M

Machine Language - A very limited instruction set designed to control the CPU. Contains only the most basic operations

Macro - ‘Macro Instruction,” a facility which assigns a sequence of instructions to a keyword, or to a single keystroke

Macro Focus - This allows a Ions to focus on small objects at very close distances.

Magnetic Card Reader - A device for recording and reproducing sound on a card with a magnetic stripe. The card may contain verbal and/or pictorial information. Separate tracks may provide for a protected master and erasable student responses

Magnetic Sound - Sound that is recorded in the form of varying magnetic patterns. May be on discs, tapes, cards or film

Magnetic Tape Developer - A chemical solution which when applied to the control track edge of videotape makes control pulses visible to the human eye and allows precise cutting for physical tape editing

Magneto-optical Disc - Using magnetic material for recording, this disc allows playback and repeated recording of information (unlike CD’s) using semiconductor laser light. Applications include OA equipment and video discs.

Mainframe - Large, powerful computer, often used by large businesses, with extensive capabilities and memory

Maintained (Switch) - A switch which remains at the operated circuit condition when the actuating force is removed. It returns to the normal circuit condition, or moves to another position, when actuated a second time. Compare with MOMENTARY SWITCH

Mapping - A system of coordinating information in the computers memory with the format acceptable to the display device

Master - Original, as in a recording

Matte White - See SCREEN SURFACES

MOPS (also Mb/s or Mbps) - Mega Bits Per Second; a data transmission rate, one million bits per second.

MCGA - Multicolor Graphics Adaptor

MCU (Multipoint Control Unit) - Used to ink up to eight or more remote sites into a single conference or manage several simultaneous, independent conferences (segmenting).

MDA - Monochrome Display Adaptor

MDS - Multipoint Distribution Service

Media Conferencing - The ability to conduct a complete information exchange across distance, including video, audio, document, computer, and time conferencing. (VTEL)

Megabyte - One million bytes. See BYTE

Megasamples per second (MS/s) - A sample rate unit equal to one million samples per second.

Memory - Storage space for data. Usually resident within the computer, but may also include disk space. See VIRTUAL MEMORY

Menu - The display of tiger options at any given point in a program

Menu Driven - Type of a program in which the user is continually given options and prompts on the screen. Choosing one of the options often calls up another set of options, thus guiding the user through the program

MHz - Megahertz; millions of cycles per second

Micro/Mini Cassette - One of several audiocassettes much smaller than the compact cassette; used principally for note taking and dictation

Microcomputer - A small self-contained computer, often called desktop, personal, or even portable

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Microfiche - A sheet of microfilm (usually 4 x 6”) containing multiple micro-images in a grid pattern. It usually contains a title which can be read without magnification

Microfilm - A film in which each frame is a miniaturized image of a printed page or photograph. May be 16, 35, 70 or 105mm

Microform.  Any  materials, film or paper, printed or photographic, containing micro-images such as a page of text or drawing, too small to be read without magnification. See MICROFILM, MICROFICHE, ULTRAFICHE

Microform Reader - Apparatus with built-in screen or viewing glass arranged to magnify microfilm so it can be read comfortably at normal reading distances

Microform Reader/Printer - Same as MICROFORM READER but with equipment built in to produce paper copy at a size equivalent to the original

Microphone - A device that converts sound into electrical signals usable by other pieces of audio equipment. Microphones vary in sound quality, generating system used, directional patterns and impedance

Microphone Bidirectional and Unidirectional Microphone Directional Patterns include:
Omnidirectional - Picks up sound from all directions; Cardioid, Unidirectional - Picks up sound primarily in the direction it is pointed, rejecting sounds from the rear of the microphone: Bidirectional, which picks up sound in front of and behind itself; rejects Sound from the sides

Microphone Generating Systems include: Microphone, Ceramic - a microphone or phono pickup which uses a piezo-electric element to generate voltage when it is deflected by sound or needle pressure: Crystal - Similar to ceramic; no longer used in A/V applications; Carbon - a microphone made with a diaphragm which compresses carbon granules to vary the current; no longer used in A/V applications

Microphone. Dynamic - A microphone with a diaphragm connected to a fine wire coil moving in a magnetic field. may be any pattern; Condenser, Electrostatic or Capacitor - a microphone with a conductive diaphragm that varies high-voltage electric field to generate a signal, may be any pattern, requires a mini amp and power supply; Electret - similar to electrostatic except the diaphragm is permanently charged, eliminating the need for high voltage supply; usually requires an internal battery for a built-in pre-amp. suited for handheld/machine use because of low susceptibility to vibration noise, any directional pattern; Ribbon - a microphone with a thin sound-sensitive metallic ribbon supported between the poles of a magnet, seldom used

Microphonics - Audio signals (noise) caused by the mechanical vibration of elements within a system

Microprocessor - The brain of the microcomputer: the electronic chip or circuit which does all the calculations for and control of data. In larger machines, it is called the Central Processing Unit (CPU) Used increasingly in projector control and video equipment

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Micro-Projector - Designed to enlarge and project microscopic slides, prepared specimens and/or projection of live microscopic specimens: primarily used in science

Microsecond - A unit of time equivalent to 0.000001second

Millisecond (ms) - A unit of time equivalent to 0.001 second

Minicomputer - Small computer, larger in capability than a micro or desktop but smaller in size and capability than a mainframe

Minisupercomputers - An emerging class of scientific computers which offer roughly a quarter of the power of an original CRAY-1 for about $500,000. Sometimes referred to as “near-supercomputers” or “Crayettes”

MIPS - Millions of Instructions Per Second: a common measure of scalar processing speed in traditional computers. Technical workstations operate in the 1-4 mips range; compared with top-end PCs, which operate at about .5 mips

Mirror - Device for reflecting light; may be plane or curved, Used in projectors behind lamps to concentrate and distribute light, to reverse images for correct viewing, and to fold light beams for more compact or more convenient systems. They may have the reflective coating on the back as in household mirrors (second surface~, but it is more often on the first or exposed surface to prevent double images. A mirror has a specular surface

MODEM - Modulator Demodulator, a device that connects computers to communications devices and encodes and decodes the information to be communicated, enabling computers to send information and data over telephone lines

Moiré - A wavy or satiny effect produced by the convergence of lines

Momentary (Switch) - A switch which returns to its normal circuit condition when the actuating force is removed. Compare with MAINTAINED SWITCH

Monitor - A device to inspector preview a program: to watch over a program for quality control. See also VIDEO MONITOR and AUDIO MONITOR

Monochrome Adaptor - Provides a high resolution text image and requires the IBM monochrome monitor. Its output has an 1 SkI-k scanning rate and it does not support IBM graphics images

Motion Picture Film - A strip of flexible transparent film with a sequence of images and perforations or sprocket holes for advancing it through a projector. Films come in various widths measured in millimeters, Most theaters use 35mm or 70mm: schools have traditionally used 16mm; home movies are 8mm often called standard 8, regular 8 or R8) or Super 8 (S8). School films for individual or small group use are most often Super 8 on open reels or enclosed in a cartridge or cassette requiring a compatible projector. Some projectors will accommodate both regular 8 and Super 8 films

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Motion Picture Film Editor - A device for editing film in which the visual image is displayed on a small screen. Transport of the film may be either motorized or by hand turned cranks. Some models have built-in sound heads for audio playback of sound film

Mouse - An input device used for cursor control, drawing, or pointing that is rolled across a flat surface such as a desktop

MPEG-I - ISO Motion Pictures Experts Group standard for the compression of motion or still video for transmission or storage

MPEG-2 - Standard for compression of progressive scanned and interlaced video signals over a large range of compression rates with a range of bit rates from 1..5 to 100 Mbps

MS-DOS - Microsoft Disk Operating System; the operating system adopted for the IBM PC and compatibles, See DOS, OPERATING SYSTEM

MTS/DBX Stereo Sound - The U.S. Standard for broadcast stereo TV sound.

Multiplexer - A device that permits subdivision of a given bandwidth. For example, a T1 multiplexer may divide a T1 line (1,544Kbps) into two capacities of 768Kbps each. (See MUX}

Multiplexer (Film Chain) - A unit which projects 16mm film, 2 x 2” slides or filmstrips into a video camera

Multipoint - A communication system which allows three or more sites both to transmit and receive voice, video and data signals (see MCU}.

Multi-standard Decoder - A device that converts NTSC, PAL, SECAM or NTSC 4.43 video to RGB video

Multiway - Interactive communication between more than two sites, Multiway communication may occur through a digital switch or through an analog gateway.

Multiway Control Unit - A device which allows more than two sites to be voice, video and data connected in a videoconference. Sometimes called a digital switch or video bridge.

Muse - Multiple sub-Nyquist Sampling Encoding; one of several HDTV transmission methods; also one of the first. Some versions, including Muse-6 and Muse-9 are receiver-compatible while others are not

MUX - A Multiplexer - Combines several different signals (e.g. video, audio, data) onto a single communication channel for transmission. Demultiplexing separates each signal at the receiving end.

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N

NAB - National Association of Broadcasters

NABET - National Association of Broadcast Employees & Technicians, a broadcast technicians union

NAEB - National Association of Educational Broadcasters

Nanosecond - One billionth of a second

Narrow Band - An FM signal in which the deviation is much less than the modulating frequency

NCTA - National Cable TV Association

NET - National Educational Television

Nibble . 4 bits, half of a BYTE

Nickel Cadmium Batteries - These rechargeable batteries can usually handle about 1000 recharges in their lifetime.

Noise - In audio systems, noise is electrical interference or any unwanted sound. In video it refers to random spurts of electrical energy or interference. It can produce a “salt-and-­pepper" pattern over the televised picture. Heavy noise is commonly called snow

Noise-Canceling - A microphone designed to cancel ambient noise so it will not be broadcast or recorded. The housing of the microphone allows noise to reach both sides of the diaphragm simultaneously, thereby canceling each other out. A close-speaking voice strikes the diaphragm on only one side so generating a stronger signal with less background or room noise

NOM - Number of open microphones in a sound system. Decreases gain-before-feedback by 3dB every time NOM doubles

Non-Interlace - A scanning system that repeats the exact vertical retrace period for every field, resulting in every other scan Pine in a 525 fine system being refreshed 60 times a second. This results in a flicker-free image with half the vertical resolution. See INTERLACE

Non-Linear Optical Device - A device that converts the wave length of a laser Theoretically, recording density using this technology could be increased by a factor of 4.

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Nonvolatile RAM - NVRAM, memory which can be written to and read from, but which is permanent in the sense that it is retained even when the power is turned off. Data is usually held in memory with the assistance of an internal power supply, such as a battery or capacitor

NTSC - National Television Standards Committee, which established the US standard 525-line 60-field system, often referred to as just the NTSC format. This format is color compatible. Humorously referred to as: “Never Twice the Same Color”

NTSC 4.43 Video - This term refers to the video output of videotape or disk players used mainly in Middle East

0

Objective Lane - See PROJECTION LENS

Oscillator - A circuit that produces a continuous periodic output

OCR - Optical Character Reader/Recognition

OEIC - Opto Electronic Integrated Circuit, a device integrating optical and electronic circuits in one chip

OEM - Original Equipment Manufacturer. Companies often buy products from OEMs for resale under their own label

Opaque Projector - Uses the principle of light reflection to create an Image of any nontransparent object, such as printed/typed pages, stamps, coins, photographs, drawings, maps, diagrams, or flat objects in single sheets or in book form. May be called reflectoscope or episcope. Screen images ordinarily require a well-darkened room

Open Reel - Audio or videotape or film mounted on a reel that is not enclosed in a cartridge or cassette

Operating System - The software which enables the computer to read programs and carry out all internal operations. Programs and data are not usually compatible from one computer to another unless the same operating system software is used. See DISK OPERATING SYSTEM

OPIC - Optical Integrated Circuit

Optical Communications - A communications technology that uses optical signals with a large information-transmitting capacity and minimal noise interference. Electrical signals are converted into optical signals by semiconductor, sent through optical fiber cables and ultimately reconverted to electrical signals,

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Optical Disc - A type of video disc storage that records and reproduces digital information using semiconductor lasers. Features high-capacity recording and high-speed reading and comes in read-only and write-to types

Optical Fiber - A long, thin thread of fused silica or other transparent substance used to transmit light. Since it has a capacity approximately 1000X conventional cable and it is lightweight and non-corrosive, it is perfect for sea bottom and underground use

Optical Sound - Sound that is recorded by photographic means on film. The sound track is printed along the edge opposite from the sprocket holes. The sound is reproduced by projecting a narrow beam of light from an exciter lamp through the sound track into a photoelectric cell which converts it to electrical impulses for amplification

Organic Photo-Chromic Material - Organic compounds that change color according to the wavelength of reflected light. Future uses are expected in rewriteable optical discs but stability and durability pose problems in implementation oscillator - A circuit that produces a continuous periodic output

Oscilloscope - An instrument used to make voltage changes visible overtime. The word oscilloscope come from oscillate since oscilloscopes are often used to measure oscillating voltages

Out of Band - Transmission taking place external to allocated bandwidth. A video call with out-of-band audio requires a separate phone line for the audio.

Output - Signal delivered from any audio or video device; also a jack, connector or circuit which feeds the signal to another piece of equipment such as a speaker or headphones

Overhead Projector - A device which produces an image on a screen by transmitting light through a transparency lying on the face or stage of the projector. The lens and mirror arrangement in an elevated housing makes possible a bright projected image in semi-darkened or lighted room. Allows a lecturer to sit or stand in front of and facing an audience, to point our items on the transparency, or to write on the transparency as the audience watches

Overscan - Deliberate scanning in a television set or monitor in which the active display area of the CAT is filled with slightly less than the complete video image. This enables the physical edges of the display device to become the picture’s borders rather than the blanking portions of the signal

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