Synth Glossary 1

Access : Find. Access an item of information find in item of information.

ADC : Analog to Digital Converter. A device which takes-in analog (electrical) information and converts it to numeric (digital) information. In music computers, the device which takes input from a keyboard (or other analog sound source) and converts it into information the computer can store.

Additive synthesis : The process of building up a sound by adding harmonic waveshapes to a fundamental.

ADSR : An acronym for Attack, Decay, Sustain and Release, referring to the dynamic characteristics common to all sounds. In an analog synthesizer the ADSR control provides control over these parameters and considerable sound modifying possibilities.

Alphanumeric : Alphanumeric keyboard: a keyboard with letters and numbers as in a typewriter keyboard. Alphanumeric information: information consisting of letters and numbers.

Algorithm : The various steps necessary to find the solution to a problem. A logical progression of procedures that will lead to the end result.

ALU : Arithmetic and Logic Unit. Part of a central processor that actually executes the operations requested by an input command.

Analog : An electronic signal whose waveform resembles that of the original signal. Analog synthesizers are those that produce sound by electronic means. Conversely, computers produce sound digitally, which is the numeric representation of sound. Computer music is not, and should not be called, electronic music.

ASCII : The ASCII code is the 'American Standard Code for Information Interchange.' This code has been developed to allow computers to communicate in a common language. Communication is often by telephone, computers connected via modems. The rate at which information passes is relatively slow.

Assembler language : A language that is close to the original binary language of computers. The language includes symbolic machine language statements which relate directly to the instruction and data formats of the computer. Used by advanced programmers.

Assignable : Capable of altered function. An 'assignable' control may have several functions under the control of software.

Audio-cassette : A connection allowing ordinary cassette interface recorders to be connected to computers for the purpose of storing programs on cassette tapes.

Backup : Copy. For safety reasons every computer program should be backed up so that if a program is lost during operation, or if a storage medium should become damaged, a safety copy, or backup is available. 'To backup' = to copy.

Bandwidth : Frequency range. A hi-fi system can typically deliver sound between 20Hz and 20KHz (20 and 20,000 cycles). Many computer music systems can only produce sound in relatively narrow bandwidths - up to 10K for instance - but these can make acceptable sounds. The human auditory circuits classify everything above 5K as very high treble. When high- end is missing clarity and sparkle is the most noticeable lack.

BASIC : 'Beginner's All-purpose Symbolic Instruction Code.' A high-level computer language developed in the fifties at Dartmouth College. BASIC is the language that most home computers work on. It is an ideal language for amateur programmers, but is too slow in operation for professional use.

Boot : To 'boot up' a disk. Jargon for inserting a disk, issuing the instruction to the computer to identify and initialize the disk and place it 'on line' for information storage and retrieval. A 'boot track' on a disk is a built-in program which carries out the above procedure.

Bubble memory : A non-volatile memory device which stores numeric information safely even when power is withdrawn. Information is stored as magnetic 'bubbles' on a sliver of synthetic garnet. Microscopic in size, the bubbles follow a path through a circuit and when stopped provide a pattern of 1 and 0 information which is a permanent memory. Expensive but excellent.

Bug : An error in a computer program. Software is such a complex science that many programs are sold to the public before all the errors (bugs) have been discovered. During use some of the errors show up and the manufacturers usually develop revised programs which are 'de-bugged' and supply them it nominal cost to existing users.

Byte : A byte is a 'phrase' made up of the smallest items in computer language - the 'bits.' Often 8-bits make a byte and that phrase can represent one character or two numerals.

C language : A high level programming language used by factory software writers. Soon to be used as: the main language in a major dedicated music-computer.

Chip : Slang for microprocessor. Actually a very thin slice of semi-conductor material of which microscopic electronic components are photo-etched to make circuits. It becomes an 'integrated circuit' when connection tags and a plastic case are added. Complete microcomputers on chips are now possible, usually measuring only a quarter or an inch square.

Click-track : Once tempo is set for recording, a click track is placed on to one track of a multi-track tape machine. This track provides synchronization for later parts.

Come up : Jargon for powering up a computer.

Control voltage : The electrical signal which, in an analog synthesizer, specifies which frequency is played by the oscillators.

CPU : Central Processing Unit. The primary unit of a microcomputer that includes the circuits controlling the interpretation and execution of instructions.

CRT : Cathode Ray Tube. A television-type screen.

Cursor : The 'blinking dot' on a computer screen that shows the user where he is working.

DAC : Digital to Analog Converter. A device which converts digital information in computers into analog (electrical or physical) signals which an audio system can amplify.

Data : Information that defines a specific task. A computer program may be written to solve a particular type of problem but specific 'data' must be provided before an individual calculation can be computed.

Debug : To find the fault in a computer program. Only necessary when new programs are generated, not when programming musically. A debugger is a program within a program that automatically searches for illegal program entries and reveals them to the user.

Dedicated : As in dedicated music computer. A computer designed specifically for one task.

Dot-matrix : Dot-matrix printer. A computer printer that makes up letters and graphics by firing dots of ink at the paper. More versatile than typewriter-quality printers and good for printing music.

Dump : 1) 'Off load': usually applied when a program is 'dumped,' or off-loaded to storage medium such as disk or cassette. 2) A power dump, when all power is removed from the computer.

Digital : The binary code: the 01011001-style numeric language on which all computers are based. Refers to systems that are computer based. Digital sound -sound that is stored as numbers.

Disk drive : The mechanical system which spins a floppy disk at high speed and applies a magnetic head immediately above the surface of the disk for information access. In some computers the disk drives are built into the chassis. in others they are supplied as separate, free- standing-units connected by ribbon cable. A typical disk drive provides 150-300K of storage.

DMA : Direct Memory Access. A form of data transfer employed when it is vital that information should be stored and retrieved quickly from disk. In this system, data is transferred automatically after the CPU has initiated the transfer without requiring super vision, freeing the CPU for other tasks.

Dolby : A Method of noise reduction for audio signals created by Ray Dolby.

Eight(8)-bit : See Sixteen(16)-bit.

Envelope : The 'shape' of a sound, when displayed graphically; typically of an 'ADSR' pattern. A graph indicating the development of a sound.

Event-recorder : Used by some music-computer companies to describe a sequencer-type program. Note- rests, and ties are all events in music and when a sequencer is described as an event recorder it usually means that the system will store information about which notes were played but will not store information about how they were played: key velocity, etc.

Fourier synthesis : The Fourier mathematical formula argues that any complex waveform may be resolved into a fundamental plus a set number of harmonics. A formula widely used to allow computers to compute the gaps between information supplied about harmonic envelopes.

Floppy disks : A storage medium for computer information. Looks similar to flimsy disks used for promotions by the record industry but is protected in a paper sleeve. Disk spins at high speed inside paper sleeve when inserted in disk drive and the information, stored in 'tracks' on the disk, is read by a magnetic head that floats above the surface of the disk. An efficient, cost-effective method of information storage and retrieval.

Free-standing : Not part of a greater item of equipment.

Fundamental : In waveshaping, the root harmonic on which other harmonics are built.

Graphics display : A CRT screen built specifically for displaying graphics. Many ordinary computer screens do not have sufficiently high-resolution for high-quality graphics displays. Fairlight had to have a screen custom-built to allow its graphic displays of sound waves to be shown.

Go down : Letting the system 'go down.' Turning the thing off. Sole meaning in computer parlance.

Hard copy : Printout on good old-fashioned paper.

Hard disk : An advanced, large capacity, storage system for microcomputers. Only just available (for a few dedicated music-computers), hard disks operate like floppy disks, but store four or more times the amount of information.

Headroom : A term that has spilled over into music- computing from the recording industry. Headroom was the gap between the peak working level on tape and the point at which the sound might actually distort. In computer parlance 'having the headroom' means having sufficient spare computing power.

Hexadecimal : A code of counting in which 16 is used as the base. Used in low-level computer languages which are slow to write but very flexible.

High-level language : The language in which the end-user writes programs. These languages usually allow programming in English-type statements such as 'goto' or 'next' and are developed to allow users to consider the problems in hand rather than worrying about correct addressing of the microprocessor. Machine language is the final target language and is controlled by a structure of high-level language controlling intermediate languages. In effect this is a layered operation: the user says what he or she wants in plain terms, the high-level language translates that into compiler, the compiler issues instructions to assembler which generates machine code.

I/O device : See input/output device.

Illegal commands : An instruction the computer is unable to recognize.

Initialize : The start-up procedure for computer systems using peripheral units such as disk drives or printers. The initialization program sets up the starting condition.

Input/output device : Any device which allows the computer to communicate with the outside world, and vice versa. An alphanumeric keyboard is an I/O device, so is a CRT screen (when a light pen is added for input), a musical keyboard is often an input device and sometimes also an output device.

Instruction : A coded program step that tells the computer what to do next.

Integrated circuit : IC. A group of circuits formed at the same time which are interconnected and capable of performing a complete function. The IC is usually mounted in a plastic package and connecting pins protrude from two sides rather like legs.

Interface : Matching connection. For a computer to interface with a synthesizer a suitable interface (matching connection) must be made.

Keys-down : Keys-down information. Information from musical-keyboard keys: how hard the key was played, how fast it was pushed down, how long was it held down etc. This is the 'keys-down' information that a high-quality music computer system should be able to read from the musical keyboard. This information is stored and reproduced to control replay of the sounds. It may be edited by the user.

Keystroke : One 'press' of a key on an alphanumeric keyboard.

LCD : Liquid-Crystal Diode. A display system often found in inexpensive electronic items. Made by sandwiching liquid-crystal and electrodes between two sheets of glass. Current causes the liquid to change its light-trapping proper ties so forming letters or numbers.

Light pen : A clever, high-speed pen-shaped device which, when held against a CRT, can issue instructions for program or graphics purposes. The pen usually doesn't admit light, a photo-sensitive cell in the pen reacts to light from the screen. Placing the pen over the relevant command shown on a screen will cause that command to be carried out. Simple versions can be seen reading bar codes at supermarket check-outs. Casio apply a similar system for entering music from bar codes into their small microprocessor keyboards.

Load : To place the program into the computer's 'live' RAM memory usually loading is done from a storage device such as cassette or disk.

Lockout : A situation during computer operation when the arithmetic and logic units both try to access the CPU at the same time - usually the result of illegal commands in an unfriendly program. The computer just ceases to work. Only solution is to turn the damn thing off and start again - losing the work in hand.

Low-pass filter : Also high-pass filter. Filters which allow certain frequencies to pass, but 'cutoff' unwanted frequencies. Used in music computers to reduce unnecessary frequency analysis.

LSI : Large Scale Integration. The state of the art before the VLSI. Refers to a component density of more than 100 per chip.

Machine language : Binary language, the language of 0 and 1 that all computers finally work on.

Mainframe : Mainframe refers to the basic or main part of the computer, the CPU. In everyday use mainframe computer refers to the large, ultra-powerful computers operated by governments and multi-national corporations in which the 'main' element in the name distinguishes the unit from smaller satellite terminals which may be able to interface with it.

Menu-driven : A software-design style in which the program offers the user a 'menu' of choices whenever a decision has to be made. Rapidly gaining in popularity, menu-driven programs are easy to use and reduce the demands on the end user to a minimum.

Microcomputer : A small computer system, usually based on one or two microprocessors, which sells for a few hundred dollars or pounds. Typical units use domestic television screens for display, interface with domestic cassette recorders for ROM and have no hard printout facility built-in.

Microprocessor : The CPU (Central processing unit) of a computer. Built in layers on a microscopic chip of silicon.

Modem : A MODulation/DEModulation device that allows computers to connect to telephone lines. Using a Modem to hook into the telephone lines allows computers in remote locations to interchange information using the ASCII code.

Monophonic : One note. A monophonic system can play only one note at one time.

Multiplexer : A device that takes input from several sources and delivers them in one high-speed stream of information.

Music Concrète : The pioneering style of electronic music popular in the 1950s and 1960s which, to some extent, has got synthesized and computer music a bad name.

Nanosecond : Particle of time equal to one billionth of a second (UK equivalent is one thousand, millionth of a second).

Nest(ed) : A program within a program. Nested menus are menus that offer decision choices subsequent to original menu choice.

Off-load : To store program on magnetic storage device such as cassette or disk.

On-line : 1) Available. Being 'on line' means that a piece of information, a program or a computer peripheral is ready to be used. 2) Communicating.

Operating system : The basic programs that cause the computer to operate before specific function programs are loaded.

Overlay : A system of software design which allows long programs to be written and stored on disk ready to be called when required. During operation the part of the program currently in RAM will automatically call the next part of the program out of ROM which will load into RAM 'overlaying' and erasing the earlier program.

Parameter : A variable; a measurement.

Peripheral : A computer peripheral is a unit that is separate to the main computer - a printer, a disk drive, a musical keyboard.

Port : A socket, usually built into the computer, which allows information to pass in and out.

Polyphony : The ability to sound more than one note at the same time. 8-voice polyphony the ability to sound eight separate notes at once.

Program : Never programme. A list of instructions telling a computer precisely what to do. In musical applications a program might be the order of musical events as entered by a musician into a computer-based instrument.

Quantization : 1) Quantization noise/quantization error. The noise which occurs in digital sound reproduction when numerical expressions of sound are rounded off to their nearest numerical equivalent. Every measurement may be expressed in infinite terms, but when measurement is rounded off for the purposes of finite computation, small errors occur and, in sound reproduction, cause background noise. In musical applications, the more power the computer has the greater degree of measurement accuracy is possible, thus the lower the level of background noise. A problem that has been largely overcome. 2) Rounding a note to the nearest time segment

RAM : Random Access Memory. The operating part of a computer's memory. The user can access any part of this memory at random and order it to perform computations. RAM is the main measurement of computer power. Home computers currently offer between 1K and 128K RAM, although some home/business machines are capable of offering up to 900K RAM. Music computers rise to 256K RAM and above.

Real-time : Live: happening now. When you play a piano you are playing in real-time. When you program a computer to play a piano part you are programming in real-time but, as a whole, the piece of music has been created out of. real-time. When the computer plays the program it is playing non-real-time music.

Reset-switch : A switch found on most microcomputers which completely wipes all RAM and resets the computer to an 'empty' mode.

ROM : Read Only Memory. A non-volatile (permanent) memory system which can only be 'read from' in a certain sequence. Information stored in the memory cannot be accessed at random, but must be loaded into RAM where it may be accessed. ROM is used for the permanent and semi-permanent storage of information and typical ROM mediums include ROM chips (on which a program is written by the factory), floppy disks, hard disks and cassette tapes.

Sampling Rate : In musical applications, the rate at which a computer measures sound. External sound is fed to a music computer, e.g. the Fairlight, via an analog to digital converter. Within this device the sound wave is measured a fixed number of times per second. The frequency at which the sound is measured is called the sampling rate and the higher the rate, the more accurate the sample. For professional fidelity, the sampling rates chosen by the recording industry are between 40,000 and 50,000 times per second.

Semiconductor : The item at the heart of the computer. A material with an electrical conductivity some where between a good conductor (metal) and a poor conductor (insulating material.) Its conductivity increases as its temperature rises. As a device, a semiconductor is made from silicon, germanium or similar material and its basic function in computer applications is to represent 'on' or 'off': expressed another way, 1 or 0.

Sequencer : A microprocessor device for remembering control information. In the past sequencers have been used to control analog synthesizers, but now most computer-based instruments have built-in sequencers which act like tape recorders. They record all of the information from a series of notes and will replay those notes on demand. Many allow 'overdubbing.'

Silicon : One of the earth's most common materials (covering our beaches), silicon has proved to be one of the most important materials ever applied in technology. A perfect semiconductor and the material from which most microprocessors are constructed.

Sixteen(16)-bit : The 'bit' size in computer measurement parlance refers to the number of bits that can move through a computer at once - the width of information that can be handled. The wider the path, the more information can pass through at one time. Many TV games operate quite successfully on a 4-bit system, standard home computers are currently 8-bit and the new generation of microcomputers use 16-bit - e.g. the IBM personal and the Radio Shack Model 16. Some computer designs use 16-bit systems in one part of the information path and 8-bit in others. Microprocessors themselves are designed as 8-bit or 16-bit units. At the beginning of 1981 several US corporations announced the development of 32-bit microprocessors and although there are, as yet, no domestic systems or software programs available using this technology, the 32-bit system will produce a microcomputer with power equivalent to some of the mainframe computers. Most music computers are currently using 8-bit technology. [As of now the 8 and 16 bit machines have been superceded]

Soft : Soft-instrument. An increasing number of musical instruments are now soft. The phrase means that the instrument is computer-based and performs according to software instructions. Modification in the software results in a change in the instruments performance. Fully soft instruments are not yet with us; all current music computers require some special hardware to carry out musical functions. This special hardware limits the adaptability of the instruments. It is likely that the first really soft instruments will appear within five years.

Software : A collective name for all computer programs. Instructions for the computer are always soft, the mechanical and electrical elements of the computer are hardware.

Software gap : A gap that is opening between the capabilities of hardware and the people who write programs to control it. Computer development is following an exponential curve and artificial intelligence capability is increasing by compound leaps each year. Programmers are struggling to write programs that make efficient use of power now available.

Solid-state : Any electrical circuit built without electro mechanical parts such as tubes (valves). Transistor circuitry.

Speech-analyzer : A system that can recognize spoken words and transform them to computer commands. Under heavy research, but proving difficult to perfect. Ask a computer to differentiate between 'I saw' and 'eyesore.' Speech recognition is one of the major goals of the Japanese drive to develop the '5th Generation' of computers, but successful recognition systems capable of fully understanding speech might not be available for ten years.

String : A string of numbers or letters grouped together: usually in a computer program.

Stripe card reader : A device that decodes information contained in a strip of magnetic tape usually embedded in a plastic card. As used in Yamaha digital instruments and others.

Subroutine : A secondary part of a computer program which is called up during program operation to carry out a specific task.

Tracks : A term sometimes used by companies producing soft instruments to describe a multiple sequencer. In suggesting that a digital sequencer has 16-tracks, the manufacturers are comparing the system to 16-track analog tape recorders to help users visualize the facility. Often the facility isn't identical as tracks placed on top of tracks can't he accessed separately for subsequent editing or mixing.

Trigger : To trigger: to set-off, to start. A trigger into an analog input causes the relevant note to sound.

User-friendly : Usually applied to program design. A user friendly program or system is one that makes operation easy for unskilled operators.

User language : The language in which the user communicates with the computer - often bad!

Utilities : Basic programs in a computer system such as DOS (disk operating systems) and languages.

VDU : Visual Display Unit. VDUs are intended for business use and display 80 characters horizontally against the more normal 40 characters found on micro-computer screens.

Wave : As in sound wave. The shape of the graph (wave-like) that represents the frequency of a sound.

Waveform memory : A computer memory device, either RAM or ROM, which holds all of the information pertaining to a waveform.

Waveform table : A method of arranging information about a waveform that sets it out as a table in computer memory allowing the user rapid access to any part of the information.

Write : To copy. To write to disk means to copy the information on to a disk for storage purposes.





Chaos Quantum Logic Cosmos Conscious Belief Elect. Art Chem. Maths

The Musician and the Micro File Info: Created 15/7/2000 Updated 8/7/2004 Page Address: