (computer)
Term used in computer programming to describe a set of instructions to perform a programmed operation, typically, in response to an interrupt.

Servo Stabilizer (A/V)
In audio/visual terms, a mechanism in special camera mounts, such as the Steadicam, that can absorb wobbles and jitters that occur during the production.

Servo System (A/V)
In audio/visual production, any components of the videotape editing systems that use tracking and sync pulse to regulate videotape speed and video head rotation.

Servo Zoom Control (A/V)
In audio/visual terms, a zoom control that activates motorized mechanisms.

Session (communications)
In communications and local area networking, a term used to describe a logical and physical path under SNA (IBM System Network Architecture) that connect two NAUs (network access units) for data transmission.

Session Layer (communications)
Fifth Layer of the seven-layer ISO/OSI model concerned with network management functions including passwords and network monitoring/reporting (ISO - International Standards Organization, OSI - Open Systems Interconnection).

Set (computer/microelectronics)
In microelectronics, an input on a flip-flop not controlled by the clock, and used to effect the Q output. It is this input through which signals can be entered to get the Q output to go to "1"; NOTE: it can never get Q to go to "0" (see Asynchronous Inputs).

Set (A/V)
In audio/visual terms, arrangement of scenery and properties to indicate a locale or mood.

SET (computer/DOS)
DOS Command that sets or displays environment variables. These variables can be set and used to control batch files and programs.

Set Light (A/V)
In audio/visual, a term used to describe lighting for a set (see background lighting).

Set Module (A/V)
In audio/visual production terms, a piece of scenery of standard dimensions that allows a great variety of interchange, placement, and re-configuration.

SETVER (computer/DOS)
DOS Command that displays or sets the version table. The version table sets the version number that the VER command returns when specific programs are run; instead of returning the default.

Shading (A/V)
In audio/visual production, a term used to describe the adjustment of the picture contrast; controlling the color and/or black & white levels. The term is sometimes, also used to describe an image defect associated with camera pickup tubes in which some portion of the image is darker. It is generally the outer edges which are darker, and shading can be corrected by processing the signal. This term can also refer to the process of manipulating camera exposure in a video image.

Shadow Mask (A/V)
In audio/visual production, a perforated metal screen used as a component part of a kine tube on a picture monitor or TV receiver, which, through the use of holes or slots, aligns the three RGB (red, green, blue) beams so that they strike the correct phosphor coating elements on the inside surface, viewing screen of the cathode-ray tube.

Share (A/V, computer/Windows)
Making resources (directories, printers, ClipBook pages), available to network users. In audio/visual terminology, the percentage of television households tuned to a station in relation to all other stations in the viewing area.

Share Name (computer/Windows)
In Windows Networking, the name of a shared resource.

Shared Directory (computer/Windows)
Directory that network users can connect to (same as Shared Network Directory).

Shared Page (computer/Windows)
In ClipBook, a page that has been made available for others to access.

Shared Resource (computer/Windows)
Device, data, or program that is used by more than one other device or program. For Windows Networking, shared resources refer to any resource that is made available to network users, such as directories, files, printers, and named pipes.

Shareware (computer)
Term sometimes used to describe software that is given away free, although the author(s) or creator(s) hopes the satisfied users will voluntarily contribute to pay for it.

Shear Tester (computer/microelectronics)
In microelectronics fabrication, shear testers are used to determine the integrity of a material, or to test the adherence between two attached items. It is used for testing eutectic and epoxy die-bond strengths, and for adherence testing gold-wire ball bonds, gold and solder chip bumps, external lead frame, coined and welded gold electrical contacts, thick film plating, and other fabrications for their integral strengths.

Shell (computer)
Outer layer of a program that provides the user interface, or way of commanding the computer. Shells are typically add-on programs created for command-driven operating systems, such as UNIX and DOS. The shell provides a menu-driven or graphical icon-oriented interface to the system in order to make it easier to use.

Shift (computer/microelectronics)
Process of moving information, data, bits, from one place to another. Generally, many bits are moving in an integrated circuit, at any one time. Shifting is done synchronously and by command of the microprocessor clock. An 8-bit word (byte), for example, can be shifted sequentially (serially); if one bit goes out, a second bit takes its place, the 3rd bit takes the place of the 2nd bit, and so on, up to the completed 8-bit word (byte). This is also referred to as Shifting Left - or - Shifting Right. It takes 8 clock pulses to shift an 8-bit word (byte). By contrast, in a parallel load or parallel shift, all 8 bits of a word (byte) can be shifted simultaneously, but they must remain in their intact position.

Shifting (computer/microelectronics)

Term also used for the process of moving data that is "store", in a storage device relative to the boundaries of the devices (as opposed to moving it in and out of the device). This device, in which the shift is performed, is called the shift register.

Shift Register (computer/microelectronics)
Arrangement of circuits, specifically flip-flops, which are used to shift serially or in parallel. Binary words (8, 16, 32, 64 bit-length etc.) are generally parallel loaded and then held temporarily in parallel mode, or serially shifted out of the registers.

Shooting Ratio (A/V)
In audio/visual production, the amount of videotape actually used expressed as a percentage of the amount recorded.

Shortcut Key (computer)
Key combination providing access to a menu choice, macro, or other application function. A shortcut key is used in place of the mouse. Also called an accelerator key.

Shot (A/V)
In audio/visual production, the amount of videotape recorded from the instant the camera is triggered to run to the instant it is triggered to stop: used interchangeably with the terms "scene" and "take"; several shots make a sequence.

Shotbox (A/V)
In audio/visual production, a box containing various controls for presetting zoom speed and field of view; usually mounted on the camera panning bar.

Shotgun Microphone (A/V)
Highly directional microphone that can be aimed directly at a sound source, thus picking up the desired sound at a fairly long distance (up to several hundred feet) while excluding surrounding extraneous noise.

Shot List (A/V)
In audio/visual production, a chronological list of each shot of raw videotape together with notation of its content, and running time.

Shot Sheet (A/V)
In audio/visual production, a list of every shot a particular camera has to capture. It is usually attached to the camera to help the camera operator remember the shot sequence.

Show Format (A/V)
In audio/visual production, listing the order of the elements or segments of the program, or show, in their order of appearance.

Show Rhythm (A/V)
Term used in audio/visual production to indicate how well the parts of the program or show relate to each other sequentially; how well the show is flowing along.

Shrink (computer/Window)
In Windows, to reduce a window to an icon at the bottom of the desktop using the Minimize button. The document or application remains open and can be the active document or application (still open and available to the user).

Shunting (computer/microelectronics)
Act of connecting one device to the terminals of another so that the current is divided between the two devices in proportion to their respective admittances. Shunting is widely used in ammeters, galvanometers, and other current-measuring instruments to bypass part of the current around the instrument so as to change the measuring range. Resistors are frequently shunted across tuned circuits to broaden the tuning characteristics. Shunting is equivalent to connecting in parallel. Shunting one resistor with another gives a lower resistance for the combination, whereas shunting one capacitor with another gives a total capacitance equal to the sum of the individual values.

Shuttle Search (A/V)
In audio/visual production, a feature on a videocassette recorder that allows a picture to be seen while the tape is running at high speed forward and reverse.

SIC (computer/microelectronics)
Abbreviation sometimes used for Semiconductor Integrated Circuit.

SID: Security ID (computer/Windows)
Unique name that identifies a logged-on user to the security system. Security IDs can identify one user or group of users.

Sideband (communications)
Frequency band located either above or below the carrier frequency within which fall the frequency components of the wave produced by the process of modulation. Apart from the carrier, all components of an amplitude-modulated sinusoidal carrier, when taken together, form a pair of sidebands extending on either side of the carrier frequency in mirror symmetry and containing all the frequency components of the modulating wave. Sidebands above and below the carrier frequency are called upper and lower sidebands.

Side Bar (A/V)
In audio/visual production, term used to describe an offshoot of the main story, and oddity, something offbeat, a story within a story.

Side Effect (computer)
Consistent result of a computing procedure that is in addition to, or peripheral to, the basic result. It is often evidenced as a change in values of variables that are not local to the procedure. Although a side effect may be of no consequence or undesired, in many cases, it is just what is desired from the procedure: for example, when one of the procedure arguments is an output argument. Side effects can sometimes result in difficult problems associated with the evaluation of arithmetic expressions.

Side Light (A/V)
In audio/visual production, a directional light that may be coming from the side of an object; it acts as additional fill light, helping to provide image and object contour.

Sigma Delta Modulation (A/V, communications)
Type of differential pulse code modulation (DPCM). In sigma-delta modulation, the difference (delta) used to convert to and from digital and analog signals is based on the sum (sigma) of a number of preceding samples rather than the preceding sample itself. Sigma-delta (or delta-sigma) modulation is used with 1-bit converters and requires high values of oversampling. 64x is common in consumer, prosumer audio CD drives.

Signal (communications)
Physical form of transmitted data, such as electrical pulses and frequencies.

Signal Generator (communications)
Piece of electronic test equipment that delivers a sinusoidal output of accurately calibrated frequency. The frequency may be anywhere from audio to microwave, depending upon the intended use of the instrument.

Signal to Noise Ratio (communications)
The ratio of the amplitude (power, volume) of a data signal to the amount of noise (interference) in the line. Usually measured in decibels, the signal to noise ratio measures the clarity or quality of a transmission channel or electronic device. Signal-to-noise ratio is expressed in dB or dBr (relative). A large negative number is desired or preferred.

Signature (A/V, computer/printing)
In audio/visual terms, a specific video and/or audio symbol characteristic of a program. In computerized printing systems, the signature is a group of pages printed on a sheet of paper which, when folded and trimmed, will appear in their proper sequence.

Significance Arithmetic (computer)
Applied accuracy-monitoring technique providing rules for estimating the number and positions of significant digits of the possible approximations that result when an arithmetic operation is applied to operands in an approximation equation. For example, the significance arithmetic rule for addition/subtraction of possible approximations is that (if no overflow to a higher indexed most significant digit occurs) the position of the least significant digit is the higher index of the least significant digit positions of the operands, and (if overflow does occur) the least significant digit position is taken as one unit higher.

Silent Film (A/V)
Film that does not have a sound track, or film that is run silent.

Silicon (computer/microelectronics)
Brittle gray, crystalline chemical element which, in its pure state, services as a semiconductor substrate in microelectronic fabrication. It is naturally found in compounds such as silicon dioxide. It is the base material for making chips. Next to oxygen, silicon is the most abundant element in nature and is found in a natural state in the majority of rocks and sand on earth. The silicon used in chips is mined from rocks and purified. Its atomic structure (Si) and abundance make it an ideal semiconductor material. Pure silicon is obtained by putting it through a chemical process at high temperatures. In its molten state, the silicon is mixed (doped) with other chemicals to alter its electrical nature.

Silicon Diode (computer/microelectronics)
Small silicon rectifier of either the point-contact, bonded-contact, or junction type. It is distinguished from a silicon rectifier by size only, with the rectifier being used for units of relatively large power-handling capacity. Point-contact types originally found application in microwave detectors and mixers. The bonded and microjunction types have shown a marginal life and stability. Almost all modern diodes are of the diffused planar type. Silicon diodes, contrasted with germanium diodes, are capable of operating at higher temperatures and therefore at higher power levels. Operation at temperatures as high as 200 degrees Celsius, and voltages up to 1,000 volts are possible.

Silicon Gate (computer/microelectronics)
Type of MOS (metal oxide semiconductor) in which the gate is made of silicon instead of metal. It is faster and denser than the metal-gate MOS.

Silicon Nitride (computer/microelectronics)
Compound of silicon and nitrogen deposited on the surface of silicon monolithic ICs (integrated circuits), to impart greater stability.

Silicon On Sapphire (computer/microelectronics)
Transistor Device: silicon is grown on a passive insulating base (sapphire) and then selectively etched away to forma a solid state device.

Silicon Oxide (computer/microelectronics)
Silicon monoxide or dioxide (or a mixture). Silicon Dioxide can be deposited on a silicon IC (integrated circuit) as insulation between metallization layers.

Silicon Valley (computer)
Area around Palo Alto and Sunnyvale in the Santa Clara Valley of California (south of San Francisco) that is noted for its large number of high-technology companies.

SIMD (computer)
Single Instruction stream Multiple Data Stream - a computer architecture that performs one operation on multiple sets of data, for example, an array processor. One computer or processor is used for the control logic and the remaining processors are used as slaves, each executing the same instruction (contrast with MISD or MIMD).

SIMM (computer)
Single In-line Memory Module - a narrow, printed circuit board about three inches long that holds eight or nine memory chips. SIMMs plug into special sockets.

Simple Device (computer, M/M)
Multimedia (MCI) devices not requiring a file or other identifying element to fully describe it. The CDAudio device is a simple device because Windows does not consider and audio CD track to be a file.

Simplex Transmission (communications)
Transmission of information in one, pre-assigned, pre-designated direction only.

Simulator (computer/microelectronics)
Software development tool which executes a program, almost as the final system would, but slowly so as to produce a detailed program recording of all testing events.

Simulation (computer)
Development and use of computer models for the study of actual or postulated dynamic systems. The essential characteristic of simulation is the use of models for study and experimentation rather than the actual system modeled. In practice, it has come to mean the use of computer models because modern electronic computers are so much superior for most kinds of simulation: computer modelling dominates the field.

Simulcast (A/V)
In audio/visual production, a feature on a videocassette recorder, also known as FM simulcast, that enables the user to record audio from an FM tuner or Receiver.

Simultaneous Processing (computer)
Execution of more than one program at the same time, each using a separate CPU.

Sine Wave (communications)
Uniform wave that is generated by a single frequency.

Single Channel Per Carrier (communications)
Technique for allocating satellite capacity in which the bandwidth is divided into a number of individual frequency channels.

Single Entry (computer)
Term sometimes used for a unique point where execution of a program module begins.

Single Exit (computer)
Term sometimes used for a unique point where termination of a program module occurs.

Single In-Line Memory Module: SIMM (computer)
Printed circuit board that holds RAM chips (in increments of 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 or more megabytes) for easy installation of extra memory in a personal computer system.

Single Range Bar Graph (computer)
Bar graph that plots the values of only one variable.

Single Sideband (communications)
Electronic signal processing technique in which a spectrum of intelligence is translated from a zero reference frequency to a higher frequency without a change of frequency relationships within the translated spectrum. Single-sideband signals have no appreciable carrier. After translation, only the single-sideband energy remains. This form of intelligence transmission requires amplification of the SSB signal prior to transmission and occupies only the spectrum bandwidth of the intelligence. These advantages allow SSB to be selected for communication of voice and digital data wherever there is a premium on having a minimum of transmitted power and available frequency spectrum.

Single Stepping (computer)
Debugging process executing the source code one line at a time. The process enables the inspection of the value of variables, finding infinite loops, or removing other bugs.

SISD (computer)
Single Instruction stream Single Data stream - the architecture of a serial computer (contrast with SIMD, MISD or MIMD).

Site License (computer)
License permitting a customer to make multiple copies of a software application.

Sizing Handle (computer)
Small black rectangles on the perimeter of Visual Basic that control objects that appear on the surface of the form in design mode. Sizeable control objects may be shrunk or enlarged by dragging the rectangles.

Skewing (A/V, computer/microelectronics)
Term that is sometimes used to describe the time delay or offset between any two signals in relation to each other. In audio/visual terms, it describes distortion of videotape caused by variations in tape tension which affect the length of the video tracks. It shows up as a hook-like curve at the top of the screen or a curve swinging back and forth. It can be corrected by adjusting the skew control.

Slave (computer)
Computer or peripheral device that is controlled by another computer. For example, a terminal or printer in a remote location that only receives data is a slave. When two personal computers are hooked up via their serial or parallel ports for transmission, the file transfer program may make one computer the master and the other the slave.

Slide Effect (A/V)
In audio/visual production, a visual effect in which the original picture slides off to one corner, revealing a second picture that seems to lie beneath the first.

Slider (computer/Windows)
Synonym for Windows scroll bar. A slider is often used as a fader in audio applications.

Sliding Window Technique (communications)
Method of flow control where transmitting station may send numbered packets within a window of numbers: the window changes dynamically to allow additional packets to be sent.

Slow Lens (A/V)
In audio/visual production, a lens that permits a relatively small amount of light to pass through (high f-stop number); it can be used only in well-lighted areas.

Slow Motion (A/V)
In audio/visual production, a scene in which objects appear to move more slowly than normal. In film, slow motion is achieved through high-speed photography and normal playback. In television, slow motion is achieved by a multiple scanning of each frame. On some videocassette recorders, this special effects feature lets the user view images in slow motion without sound; most even adjust the speed of the slow motion.

Slow Scan TV (A/V, communications)
The transmission of individual video frames over ordinary telephone lines. It is not realtime transmission; it takes several seconds to transmit one frame. Also called electronic still photography (ESP).

SLSI (computer/microelectronics)
Abbreviation for Super Large Scale Integration, the next generation, above VLSI, of integrated circuit density and design that may contain more than 10 million transistors and circuit components on one, monolithic chip substrate.

Slug (A/V)
In audio/visual production, one or two words for quick identification of individual news stories; also, more broadly, identifying information put on each news story, such as the date, the newscast the story is for, the writer's name or initials, and other information.

Small Format (A/V)
In audio/visual terms, small format refers to the small size of the camera pickup tube (in tube-style cameras - usually 2/3rd. inch) or, more frequently, to the narrow width of the videotape; 1/4 inch, 1/2 inch/ 3/4 inch. Small format equipment (cameras and videotape recorders) is actually very small in size and highly portable.

Small Scale Integration (computer/microelectronics)
Circuit of under 10 gates, generally involving one metallization level implemented on a circuit function, in a monolithic (one piece) silicon substrate.

Smart Card (computer)
Credit card sized card, with a built-in microprocessor and memory that can be used as an ID or financial transaction card. When inserted into a reader, it transfers data to and from a computer. It is more secure than a magnetic stripe card and can be programmed to self-destruct if the wrong password is entered too many times. As a financial transaction card, it can store transactions and maintain a bank balance.

SmartDrive (computer/Windows)
In Windows, the Windows cache program.

Smart Terminal (computer)
Terminal without disks that has some local memory to do some processing (on-line edits).

SMDR (communications)
In communications, a feature of PBX systems (private branch exchange - customer owned telecommunications switching system) that provides Station Message Detail Reporting; a sophisticated package providing detailed listings and information on telecommunications usage, by outlet, by device, by feature/function.

Smear (A/V)
In audio/visual production, an image defect caused by image retention on a camera pickup tube as an object moves through the frame (comet tailing effect, can also be evident).

SMP: Symmetrical Multiprocessing (computing, Windows)
Multiprocessing technique used by Windows Networking, sometimes called "scalability": the ability to use multiple processors to enhance performance; for example, the ability to launch two or more (4, 6, 8) processes concurrently, with each process performing multiple tasks on different streams or threads of a program.

SMPTE (A/V, communications)
Society of Motion Picture and Television Engineers: SMPTE time standard, used to synchronize MIDI based music with motion picture or TV frames, is supported by MMEs.

SMPTE/EBU Time Code (A/V)
Electronic signalling recorded on the cue or address track of videotape, on an audio track of a multitrack tape through a time code generator, providing a time address (birthmark) for each frame in hours, minutes, seconds, and frame numbers of elapsed time.

SMT (computer)
Surface Mount Technology - a board packaging technique that mounts chips directly onto the board rather than into receptacles that have been previously soldered onto the board. Boards, generally, can be smaller and built faster with surface mount technology.

SMTP (communications, computer)
Simple Mail Transfer Protocol (UNIX) for sending e-mail messages on a TCP/IP network.

SNA (communications)
Systems Network Architecture: the architecture used by IBM for networking their minicomputer and mainframe systems.

SNADS (communications)
Abbreviation for IBM's System Network Architecture - Distribution Services: an e-mail feature with store and forward messaging capabilities within IBM products.

Snap-Off (computer/microelectronics)
In microelectronics fabrication, the distance from the top of a substrate, in screen printing, to the bottom surface of the screen. A squeegee must stretch the screen this far to meet the substrate to deposit ink. It is set by the "Z" motion adjustment.

Snapshot (A/V)
In audio/visual production, a visual effect in which the individual screen divisions show successively updated freeze frames.

Snapshot (computer, M/M)
Term sometimes used for a single, digitized frame (from a camera, VCR) that can be grabbed (provided it is digitized) and printed while viewing a multi-media program.

Snapstrate (computer/microelectronics)
In microelectronics fabrication, the scored, large area substrate which, after screen printing, may be snapped off or broken apart into smaller sized substrates.

SNMP (communications)
Simplified Network Management Protocol used on TCP/IP (protocol) networks.

SNOBOL (computer)
Software program using string-processing language used mostly by language processors.

Snow (A/V)
In audio/visual terms, electronic interference, looking like snow on the television screen.

SNR (communications)
Signal to Noise Ratio abbreviation.

Sneaker Net (communications, computer)
Human alternative to a local area network. It is made up of people who pass floppy disks back and forth. In small areas it may make more common sense, rather than a LAN.

Snugger (computer/microelectronics)
In microelectronics fabrication, a device for automatically positioning and holding the substrate in proper position during the print cycle, in screen printing.

SOF (A/V)
In audio/visual terms, an abbreviation for Sound On Film.

Soft Fail (communications, computer)
Noise bursts in microelectronic circuits, caused by cosmic-ray particles, that result in spontaneous changes in the information stored in computer memories. These changes are called soft fails. This sensitivity to cosmic rays is one of the unanticipated results of the ever-decreasing size of the components of integrated microelectronic circuits, and it presents new considerations in the development of very-large-scale integrated circuits. The existence of soft fails adds an additional load to any internal correction schemes. Spontaneous flipping a bit stored in a computer memory is referred to as a soft fail, as distinguished from a hard fail where a circuit component is damaged.

Soft Font (computer/printer)
Font that can be downloaded from a personal computer disk to a printer.

Soft Hyphen (computer/printer)
Marker that indicates where a word processing program may hyphenate a word if the word is too long to fit at the end of a line: also called a discretional hyphen. Soft hyphens are not printed unless they are used at the end of a line of text.

Softlight (A/V)
In audio/visual production, a television floodlight that produces extremely diffused light. It has a pan-like reflector and a light-diffusing material over its opening.

Software (computer)
Instructions for the computer. A series of instructions that perform a particular task is called a program or software program. The two major categories of software are system software and application software.

Software Documentation (computer)
Program listings and technical manuals describing the operation and use of the program.

Software Engineering (computer)
Term used to define the process of creating software systems and applies loosely to techniques that reduce high software cost and complexity while increasing reliability.

Software Flexibility (computer)
Term used to describe a property of software that can change easily in response to different user and system requirements. The necessary changes can be classified roughly according to purpose: (1) to adapt the user image (appearance of the program to the user); (2) to adapt to different machine implementations; (3) to accept, support, and/or tolerate different system constraints.

Software Monitor (computer)
Term used to describe an element of a software package that is used for performance measurement purposes. Like other types of instruments (machine monitors), a software monitor is capable of measuring the performance of two categories of objects: the computer system itself; and the computer software programs.

Software Packages (computer)
Term used to describe a computer program or a set of programs which has been designed to perform specific functions useful to a large number of computer users. They are also called software applications packages (word processing, database, spreadsheets, etc.).

Software Piracy (computer)
Piracy refers to the process of copying commercial software without the permission of the originator. It is the dark side of software portability: without portability piracy could not exist. Piracy is found among amateurs, who copy programs for friends without direct monetary gain, and professionals who copy programs for sale at low prices to amateurs.

Software Portability (computer)
Portability for software programs refers to the ease with which a program can be moved from one computer environment to another.

Software Science (computer)
Term used to describe an experimental and theoretical discipline concerned with measurable properties of computer programs. The underlying hypothesis is that a computer program need not be considered solely as an art form, or even as an example of logic, but that instead it could be treated as a structure which may be studied using the classical methods of natural science.

Soft Wipe (A/V)
In audio/visual production, a term used to describe a special effect wipe in which the demarcation line between the two images is softened so the images blend into each other.

Solar Cell (computer/microelectronics)
Semiconductor electrical junction device which absorbs and converts the radiant energy of sunlight directly and efficiently into electrical energy. The conversion of sunlight into electrical energy in a solar cell involves three processes: absorption of the sunlight in the semiconductor material; generation and separation of free positive and negative charges to different regions of the solar cell, creating a voltage in the solar cell; and transfer of these separated charges through electrical terminals to the outside application in the form of electrical current. Growing worldwide demand for energy, increased cost, depletion of non-renewable energy reserves make solar power systems an attractive alternative electricity for a wide range of uses in systems and technology.

Solarize (A/V, computer)
A special effect applied to an image causing luminous flaring of the color transitions as if the image was being viewed directly against the sun.

Solder Systems (computer/microelectronics)
In microelectronic fabrication, processes for ceramic hybrid microcircuits, substrates, lead frames, microassemblies, flat packs, wire memory arrays, ceramic headers, magnetic wire, whereby solder normally has been pre-tinned on the substrate or individual components; or solder pastes provide solder without the need for pre-tinning operations. Temperature controlled preheat, reflow, cooling stages are involved (reflow is almost instantaneous).

Solid Color (computer/Windows)
Color that appears on a display when all pixels are the same color. On a monochrome display (black & white), there are only two solid colors: black and white.

Solid State (communications, computer)
Electronic properties of crystalline materials (usually semiconductor types). The interaction of light, heat, magnetic fields, and electric current in these crystalline materials are involved in producing solid state devices. Less power is required to operate solid state devices and a greater variety of effects can be obtained. It is the technology of utilizing solid semiconductors in the place of vacuum tubes for state-of-the-art amplification, rectification, and switching systems.

Solion (computer/microelectronics)
Dynamic electronic circuit element that supplements vacuum tubes and transistors. The term solion applies to a class of devices that use ions in solution instead of two or more electrons as the charge carriers. A solion consists of two or more electrodes sealed in an electrolyte. At the surfaces, conduction changes from ionic to electronic by means of electrochemical reactions.

Song (A/V, computer, M/M)
MIDI drum-machine terminology describing a sequence of repeated rhythmic percussion patterns designed to create the percussion track for a MIDI composition.

Song Position Pointer (SPP) (A/V, computer, M/M)
MIDI message indicated a specific location in a song or song file. Song position pointer is measured in sixteenth notes from the beginning of the son. It is one of the timing elements supported by the MMEs.

Solid State (communications, computer)
Electronic component or circuit made of solid materials, such as transistors, chips and bubble memories. There is no mechanical action in a solid state device; however, there is an unbelievable amount of electromagnetic action inside semiconductor and thin film materials. For data storage, solid state devices are much faster and more reliable than mechanical disks and tapes, but they are more expensive. Although solid state costs continually drop, disks, tapes, optical disks continue to improve their cost/performance ratio. It appears that there will always be a hierarchy of storage environments, ranging from slower mass storage devices to the highest speed solid state devices. The first solid state device was the "cat's whisker" of the 1930s, in which a whisker-like wire was moved around on a solid "crystal set" in order to detect a radio signal.

Solid State Memory (computer)
Transistorized, semiconductor, or thin film memory that contains no mechanical parts. Disks, tapes, etc, are not in this category.

SORT (computer/DOS)
DOS Command that sorts lines of input, based on the characters in a column. If the selected column for two or more lines contains the same character, this command moves to the next column to determine the order of those particular lines within the large order. The output for this command is sent to the screen unless directed to another device.

Sorting (computer)
Process by which a list of items or records, normally disordered, is put into order according to some criterion based on the content of each record.

SOT (A/V)
In audio/visual terms, an abbreviation for Sound On Tape. The videotape is played back with pictures and sound.

Sound Bandwidth (A/V, communications, M/M)
The range of frequencies of sound. The human ear can perceive approximately from 20 to 20,000 Hz, but human voice is confined to within 3,000 Hz.

Sound Bed (A/V)
In audio/visual production, the background sound that is loud enough to be barely audible but not so loud as to intrude on the primary sound and information.

Sound Bite (A/V)
In audio/visual production, a term used to describe the videotaped portions of an interview in which lip-sync must remain intact.

Source (computer)
In a data flow diagram, an origin outside the data flow indicated organization. Also, a term used to describe the disk or directory from which a copy is made or to move a file.

Source Code (computer)
A program in its original form as written by the programmer. Source code is not executable by the computer directly. It must be converted into machine language by compilers, assemblers, and interpreters. In some cases, source code may be automatically converted into another dialect or different language by a conversion program.

Source Directory (computer/Windows)
Directory that contains the file or files that are intended to copy or move.

Source Document (computer/Windows)
Document where a linked or embedded object was originally created.

Source Module (computer)
Program as originally coded, before being translated into machine language.

Source Program (computer)
Program written in a language one or more steps removed from machine language, such as assembly (symbolic) language (process of translating it to machine language is called assembling). The result is an object program in machine language, ready to be executed. If a source program is in high-level language like BASIC, or "C", the translation process is called compiling, and may involve one or more stages of compilation before reaching the object program in machine language, ready to be executed.

Source Program Listing (computer)
Printed version of a program as the programmer wrote it.

Source VTR (A/V)
In audio/visual production, the videotape recorder that supplies the various program segments to be assembled by the "recording" video tape recorder.

Space Bandwidth Product: SBW or SBP (communications/photonics)
Product of the aperture of an analog optical system and the highest spatial frequency it can tolerate. This gives the number of resolvable points, and thus the maximum number of parallel channels that are processed.

Space Charge (computer/microelectronics)
Net electric charge within a given volume. If both positive and negative charges are present, the space charge represents the excess of the total positive charge diffused through the volume in question over the total negative charge.

Space Division Switching (communications)
Circuit switching technique in which each connection through the switch takes a physically separate and dedicated path.

Space-Integrating Element: SI (communications/photonics)
Optical element that collects light from a large area and focuses it together (lens).

Spaghetti Code (computer)
Program that is written without a coherent structure. It often implies an excessive use of the GOTO instruction. Each decision point in a program (if this, do that) directs the computer to branch to some other part of the program. A GOTO instruction directs the computer elsewhere in the program with no assurance of returning. If, after branching to another routine, another GOTO instruction branches somewhere else, the logic in the program is hard to follow. If a branch is made to a function, however, or subroutine that, after accomplishing its task, automatically returns to the place that called it, the logic in the program can be followed.

SPARC (computer)
Scalable Performance Architecture - a 32-bit RISC computer from Sun Microsystems, Inc.

Spark Gap (computer/microelectronics)
Region between two electrodes in which a disruptive electrical spark may take place. The gap includes the electrodes as well as the intervening space. Such devices may have many uses. The ignition system in a gas engine furnishes a very important example. Another important case is the use of a spark gap as a protective device in equipment. Here, surges in potential may be made to break down such a gap so that expensive equipment will not be damaged.

Spatial Carrier Modulation (communications/photonics)
Modulation of a spatial carrier frequency by a complex information signal: the amplitude and phase of the signal govern the amplitude and phase of the carrier.

Spatial Frequency (communications/photonics)
Number of repetitions in a unit of length that a cyclic pattern goes through.

Spatial Light Modulator: SLM (communications/photonics)
Optical device that modulates the cross section of a beam of light passing through it (or that is reflected from it).

S/PDIF (A/V, computer, M/M)
Sony/Philips Digital Interface - S/PDIF is a consumer products serial audio transmission standard for digital stereo signals. S/PDIF is similar to, but less robust than, the AES/EBU standard. S/PDIF ("speediff") uses smaller (miniDIN) connectors than the XLR microphone types required for AES/EBU compatibility.

Special Effects Controls (A/V)
In audio/visual production terms, the buttons on a switcher that regulate special effects (also called SFX controls). They include buttons for specific wipe patterns, the joystick positioner, DVE, and chroma key controls.

Special Effects Generator: SEG (A/V)
Electronic image generator that produces a variety of special effects, wipe patterns (circle wipes, diamond wipes) and key effects.

Spectrum (communications)
Refers to an absolute range of radio frequencies. For example the spectrum for television signal communications through cabling is now about 5 MHz to 400 MHz (megahertz).

Spectrum Analyzer (communications, microelectronics)
Device which sweeps a portion of the frequency spectrum, responds to signals whose frequencies lie within that band, and displays them in relative magnitude and frequency on a cathode-ray-tube screen. In essence, it is a superheterodyne receiver having a local oscillator whose frequency is varied cyclically, usually at the power-line frequency.

Speech Recognition (communications, computer)
Process of analyzing an acoustic speech signal to identify the linguistic message that was intended, so that a machine can correctly respond to spoken commands. Procedures must be incorporated for distinguishing linguistic contrasts from irrelevant acoustic changes due to the human speaker variables and environmental conditions (it’s hard for a computer to try and differentiate between this example – hair, hare, heir).

Speech Recognition Input Device (computer)
Device that accepts the spoken word through a microphone and converts the spoken information to instructions that the computer can understand and utilize.

Speech Synthesis (communications, computer)
Generation of machine voice by arranging phonemes (speech utterances, such as "k" "ch" "sh") into words. It is used in text to speech applications, which turns text input into spoken words for the handicapped. Although spoken words can be digitized and stored in the computer, it would require a much larger database of words compared to speech synthesis methods.

Speed of Electricity/Light (communications, computer)
Approximately 186,000 miles or 300,000 meters per second. This inherent speed of Mother Nature is why computers are so fast. Within the tiny chip, electricity has to flow only a couple of micrometers, and within an entire computer, only a few feet.

Spelling Checker Program (computer)
Word processing application function that checks spelling on a page, in a document.

Spherical Wave (communications/photonics)
Light wave whose wave fronts are spherical (i.e. light diverging from a point source).

Splice (A/V)
In audio/visual productions terms, to be able to see where two shots are actually joined, or the act of joining two shots on film or tape. Physically, a splice is only used when the material (film or videotape) is damaged to the point where it must be cut and glued.

Split Bar (computer/Windows)
Divides a directory window in two parts: the directory tree is displayed on the left, and the contents of the current directory are on the right.

Split Edit (A/V)
In audio/visual production, a type of edit whereby either the audio or video of the source is delayed from being edited for a defined amount of time.

Split Mode (A/V, music, M/M)
Dividing a MIDI keyboard into two or more zones of pitches with each zone playing a different instrument sound.

Split Seeks (computer)
With duplexed disk drives, a function that allows the system to check and verify which disk drive in the array can respond more quickly at any given moment.

Splitter (A/V, communications, computer)
Device used in audio/visual, communications, and computer configuration, to split an incoming signal (most commonly an rf signal) into two or more different paths. These passive devices can be two-way, three-way, or four-way. Generally, after a four-way split the signal level has been lowered to the point where re-amplification may bes required.

Spool File (computer/Windows)
Temporary disk file used to hold data waiting to be printed.

Spooling (computer)
Term that was originally an anagram for Simultaneous Peripheral Operations On Line, it is a method of handling low-speed input/output devices commonly implemented in operating systems or application programs to increase throughput.

Spot Color (computer/printing)
Solid color, such as those specified by the PANTONE MATCHING SYSTEM; it is the opposite of what is termed process color.

Spotlight (A/V)
In audio/visual production, a light that produces directional, relatively undiffused light.

Spotlight Effect (A/V)
In audio/visual production, a visual effect that looks like a soft-edge circle wipe with the base picture showing through: it is used to draw attention to a specific picture area.

Spread (computer/printing)
Pair of facing pages. In printing terms, the enlargement of a color area to build trap with adjacent areas of different color.

Spreadsheet (computer)
Software that simulates a paper spreadsheet, or worksheet, in which columns of numbers are summed for budgets and plans. It appears on screen as a matrix of rows and columns, the intersections of which are identified horizontally and vertically in order to view them. Cells are filled with: labels - numeric values - formulas, etc.

Sputtering (computer/microelectronics)
In microelectronic fabrication, a method of depositing a thin film of material onto a substrate. The substrate is placed in a large de-mountable vacuum chamber, having a cathode made of the metal or ceramic to be sputtered. The chamber is then operated so as to bombard the cathode with positive ions. As a result, small particles of the material fall uniformly onto the substrate.

Sputtering Targets (computer/microelectronics)
In microelectronic fabrication, these targets are usually in the form of simple, circular or rectangular plates, comprised of a variety of materials, and bombarded by gas ions that transfer their momentum to particles of the target, ejecting them into the vacuum chamber that houses the operation. These particles are then deposited in a thin film, on strategically located substrates, within the vacuum chamber.

SQL (computer)
Structured Query Language pronounced "SQL" or "see quill" - a language used to interrogate and process data in a relational database. There have been many implementations of SQL for mini and micro database applications. SQL commands can be used to interactively work with a database or can be embedded within a programming language to interface to a database.

Square Wave (computer, A/V)
A graphic image of a digital pulse as visualized on an oscilloscope. It appears square because it rises quickly to a particular amplitude, stays constant for the duration of the pulse and drops fast at the end of it.

Squeegee (computer/microelectronics)
In microelectronic fabrication, a hard, flexible blade with a precision edge which, with applied pressure, forces or pushes ink through the screen in screen printing.

Squeegee Pressure (computer/microelectronics)
In microelectronic fabrication, the downward force exerted upon the screen and substrate by the squeegee during screen printing.

Squeegee Speed (computer/microelectronics)
In microelectronic fabrication, the rate of speed at which the squeegee is driven across the screen during screen printing.

Squeeze Frame (A/V)
In audio/visual production, and electronic video effect that begins with a full frame of picture and squeezes it until it occupies only a portion of the screen, with the rest of the screen space being given to other visual material.

SRAM: Static Random Access Memory (computer)
Type of RAM that requires a continuous current to hold data: SRAM is considerably faster than traditional RAM, but larger, more expensive, and more energy consuming.

SRPI (communications, computer)
Server/Requester Programming Interface: allows personal computer applications to request services from IBM mainframes. The SRPI runs under IBM's SNA protocol scheme (Systems Network Architecture).

SSCP (communications, computer)
System Services Control Point: a network manager from IBM for a single SNA domain.

SS/TDMA (communications)
Satellite Switched Time Division Multiple Access: a form of TDMA in which circuit switching is used to dynamically change the channel assignments.

Stability (A/V, computer/microelectronics)
Specific ability of electronic circuits or other devices to withstand use and environmental stresses without changing: continued operations despite adverse conditions. In audio-visual terms, the degree to which a camera maintains its initial electronic setup.

Stabilizer (A/V)
In audio/visual production, in some videocassette recorders, a circuit that compensates for missing sync pulses in video recording that have been protected against copying.

Stack (computer/microlectronics)
In microelectronics fabrication, the frequency of registers or memory storage locations accessible on a Last-In-First-Out basis (LIFO). In computer programming can be described as a linear list where insertions, deletions, and usually access calls, are made at one end of the list (also LIFO).

STACKS (computer/DOS)
DOS Command that sets the RAM DOS reserved for processing hardware interrupts. Hardware interrupts are signals from hardware, such as pressing CTRL-C on the keyboard or turning off the printer. When DOS receives multiple hardware interrupts, it puts the information for each unprocessed interrupt in a stack.

Stacked Bar Graph (computer)
Graph in which all data common to a given row or column appears stacked in one bar.

Staff (A/V, music)
Five horizontal lines where symbols for musical notes are placed to indicate their pitch.

Staircase (A/V)
In audio/visual production, a test signal containing several steps at increasing luminance levels. The staircase signal is usually amplitude modulated by a subcarrier frequency and helps check for amplitude & phase linearities in video systems, as well as the gamma reproduction characteristics.

Standalone Programs (computer)
Independent programs, such as word processing, database, spreadsheet programs.

Standard (communications, computer)
Format or method accepted by a majority of users. In some cases, standards are set by national and international organizations. In others, the sheer popularity of a program can create the standard: usually, by popularity, this is called a de-facto standard.

Standard MIDI File: SMF (A/V, computer/Windows, M/M,)
Standard file format containing a series of MIDI messages in a known order. SMFs can also contain non-MIDI data such as track names and text in a data type known as a "meta-event". SMFs may also include or be comprised entirely of MIDI system exclusive (SysEx) messages. Three types of standard MIDI files covered by the SMF specification issued by the IMA formats 0, 1, and 2 exist. Format 0 files combine all tracks into a single chunk. Format 1 files maintain track separation. Both formats are supported by the MMEs and most modern sequencer applications. Format 2 files can combine a series of format 0 files in one file. They are seldom seen and not supported by Windows.

Standard Mode (computer/Windows)
Normal operating mode for running Windows. This mode provides access to extended memory and also lets the user switch among non-Windows applications.

Standard Setting (computer/Windows)
Settings that are shipped when ordering Windows. For example, if a user prints a drawing or document from one of the Windows accessories without entering new margin settings, the accessory uses standard margin settings to print the document.

Standards (A/V, communications, computer, M/M)
Possibly, the most important issue in the computer, communications, and audio/visual fields. In an unregulated industry, there are thousands of formats and languages, but very few standards that are universally used. This subject is as heated as politics and religion to hardware and software vendors and industry planners. If a format or language is used extensively and others copy it, it becomes a de facto standard and may become as widely used as official standards from such organizations as the American National Standards Institute (ANSI) or the Institute of Electrical and Electronic Engineers (IEEE).

Stand-by (A/V)
In audio/visual production, a warning cue for any kind of action in television production. Also a term used for a button on a videotape recorder that activates the rotation of the video heads or head drop independently of the actual tape motion. In the stand-by position, the video heads can come up to speed before the videotape is actually started.

Standing Wave Detector (communications/microelectronics)
Electrical indicating instrument used for detecting standing waves along a transmission line or in a waveguide and measuring the resulting standing-wave ratio. It can also be used to measure the wavelength and, hence, the frequency of an electromagnetic wave.

Standup (A/V)
In audio/visual production, a reporting technique in which the reporter on the scene delivers a monologue while facing the camera, either as an opener, or a transition, or a closer, or some combination of these. A variation is the walking standup. The reporter walks (usually toward the camera, less frequently away from it) as they deliver the monologue; or the reporter may walk at right angles to the camera while the camera moves with the reporter in a trucking movement.

Star Filter (A/V)
In audio/visual production, a filter-like lens attachment that changes high-intensity light sources into starlike light images.

Star Network (communications)
Communications network where all terminals can be connected to a central hub location by individual dedicated wire/cabling. PBXs (telecom switches) are prime examples.

Start/Stop Symbol (computer)
In flow charting, an oval symbol used to indicate the beginning and end of a flowchart.

Start/Stop Transmission (communications/computer)
Another term for Asynchronous communications (see asynchronous).

State (computer/microelectronics)
In microelectronic fabrication, this refers to the condition of an input or output of a circuit as to whether it is a logic "1", or a logic "0". The state of a circuit (gate or flip-flop) refers to its output. The flip-flop is said to be in the "1" state when its Q output is "1". A gate is in the "1" state when its output is "1".

Statement (computer)
Syntactically acceptable combination of instructions, keywords, symbols, constants and/or variables - to the interpreter or compiler of a chosen language. In Visual Basic, a statement must appear on a single line. Other languages use symbols to define the statement's termination, such as semicolon terminators used in Pascal.

Static (computer)
Variable retaining its last value until another is assigned, even though the procedure in which it is defined has completed execution. All global variables are static. Static is used to distinguish between statically-linked executable files and files using DLLs.

Static Colors (computer/Windows/printer)
Synonym for system colors. Static colors are the basic colors of the Windows display.

Static Induction Transistor (computer/microelectronics)
Field-effect transistor whose drain current is controlled by an electrostatic potential barrier. The SIT is under development for use at high current and voltage. It is similar in structure to a short-channel, vertical junction, field-effect transistor (JFET).

Static RAM: SRAM (computer/microelectronics)
Static Random Access Memory - Memory chips that require power to hold their content. A static RAM bit is made up of a pretzel-like flip-flop circuit that lets current flow through one side or the other based on which one of the two transistors is activated. Static RAM chips have access times in the 10 to 30 nanosecond range, whereas dynamic RAMs are usually above 30 nanoseconds (billionths of a second). SRAM is faster than traditional RAM but is larger, more expensive, energy consumptive (power must be on).

Station Break (A/V)
In audio/visual production, the planned interruption of a program to give station identification (usually on the half-hour or hour) and present nonprogram materials (commercials, public service announcements, etc.).

Statistical Multiplexer (communications)
A device that combines several low-speed channels into a single high-speed channel and vice versa. A standard multiplexer has a fixed interleaving pattern, but statistical multiplexers analyze traffic load and dynamically switch to different channel patterns to speed up the transmission.

Statistical Time Division Multiplexing (communications)
Method of TDM whereby time slots on a shared transmission line are allocated to I/O (input/output) channels on demand (it is not Synchronous Time Division Multiplexing).

Status Bar (computer/Windows)
Line of information related to the application in the window: Usually located at the bottom of a window. Not all windows have a status bar.

Steadicam (A/V)
Device used by camera operators that contains a body mount worn by a field camera operator. Built-in stabilizers and balancing weights maintain the stability of the camera while the operator moves. A smaller version, called Steadicam Jr. that works on the same principals, is available for consumer, hand-held, lightweight, camcorders (Inventor is an Academy Award Winner).

Steatite (computer/microelectronics)
Ceramic material composed mainly of silicate of magnesium, used as a circuit substrate in microelectronic fabrication.

Stochastic Process (computer)
Theory that deals with events that develop in time or space and which cannot be described precisely except in terms of probability theory. Formally, a stochastic process is a collection of random variables X, indexed by the parameter t, such that for any finite set of t's, the joint probability distribution of corresponding X's is specific. This definition is broad enough to envelop all of probability and statistics. In practice the term stochastic process is usually used to describe events that develop in time and whose realities are curves, either continuous or with jumps (see Monte Carlo method).

Stock (computer/printing)
Term used in printing to describe paper or other material to be printed on.

Stock Shot (A/V)
In audio/visual production a shot, or film clip, of common occurrence (clouds, crowds, cities, traffic) that can be repeatedly used in a variety of contexts because its qualities are typical. There are libraries of stock-shots available, all cataloged and indexed.

Stop And Wait (communications)
Flow control protocol in which the sender transmits a block of data and then awaits an acknowledgment before transmitting the next block of data.

Stop Bits (communications, computer)
Bits used to mark the beginnings and ends of characters in serial communications.

Stop Motion (A/V)
In audio/visual production, a slow-motion effect in which one frame jumps to the next, showing the object in a different position.

Storage (computer)
Term that is sometimes used interchangeably with Memory, although storage is generally associated with and restricted to external mass storage devices.

Storage Allocation (computer)
Term used in large, multiuser systems to describe the allocation of several levels of memory storage (main or primary, secondary or auxiliary, etc.).

Storage Hierarchy (computer)
Term used in large, multiuser systems to describe a hierarchy of access to several levels of memory, and storage resources (some systems have automatic storage hierarchies).

Storage Management Structures (computer)
Term used in large, multiuser systems to describe different storage structures such as: physical storage structure; logical storage structure; storage allocation structure; storage structure for removable disk storage; storage structure for magnetic tape files.

Storage Tube (computer/microelectronics)
Electron tube into which information can be introduced and then extracted at a later time; also called a memory tube. The widespread availability of low-cost solid-state memory devices and integrated circuits which will perform many of the same functions as electrical storage tubes has led to the decline in use of these tubes in equipment designs.

Store and Forward (communications)
Temporary storage of a message for transmission to its destination at a later time. Store and forward techniques allow for routing over networks that are not accessible at all times, for example, messages headed for different time zones can be stored and forwarded when daytime arrives at the destination location. Messages can be stored and forwarded at night in order to obtain off-peak telecommunications rates.

Stored Program Concept (computer)
Term used to describe a key design feature of computers, which allows the instructions to be held in the internal store while they are awaiting execution.

Storyboard (A/V)
In audio/visual production, a series of sketches of the key visualization points of an event, accompanied by corresponding audio information.

Streaming (computer)
Technique used to transfer information from a file structure, such as on a disk or CD drive, to the computer's memory. Streaming takes place in groups of bytes less than the entire file's length, usually processed in memory as a background activity.

Strike (A/V)
In audio/visual production, to remove certain objects; to remove scenery and equipment from the studio floor after the program, or show.

String (computer)
Contiguous set of alphanumeric characters that does not contain calculations for numbers (i.e. names, addresses, words and sentences). Any connected set of structures, such as a string of bits, fields, or records. Numbers may be included in or constitute the value of string variables, but they cannot be manipulated by mathematical operators.

String Processing Languages (computer)
Four operations that have achieved general acceptance in string processing languages are: (1) concatenation (the process of appending one string to another to produce a longer string; (2) identification of substrings (string within a string); (3) pattern matching (examining a string to determine certain properties); (4) transformation (using results from pattern matching to effect a replacement of substrings).

Stripe (A/V)
Synchronization signal recorded on one track of a multitrack tape recorder: Also used as a verb, as in striping, in audio/visual production terminology.

Striped Filter (A/V)
In audio/visual terms, this describes a filter with extremely narrow, vertical stripes of red, green, and blue filters attached to the front surface of the pickup tube of a single-gun camera. They divide the incoming white light into the three light primaries without the aid of dichroic mirrors or prism beam splitters.

Strip Light (A/V)
In audio/visual production the term is also called cyc light: several self-contained lamps arranged in a strip; used mostly for illumination of the cyclorama.

Structure (computer)
Two or more keywords used to create an instruction usually conditional in nature.

Structured Programming (computer)
Term used to describe a methodology or style whereby a computer program is constructed by concatenating or coherently nesting logical subunits which either are themselves structured programs, or else are of the form of one or another of a small number of particularly well-understood control structures.

Stub (computer)
Procedural function with the name of procedure/function only, containing no intervening code. Stubs block out procedures required by the application which can be called by the Main program. Intervening code statements are filled during the programming process.

Studio Camera (A/V)
Heavy, high-quality camera that is designed for indoor studio work; it cannot be moved around successfully without the aid of a pedestal or some type of camera mount.

Studio Monitor (A/V)
In audio/visual production, a monitor located in the studio carrying assigned video sources, usually the video of the line monitor (television set).

Studio Talkback (A/V)
In audio/visual production, a public address loudspeaker system from the control room to the studio: also called S.A. (studio address), or P.A. (public address) system.

Style (computer)
In word procession applications, the way a typeface is printed, for example, in italics.

Subchannel (A/V, communications, M/M)
In audio CDs and CD-ROMS, digital information that is not part of the primary data (such as digitized sound or text data) stored on the CD. Subchannel data includes a table of contents (a track list), product codes, and ownership (copyright) data. Subchannels can be used to store other information such as MIDI data (CD+MIDI) and graphics (CD+G).

Subdirectory (computer/DOS/Windows)
Directory within a Directory. All directories are subdirectories of the root directory.

Submenu (computer/Windows)
Set of choices presented when a main menu choice is made. In Windows, the first level of submenus is similar to drop down dialog boxes. The second level is usually fly-out menus appearing horizontally at the point of the first submenu choice.

Subprocedure (computer)
Procedure called by another procedure other than computer program's main component.

Subroutine (computer)
Portion of a program, which may be prewritten, that is a logically separate part of the program, that performs a specific task necessary for the execution of the program. Normally, a subroutine represents a unique implementation of a process that is utilized many times in a program, thereby saving programming time. In high-level languages, subroutines are implemented, for example, as procedures. In assembly language programs, subroutines are also in common use, as in a macroinstruction facility.

Substrate (computer/microelectronics)
Physical material upon which an electronic circuit is fabricated: used primarily for mechanical support, but it may serve a useful thermal or electrical function. Also, a material upon whose surface an adhesive substance is spread for bonding or coating: any material which provides a supporting surface for other materials.

Subsystem (computer/microelectronics)
Part or division of a system which, in itself, has the properties of a system.

Subtractive Primary Colors (A/V)
Colors that when mixed, act as filters, subtracting certain colors: the subtractive colors are Magenta (bluish red); Cyan (greenish blue); and Yellow.

Super (A/V)
In audio/visual production terms, shortened version for superimposition, the simultaneous showing of two full pictures on the same screen.

Supply Reel (A/V)
Reel that holds film or tape, which it feeds to the takeup reel.

Supercomputers (computer)
Term that is differently applied at any one time in computer system developments that may be used to describe (at any given time) computers of the highest speed, largest functional size, largest physical dimensions, or even the greatest cost. In terms of functionality there have been a number of recognizable terms used to describe different aspects of supercomputing: (1) multiprocessing (so that each processor can execute the same or a different program at the same time); (2) parallel processing (replicating and interconnection processors and memories but retaining central control that sequences all the processors together); (3) multifunctioning (replicating certain processing and control hardware to allow simultaneous execution of several operations in one processor); (4) pipeline processing (slicing functions of a sequential computer into short segments, allowing more than one set of operands to be processed simultaneously); (5) all of the above claimed to be available at any time in one supercomputer system.

Superconducting Devices (computer/microelectronics)
Devices that perform functions in the superconducting state that would be difficult or impossible at room temperature, or that contain components which perform such functions. The superconducting state involves a loss of electrical resistance and occurs in many metals and alloys at very low, sub-zero temperatures (some near absolute zero).

Superconductivity (computer/microelectronics)
Phenomenon occurring at very low temperatures in many electrical conductors, in which the electrons responsible for conduction undergo a collective transition to an ordered state with many unique and remarkable properties. These include the vanishing of resistance to the flow of electric current; the appearance of large diamagnetism and other unusual magnetic effects; substantial alteration of many thermal properties; and the occurrence of quantum effects otherwise observable only at the atomic or subatomic level.

Superheterodyne Receiver (communications)
Receiver that uses the heterodyne principle to convert the incoming modulated radio-frequency signal to a predetermined lower carrier frequency, the intermediate-frequency (i-f) value. This is done by using a local oscillator tuned simultaneously with the input stage of the receiver, so that the oscillator frequency always differs from that of the incoming carrier by the i-f value.

Supermicro (computer)
Term being used to describe a multiuser, multitasking microcomputer that has a high-speed microprocessor (or redundant processors), a large amount of RAM (1 Gigabyte and more), with a large disk storage capacity up to 40 gigabytes (with options for stacked disks of 2 or more 40GB hard drives), and a processing speed approaching 500 MIPS.

Supermini (computer)
Term used to describe minicomputers that now have the processing speed and capabilities of a mainframe computer of just several years past.

Super Motion (A/V)
In audio/visual production, a slow-motion technique achieved by increasing the field rate of the picture from 60 per second to 180 per second (Sony Corporation "Super Motion").

Superposition Theorem (computer/microelectronics)
If there are two or more sources of electromotive force (emf) in a linear electrical network, it is possible to compute at any element of the network the response of voltage or of current that results from one source alone, and then the response resulting from another source alone, and so on, for all sources, and finally to compute the total response to all sources acting together by adding these individual responses.

SuperScalar (computer/microelectronics)
Processor design method including two or more pipelines allowing more than one instruction to be issued to each pipeline and simultaneously processed. The Intel "Pentium" chips utilize superscalar processor design.

Supertwist (A/V, computer)
Technology that provides larger size, wider viewing angle and improved contrast on LCD (liquid crystal display) screens. By twisting the liquid crystals beyond the standard 90 degrees to 180 degrees and more, the light is better controlled.

Supervisor Call (computer)
Term used to describe a set of system programs in a typical operating system collectively known as the supervisor, whose function it is to provide services for, and to supervise the running, of a number of user programs. Control goes to the supervisor every time the normal flow of processing is interrupted by a change of state in the system.

Supervisor Program (computer)
Operation system program that controls the entire operating system and can call in other operating system programs from disk storage, if and when required.

Suppressor (communications, microelectronics)
Device used to reduce or eliminate noise or other signals that interfere with the operation of a communications system. The term may be applied to a noise filter in a radio receiver, but it is more frequently used to describe a device applied at the noise source, such as a resistor used in series, or a capacitor across terminals of a commutator motor.

Surface Acoustic-Wave Device (communications)
Devices which employ surface acoustic waves (SAW) in the analog processing of electronic signals with frequencies in the 10 megahertz to 10 gigahertz range. Surface acoustic-waves contain both compressional and shear components in phase quadrature, propagating non-dispersively along and bound to solid surfaces. As an example, earthquakes furnish sources for propagating these waves on the Earth's surface. It is of importance for electronic applications that, if the solid is a piezoelectric material, the surface acoustic energy is complemented by a small amount of electric energy. This electric energy provides the physical mechanism for the coupling between conventional electromagnetic signals and propagating surface acoustic-waves. SAW devices have led to a versatile microminiature technology for analog signal processing. Notable devices include bandpass filters, resonators, oscillators, pulse compression filters, and fast Fourier transform processors. Application areas include the color television consumer market, radar, sonar, communication systems, and nondestructive testing.

Surface Diffusion (computer/microelectronics)
In microelectronic fabrication, the high temperature injection of atoms into the surface layer of a semiconductor material to form the junctions: a gaseous diffusion process.

Surge Protector (computer)
Electronic device that prevents electrical fluctuations from affecting magnetic storage.

Surging (computer/microelectronics)
Sudden and momentary change of voltage or current in a circuit. It can be due to a sudden change in the applied input signal, a sudden change in the load placed on the circuit, or to the action of a relay, switch, or other device that changes operating conditions within the circuit. The resulting surges or transients are often called pulses or impulses when they have only one polarity. An oscillatory surge includes both positive and negative polarity values. Surging in electric circuits corresponds to overshooting.

Surround Sound (A/V)
Trademarked process for an enhancement to stereophonic sound including an additional audio channel. Surround Sound creates the illusion of sound coming from all directions similar to what might be experienced in a live acoustic environment like a concert hall.

S-VHS (A/V)
VHS format videocassette recorder or camcorder that has this VHS format ("Super-VHS") that allows for greater horizontal luminance resolution; approaching or slightly exceeding that available from standard broadcast television (not to be confused with S-Video).

S-Video (A/V)
Super-Video - a video signal with enhanced quality used for recording. Some video cards and a few consumer VCRs support S-Video. S-Video separates the chrominance signal from the luminance signals of composite video. It uses 4-pin DIN connectors (similar to the keyboard connector on PCs) for video I/O (not to be confused with S-VHS connection, which would be a mistake). S-Video capability is found primarily in prosumer and industrial video equipment.

Swap File (computer/Windows)
Special file on the hard disk. With virtual memory under Windows Networking, some of the program code and other information is kept in RAM while other information is temporarily swapped to virtual memory. When that information is required again, Windows pulls it back into RAM and, if necessary, swaps other information to virtual memory (also called a paging file).

Swapping (computer)
Term used to describe the information transfer that occurs when a program is temporarily unloaded from main to a secondary storage and later reloaded to continue processing. The term originated in the time-sharing systems of the early 1960s. Because there was no memory protection hardware to isolate multiple programs, these early systems permitted only one user program at a time to reside and execute in the main memory. When a program reached the end of a time slice, the operating system exchanged it for another waiting program.

Swatch Book (computer/printing)
Collection of colors on paper produced by a final output press or printer.

Sweep (A/V)
In audio/visual production, a curved piece of scenery, similar to a large pillar cut in half; also the term describes the electronic scanning performed by scanning equipment.

Sweep Generator (computer/microelectronics)
Electronic circuit that generates a voltage or current, usually recurrent, as a prescribed function of time. The resulting waveform is used as a time base to be applied to the deflection system of an electron-beam device, such as a cathode-ray tube. Sweep generators are classified as linear, circular, rotating, radial, or hyperbolic.

Sweep Reversal (A/V)
Electronic scanning reversal: results in a mirror image (horizontal sweep reversal) or in an upside-down image (vertical sweep reversal). Used with monochrome cameras only.

Switched Communications Network (communications)
Communications network consisting of a network of nodes connected by point-to-point links. Information is transmitted from source to destination through intermediate nodes.

Switcher (A/V)
In audio/visual production a term used to describe an engineer or production person who does the video switching (usually the technical director); also, a panel with rows of buttons that allows the selection and assembly of various video sources through a variety of transition devices, and the creation of electronic special effects.

Switching (A/V)
In audio/visual production, a change from one video source to another during a show, or show segment, with the aid of a switcher.

Switch Register (computer/microelectronics)
Set of manual switches, typically equal to the number of bits in the microcomputer word-length, usually located on the control panel.

Switched Capacitor (computer/microelectronics)
Module consisting of a capacitor with two metal oxide semiconductor (MOS) switches connected. These elements in the module are easily realized as an integrated circuit on a silicon chip by using MOS technology. The switched capacitor module is approximately equivalent to a resistor. The fact that resistors are relatively difficult to implement gives the switched capacitor a great advantage in integrated circuit applications. Some of the advantages are that cost is reduced, chip area needed is reduced, and precision is increased. Although the switched capacitor can be used for any analog circuit realization such as analog-to-digital or digital-to-analog converters, the most notable applications has been to voice-frequency filtering.

Switched Line (communications)
Term used to describe a communications line that connects through a switching center to a variety of destinations, across geographic distances.

Switching Circuit (computer/microelectronics)
Constituent electric circuit of switching or digital data-processing systems. Well known examples of such systems include digital computers, telephone switches, automated accounting and inventory systems and the ubiquitous personal computer. In these and other switching systems the component circuit units receive, store, and manipulate information in coded (digital) form to accomplish the specified objectives of the system.

Switching Systems (communications)
Assemblies of switching and control devices provided so that any node, or outlet, or device in a communications system may be connected as desired with any other node, outlet, or device. A telecommunications network consists of transmission systems, switching systems, and outlets (single units, devices, nodes). Transmission systems carry information from an originating outlet (workstation) to one or more distant outlets (or workstations). To enable any transmission facility to be shared, the outlets, the end-points (workstations) are connected to and reached through switching system nodes that are part of telecommunications networks. Switching systems act under built-in control to direct information toward their ultimate destination or address. Telecommunications switching systems generally perform three basic functions: (1) they transmit signals over the connection or over separate channels to convey the identity of the called and the calling address and alert the called device, workstation, or outlet; (2) they establish connections through a switching network for information exchange during the entire connection; (3) they process the signal information to control and supervise the establishment and disconnection of the switching network connection. In some cases, during the information or message switching, when real-time communications is not necessary, the switching network is replaced by a temporary memory for data storage. This type of switching is known as store-and-forward switching.

Switching Theory (communications, computer)
Circuit and switching theory enabled by ideal digital devices. Included are the theory of circuits and networks for telecommunications switching, digital computing, digital control, and information processing. Switching theory, in general, is concerned with circuits made of devices or elements that can be in two or more discrete conditions or states. Switching theory establishes an ideal representation of the digital circuit, examines properties of the representation, then interprets these as properties of the circuit. Switching theory is not concerned with physical phenomena of action or stability or with details of transition from one state to another. Switching theory is concerned with circuits made of binary (two-value) devices. Switching theory is based, in part, on mathematical logic. A switched circuit whose outputs are determined only by concurrent inputs is called a combinatorial circuit (logic circuit). A circuit in which outputs at one time may be affected by inputs at a previous time, is called a sequential circuit.

Symbolic Language (computer)
Computer languages that use abbreviations for instructions rather than numbers.

Symmetrical Multiprocessing: SMP (computer, Windows)
Multiprocessing technique used by Windows Networking, sometimes called "scalability", the ability to use multiple processors to enhance performance; for example, the ability to launch two or more (4, 6, 8) processes concurrently, with each process performing multiple tasks on different streams or threads of a program.

Sync (A/V)
Portion of video signals used to synchronize the horizontal and vertical scans: an abbreviation for synchronization, it applies to the synchronization signals, or timing pulses, that lock the electron beam of the picture monitors in step, both horizontally and vertically, with the electron beam of the pickup tube. The color sync signal (NTSC) is known as the color burst (NTSC = National Television Systems Committee).

Sync Generator (A/V)
Device that supplies synchronization signals to a series of cameras to keep them in phase.

Synchronize (computer, Windows)
Replicate the domain database from the domain controller to one server of the domain, or to all the servers of a domain. This is usually performed automatically by the system, but can also be invoked manually by an administrator.

Synchronization (A/V, computer)
In synthesized sound, process of controlling multiple sound sources and recording devices, so the time of the occurrence of a sound or image (frame) can be precisely determined. In computing terms, the process of maintaining one operation in step, with another. In television, synchronization is essential in order that the electron beams of receivers (televisions) are at exactly the same spot on the screen at each instant as is the beam in the television camera at the transmitter. Synchronism in television is achieved by transmitting a synchronizing pulse at the end of each scanning line, to make all receivers move simultaneously to the start of the next line. A similar vertical synchronizing pulse is transmitted when the camera beam reaches the bottom of the picture, to make all beams go back to the top for the start of the next field.

Synchronous (communications, computer)
In microelectronics term usage, the operation of a switching network by a clock pulse generator: all circuits in the network switch simultaneously; all actions take place synchronized by the microprocessor clock.

Synchronous Inputs (communications, computer)
In microelectronics term usage, those terminals on a flip-flop through which data can be entered, but only upon command of the clock. These inputs do not have direct control of the output such as those of a gate (only when the clock permits or commands).

Synchronous Operation (communications, computer)
In microelectronics term usage, a circuit operation using a common timing source (clock) to time the circuit or data transfer operations.

Synchronous Time Division Multiplexing (communications)
Method of TDM in which time slots on a shared transmission line are assigned to I/O (input/output) channels on a fixed, predetermined basis (not Statistical TDM).

Synchroscope (computer/microelectronics)
Instrument used for indicating whether two alternating-current (ac) generators or other ac voltage sources are synchronized in time phase with each other. In one type, for example, the position of a continuously rotatable pointer indicates the instantaneous phase difference between the two sources at each instant; the speed of rotation of the pointer corresponds to the frequency difference between the sources, while the direction of rotation indicates which source is higher in frequency. In more modern synchroscopes, a cathode-ray tube serves as the indicating means. The term synchroscope is also applied to a special type of cathode-ray oscilloscope designed for observing extremely short pulses, using fast sweeps synchronized with the signal to be observed.

Syncopation (A/V, music)
Musical term describing a rhythm in which specific notes precede or trail the beat. Syncopation is one of the characteristics of jazz.

Sync Roll (A/V)
In audio/visual production, the vertical rolling of a picture caused by switching from remote to studio, thereby momentarily losing synchronization.

Syntax (computer, Windows)
Rules governing a language's expression. Like English, Spanish, French; programming languages also have their own syntax. The order in which you must type a command and the elements that follow the command. Windows Networking commands have up to four elements: command name, parameters, switches, and values.

Synthesis By Analysis (computer)

Term used in speech synthesis to describe a device that analyzes the input of an actual human voice, stores & processes the spoken sounds, and reproduces them when required.

Synthesis By Rule (computer)
Term used in speech synthesis to describe a devices that applies linguistic rules to create an artificial, but human-like, spoken language.

Synthesizer (A/V, computer, M/M)
Electronic instrument that, by creating waveforms, creates sounds simulating conventional musical instruments as well as non-conventional sounds. Synthesizers usually have built-in keyboards (synthesizers that do not are called expanders). Synthesizers using digitized sound samples to create voices are called sample-playback or sampling synthesizers.

Synthetic Aperture Radar: SAR (communications/photonics)
Method of radar mapping in which a small antenna carried by a plane or satellite is used to reproduce the effect of a much larger antenna.

Synthetic Discriminant Function (communications/photonics)
Filter that is synthesized out of a training set of objects taken from different classes of objects, so as to discriminate between them.

System (computer/microelectronics)
In microelectronics fabrication, the term System refers to a group of integrated circuits or other components interconnected to perform a single function or number of related functions. If further interconnected into a large system, the individual elements are referred to as subsystems. In computer system terms, an organized set of related components established to perform general purpose as well as specific purpose tasks.

System(s) Analysis (computer)
Term used to describe the process of studying an existing system to determine how it is operating and how it is responding to the user needs.

System(s) Analyst (computer)
Term most often applied to the people who investigate, analyze, design, install, and evaluate information systems.

System Attribute (computer/DOS/Windows)
One of four markers that Microsoft MS-DOS can use to classify a disk file. Files with the system attribute are not ordinarily displayed in File Manager's directory panes (the user can use the View menu's By File Type command to make them appear, however).

System Call (computer)
Also called an operating system function, or operating system routine: a command that a program sends to the operating system to instruct it to perform a task related to the hardware components or the operating environment.

System Colors (computer/Windows)
Standard colors used by Windows for elements of its predefined objects such as backgrounds, scroll bars, borders, and title bars. The system colors may be changed from the defaults through Control Panel's Color and Desktop functions.

System Common (A/V, computer, M/M)
MIDI message to which all instruments respond regardless of their channel assignment. SysEx, tuning, song position, pointer set messages, are typical system-common messages.

System Chart (computer)
Variation of a flowchart, it is distinguished from other varieties of flowcharts by its stress on the component operations that, in sequence, make up a system. Usually, these component operations are programs to be executed by a computer, but they may also be operations to be done by other machines or by people.

System Default Profile (computer/Windows)
For Windows Networking Advanced Server, the user profile that is loaded when Windows Networking is running and no user is logged on. When the Welcome dialog box is visible, the system default profile is loaded. (see default profile, user profile).

System(s) Design (computer)
Term used to describe the process of developing a plan for a system, based on the results of an analysis that may have been performed by System(s) Analysts.

System(s) Development (computer)
Term used to describe the process of programming and testing cycles for a new system.

System(s) Engineering (communications, computer)
Process of engineering systems: not just the implementation, but also the requirements definitions, functional specifications, feasibility studies, business cases and return on investments, design description, system implementation, and monitoring the operational performance of the system recommendations, are all part of the system engineering code. Engineering implies the systematic application of scientific and technological knowledge through the medium of sound engineering principles to reach a practical goal. This goal becomes more practical through the process of trading off performance, reliability, cost, and other characteristics of the resulting product in the light of the funds and time available for development. In short, systems engineering is based on fundamental engineering principles and guided by economic considerations.

System Exclusive (A/V, computer, M/M)
Special type of MIDI message transmitting on all channels but intended for only one device identified by its manufacturer codes. SysEx messages, as they are called, set the operating characteristics of synthesizers, edit their individual voice parameters, change banks of voices, or load samples into their memories. The Format of SysEx messages is determined by each manufacturer independently, and no standard for their format exists other than the beginning and ending bytes identifying them as the SysEx type.

System Fault Tolerance (communications, computer)
Term sometimes used to describe the duplication of hardware and information to ensure that failure of part of a network will not result in total network downtime.

System(s) Flowchart (computer)
Term used to describe a drawing that depicts the flow of data through a computer system.

System Generation (computer)
Process of initiating a basic system at a specific installation. A program known as the system generator receives as input a description of the basic operating system to be generated and a specification of parameters describing the specific installation (such as the types, quantities, and configuration of the system equipment). The generator processes the description of the basic system, substituting the parameters for variables in the description, and produces as output a specific system tailored to the installation.

SYSTEM.INI (computer/DOS/Windows)
File used by Windows to store information about device drivers used by the personal computer system: whether the user is attached to a network; the name of the user-defined default shell; how the user may want time to be divided between Windows & non-Windows applications.

System Journal (computer)
Term used for a file whose records represent, and record, all on-line transactions.

System Menu (computer/Windows)
In Windows, the Control Menu.

System Microphone (A/V)
Configuration of a microphone consisting of a base upon which several heads can be attached.

System Partition (computer/Windows)
Volume that contains hardware-specific files needed to load Windows Networking(see partition).

System(s) Programming (computer)
Development and production of programs for translation, loading, supervision, maintenance, control, and running of computers and computer programs. The distinction between systems and applications programming is that systems programming produces the software tools which applications programmers use to develop the applications for which the computer is actually used. This distinction between the two is, however, not always obvious.

System Survey (computer)
Term used to describe the first phase of systems analysis, in which planners determine if and how a project should proceed (can also be called a feasibility study).

System Testing (computer)
Term used to describe a testing process in which a development team use test and modelling data to determine whether systems are performing up to expectations.

System Time (computer)
Time set by the personal computer's internal clock.