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.munications standards.Three main sets ofstandards have been established:constant angular velocity Abbreviat-CCITT Groups 1 4 standards apply toed CAV.An unchanging speed of rotation.facsimile transmissions.Hard disks use a CAV encoding scheme.CCITT V series of standards apply to mo-The constant rate of rotation means thatdems and error detection and correctionsectors on the disk are at the maximum den-methods.sity along the inside track of the disk.As theread/write heads move outward, the sectors CCITT X series standards apply to LANs.must spread out to cover the increased trackRecommendations are published every fourcircumference, and therefore the data-years.In 1993, after a reorganization, thetransfer rate falls off.name was changed to International Tele-communication Union (ITU), and evenSee also constant linear velocity.though ITU now creates recommendationsand standards, you will still hear the CCITTConstant Bit Rate Abbreviated CBR.Astandards mentioned.type of Asynchronous Transfer Mode(ATM) service reserved for voice or video See also International Telecommunicationor other data that must be transmitted at a Union.constant rate and are intolerant of data loss.container One of the Java programmingSee also Asynchronous Transfer Mode;language classes that can contain graphicalAvailable Bit Rate; Unspecified Bit Rate;user interface components.Components inVariable Bit Rate.a container usually appear within theboundaries of that container.For example,constant linear velocity Abbreviatedthe classes Dialog, Frame, and Window areCLV.A changing speed of rotation.CD-all containers.ROM disk drives use a CLV encodingSee also Java.scheme to make sure that the data densityremains constant.Information on a com-container administrator In Novell Di-pact disc is stored in a single, spiral track,rectory Services, an administrator who isdivided into many equal-length segments.granted rights to a container object and allTo read the data, the CD-ROM disk drivethe objects that the container holds.A con-must increase the rotational speed as thetainer administrator can be exclusive, indi-read head gets closer to the center of the disccating that no other administrator isand decrease as the head moves back out.allowed access to that container.See also constant angular velocity.See also container object; leaf object.89Copyright © 2000 SYBEX Inc., Alameda, CA.www.sybex.com 2461book Page 90 Thursday, May 4, 2000 11:59 AMcontainer objectcontainer object In Novell Directory other programs loaded onto your systemServices, an object that can contain other must halt.objects and that is used to represent a logi-control character A nonprinting char-cal or physical organizational element with-acter with a special meaning.in a company, such as a department or adivision.The Tree, Country, Organization, Control characters, such as Carriage Re-and Organizational Unit objects are all con- turn, Line Feed, Bell, or Escape, perform atainer objects.specific operation on a terminal, printer, orcommunications line.They are grouped to-See also container administrator; Countrygether as the first 32 characters in the ASCIIobject; leaf object; Organization object; Or-character set; see Appendix C for details.ganizational Unit object; Tree object.You can type a control character from thecontainer security equivalence Seekeyboard by pressing and holding the Ctrlimplied security equivalence.key while you simultaneously press anoth-er key.For example, if you press and holdcontention The competition betweenthe Ctrl key and then press C, you generatetransmitting nodes for access to communi-Ctrl+C, also known as Break.Controlcations lines or network resources.The firstcharacter sequences are often used insidedevice to gain access to a channel takes con-application programs as menu commandtrol of the channel.In the event of a colli-shortcuts.sion, when two nodes attempt to transmitSee also American Standard Code forat the same time, some arbitration schemeInformation Interchange; Extendedmust be invoked.Binary Coded Decimal Interchange Code;See also Carrier Sense Multiple Access/Unicode.Collision Detection; token passing.control code A sequence of one or morecontext In Novell Directory Services, ancharacters used for hardware control; alsoobject s location within the Directory tree.known as setup strings or escape sequences.The context is the full path to the containerControl codes are used with printers, mo-object in which the object is placed.If andems, and displays.Printer control codesobject is moved from one container to an-often begin with an escape character, fol-other, it has changed contexts.lowed by one or more characters that theSee also container object; leaf object.printer interprets as commands it must per-form rather than as text it must print.context switching Switching from oneprogram to another without ending the first Control Panel In Microsoft Windows, aprogram.Context switching allows you to special system folder that contains appletsoperate several programs at the same time; used to look at or change configuration in-but it differs from true multitasking in that formation.Each applet manages a singlewhen you are using one program, all the task such as adding or removing a program90Copyright © 2000 SYBEX Inc., Alameda, CA.www.sybex.com 2461book Page 91 Thursday, May 4, 2000 11:59 AMcooperative multitaskingfrom your system, setting up a connection See also expanded memory; extendedto the Internet, or changing display settings.memory; high memory area; memorymanagement; protected mode.See also Network and Dial-upConnections [ Pobierz caÅ‚ość w formacie PDF ] |
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