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clock-through-color

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clock

n. 1. The electronic circuit in a computer that generates a steady stream of timing pulses--the digital signals that synchronize every operation. The system clock signal is precisely set by a quartz crystal, typically at a specific frequency between 1 and 50 megahertz. The clock rate of a computer is one of the prime determinants of its overall processing speed, and it can go as high as the other components of the computer allow. Also called system clock. 2. The battery-backed circuit that keeps track of the time and date in a computer--not the same as the system clock. Also called clock/calendar.

clock/calendar

n. An independent timekeeping circuit used within a microcomputer to maintain the correct time and calendar date. A clock/calendar circuit is battery powered, so it continues running even when the computer is turned off. The time and date kept by the clock/calendar can be used by the operating system (for example, to "stamp" files with the date and time of creation or revision) and by application programs (for example, to insert the date or time in a document). Also called clock, internal clock.

clock doubling

n. A technology employed by some Intel microprocessors that enables the chip to process data and instructions at twice the speed of the rest of the system. See also i486DX2.

clock rate

n. The rate at which the clock in an electronic device, such as a computer, oscillates. The clock rate is normally given in hertz (Hz, one cycle per second), kilohertz (kHz, one thousand cycles per second), or megahertz (MHz, one million cycles per second). Clock rates in personal computers increased from about 5 MHz to about 50 MHz between 1981 and 1995. Also called clock speed, hertz time. See also clock (definition 1).

clone

n. A copy; in microcomputer terminology, a look-alike, act-alike computer that contains the same microprocessor and runs the same programs as a better-known, more prestigious, and often more expensive machine.

close1

n. An FTP command that instructs the client to close the current connection with a server. See also FTP1 (definition 1), Web site.

close2

vb. 1. To end an application's relationship with an open file so that the application will no longer be able to access the file without opening it again. 2. To end a computer's connection with another computer on a network.

close button

n. In the graphical user interface for Windows 95, Windows NT, and the X Window System, a square button in the right corner (left corner in X Windows) of a window's title bar with an × mark on it. Clicking on the button closes the window. Also called X button. Compare close box.

closed architecture

n. 1. Any computer design whose specifications are not freely available. Such proprietary specifications make it difficult or impossible for third-party vendors to create ancillary devices that work correctly with a closed-architecture machine; usually only its original maker can build peripherals and add-ons for such a machine. Compare open architecture (definition 1). 2. A computer system that provides no expansion slots for adding new types of circuit boards within the system unit. The original Apple Macintosh was an example of a closed architecture. Compare open architecture (definition 2).

cluster

n. 1. An aggregation, such as a group of data points on a graph. 2. A communications computer and its associated terminals. 3. In data storage, a disk-storage unit consisting of a fixed number of sectors (storage segments on the disk) that the operating system uses to read or write information; typically, a cluster consists of two to eight sectors, each of which holds a certain number of bytes (characters).

CMOS

n. 1. Acronym for complementary metal-oxide semiconductor. A semiconductor technology in which pairs of metal-oxide semiconductor field effect transistors (MOSFETs), one N-type and the other P-type, are integrated on a single silicon chip. Generally used for RAM and switching applications, these devices have very high speed and extremely low power consumption. They are, however, easily damaged by static electricity. See also MOSFET, N-type semiconductor, P-type semiconductor. 2. The battery-backed memory (presumably made with complementary metal-oxide semiconductor technology) used to store parameter values needed to boot IBM Personal Computers and compatibles, such as the type of disks and the amount of memory, as well as the clock/calendar time.

CMOS RAM

n. Random access memory made using complementary metal-oxide semiconductor technology. CMOS chips consume extremely little power and have high tolerance for noise from the power supply. These characteristics make CMOS chips, including CMOS RAM chips, very useful in hardware components that are powered by batteries, such as most microcomputer clocks and certain types of scratchpad RAM that are maintained by the operating system. See also CMOS (definition 1), parameter RAM, RAM.

CMOS setup

n. A system configuration utility, accessible at boot time, for setting up certain system options, such as the date and time, the kind of drives installed, and port configuration. See also CMOS (definition 2).

CMY

n. Acronym for cyan-magenta-yellow. A model for describing colors that are produced by absorbing light, as by ink on paper, rather than by emitting light, as on a video monitor. The three kinds of cone cells in the eye respond to red, green, and blue light, which are absorbed (removed from white light) by cyan, magenta, and yellow pigments, respectively. Percentages of pigments in these subtractive primary colors can therefore be mixed to get the appearance of any desired color. Absence of any pigment leaves white unchanged; adding 100 percent of all three pigments turns white to black. Compare CMYK, RGB.

CMYK

n. Acronym for cyan-magenta-yellow-black. A color model that is similar to the CMY color model but produces black with a separate black component rather than by adding 100 percent of cyan, magenta, and yellow. See also CMY.

coaxial cable

n. A two-conductor cable consisting of a center wire inside a grounded cylindrical shield, typically made of braided wire, that is insulated from the center wire. The shield prevents signals transmitted on the center wire from affecting nearby components and prevents external interference from affecting the signal carried on the center wire.

code1

n. 1. Program instructions. Source code consists of human-readable statements written by a programmer in a programming language. Machine code consists of numerical instructions that the computer can recognize and execute and that were converted from source code. See also data, program. 2. A system of symbols used to convert information from one form to another. A code for converting information in order to conceal it is often called a cipher. 3. One of a set of symbols used to represent information.

code2

vb. To write program instructions in a programming language. See also program.

codec

n. 1. Short for coder/decoder. Hardware that can convert audio or video signals between analog and digital forms. 2. Short for compressor/decompressor. Hardware or software that can compress and uncompress audio or video data. See also compress2, uncompress. 3. Hardware that combines the functions of definitions 1 and 2.

cold boot

n. A startup process that begins with turning on the computer's power. Typically, a cold boot involves some basic hardware checking by the system, after which the operating system is loaded from disk into memory. See also boot1. Compare warm boot.

collate

vb. In data handling, to merge items from two or more similar sets to create a combined set that maintains the order or sequence of items in the original sets.

collision

n. The result of two devices or network workstations trying to transmit signals at the exact same time on the same channel. The typical outcome is a garbled transmission.

collision detection

n. 1. The process by which a node on a local area network monitors the communications line to determine when a collision has occurred; that is, when two nodes have attempted to transmit at the same time. Although network stations usually avoid collisions by monitoring the line and waiting for it to clear before transmitting, the method is not foolproof. When a collision does occur, the two nodes involved usually wait a random amount of time before attempting to retransmit. See also contention, CSMA/CD. 2. The process by which a game or simulation program determines whether two objects on the screen are touching each other. This is a time-consuming, often complicated procedure; some computers optimized for graphics and games, such as the Amiga, have special hardware built in specifically to detect collisions.

color

n. In physics, the component of the human perception of light that depends on frequency. For light of a single frequency, color ranges from violet at the high- frequency end of the visible-light band (a small portion of the total electromagnetic spectrum) to red at the low-frequency end. In computer video, color is produced by a combination of hardware and software. Software manipulates combinations of bits that represent the distinct shades of color that are destined for particular positions on the screen (characters or individual dots, called pixels). The video adapter hardware translates these bits into electrical signals, which in turn control the brightnesses of different-colored phosphors at the corresponding positions on the screen of the monitor CRT. The user's eye unites the light from the phosphors to perceive a single color. See also color model, color monitor, CRT, HSB, monitor, RGB, video, video adapter.

 

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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