Dictionary of Computing - 5th Edition

verb to identify oneself to a computer using a personalised signature to sign off to log off a system to sign on to log on to a system

signal / s n(ə)l/ noun 1. a generated analog or digital waveform used to carry information The signal received from the computer contained the answer. 2. a short message used to carry control codes verb to send a message to a computer

Signal to the network that we are busy. signal conditioning / s n(ə)l kənd ʃ(ə)n ŋ/ noun the process of converting or translating a signal into a form that is accepted by a device

signal conversion / s n(ə)l kənv ʃ(ə)n/ noun the process of processing,

changing or modulating a signal

signal distance / s n(ə)l d stəns/ noun a number of bit positions with differ-

ent contents in two data words

signal element / s n(ə)l el mənt/ noun the smallest basic unit used when transmitting digital data

signalling / s n(ə)l ŋ/ noun 1. a method used by a transmitter to warn a receiver that a message is to be sent 2. a communication to the transmitter about the state of the receiver in band signalling use of a normal voice grade channel for data transmission

signal processing / s n(ə)lprəυses ŋ/ noun processing of signals to

extract the information contained The system is used by students doing research on signal processing techniques.

signal to noise ratio / s n(ə)l tənɔ z re ʃiəυ/ noun the difference be-

tween the power of the transmitted signal and the noise on the line. Abbr S/N

sign and magnitude / sa n ənm n tju d/ noun a number representation in which the most significant bit indicates the sign of the number, the rest of the bits its value

sign and modulus / sa n ənmɒdjυləs/ noun a way of representing

numbers, where one bit shows if the number is positive or negative (usually 0 = positive, 1 = negative)

signature / s n tʃə/ noun a special authentication code, such as a password, which a user gives prior to access to a system or prior to the execution of a task (to

prove identity)

signature file / s n tʃə fa l/ noun a short text file, containing information such

as the user’s name and address, that is used as a signature at the end of e-mails and Usenet messages

sign bit / sa n b t/ noun a single bit which indicates if a binary number is positive or negative (usually 0 = positive, 1 = negative)

sign digit /sa n d d' t/ noun one digit which indicates if a number is positive or

negative

signed field / sa nd fi ld/ noun a storage field which can contain a number and a sign bit

signed magnitude / sa ndm n tju d/ noun same as sign and

magnitude

significance /s n f kəns/ noun a

special meaning

significant /s n f kənt/ adjective which has a special meaning

significant digit codes /s n f kəntd d' t kəυdz/ plural noun codes which

indicate various details of an item, by assigning each one a value

signify / s n fa / verb to mean A carriage return code signifies the end of an

input line.

sign indicator /sa n nd ke tə/ noun

same as sign bit

sign position /sa n pə z ʃ(ə)n/ noun a digit or bit position which contains the sign bit or digit

silicon / s l kən/ noun an element with semiconductor properties, used in crystal form as a base for IC manufacture

COMMENT: Silicon is used in the electronics industry as a base material for integrated circuits. It is grown as a long crystal which is then sliced into wafers before being etched or treated, producing several hundred chips per wafer. Other materials, such as germanium or gallium arsenide, are also used as a base for

ICs.

silicon chip / s l kən tʃ p/ noun a small piece of silicon in and on the surface of which a complete circuit or logic function has been produced by depositing other

substances or by doping

silicon disk / s l kən d sk/ noun a section of RAM made to look and behave like a high speed disk drive. Also called RAM

disk

silicon foundry / s l kən faυndri/ noun a machine used to create crystals of

silicon, then slice them into silicon wafers

Silicon Valley / s l kən v li/ noun an area in California where many US semiconductor device manufacturers are based

silicon wafer / s l kən we fə/ noun a thin slice of a pure silicon crystal, usually around 4 inches in diameter on which integrated circuits are produced (these are then cut out of the wafer to produce individual chips)

SIMD / es a em di / noun the architecture of a parallel computer which has a number of ALUs and data buses with one control unit. Full form single instruction

stream multiple data stream

SIMM / es a em em/ noun a small, compact circuit board with an edge connector along one edge that carries denselypacked memory chips You can expand the main memory of your PC by plugging in two more SIMMs. Full form single in-

line memory module

simple device / s mp(ə)l d va s/ noun a multimedia device that does not require a data file for playback, such as a CD drive used to play audio CDs

simple mail transfer protocol

/ s mpəl me l tr nsf prəυtəkɒl/ noun full form of SMTP

simple network management protocol / s mpəl netw k m n d'məntprəυtəkɒl/ noun a network management

system which defines how status data is sent from monitored nodes back to a control station; SNMP is able to work with virtually any type of network hardware

and software. Abbr SNMP

simple to use / s mp(ə)l tə, tυ/ adjective (of a machine or software) easy to use

and operate

simplex / s mpleks/ noun full form of

SPX. opposite duplex

simulate / s mjυ le t/ verb to copy the behaviour of a system or device with another This software simulates the action

of an aircraft.

simulation / s mjυ le ʃ(ə)n/ noun an operation where a computer is made to imitate a real life situation or a machine, and shows how something works or will work in the future Simulation techniques have reached a high degree of sophistication. simulator / s mjυ le tə/ noun a device which simulates another system simultaneity / s m(ə)ltə ni əti/ noun in which the CPU and the I/O sections of a computer can handle different data or

tasks at the same time

simultaneous / s m(ə)l te niəs/ adjective which takes place at the same time as something else

simultaneous processing

/ s m(ə)lte niəs prəυses ŋ/ noun two or more processes executed at the same time

COMMENT: True simultaneous processing requires two processors, but can be imitated by switching rapidly between two tasks with a single processor.

simultaneous transmission

/ s m(ə)lte niəs tr nz m ʃ(ə)n/ noun the transmission of data or control codes in two directions at the same time (NOTE: same as duplex)

single address code / s ŋ (ə)l ədres kəυd/ noun a machine code in-

struction which contains one operator and one address

single address instruction

/ s ŋ (ə)l ə dres n str kʃən/ noun same as single address code

single address message / s ŋ (ə)l ədres mes d'/ noun a message with a sin-

gle destination

single attachment station / s ŋ (ə)l ə t tʃmənt ste ʃ(ə)n/ noun (in an FDDI

network) a station with only one port through which to attach to the network; SAS stations are connected to the FDDI ring through a concentrator. Abbr SAS

single board computer / s ŋ (ə)l bɔ d kəm pju tə/ noun full form of SBC

single-board microcomputer

/ s ŋ (ə)l bɔ d ma krəυkəm pju tə/ noun a microcomputer whose components are all contained on a single printed circuit board

single chip computer / s ŋ (ə)l tʃ p kəm pju tə/ noun a complete simple computer including CPU, memory and input/output ports on one chip

single-chip microcontroller

/ s ŋ (ə)l tʃ p ma krəkən trəυlə/ noun one integrated circuit that contains a CPU, I/O ports, RAM and often a basic programming language

single density disk / s ŋ (ə)ldens ti d sk/ noun a standard magnetic disk able to store data. Abbr SD

single frequency signalling

/ s ŋ (ə)l fri kwənsi s n(ə)l ŋ/ noun the use of various frequency signals to represent different control codes. Also called sf signalling

single function software / s ŋ (ə)lf ŋkʃən sɒftweə/ noun an applications

program used for one kind of task only

single in-line memory module

/ s ŋ (ə)l n la n mem(ə)ri mɒdju l/ noun full form of SIMM

single in-line package / s ŋ (ə)l n la n p k d'/ noun an electronic component which has all its leads on one side of its package. Abbr SIP

single instruction stream multiple data stream / s ŋ (ə)l n str kʃən stri m m lt p(ə)l de tə stri m/ noun

full form of SIMD

single instruction stream single data stream / s ŋ (ə)l n str kʃən stri m s ŋ (ə)l de tə stri m/ noun full

form of SISD

single key response / s ŋ (ə)l ki rspɒns/ noun software which requires only one key to be pressed to select an option

single length precision / s ŋ (ə)l leŋθ pr s '(ə)n/ noun a number stored in

one word

single length working / s ŋ (ə)l leŋθw k ŋ/ noun the process of using numbers that can be stored within a single

word

single line display / s ŋ (ə)l la n d sple / noun a small screen which displays

a single line of characters at a time single mode fibre / s ŋ (ə)l məυd

fa bə/ noun an optic fibre that has a very narrow diameter (of 10 microns or less) and is designed to transmit a single light signal over a long distance; this type of fibre has a bandwidth of 5Gbits/second and is normally used for long distance telephone networks

single operand instruction

/ s ŋ (ə)l ɒpər nd n str kʃən/ noun

same as single address code

single operation / s ŋ (ə)l ɒpəre ʃ(ə)n/ noun a communications system which allows data to travel in only one direction at a time (controlled by codes S/O = send only, R/O = receive only, S/R = send or receive)

single-pass assembler / s ŋ (ə)l pɑ s ə semblə/ noun an object code pro-

duced in one run through the assembler of the source program

single pass operation / s ŋ (ə)l pɑ s ɒpə re ʃ(ə)n/ noun software which

produces the required result or carries out

a task after one run

single precision / s ŋ (ə)l prs '(ə)n/ noun a number stored in one word

single quotes / s ŋ (ə)l kwəυtz/ plu-

ral noun single inverted commas

single sheet feed / s ŋ (ə)l ʃi t fi d/ noun a paper feed system which puts single sheets of paper into a printer, one at a time

single-sided disk / s ŋ (ə)l sa d dd sk/ noun a floppy disk that can only store data on one side, because of the way it is manufactured or formatted. Abbr SSD single speed / s ŋ (ə)l spi d/ noun the speed at which a CD-ROM is spun by a drive, usually 230rpm

single step / s ŋ (ə)l step/ noun the process of executing a computer program one instruction at a time, used for debug-

ging

single-strike ribbon / s ŋ (ə)l stra kr bən/ noun a printer ribbon which can only be used once

single-system image / s ŋ (ə)ls stəm m d'/ noun an operational view of multiple networks, distributed databases or multiple computer systems as if they

were one system

single-user system / s ŋ (ə)l ju zəs stəm/ noun a computer system which can only be used by a single user at a time (as opposed to a multi-user system)

sink /s ŋk/ noun the receiving end of a communications line. Opposite source sink tree / s ŋk tri / noun a description in a routing table of all the paths in a network to a destination

SIO abbr serial input/output SIP abbr single in-line package

SIPO abbr serial input/parallel output SISD / es a es di / noun the architecture of a serial computer, which has one ALU and data bus, with one control unit. Full form single instruction stream single data stream

SISO abbr serial input/serial output site /sa t/ noun a place where something

is based

site licence /sa t la s(ə)ns/ noun a licence between a software publisher and a user which allows any number of users in that site to use the software We have negotiated a good deal for the site licence for

the 1200 employees in our HQ.

site poll / sa t pəυl/ verb to poll all the terminals or devices in a particular location or area. polling

6 degrees of freedom / s ks d ri z əv fri dəm/ noun (in virtual reality) a de-

scription of the movements and vision that a user can interpret: normally three visual

dimensions together with movement 16-bit / s ksti n b t/ data that is trans-

ferred sixteen bits at a time along sixteen parallel conductors; in a processor this refers to its ability to manipulate data that is sixteen bits wide representing numbers up to 65,536

sixteen-bit / s ks ti n b t/ adjective (of a microcomputer system or CPU) which handles data in sixteen bit words, providing much faster operation than older eight-

bit systems

16-bit sample / s ksti n b tsɑ mp(ə)l/ noun single sample of an analog signal which is stored as a 16-bit number, meaning that there are 65,536 possible levels. A ‘16-bit sound card’ can sometimes mean that the card generates 16-bit samples, but it can also mean that it generates 8-bit samples, but fits into a 16bit expansion slot. 8-bit sample, 24-bit sample

size /sa z/ noun the physical dimensions of an image, object or page verb to calculate the resources available, and those

required, to carry out a particular job skeletal code / skel t(ə)l kəυd/ noun a

program which is not complete, with the basic structure coded

skew /skju / noun the amount by which something is not correctly aligned verb to align something incorrectly This page is badly skewed.

skin /sk n/ noun 1. a piece of software that changes the appearance of images produced by existing software without changing their function 2. the changed image that is produced by a piece of skin software verb to change the appearance of images produced by existing software, without changing their function

skip /sk p/ verb to ignore an instruction in a sequence of instructions The printer

skipped the next three lines of text.

skip capability /sk p ke pə b ləti/ noun a feature of certain word-processors to allow the user to jump backwards or forwards by a quantity of text in a document skip instruction /sk p n str kʃən/ noun a null computer command which directs the CPU to the next instruction slash /sl ʃ/ noun a punctuation mark (/) that is used to separate optional items in a list and to express fractions or ratios, and that has various uses in computer pro-

gramming, e.g. to separate off certain sec-

tions of an Internet address

slashed zero /sl ʃd z ərəυ/ noun a printed or written sign (Ø)

slave /sle v/ noun a remote secondary computer or terminal controlled by a central computer

slave cache / sle v k ʃ/ noun a section of high-speed memory which stores data that the CPU can access quickly slave processor /sle v prəυ sesə/ noun a dedicated processor controlled by a

master processor

slave store / sle v stɔ / noun same as

slave cache

slave terminal /sle v t m n(ə)l/ noun a terminal controlled by a main computer or terminal

slave tube / sle v tju b/ noun a second CRT display connected to another so that it shows exactly the same information sleep /sli p/ noun the state of a system that is waiting for a signal (log-on) before doing anything

sleeve /sli v/ noun a paper or plastic cover for a magnetic disk

slew /slu / noun a rapid movement of paper in a printer, ignoring the normal line advance

slide /sla d/ noun one image in a presentation or a single frame of positive photographic film

slide show / sla d ʃəυ/ noun a feature of a presentation graphics software in which slides (static images) are displayed in a sequence under the control of the presenter

SLIP /sl p/ noun a method of sending TCP/IP network traffic over a serial line, such as a telephone modem connection (normally used to connect a user’s computer to the Internet via a modem link). Full form serial line internet protocol

slot /slɒt/ verb to insert an object into a hole The disk slots into one of the floppy

drive apertures.

slow peripheral /sləυ pə r f(ə)rəl/ noun a peripheral in which mechanical

movement determines speed

slow scan TV / sləυ sk n ti vi / noun a system used to transmit still video frames over a telephone line

SLSI abbr super large scale integration

small computer systems interface

/ smɔ l kəm pju tə s stəmz ntəfe s/ noun full form of SCSI

small-scale / smɔ l ske l/ adjective working with small amounts of data. Compare large-scale

small scale integration / smɔ l ske lnt re ʃ(ə)n/ noun an integrated circuit with 1 to 10 components. Abbr SSI Smalltalk / smɔ ltɔ k/ an object-orient- ed programming language developed by Xerox

smart card / smɑ t kɑ d/ noun a plastic card with a memory and microprocessor device embedded in it, so that it can be used for electronic funds transfer or for identification of the user

smart terminal /smɑ t t m n(ə)l/ noun a computer terminal which can process information. Compare dumb terminal

smart wiring hub / smɑ t wa ər ŋ

h b/ noun a network hub or concentrator which can transmit status information back to a managing station and allows management software to configure each port remotely Using this management software, I can shut down Tom’s port on the remote smart wiring hub.

SMB / es em bi / noun a system developed by Microsoft which allows a user to access another computer’s files and peripherals over a network as if they were local resources. Full form server message block

smiley / sma li/ noun a face created with text characters, used to provide the real meaning to an email message; e.g., :-) means laughter or a joke, and :-( means sad S/MIME abbr secure/multipurpose Internet mail extension

smooth scroll / smu ð skrəυl/ noun text which is moved up a screen pixel by pixel rather than line by line, which gives a smoother movement

SMPTE / es em pi ti i / noun an organisation that defines standards for television production systems; e.g., the SMPTE time code standard is widely used to synchronise audio and video equipment using hours, minutes, seconds, frame data that is stored in an 80-bit word. Full form

Society for Motion Picture and TV Engineers

SMPTE division type / es em pi tii d v '(ə)n ta p/ noun a timing format

which specifies the number of frames per second used, and in which time is shown as hours, minutes, seconds, frames; stand-

ard SMPTE division types are 24, 25 and 30 frames per second

SMPTE offset / es em pi ti i ɒfset/ noun a MIDI event that defines when a MIDI file is to be played back

SMPTE time code / es em pi ti ita m kəυd/ noun a method of assigning a unique identifying number to each frame in a video sequence

SMS abbr short message service

SMT / es em ti / noun a method of manufacturing circuit boards in which the electronic components are bonded directly onto the surface of the board rather than being inserted into holes and soldered into place Surface-mount technology is faster and more space-efficient than soldering. Full form surface-mount technology

SMTP / es em ti pi / noun a standard protocol which allows electronic mail messages to be transferred from one system to another, normally used as the method of transferring mail from one Internet server to another or to send mail from a computer to a server. Full form simple mail transfer protocol. Compare POP 3

S/N abbr signal to noise ratio

SNA / es en e / noun design methods developed by IBM which define how communications in a network should occur and allow different hardware to communicate. Full form systems network architecture

snail mail / sne l me l/ noun a slang term used to refer to the normal (slow) postal delivery rather than (near instant) electronic mail delivery

snapshot / sn p ʃɒt/ noun 1. a recording of all the states of a computer at a particular instant 2. the process of storing in main memory the contents of a screen full of information at an instant

snapshot dump / sn p ʃɒt d mp/ noun a printout of all the registers and a section of memory at a particular instant, used when debugging a program

snd /saυnd/ noun a filename extension used to indicate a file that contains digitised sound data. Full form SouND sniffer / sn fə/ noun a device or program that monitors and analyses network traffic, in order to detect bottlenecks and problems

SNMP abbr simple network management protocol

SNOBOL / snəυbɒl/ noun a high-level programming language which uses string processing methods. Full form string orientated symbolic language

snow /snəυ/ noun interference displayed as flickering white flecks on a monitor soak /səυk/ verb to run a program or device continuously for a period of time to make sure it functions correctly

Society for Motion Picture and TV Engineers /sə sa əti fə məυʃ(ə)np ktʃə ən ti vi / noun full form of

SMPTE

socket / sɒk t/ noun a device with a set of holes, into which a plug fits

socket driver / sɒk t dra və/ noun same as Winsock

SOCKS /sɒks/ noun a network protocol developed to support the transfer of TCP/IP (Internet) traffic through a proxy server. It is commonly used to provide a way for users on a local area network to access the Internet via a single shared connection.

soft /sɒft/ adjective 1. referring to material which loses its magnetic effects when removed from a magnetic field 2. referring to data which is not permanently stored in hardware. Soft usually refers to data stored on magnetic medium.

soft copy /sɒft kɒpi/ noun text listed on screen (as opposed to hard copy on paper)

soft error /sɒft erə/ noun a random error caused by software or data errors which is very difficult to trace and identify since it only appears under certain conditions

soft-fail /sɒft fe l/ adjective referring to a system which is still partly operational even after a part of the system has failed soft font / sɒft fɒnt/ noun fonts or typefaces stored on a disk, which can be downloaded or sent to a printer and stored in temporary memory or RAM

soft goods / sɒft υdz/ plural noun software that can be purchased and paid for in an online shop, and which is then downloaded directly onto a computer instead of receiving a CD-ROM sent by post soft keyboard /sɒft ki bɔ d/ noun a keyboard where the functions of the keys can be changed by programs

soft keys / sɒft ki z/ plural noun keys which can be changed by means of a program

soft reset /sɒft ri set/ noun an instruction that terminates any program execution and returns the user to the monitor

or BIOS

soft-sectored disk / sɒft sektədd sk/ noun a disk where the sectors are described by an address and start code data

written onto it when the disk is formatted software / sɒftweə/ noun any program

or group of programs which instructs the hardware on how it should perform, including operating systems, word proces-

sors and applications programs software compatible / sɒftweə kəm

p t b(ə)l/ adjective referring to a computer which will load and run programs

written for another computer

software developer / sɒftweə dveləpə/ noun a person or company which

writes software

software development / sɒftweə dveləpmənt/ noun the processes required

to produce working programs from an initial idea

software documentation / sɒftweədɒkjυmen te ʃ(ə)n/ noun information,

notes and diagrams describing the function, use and operation of a piece of soft-

ware

software engineer / sɒftweəend' n ə/ noun a person who can write

working software to fit an application

software engineering / sɒftweəend' n ər ŋ/ noun a field of study cover-

ing all software-related subjects software house / sɒftweə haυs/ noun

a company which develops and sells computer programs

software interrupt / sɒftweəntər pt/ noun a high priority programgenerated signal, requesting the use of the

central processor

software library / sɒftweə la brəri/ noun a number of specially written routines, stored in a library file which can be inserted into a program, saving time and

effort. Abbr H

software licence / sɒftweəla s(ə)ns/ noun an agreement between a user and a software house, giving details of the rights of the user to use or copy the

software

software life cycle / sɒftweə la fsa k(ə)l/ noun the period of time when a piece of software exists, from its initial design to the moment when it becomes out of date

software maintenance / sɒftweəme ntənəns/ noun the process of carry-

ing out updates and modifications to a software package to make sure the program is up to date

software modem / sɒftweəməυdem/ noun a modem that uses the

main computer’s processor to carry out all the signal processing required to modulate and demodulate data signals that can be sent to a dedicated serial port. New PCs are often fitted with a software modem (often called a WinModem) that takes advantage of the powerful processors to provide a very cheap way of adding a modem function and providing dial-up Internet access to a computer.

software-only video playback

/ sɒftweə əυnli v diəυ ple b k/ noun the ability to display full-motion video standard on any multimedia computer, without requiring special hardware software package / sɒftweəp k d'/ noun computer programs and manuals designed for a special purpose software piracy / sɒftweə pa rəsi/ noun the illegal copying of software for sale

software quality assurance

/ sɒftweə kwɒl ti ə ʃυərəns/ noun the process of making sure that software will perform as intended. Abbr SQA

software reliability / sɒftweə rla əb l ti/ noun the ability of a piece of software to perform the task required correctly

software specification / sɒftweəspes f ke ʃ(ə)n/ noun detailed informa-

tion about a piece of software’s abilities, functions and methods

software system / sɒftweə s stəm/ noun all the programs required for one or more tasks

software tool / sɒftweə tu l/ noun a program used in the development of other programs

soft zone / sɒft zəυn/ noun a text area to the left of the right margin in a wordprocessed document, where if a word does not fit completely, a hyphen is automatically inserted

solid colour / sɒl d k lə/ noun a colour that can be displayed on a screen or printed on a colour printer without dithering

solid error / sɒl d erə/ noun an error that is always present when certain equip-

ment is used

solid font printer / sɒl d fɒnt pr ntə/ noun a printer which uses a whole character shape to print in one movement, such as

a daisy wheel printer

solid modelling / sɒl d mɒd(ə)l ŋ/ noun a function in a graphics program that creates three-dimensional solid-looking

objects by shading

solid-state / sɒl d ste t/ adjective re-

ferring to semiconductor devices solid-state device / sɒl d ste t d

va s/ noun an electronic device which operates by using the effects of electrical or magnetic signals in a solid semiconductor

material

solid state disk / sɒl d ste t d sk/ noun a mass storage device that uses electronic memory components with a backup battery to store data rather than a magnetic medium (such as a magnetic disk used in a hard disk drive)

solid-state memory device / sɒl d ste t mem(ə)ri d va s/ noun a solid-

state memory storage device (usually in the form of RAM or ROM chips)

son file / s n fa l/ noun the latest working version of a file. Compare father file, grandfather file

song key / sɒŋ ki / noun a musical key used to play a MIDI song

Sony / səυni/ an electronics company that has developed a wide range of consumer and computer electronic products sophisticated /sə f st ke t d/ adjective technically advanced A sophisticat-

ed desktop publishing program. sophistication /sə f st ke ʃ(ə)n/

noun the state of being technically advanced The sophistication of the new package is remarkable.

sort /sɔ t/ verb to put data in order, according to a system, on the instructions of the user To sort addresses into alphabet-

ical order.

sorting pass / sɔ t ŋ pɑ s/ noun a single run through a list of items to put them

into order

sortkey / sɔ tki /, sort field / sɔ t fi ld/ noun a field in a stored file which is used to sort the file The orders were sorted according to dates by assigning the date field as the sortkey.

sort/merge / sɔ t m d'/ noun a program which allows new files to be sorted

and then merged in correct order into ex-

isting files

sound /saυnd/ noun 1. in a PC, a filename extension used to indicate a file that contains digitised sound data 2. in a Macintosh, the resource that contains sound information abbr snd

sound bandwidth /saυnd b ndw dθ/ noun the range of frequencies that a human ear can register, normally from

20Hz to 20KHz

Sound Blaster / saυnd blɑ stə/ a trade name for a type of sound card for PC compatibles developed by Creative Labs that allows sounds to be recorded to disk

(using a microphone) and played back sound capture /saυnd k ptʃə/ noun

the conversion of an analog sound into a digital form that can be used by a compu-

ter

sound card / saυnd kɑ d/ noun an expansion card which produces analog sound signals under the control of a computer This software lets you create almost any sound – but you can only hear

them if you have a sound card fitted. sound chip / saυnd tʃ p/ noun a de-

vice that will generate a sound or tune sound file / saυnd fa l/ noun a file

stored on disk that contains sound data sound hood / saυnd hυd/ noun a cov-

er which cuts down the noise from a noisy printer

sound pressure level / saυnd preʃəlev(ə)l/ noun full form of SPL

Sound Recorder / saυnd r kɔ də/ a utility included with Microsoft Windows that allows a user to play back digitised sound files or record sound onto disk and

carry out very basic editing

sound waves / saυnd we vz/ plural noun pressure waves produced by vibrations, which are transmitted through air (or a solid) and detected by the human ear or a microphone (in which they are converted to electrical signals)

source /sɔ s/ noun a point where a transmitted signal enters a network. Opposite sink

source address filtering / sɔ s ədres f ltər ŋ/ noun a feature of some

bridges which detects a particular address in the received packet and either rejects or forwards the data

source book / sɔ s bυk/ noun a library file from which elements or objects are copied and used

source code / sɔ s kəυd/ noun a set of codes (as a program) written by the programmer which cannot be directly executed by the computer, but have to be translated into an object code program by a compiler, assembler or interpreter

source deck / sɔ s dek/ noun a set of punched cards which contain the source code for a program

source document /sɔ s dɒkjυ ment/ noun a form or document from which data is extracted prior to entering it into a database

source editor /sɔ s ed tə/ noun software which allows the user to alter, delete or add instructions in a program source file source file / sɔ s fa l/ noun a program written in source language, which is then converted to machine code by a compiler source language /sɔ s l ŋ w d'/ noun 1. a language in which a program is originally written 2. a language of a program prior to translation. Opposite object language, target language

source listing /sɔ s l st ŋ/ noun 1. listing of a text in its original form 2. listing of a source program

source machine /sɔ s mə ʃi n/ noun a computer which can compile source code source object /sɔ s ɒbd'ekt/ noun (in Windows) the object within a drag and drop operation that is first clicked on and then dragged

source pack / sɔ s p k/ noun same as source deck

source program /sɔ s prəυ r m/ noun a program, prior to translation, written in a programming language by a programmer

source routing / sɔ s raυt ŋ/ noun a method, originally developed by IBM for its Token Ring networks, of moving data between two networks, which examines the data within the token and passes the data to the correct station

source transparent routing / sɔ s tr ns p rənt ru t ŋ/ noun a standard

developed by IBM and the IEEE, allowing IBM networks and non-IBM Token Ring networks to be bridged and so exchange data. Abbr SRT

SP abbr stack pointer

space /spe s/ noun a gap between characters or lines verb to spread out text

The line of characters was evenly spaced out across the page.

space bar / spe s bɑ / noun a long bar at the bottom of a keyboard, which inserts a space into the text when pressed space character /spe s k r ktə/ noun a character code which prints a space spacing / spe s ŋ/ noun the process of putting spaces between characters or lines of printed text The spacing on some lines is very uneven.

spam /sp m/ noun an article that has been posted to more than one newsgroup, so is likely to contain commercial messages (slang)

spam killer / sp m k lə/ noun a piece of software that automatically identifies and deals with spam in incoming e-mail span /sp n/ noun a set of allowed values between a maximum and minimum spanning tree / sp n ŋ tri / noun a method of creating a network topology that does not contain any loops and provides redundancy in case of a network fault or problem

SPARC /spɑ k/ noun a RISC processor designed by Sun Microsystems which is used in its range of workstations. Full form

Scalar Processor Architecture

spare part / speə pɑ t/ noun a small piece of a machine which is needed to replace a piece which is broken or missing spark printer /spɑ k pr ntə/ noun a thermal printer which produces characters on thermal paper by electric sparks sparse array /spɑ s ə re / noun a data matrix structure containing mainly zero or null entries

spatial measurement / spe ʃ(ə)lme'əmənt/ noun a method of allowing a

computer to determine the position of a pointer within three dimensions (often using a sensitive glove)

spec /spek/ noun same as specification

(informal)

special character / speʃ(ə)l k r ktə/ noun a character which is not a standard one in a certain font (such as a certain accent or a symbol)

special interest group / speʃ(ə)lntrəst ru p/ noun full form of SIG

specialise / speʃəla z/ verb to study and be an expert in a subject He specialises in the design of CAD systems. specialist / speʃəl st/ noun an expert in a certain field of study You need a specialist programmer to help devise a new word-processing program.

special purpose / speʃ(ə)l p pəs/ noun a system designed for a specific or

limited range of applications

special sort / speʃ(ə)l sɔ t/ noun an extra printing character not in the standard

font range

specific address /spə s f k ə dres/ noun a storage address which directly, without any modification, accesses a location or device

specification / spes f ke ʃ(ə)n/ noun detailed information about what is to be supplied or about a job to be done. Also called spec to work to standard specifications to work to specifications which are accepted anywhere in the same industry the work is not up to specification or does not meet the customer’s specifications the product was not manufactured in the way which was detailed in the spec-

ifications

specific code /spə s f k kəυd/ noun a binary code which directly operates the central processing unit, using only abso-

lute addresses and values

specific coding /spə s f k kɒd ŋ/ noun a program code which has been written so that it only uses absolute addresses and values

specificity / spes f səti/ noun the ratio of non-relevant entries not retrieved to the total number of non-relevant entries con-

tained in a file, database or library speech chip / spi tʃ tʃ p/ noun an in-

tegrated circuit which generates sounds (usually phonemes) which when played

together sound like human speech speech quality /spi tʃ kwɒl ti/ noun

a sound recorded at a low bandwidth with a small sample size; e.g., in CD-i it is Level C with 4-bit samples and a rate of 18.9KHz

speech recognition /spi tʃ rekən ʃ(ə)n/ noun the process of analysing spoken words in such a way that a computer can recognize spoken words and com-

mands

speech synthesis /spi tʃ s nθəs s/ noun the production of spoken words by a speech synthesiser

speech synthesiser / spi tʃs nθəsa zə/ noun a device which takes

data from a computer and outputs it as spoken words

speed /spi d/ noun the time taken for a movement divided by the distance travelled

speed of loop / spi d əv lu p/ noun a method of benchmarking a computer by measuring the number of loops executed

in a certain time

spellcheck / speltʃek/ verb to check the spelling in a text by comparing it with

a dictionary held in the computer spellchecker / speltʃekə/, spelling

checker noun a dictionary of correctly spelled words, held in a computer, and used to check the spelling of a text The program will be upgraded with a wordprocessor and a spelling checker. spherisation / sf əra ze ʃ(ə)n/ noun a special effect provided by a computer graphics program that converts an image into a sphere, or ‘wraps’ the image over a spherical shape

spider / spa də/ noun a program that searches through the millions of pages that make up the world wide web for new information, changes or pages that have been deleted. These changes are then added to a search engine index to ensure that it is always up to date.

spike /spa k/ noun a very short duration voltage pulse

spillage / sp l d'/ noun a situation when too much data is being processed and cannot be contained in a buffer

spindle / sp nd(ə)l/ noun an object which grips and spins a disk in the centre hole

spindling / sp ndl ŋ/ noun the process of turning a disk by hand

SPL / es pi el/ noun a measure of loudness, in decibels (dB). Full form sound

pressure level

splash screen / spl ʃ skri n/ noun the initial screen that is displayed for a few seconds when a program is started The splash screen normally displays the product logo and gives basic copyright infor-

mation.

splice /spla s/ verb to join two lengths of magnetic tape, forming a continuous

length

splicing tape / spla s ŋ te p/ noun a non-magnetic tape which is applied to the

back of the two ends of tape to be spliced split baud rate / spl t bɔ d re t/

noun a feature of a modem which receives data at one baud rate but transmits data at another The viewdata modem uses a

1200/75 split baud rate.

split screen / spl t skri n/ noun software which can divide the display into two

or more independent areas, to display two text files or a graph and a text file We use split screen mode to show the text being worked on and another text from memory for comparison.

spoof /spu f/ verb to send e-mail using a false name or e-mail address

spool /spu l/ noun a reel on which a tape or printer ribbon is wound verb to transfer data from a disk to a tape

spooler noun a device which holds a tape and which receives information from a disk for storage

spooling / spu l ŋ/ noun the process of transferring data to a disk from which it can be printed at the normal speed of the printer, leaving the computer available to

do something else

sporadic fault /spə r d k fɔ lt/ noun

an error which occurs occasionally spreadsheet / spred ʃi t/ noun 1. a

program which allows calculations to be carried out on several columns of numbers 2. a printout of calculations on wide computer stationery

sprite /spra t/ noun an object which moves round the screen in computer graphics

sprocket noun a wheel with teeth round it which fit into holes in continuous sta-

tionery or punched tape

sprocket feed / sprɒk t fi d/ noun a paper feed where the printer pulls the paper by turning sprocket wheels which fit into a series of holes along each edge of

the sheet. tractor feed

sprocket holes / sprɒk t həυlz/ plural noun a series of small holes on each edge of continuous stationery, which allow the

sheet to be pulled through the printer spurious data / spjυəriəs de tə/

noun unexpected or unwanted data or an

error in a signal, often due to noise

SPX / es pi eks/ a trade name for a network transport protocol developed by Novell and used to carry IPX network traffic. Full form sequenced packet exchange noun data transmission in only one direction. Full form simplex. Oppo-

site duplex

spyware / spa weə/ noun a type of software that can be installed on someone’s hard disk without that person’s knowledge. It is designed to send back encoded information about the computer owner’s identity and the way he or she uses the Internet to the person who installed it.