~C~

C++-through-Carrier Frequency

A/B Switch box ~ America On-line  AMI BIOS ~ Arithmetic Operation  ARP ~ AVI  Backbone ~ Bit Image  Bit Map ~ Boot Disk  Boot Drive ~ Bytes Per Inch  C++ ~ Carrier Frequency  carrier system ~ certification  CGI ~ Chooser extension  cipher ~ Clipper Chip  clock ~ color  color bits ~ communications satellite  communications server ~ computer security  CON ~ copy  copy program ~ cycle time  daemon ~ defragmentation  demand paging ~ digitize  DikuMUD ~ disk  disk buffer ~ Document Style Semantics and Specification Language  document window ~ dynamic Web page  Easter egg ~ erase  erase head ~ ezine  F2F ~ finger2  firewall ~ font suitcase  footer ~ FYI  Game Control Adapter ~ GUI  HAL ~ hot key1  hot key2 ~ Hz  i486DX ~ internal modem  internet ~ ISO 9660  ISO/OSI model ~ just-in-time  K1 ~ knowledge base  L1 cache ~ LU  luggable computer ~ LZW compression  MAC ~ MILNET  mime ~ msec  MTBF ~ MYOB  named anchor ~ network drive  Network File System ~ number crunching  object ~ overwrite mode  P5 ~ PC/XT keyboard  PDA ~ pipeline processing  piracy ~ preventive maintenance  preview ~ pwd  quasi-language ~ QWERTY keyboard  R&D ~ registration marks  Registry ~ RFI  RF shielding ~ run-time library  SAA ~ server error  server push-pull ~ soft return  software ~ style sheet  stylus ~ System  T1 ~ ToggleKeys  token ~ typography  UART ~ uupc  V.120 ~ view2  viewer ~ VxD  w3 ~ WinG  WINS ~ WWW  X.25 ~ X Windows  Yahoo! ~ yotta-  Z39.50 standard ~ Zulu time

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C++

n. An object-oriented version of the C programming language, developed by Bjarne Stroustrup in the early 1980s at Bell Laboratories and adopted by a number of vendors, including Apple Computer and Sun Microsystems. See also C, Objective-C, object-oriented programming.

C2

n. The lowest level of security in the U.S. National Computer Security Center's hierarchy of criteria for trusted computer systems, requiring user logon with password and a mechanism for auditing. The C2 level is outlined in the Orange Book. See also Orange Book (definition 1).

cabinet

n. The box in which the main components of a computer (CPU, the hard drive, floppy and CD-ROM drives, and expansion slots for peripheral devices, such as monitors) are located. See also CPU, expansion slot.

cable

n. A collection of wires shielded within a protective tube, used to connect peripheral devices to a computer. A mouse, a keyboard, and a printer might all be connected to a computer with cables. Printer cables typically implement a serial or a parallel path for data to travel along.

cable connector

n. The connector on either end of a cable. See also DB connector, DIN connector, RS-232-C standard, RS-422/423/449. cable modem

n. A modem that sends and receives data through a coaxial cable television network instead of telephone lines, as with a conventional modem. Cable modems, which have speeds of 500 kilobits per second (Kbps), can generally transmit data faster than current conventional modems. See also coaxial cable, modem.

cabling diagram

n. A plan that shows the path of cables that attach computer system components or peripherals. Cabling diagrams are particularly important for explaining the connection of disk drives to a disk controller.

cache

n. A special memory subsystem in which frequently used data values are duplicated for quick access. A memory cache stores the contents of frequently accessed RAM locations and the addresses where these data items are stored. When the processor references an address in memory, the cache checks to see whether it holds that address. If it does hold the address, the data is returned to the processor; if it does not, a regular memory access occurs. A cache is useful when RAM accesses are slow compared with the microprocessor speed, because cache memory is always faster than main RAM memory. See also disk cache, wait state.

CAD

n. Acronym for computer-aided design. A system of programs and workstations used in designing engineering, architectural, and scientific models ranging from simple tools to buildings, aircraft, integrated circuits, and molecules. Various CAD applications create objects in two or three dimensions, presenting the results as wire-frame "skeletons," as more substantial models with shaded surfaces, or as solid objects. Some programs can also rotate or resize models, show interior views, generate lists of materials required for construction, and perform other allied functions. CAD programs rely on mathematics, often requiring the computing power of a high-performance workstation. See also CAD/CAM, I-CASE.

caddy

n. A plastic carrier that holds a CD-ROM and is inserted into a CD-ROM drive. Some personal computers, especially older models, have CD-ROM drives that require the use of a caddy. Most current CD-ROM drives do not require a caddy.

calculator

n. Broadly, any device that performs arithmetic operations on numbers. Sophisticated calculators can be programmed for certain functions and can store values in memory, but they differ from computers in several ways: they have a fixed set of commands, they do not recognize text, they cannot retrieve values stored in a data file, and they cannot find and use values generated by a program such as a spreadsheet.

calendar program

n. An application program in the form of an electronic calendar, commonly used for highlighting dates and scheduling appointments. Some calendar programs resemble wall calendars, displaying dates in blocks labeled with the days of the week; others display dates day by day and enable the user to enter appointments, notes, and other memoranda. A day-of-the-week type of calendar program could, for example, be used to find out that Christmas 1999 will be on a Saturday. Depending on its capabilities, such a program might cover only the current century, or it might cover hundreds of years and even allow for the change (in 1582) from the Julian to the Gregorian calendar. A calendar/scheduler program might show blocks of dates or, like an appointment book, single days divided into hours or half hours, with room for notes. Some programs allow the user to set an alarm to go off at an important point in the schedule. Other programs can coordinate the calendars of different people on the same network, so that a person entering an appointment into his or her calendar also enters the appointment into a colleague's calendar.

call1

n. In a program, an instruction or statement that transfers program execution to some section of code, such as a subroutine, to perform a specific task. Once the task is performed, program execution resumes at the calling point in the program. See also calling sequence.

call2

vb. 1. To establish a connection through a telecommunications network. 2. To transfer program execution to some section of code (usually a subroutine) while saving the necessary information to allow execution to resume at the calling point when the called section has completed execution. Some languages (such as FORTRAN) have an explicit CALL statement; others (such as C and Pascal) perform a call when the name of a procedure or function appears. In assembly language, there are various names for a CALL instruction. When a subroutine call occurs in any language, one or more values (known as arguments or parameters) are often passed to the subroutine, which can then use and sometimes modify these values. See also argument, parameter.

callback

n. A user authentication scheme used by computers running dial-in services. A user dials in to a computer and types a logon ID and password. The computer breaks the connection and automatically calls the user back at a preauthorized number. This security measure usually prevents unauthorized access to an account even if an individual's logon ID and password have been stolen. See also authentication.

camera-ready

adj. In publishing, of or pertaining to the stage at which a document, with all typographic elements and graphics in place, is suitably prepared to be sent to a printing service. The printing service photographs the camera-ready copy and then uses the photograph to make plates for printing. Some applications are advertised as being able to bring documents to the camera-ready stage, eliminating the need for manual layout and pasteup of elements onto boards.

cancel

n. A control character used in communication with printers and other computers, commonly designated as CAN. It usually means that the line of text being sent should be canceled. In ASCII, which is the basis of character sets used by most microcomputers, this is represented internally as character code 24.

canned software

n. Off-the-shelf software, such as word processors and spreadsheet programs.

capacitor

n. A circuit component that provides a known amount of capacitance (ability to store an electric charge). A capacitor typically consists of two conductive plates separated by an insulating (dielectric) material. If other factors remain constant, capacitance increases as the plates are made larger or brought closer together. A capacitor blocks direct current but passes alternating current to an extent that depends on its capacitance and on the frequency of the current. See also capacitance. capacity

n. The amount of information a computer or an attached device can process or store. See also computer.

caps

n. Short for capital letters. Compare lowercase.

Caps Lock key

n. A toggle key that, when on, shifts the alphabetic characters on the keyboard to uppercase. The Caps Lock key does not affect numbers, punctuation marks, or other symbols.

capture

vb. In communications, to transfer received data into a file for archiving or later analysis.

card

n. 1. A printed circuit board or adapter that can be plugged into a computer to provide added functionality or new capability. These cards provide specialized services, such as mouse support and modem capabilities, that are not built into the computer. See also adapter, board, printed circuit board. 2. In programs such as the HyperCard hypertext program, an on-screen representation of an index card on which information can be stored and "filed" (saved) for future reference. See also hypertext. 3. A manila card about 3 inches high by 7 inches long on which 80 columns of data could be entered in the form of holes punched with a keypunch machine. The punched holes corresponded to numbers, letters, and other characters and could be read by a computer that used a punched- card reader. Also called punched card. See also card reader (definition 2).

card reader

n. 1. An input device used chiefly for identification purposes that reads information that has been magnetically encoded, usually in two tracks, on a plastic card, such as a credit card or an employee badge. 2. A mechanical apparatus that reads computer data from punched cards. No longer in widespread use, card readers allow computer data to be created offline and then input to the computer for processing. This need for offline data creation was because of limited CPU resources. Reading batches of punched cards was a better use of CPU time than waiting for a human operator to key data directly into the computer's memory. Also called punched-card reader.

caret

n. The small, upward-pointing symbol (^) typically found over the 6 key on the top row of a microcomputer keyboard. In some programming languages, the caret is used as an exponentiation operator. For example, the expression 3 ^ 2 represents the number 3 raised to the second power. The caret is also used to represent the Control key on the keyboard. For example, ^Z means "hold the Control key down and press the Z key."

carpal tunnel syndrome

n. A form of repetitive strain injury to the wrist and hand. Making the same small motions over and over can cause swelling and scarring of the soft tissue of the wrist, which then compresses the main nerve leading to the hand. Symptoms of carpal tunnel syndrome include pain and tingling in the fingers, and in advanced cases, carpal tunnel syndrome can lead to loss of functionality of the hands. Typing at a computer keyboard without proper wrist support is a common cause of carpal tunnel syndrome. See also repetitive strain injury, wrist support. Acronym: CTS.

carriage return

n. A control character that tells a computer or printer to return to the beginning of the current line. A carriage return is similar to the return on a typewriter but does not automatically advance to the beginning of a new line. For example, a carriage-return character alone, received at the end of the words This is a sample line of text would cause the cursor or printer to return to the first letter of the word This. In the ASCII character set, the carriage-return character has the decimal value of 13 (hexadecimal 0D).

carrier

n. 1. In communications, a specified frequency that can be modulated to convey information. 2. A company that provides telephone and other communications services to consumers.

carrier frequency

n. A radio-frequency signal, such as those used with modems and on networks, used to transmit information. A carrier frequency is a signal that vibrates at a fixed number of cycles per second, or hertz (Hz), and is modulated (changed) in either frequency or amplitude to enable it to carry intelligible information.

 

A/B Switch box ~ America On-line  AMI BIOS ~ Arithmetic Operation  ARP ~ AVI  Backbone ~ Bit Image  Bit Map ~ Boot Disk  Boot Drive ~ Bytes Per Inch  C++ ~ Carrier Frequency  carrier system ~ certification  CGI ~ Chooser extension  cipher ~ Clipper Chip  clock ~ color  color bits ~ communications satellite  communications server ~ computer security  CON ~ copy  copy program ~ cycle time  daemon ~ defragmentation  demand paging ~ digitize  DikuMUD ~ disk  disk buffer ~ Document Style Semantics and Specification Language  document window ~ dynamic Web page  Easter egg ~ erase  erase head ~ ezine  F2F ~ finger2  firewall ~ font suitcase  footer ~ FYI  Game Control Adapter ~ GUI  HAL ~ hot key1  hot key2 ~ Hz  i486DX ~ internal modem  internet ~ ISO 9660  ISO/OSI model ~ just-in-time  K1 ~ knowledge base  L1 cache ~ LU  luggable computer ~ LZW compression  MAC ~ MILNET  mime ~ msec  MTBF ~ MYOB  named anchor ~ network drive  Network File System ~ number crunching  object ~ overwrite mode  P5 ~ PC/XT keyboard  PDA ~ pipeline processing  piracy ~ preventive maintenance  preview ~ pwd  quasi-language ~ QWERTY keyboard  R&D ~ registration marks  Registry ~ RFI  RF shielding ~ run-time library  SAA ~ server error  server push-pull ~ soft return  software ~ style sheet  stylus ~ System  T1 ~ ToggleKeys  token ~ typography  UART ~ uupc  V.120 ~ view2  viewer ~ VxD  w3 ~ WinG  WINS ~ WWW  X.25 ~ X Windows  Yahoo! ~ yotta-  Z39.50 standard ~ Zulu time

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