r

R

radio button: A control that displays a setting, either on or off, and is part of a group in which only one button at a time can be set to on.

RAM

See: physical memory

ramp-AND mode: A transfer mode type in which the source and destination color components are normalized, and their product (source X destination) is the result.

ramp-OR mode: A transfer mode type in which the source and destination color components are normalized, and the result of (source + destination _ source X destination) is the result.

ramp-XOR mode: A transfer mode type in which the source and destination color components are normalized, and the result of (source + destination _ 2 X source X destination) is the result.

RAM disk: A portion of the available RAM reserved for use as a temporary storage device. A user can configure a RAM disk or disable it altogether using controls in the Memory control panel.

random-access memory (RAM): Memory whose contents can be changed. The RAM in a Macintosh computer contains exception vectors, buffers used by hardware devices, the system and application heaps, the stack, and other information used by applications.

range descriptor record: A coerced AE record of type typeRangeDescriptor that identifies two Apple event objects marking the beginning and end of a range of elements

See also: boundary objects

range locking: Locking a range of bytes in a file so that other users can't read from or write to that range, but allowing the rest of the file to be accessed.

raster imaging system: The imaging system provided by QuickDraw GX that converts QuickDraw GX shapes into data and control sequences for raster output devices such as the Apple ImageWriter family of printers.

rate: A value that specifies the pace at which time passes for a time base. A time base's rate is multiplied by the time scale to obtain the number of time units that pass per second. For example, consider a time base that operates in a time coordinate system that has a time scale of 60. If that time base has a rate of 1, 60 time units are processed per second. If the rate is set to 1/2, 30 time units pass per second. If the rate is 2, 120 time units pass per second

See also: sample rate, speech rate

raw data: In a dictionary, any information related to the key entry. The information can be the explanation of the key in a general dictionary, or perhaps all the Han characters with the pronunciation of the key entry in an East Asian dictionary.

raw key code: A key code generated by a keyboard prior to any processing by the 'KMAP' resource

See also: virtual key code

raw text: Characters in an active input area or floating input window that have not yet been converted to ideographic or other final form

See also: convert, confirm

read privileges

read-header area (RHA): A buffer that is internal to the .MPP driver. When the .MPP driver receives a frame containing a DDP packet, the .MPP driver's interrupt handler moves the frame's first 3 bytes (the frame header) into the read-header area (RHA). Eight bytes of the RHA are then available for the application's use.

read-only: A permission level granting access to view but not change information

See also: excluded, read/write

read-only memory (ROM): Memory whose contents are permanent. The ROM in a Macintosh computer contains routines for the Toolbox and the Operating System, and the various system traps.

read/write: A permission level granting access to view and change information

See also: excluded, read-only

reallocate: To allocate new space in the heap for a purged block and to update the block's master pointer to point to its new location.

real-time expansion: Audio expansion of a sound that occurs while the sound is playing

See also: buffered expansion

rebound: The ability of a file browser to recall the location last viewed

See also: default location

receive queue: An ADSP buffer in which the local connection end receives and stores bytes of data from the remote connection end until the local connection end's client application reads them.

receive routine: A software process that a multinode application must include in order to read in the contents of packets delivered to that multinode. Because the .MPP driver passes values in registers to a multinode application's receive routine when the .MPP driver calls the routine, receive routines must be written in assembly language.

recipient: (1) The ASDSP client application of the connection end that receives the request and the information from the server. (2) The end of a communications link that receives credentials and a challenge from the initiator. The recipient must respond correctly to establish an authenticated connection. (3) An addressee on an AOCE message

See also: original recipient, resolved recipient

record: The fundamental container for data storage in an AOCE catalog; analogous to a file in the HFS hierarchy. A record can contain any number of attributes.

recordable application: An application that uses Apple events to report user actions to the Apple Event Manager for recording purposes. When a user turns on recording (for example, by pressing the Record button in the Script Editor application), a scripting component translates the Apple events generated by the user's subsequent actions into statements in a scripting language and records them in a compiled script

See also: scriptable application

recordable event: Any Apple event that any recordable application sends to itself while recording is turned on for the local computer, with the exception of events that are sent with the kAEDontRecord flag set in the sendMode parameter of the AESend function.

recording: The process of creating an analog or digital representation of a sound

See also: sampling

recording process: Any process (for example, a script editor) that can turn Apple event recording on and off and receive and record recordable Apple events.

record alias: A record that enables you to store information about another record. For example, an alias could store in its attribute value the record location information for the original record.

record creation ID: A number that uniquely identifies a record within a catalog. Not all catalogs support record creation IDs.

record ID: The identity of a record, comprising the record name, record type, record creation ID, and record location information

See also: record creation ID, record type

record reference: An attribute that identifies a specific catalog record.

record type: A value that indicates the type of entity represented by a record"for example, LaserWriter, User, or Group.

recoverable error: A nonfatal QuickDraw GX error indicating fragmented memory, a problem with the backing store, or a problem with the unflattening process.

rectangle: (1) A mathematical entity defined either by its four boundaries (upper, left, lower, and right) or by two points (the upper-left and lower-right corners). Rectangles are used to define active areas on the screen, to assign coordinate systems to graphical entities, and to specify the locations and sizes for various graphical operations. (2) A rectangular shape drawn onscreen with a QuickDraw procedure such as FrameRect or PaintRect.

rectangle shape: A type of QuickDraw GX shape. The geometry of a rectangle shape contains points representing two opposing corners of a rectangle.

reduce: To remove unnecessary geometric points from a geometry.

reduced instruction set computer (RISC): A microprocessor in which all machine instructions are uniformly formatted and are processed through the same steps

See also: PowerPC microprocessor

Red Zone: On PowerPC-based computers, the area of memory immediately above the address pointed to by the stack pointer. The Red Zone is reserved for temporary use by a routine's prolog and as an area to store a leaf procedure's nonvolatile registers.

reentrancy: The ability of code to process multiple interleaved requests for service nearly simultaneously. For example, a reentrant function can begin responding to one call, become interrupted by other calls, and complete them all with the same results as if the function had received and executed each call serially.

reentrant device driver: A device driver that is capable of handling multiple requests simultaneously.

reentrant driver: A driver that can be interrupted while servicing a request, service the new request, and then complete the original request.

reentrant exception handler: An exception handler that can be interrupted while servicing an exception, then service a new exception, and then complete servicing the original exception.

reference: (1) The location within one module that contains the address of another module or entry point. (2) A longword value, neither a pointer nor a handle, through which an application accesses a QuickDraw GX object. References are created by QuickDraw GX and passed to applications.

reference count: For each prepared fragment, a value indicating the number of closures that contain the fragment.; A property of some Toolbox objects that indicates the number of references to ("owners" of) the object.

reference white point: A specific definition of what is considered white light represented in terms of XYZ space and usually based on the whitest light that can be generated by a given device.

reflection: The symmetrical movement of a mapping with respect to the Cartesian coordinate axes. The movement can be about the x- or y- or both axes.

region: (1) An arbitrary area or set of areas on the QuickDraw coordinate plane. The outline of a region should be one or more closed loops. (2) For the Macintosh script management system, a particular subset of a language. A region can represent a linguistic or cultural entity, not necessarily corresponding to a nation, whose language is different enough from other versions of the same language that it merits a specific localized version of Macintosh system software. For example, U.S. and British are two regional variations that are subsets of the English language.

region code: A number indicating the Macintosh version of the written language of a particular region. Constants are defined for each of the region codes recognized by the Macintosh script management system.

register-based routine: A routine that receives its parameters and returns its results, if any, in registers

See also: stack-based routine

regular enclosure: Any message enclosure that is not a content enclosure

See also: content enclosure, enclosure

relative colorimetric matching: A rendering intent in which the colors that fall within the gamuts of both devices are left unchanged. Relative colorimetric matching allows some colors in both images to be exactly the same, which is useful when colors must match quantitatively. A disadvantage of relative colorimetric matching is that many colors may map to a single color resulting in tone compression.

relative handle: A pointer to a block's master pointer, expressed as an offset relative to the start of the heap zone rather than as an absolute memory address. A block's relative handle is contained in its block header.

relative path: A path to the target from another file or directory on the same volume.

relative position: A position for the origin of each character or glyph in the glyph shape given in coordinates relative to the preceding character or glyph

See also: absolute position

relative search: A search that starts in a specified directory and searches for the target of an alias record by ascending the file system hierarchy to a predetermined common parent of the target and the starting directory, and then descending the hierarchy from that common parent.

release: (1) To free an allocated area of memory, making it available for reuse. (2) To allow a previously held range of pages to be movable in physical memory.

reliable delivery of data: The services a protocol provides that include error checking and recovery from error or packet loss.

relocatable block: A block that can be moved within the heap during compaction.

relocation: The process of replacing references to symbols with actual addresses during fragment preparation.

relocation block: A 2-byte portion of relocation instruction information. A relocation instruction can span one or more relocation blocks.

remote memory: Memory, such as that on an accelerator card, that is not directly addressable

See also: direct memory

rendering: In QuickDraw GX printing, the process during the imaging phase of printing during which each despooled page is converted into image data that can be printed by the output device

See also: imaging phase

rendering intent: The approach taken when a CMM maps or translates the colors of an image to the color gamut of a destination device. Each profile supports four different rendering intents: perceptual matching, relative colorimetric matching, saturation matching, and absolute colorimetric matching.

report: A message with a defined set of message blocks used to send delivery and non-delivery indications to the sender of the message.

requester: An ATP application that transmits a request for some action to be performed to an ATP responder application that carries out the action and transmits a response reporting the outcome.

required Apple event: One of the four Apple events in the Required suite that the Finder sends to applications: Open Documents, Open Application, Print Documents, or Quit Application.

required parameter: An Apple event parameter that must be included in an Apple event. For example, a list of documents to open is a required parameter for the Open Documents event. Direct parameters are often required, and other additional parameters may be required. Optional parameters are never required.

Rescued Items from volume name folder: A directory located in the Trash directory and created by the Finder at system startup, restart, or shutdown only when it finds items in the Temporary Items folder, usually after a system crash. The Rescued Items from volume name folder is named for the volume on which the Temporary Items folder exists. When a user empties the Trash, all Rescued Items folders disappear.

reselection phase: An optional phase in which a SCSI target device reconnects to the initiator.

reservation

See: memory reservation

reserve

See: memory reserve

reserved attributes: The attributes of a collection item's 32 attributes that are reserved and cannot be set.

resolution: The degree of detail at which a device such as a printer or a screen can display an image. Resolution is usually specified in dots per inch, or dpi, in the x and y directions. The higher the value, the finer the detail of the image.

resolve: (1) To find the target of an alias record. (2) To locate the Apple event object described by an object specifier record.

resolved recipient: A recipient to which an MSAM must deliver a message

See also: original recipient

resource: A data structure used to store a program's data or code. This structure is declared and defined using the Rez language. Resources used to store code are built by the linker; resources used to store data are built by a resource compiler.

resource attributes: Values associated with a resource that determine where and when the resource is loaded in memory, whether it can be changed, and whether it can be purged.

resource file: The resource fork of a file.

resource fork: One of two forks of a Macintosh file. It can contain code resources or noncode resources, or it can be empty. 68K-based runtime applications store their code in the resource fork

See also: data fork

resource ID: An integer that identifies a specific resource of a given type.

resource map: In a resource file, data that is read into memory when the file is opened and that, given a resource specification, leads to the corresponding resource data.

resource name: A string that, together with the resource type, identifies a resource in a resource file. A resource may or may not have a name.

resource specification: The information used to identify a resource: the resource name, the resource type, and the values of its attributes.

resource type: A value, typically a four-character sequence, that uniquely identifies a specific type of resource.

responder: An ATP application that carries out a request sent to it from an ATP requester application, and then transmits a response to the requester returning the resulting data or reporting the outcome.

response message: A message comprising up to eight packets that the responder client application can send to the requester client application. ATP maintains and manages the correct sequence of these packets.

restricted access error: A QuickDraw GX error indicating that the object data requested is private and not available.

rest state

See: idle state

results record: A structure that the Data Access Manager uses to store the data retrieved by the DBGetQueryResults function. This data is returned by a data source in response to a query.

result color: The color of the destination after drawing has occurred

See also: destination color, source color

result color limits: In a transfer mode, limits on the permissible values for result color to achieve in transfer-mode calculations

See also: destination color limits, source color limits

result handler: A routine that the Data Access Manager calls to convert a data item to a character string.

result matrix: A 5 X 4 matrix, part of the transfer mode structure, that allows you to manipulate the components of the result color after it is calculated.

result out of range warning: An application execution warning detected and posted by QuickDraw GX indicating that the function result was out of the valid range.

resume dispatch function: An application-defined function called by OSADoEvent or OSAExecuteEvent to dispatch an Apple event directly to an application's default handler for that event.

resume event: An event indicating that an application has been switched into the foreground and can interact with the user

See also: suspend event

resume procedure: A procedure within an application that allows the application to recover from system errors.

return receipt: A high-level event that indicates whether the other application accepted the high-level event sent to it by your application.

reversed bit-numbering: A bit-numbering scheme opposite that of the MC680x0 numbering scheme. Bit numbers are counted from left to right instead of right to left. For example, using the reversed bit-numbering scheme on a byte, the first bit is bit number 0 and the last bit is bit number 7. (That is, the most significant bit has the lowest bit number, and the least significant bit number highest bit number.) Compare MC680x0 bit-numbering.

RGBColor record: A data structure of type RGBColor used to specify a color by its red, green, and blue components, with each component defined as a 16-bit integer. Color QuickDraw compares such a 48-bit value with the colors actually available on a screen's video device at execution time and chooses the closest match.

RGB color value: A value that indicates the red, green, and blue components of a color. An RGB color value is specified in an RGBColor record.

RGB space: A three-dimensional color space whose components are the red, green, and blue intensities that make up a given color.

RHA

right-side bearing: The white space on the right side of the glyph; this value may or may not be equal to the value of the left-side bearing.

right-to-left caret: A type of caret that, at direction boundaries, appears at the proper caret position for inserting right-to-left text

See also: dual caret, left-to-right caret

RISC

See: reduced instruction set computer (RISC)

ROM

See: read-only memory (ROM)

Roman baseline: The baseline used in most Roman scripts and in Arabic and Hebrew.

Roman character set: A set of characters used for the Roman writing system. Roman character sets include the Standard Roman character set, Macintosh character set, and ASCII character set.

Roman writing system: The visual representation of words and letters based on the Roman alphabet (a, b, c, and so forth). Developed during the Roman empire, Roman is the most widely used writing system in the world today. For example, Roman is used in most countries of Europe, the Americas, Africa, Oceania, and some Asian nations.

ROM registry: A list of the import libraries that are stored in the ROM of a Macintosh computer

See also: file and directory registry

root control: The base control in an embedding hierarchy. The root control is the container for all other controls

See also: embedding hierarchy

root directory: The directory at the base of a volume.

root fragment: The initial fragment in the preparation process when the Code Fragment Manager prepares a fragment and its imports.

root node: The first index node in a B*-tree.

rotate: To turn about a point. A mapping can be used to rotate a shape about a fixed origin.

rounded rectangle: A rectangle with rounded corners. The figure is defined by a bounding rectangle and the width and height of the ovals forming the corners. The corner width and corner height are limited to the width and height of the bounding rectangle itself; if they are set larger, the rounded rectangle becomes an oval.

rounding: An action performed when a result of an arithmetic operation cannot be represented exactly in a numeric data format. With rounding, the computer changes the result to a close value that can be represented exactly.

rounding direction modes: Modes that specify the direction a computer will round when the result of an arithmetic operation cannot be represented exactly in a numeric data format. Under PowerPC Numerics, the computer resolves rounding decisions in one of the four directions chosen by the user: to nearest (the default), upward, downward, and toward zero.

roundoff error: The difference between the exact result of an IEEE arithmetic operation and the result as it is represented in the numeric data format if the result has been rounded.

router: Software that interconnects AppleTalk networks to create a single, large, dispersed AppleTalk internet.

routine descriptor: A data structure used by the Mixed Mode Manager to execute a routine. A routine descriptor contains information about the routine being called such as its architecture and calling conventions. Defined by the RoutineRecord data type.

routine record: A data structure that contains information about a particular routine. A routine record specifies, among other things, a routine's instruction set architecture, the number and size of its parameters, its calling conventions, and its location in memory. Defined by the RoutineRecord data type.

Routing Table Maintenance Protocol (RTMP): An AppleTalk protocol that provides routers with a means of managing routing tables used to determine how to forward a packet from one socket to another across an internet based on the packet's destination network number.

RSA: RSA Data Security, Inc., a prime issuing organization for public-key certificates.

RTMP

See: Routing Table Maintenance Protocol (RTMP)

RTOC

See: Table of Contents Register (RTOC)

run: A sequence of characters that are contiguous in memory and share a set of common attributes. See, for example, direction run, font run, script run, style run.

runtime architecture: A set of basic rules that define how software operates. It dictates how code and data are addressed, the form of generated code, how applications are handled, and how to enable system calls. The runtime architecture defines the core of the runtime environment

See also: runtime environment

runtime environment: The execution environment provided by the Process Manager and other system software services. The runtime environment dictates how executable code is loaded into memory, where data is stored, and how routines call other routines and system software routines

See also: runtime architecture

runtime library

See: implementation library

run controls: A style object property used only by layout shapes. It is a set of values and flags that control various aspects of how the text in a style run is displayed.

run controls structure: An array that is a property of every style object but is used only by layout shapes. This structure controls various features associated with text in a style run.

run features

See: font features

run features array: A style object property used only by layout shapes. It is an array specifying the set of font features"typographic capabilities as defined by the font"to apply to the text of a style run.