(1) A set of nodes and their
interconnecting links providing the primary data path across a network.
(2) A central high-speed computer
network that connects smaller, independent
networks.
background color
In the GDDM
function, the first color of the display medium; for example, black on a
display or white on a printer. Contrast with neutral
color.
background skulk time
In the
Distributed Computing Environment (DCE), an automatic timer that guarantees a
maximum lapse time between skulks of a Cell Directory Service (CDS) directory,
regardless of other factors, such as namespace management activities and
user-initiated skulks. For every 24 hours, as CDS server checks each
master replica in its clearinghouse and initiates a skulk if changes were made
in a replica since the last time a skulk of that replica completed
successfully. See skulk.
back out
(1) To remove changes from a
physical file member in the inverse order from which the changes were
originally made.
(2) An operation that reverses all
the changes made during the current unit of recovery or unit of work.
After the operation is complete, a new unit of recovery or unit of work
begins.
backout recovery
The process of
returning a file to a particular point by removing journaled changes to the
file. Contrast with forward
recovery.
back up
To save some or all of
the objects on a system, usually to tape or diskette, for
safekeeping.
backup
(1) Pertaining to an
alternative copy used as a substitute if the original is lost or destroyed,
such as a backup log.
(2) The act of saving some or all of
the objects on a system to a tape, diskette, or save file.
(3) The tapes, diskettes, or save
files with the saved objects.
(4) For communications, see
switched network backup (SNBU).
(5) In Backup Recovery and Media
Services, a service that makes a duplicate copy of current direct access data
on removable media for use in
recovery.
backup control group
In Backup
Recovery and Media Services, a group of libraries, system keywords, and lists
that share common backup characteristics. The default values for a
backup control group are defined in the backup policy and can be used or
overridden by each backup control group.
backup list
(1) In Backup Recovery
and Media Services, a group of objects or folders that are grouped together
for processing in a backup control group. Each list is assigned a
unique list name.
(2) In the Operational Assistant
function, a list of libraries or folders to be saved on a regular basis, such
as daily or weekly.
backup node
A cluster node on
which there is a secondary copy of a cluster resource. The copy is kept
current through replication. See also primary node and
replicate node.
backup policy
In Backup Recovery
and Media Services, a policy that is used in backup control groups.
Backup policy values can be overridden at the individual backup control group
level. The backup policy inherits defaults from the system
policy. System policy defaults can be used or overridden in the backup
policy.
Backup Recovery and Media Services (BRMS)
An IBM
licensed program that provides user-modifiable backup, archive, recovery, and
media management functions and policies.
bandwidth
The capacity of a
communications line, normally expressed in bits per second
(bps).
bar chart
In the GDDM function, a
chart consisting of several bars of equal width. The value of the
dependent variable is indicated by the height of each
bar.
bar code
A pattern of bars of
various widths containing data to be interpreted by a scanning
device.
bar graph
In Performance Tools, a
graph consisting of several bars of equal width. The value of the
dependent variable is indicated by the height of each
bar.
base
The numbering system in
which an arithmetic value is
represented.
base aggregate table
A target
table that contains data collected at intervals from a user table or
point-in-time table.
baseband
A frequency band that
uses the complete bandwidth of a transmission and requires all stations in the
network to participate in every transmission. See also
broadband.
base number
In SDA, the part of a
self-check field from which the check digit is
calculated.
base pool
A storage area that
contains all unassigned main storage on the system and whose minimum size is
specified in the system value QBASPOOL. The system-recognized
identifier is *BASE.
base project
In VisualAge RPG, a
collection of files that make up a VRPG
component.
basic assistance level
The type
of displays that provides the most assistance. Basic assistance level
supports the more common user and operator tasks, and does not use computer
terminology.
A
programming language with a small list of commands and a simple syntax,
primarily designed for numeric
applications.
basic characters
Frequently used
double-byte characters that are stored in the hardware of a DBCS-capable work
station. The number of double-byte characters that are stored in the
work station varies with the language supported and the storage size of the
work station. A DBCS-capable work station can display or print basic
characters without using the extended character processing function of the
operating system. Contrast with extended characters.
See also extended character
processing.
basic conversation
In APPC, a
temporary connection between an application program and an APPC session in
which the user must provide all the information on how the data is
formatted. Contrast with mapped
conversation.
basic data exchange
A file format
for exchanging data on diskettes or tape between systems or
devices.
basic DST capability
A dedicated
service tools (DST) capability used by a service representative or an
experienced system user that provides access to DST functions that do not
access sensitive data. See also full DST capability and
security DST
capability.
Basic Encoding Rules (BER)
A set of
rules used to encode ASN.1 values as strings of
octets.
basic information unit (BIU)
In SNA, the
unit of data and control information passed between the transmission and
control layers. It consists of a request or response header followed by
a request or response unit.
basic input and output system (BIOS)
The
personal computer code that controls the basic hardware operations of diskette
drives, hard disk drives, and the keyboard on a personal
computer.
basic link unit (BLU)
In SNA, the
unit of data and control information transmitted over a communications line by
data link control.
basic mapping support (BMS)
(1) A CICS
facility that handles data stream input and output from a terminal. Its
use provides device and format independence for application programs.
(2) In the Distributed
Computing Environment (DCE), a facility that moves data streams to and from a
terminal in CICS. It is an interface between CICS and its application
programs. It formats input and output display data in response to BMS
commands in programs.
basic rate interface (BRI)
In ISDN,
an interface that provides two 64 000 bps data channels (B-channels) and
one 16 000 bps signaling channel (D-channel). Also known as
2B + D. Contrast with primary rate interface
(PRI).
basic telecommunications access method (BTAM)
A
System/370-type access method that permits read or write communications with
BSC remote devices.
batch
Pertaining to a group of
jobs to be run on a computer sequentially with the same program with little or
no operator action. Contrast with
interactive.
batch accumulator
In DFU, an
accumulator in which subtotals for a field are stored. Contrast with
total accumulator.
batch device
Any device that can
read serial input or write serial output, or both, but cannot be used to
communicate interactively with the system. Examples of batch devices
are printers, magnetic tape units, or diskette
units.
batch file
A personal computer
file that contains DOS commands organized for sequential processing.
Batch files are identified with the .BAT file name
extension.
batch job
A predefined group of
processing actions submitted to the system to be performed with little or no
interaction between the user and the system. Contrast with
interactive job. See also autostart job,
communications job, prestart job, scheduled
job, spooling job, and system
job.
batch mode
In query management,
the query mode associated with a query instance that does not allow users to
interact with the query commands while a procedure is
running.
batch processing
A method of
running a program or a series of programs in which one or more records (a
batch) are processed with little or no action from the user or
operator. Contrast with interactive
processing.
batch shell
In CICS, a shell
started to handle CICS interval control timer requests. The batch shell
is transparent to the user; each user's program runs under its own
user shell. Contrast with user
shell.
batch subsystem
A part of main
storage where batch jobs are processed.
BCC
See block-check
character (BCC).
B-channel
In ISDN, a duplex
channel for transmitting data or digital voice across the network.
Contrast with D-channel.
beaconing
Pertaining to an
adapter in a token-ring network that repeatedly sends a frame (beacon message)
when it is not receiving a normal signal because of serious error, such as a
line break or power failure. The message frame repeats until the error
is corrected or bypassed.
beacon message
A message frame
sent repeatedly by an adapter indicating a serious network problem, such as a
broken cable. See also beaconing.
bean
In Java, a reusable software
component. Beans can be combined to create an
application.
BEC
See bus extension card
(BEC).
BED
See bus extension driver
(BED) card.
before-image
The contents of a
record in a physical file before the data is changed by a write, an update, or
a delete operation. Contrast with
after-image.
beginning attribute character
For a
display file, the character that precedes the first position in a field and
that defines how the data in the field is
displayed.
beginning-of-tape marker (BOT marker)
A reflective
material placed on a magnetic tape to indicate where the recording area
starts.
BER
See bus extension
receiver (BER) card or Basic Encoding
Rules.
BEST/1 for the AS/400
The capacity
planner for the AS/400 system. The BEST/1 for the AS/400 capacity
planner is a function of the IBM Performance Tools licensed
program.
bezel
A rim or surrounding part
to keep another part.
BGU
See Business Graphics
Utility (BGU).
BID
(1) In
SNA, a command used to request permission to start a bracket.
(2) In BSC, a protocol exchange in
preparation for sending and receiving data. The sending station sends
an ENQ character and the receiving station acknowledges receipt of the ENQ
character by sending an ACK0 control character.
bidder
An SNA LU-LU half-session
that is defined as requesting and receiving permission from another LU-LU
half-session to begin a bracket at the start of a session. Contrast
with first speaker. See also bracket
protocol.
bidirectional language
The
ability to write and read a language in two directions, such as from left to
right and from right to left.
big endian
In the Distributed
Computing Environment (DCE), an attribute of data representation that reflects
how multi-octet data is stored in memory. In big endian representation,
the lowest addressed octet of a multi-octet data item is the most
significant. See endian and little
endian.
bin
In
AFP support, the standard-size paper source on the IBM
3820.
binary
(1) Pertaining to a selection,
choice, or condition that has two possible values. (I)
(2) A numbering system with a base of
two (0 and 1).
(3) In DB2 UDB for AS/400, a data
type indicating that the data is a binary number with a precision of 15
(halfword) or 31 (fullword) bits.
binary file
A file that contains
codes that are not part of the ASCII character set. Binary files can
utilize all 256 possible values for each byte in the
file.
binary floating-point number
The
conceptual form of a numeric value that contains a significand and a signed
exponent. The number's numeric value is the signed product of the
number's significand and 2 raised to the power of the number's
exponent.
binary format
Representation of a
decimal value in which each field must be 2 or 4 bytes long. The sign
(+ or -) is in the far left bit of the field, and the number value is in
the remaining bits of the field. Positive numbers have a 0 in the sign
bit and are in true form. Negative numbers have a 1 in the sign bit and
are in twos complement form.
binary integer
In DB2 UDB for
AS/400, a basic data type that can be further classified as small integer or
large integer.
binary item
Numeric data that is
represented internally as a number in the base 2 numbering system;
internally, each bit of the item is a binary number with the sign as the far
left bit.
binary large object
A binary
string that contains bytes with no associated code page. Also known as
BLOB.
binary operator
A symbol
representing an operation to be performed on two data items, arrays, or
expressions. The four types of binary operators are numeric, character,
logical, and relational. Contrast with unary
operator.
binary stream
In the C language,
a sequence of characters that corresponds on a one-to-one basis with the
characters in the file. No character translation is performed on binary
streams.
binary string
In REXX, a literal
string expressed using a binary (base 2) representation of a value. The
binary representation is a sequence of zero or more binary digits (the
characters 0 or 1) enclosed in quotation marks and followed by the character
b.
binary synchronous communications (BSC)
A data
communications line protocol that uses a standard set of transmission control
characters and control character sequences to send binary-coded data over a
communications line.
binary synchronous communications equivalence link (BSCEL) support
The
intersystem communications function (ICF) support on the AS/400 system that
provides binary synchronous communications with another AS/400 system,
System/36, System/38, and many other BSC computers and
devices.
binary timestamp
In the
Distributed Computing Environment (DCE), an opaque 128-bit (16-octet)
structure that represents a Distributed Time Service (DTS) time
value.
bind
(1) In DB2 UDB for AS/400, to
convert the output from the SQL precompiler to a usable structure called an
access plan. The process of converting is the one during which access
paths to the data are selected and some authorization checking is
performed. See also automatic bind and dynamic
bind.
(2) To create a program, which can be
run, by combining one or more modules created by an Integrated Language
Environment (ILE) compiler. See also binder and
binding.
BIND command
In SNA, a command
used to start a session and define the characteristics of that session.
Contrast with UNBIND command.
binder
The system component that
creates a bound program by packaging Integrated Language Environment (ILE)
modules and resolving symbols passed between those
modules.
binder language
A small set of
commands (STRPGMEXP, EXPORT, and ENDPGMEXP) that defines the external
interface (signature) for a service program. These commands cannot be
run alone and are of the source type BND. See also public
interface.
binding
(1) The process of creating a
program by packaging Integrated Language Environment (ILE) modules and
resolving symbols passed between those modules.
(2) In the Distributed Computing
Environment (DCE), a relationship between a client and a server involved in a
remote procedure call.
binding directory
A list of names
of modules and service programs that may be needed when creating an ILE
program or service program. A binding directory is not a repository of
the modules and service programs. Instead, it allows them to be
referred to by name and type.
binding handle
In the Distributed
Computing Environment (DCE), a reference to a binding. See binding
information.
binding information
In the
Distributed Computing Environment (DCE), information about one or more
potential bindings, including a Remote Procedure Call (RPC) protocol sequence,
a network address, an endpoint, at least one transfer syntax, and an RPC
protocol version number. See binding. See also
endpoint, network address, RPC protocol,
RPC protocol sequence, and transfer
syntax.
BIOS
See basic input and
output system (BIOS).
bit
A
contraction of binary digit. Either of the binary digits, 0 or
1. Compare with byte.
bit data
In DB2 UDB for AS/400,
data that is not associated with a coded character set; therefore, it is
never converted.
bit mask
A pattern of bits
designed to be logically compared to an existing bit value. The mask
pattern allows only certain desired parts of the existing bit value to appear
in the result of the comparison.
bit string
A series of bits
consisting of the values 0 and 1.
BIU
See basic information
unit (BIU).
blank after
In RPG, an output
specification option that changes the contents of a field so that it contains
either zeros (if it is a numeric field) or blanks (if it is a character field)
after that field is written to the output record.
BLOB
See binary large
object.
block
(1) A group of records that are
recorded or processed as a unit.
(2) A set of adjacent records stored
as a unit on a disk, diskette, or magnetic tape
(3) In data communications, a group of
records that are received, processed, or sent as a unit.
(4) A sequential group of statements
(defined using line commands) that are processed as a unit.
(5) In the OfficeVision program, a
sequential string of text (defined using cursor-movement keys or line
commands) that is processed as a unit.
(6) In COBOL, a unit of data that is
moved into or out of the computer storage.
(7) In SEU, a group of records
(defined using line commands) that are processed as a
unit.
block-check character (BCC)
The BSC
transmission control character that is used to determine if all of the bits
that were sent were also received.
block control byte (BCB)
In a
multileaving telecommunications access method, a control character used for
transmission block status and sequence count.
block copy
(1) In the OfficeVision
program, to copy a sequential string of text (defined using the
cursor-movement keys) from one part of a document to another part.
(2) In SEU, to copy two or more
adjoining source records from one part of a source member to another part, or
from one source member to another.
block delete
(1) In the OfficeVision
program, to delete a sequential string of text (defined using the
cursor-movement keys) in a document.
(2) In SEU, to delete two or
more adjoining source records from a source
member.
block edit function
In AFP
Utilities, a function that moves, copies, or removes all elements defined in a
specified scope on the image area at one
time.
blocked signal
In POSIX, a
condition that prevents a signal-handling action associated with a signal from
being performed. See also signal. Contrast with
unblocked signal.
block exclude
In SEU, to exclude
two or more adjoining records from the Edit or Browse
display.
blocking call
In the Distributed
Computing Environment (DCE), a call in which the caller is suspended until a
called procedure is completed.
blocking factor
The number of
records in a block. A blocking factor is calculated by dividing the
size of the block by the size of the record.
block move
(1) In the OfficeVision
program, to move sequential strings of text (defined using the cursor-movement
keys) from one part of a document to another part.
(2) In SEU, to move two or more
adjoining source records from one part of a source member to another part, or
from one source member to another.
block overlay
In SEU, to overlay
two or more adjoining records with other records defined by the Copy or Move
line command.
block statement
In the C
language, a group of data definitions, declarations, and statements appearing
between a left brace and a right brace that are processed as a unit.
The block statement is considered to be a single, C-language
statement.
BLU
See basic link unit
(BLU).
BMS
See basic mapping
support (BMS).
BMS, minimum function
In CICS,
support that is provided for 3270 displays and printers only. Minimum
BMS supports extended attributes and large displays. It does not
support cumulative mapping, terminal operator paging, routing, or message
switching.
bookshelf
A grouping of online
books within a softcopy library.
Boolean data
In COBOL, a category
of data items that are limited to a value of 1 or
0.
Boolean literal
In COBOL, a
literal composed of a Boolean character enclosed in double quotation marks and
preceded by a B; for example, B "1". See also
literal.
Boolean operator
In REXX, an
operator each of whose operands and whose result take one of two values (0 or
1).
BOOTP
See Bootstrap Protocol
(BOOTP).
bootstrap
See Bootstrap
Protocol (BOOTP).
Bootstrap Protocol (BOOTP)
A protocol
that allows a client to find both its Internet Protocol (IP) address and the
name of a file from a server on the
network.
border system
A system that
exists within a trusted system but communicates between trusted and untrusted
systems. A border system prevents security from being
compromised.
both field
A field that can be
used for either input data or output data.
BOT marker
See
beginning-of-tape marker (BOT
marker).
bottleneck
In CICS, a symptom
that characterizes a performance problem. It can be due to a task
failing to start, failing to continue after starting, or taking a long time to
complete.
bottom margin
In COBOL, an empty
area that follows the page body.
boundary violation
In COBOL, an
attempt to write beyond the externally defined boundaries of a sequential
file.
bound program
An AS/400 object
that combines one or more modules created by an Integrated Language
Environment (ILE) compiler. See also service
program.
box
In
AFP Utilities, a continuous line constructing a
rectangle.
bpi
Bits per
inch.
bps
Bits per
second.
bracket
In SNA, one or more
chains of request units and their responses, representing a complete
transaction, exchanged between two logical unit (LU) half-sessions. See
also RU chain.
bracketed DBCS
A character string
in which each character is represented by 2 bytes. The character string
starts with a shift-out (SO) character and ends with a shift-in (SI)
character. Contrast with
DBCS-graphic.
bracket protocol
In SNA, the
rules for controlling the data flow in which exchanges between the two logical
unit (LU) half-sessions are achieved through the use of brackets, with one LU
assigned at the beginning of the session as first speaker and the other LU as
the bidder. The bracket protocol involves bracket start and stop
rules. See also first
speaker.
branch instruction
An instruction
that changes the sequence of instructions processed in a computer
program. The sequence of instructions continues at the address
specified in the branch instruction.
break delivery
The method of
delivering messages to a message queue in which the job associated with that
message queue is interrupted as soon as the message
arrives.
break field
In AFP Utilities, a
field that causes a page break. When the Print Format Utility
encounters a record with a value that is not equal to that of the previous
record, a page break occurs.
breakpoint
(1) A place in a program
(specified by a command or a condition) where the system stops the processing
of that program and gives control to the display station user or to a
specified program.
(2) In CoOperative Development
Environment/400, a place in a program, usually specified by a command or a
condition, where processing may be interrupted and control given to the
workstation user or to a specified debugger
program.
breakpoint program
For a batch
job, a user program that can be called when a breakpoint is
specified.
BRI
See basic rate interface
(BRI).
bridge
(1) A device that
interconnects two local area networks that use the same logical link control
protocol but may use different medium access control
protocols.
(2) A device that interconnects
multiple LANs (locally or remotely) that use the same logical link control
protocol but that can use different medium access control protocols. A
bridge forwards a frame to another bridge based on the medium access control
(MAC) address.
(3) A device that connects two or
more networks; for example, an Ethernet-to-Ethernet network or Ethernet
to token-ring network. A bridge stores and forwards information in
packets between the networks. See also VM/MVS
bridge.
British thermal unit (Btu)
A
measurement of heat produced in one hour.
BRMS
See Backup Recovery and
Media Services (BRMS).
broadband
A communication channel
having a wider band of frequencies than a voice-grade channel, and therefore
capable of higher-speed data transmission.
broadcast
(1) In the Distributed
Computing Environment (DCE), a notification sent to all members within an
arbitrary grouping, such as nodes in a network or threads in a process.
See also signal.
(2) The simultaneous transmission
of the same data to all nodes connected to a
network.
broadcast and unknown server
A server that
provides necessary frame-forwarding and broadcast-related services to its
clients. Each local area network (LAN) emulation domain must contain a
broadcast and unknown server.
broadcast message
A message sent
to all work stations.
broadcast semantics
In the
Distributed Computing Environment (DCE), a form of idempotent semantics that
indicates that the operation is always broadcast to all host systems on the
local network, rather than delivered to a specific system. An operation
with broadcast semantics is implicitly idempotent. Broadcast semantics
are supported only by connectionless protocols. See at-most-once
semantics, idempotent semantics, and maybe
semantics.
browse
In MQSeries message
queueing, to copy a message without removing it from the queue. See
also get.
browse cursor
In MQSeries message
queuing, an indicator used when browsing a queue to identify the message that
is next in sequence.
browser
(1) See Web
browser.
(2) In the Distributed Computing
Environment (DCE), a Motif-based program that lets users view the contents and
structure of a cell namespace.
BSC
See binary synchronous
communications (BSC).
BSCEL support
See binary
synchronous communications equivalence link (BSCEL)
support.
BSC 3270 device emulation
A function
of the operating system that allows an AS/400 system to appear to a BSC host
system as a 3274 Control Unit.
BTAM
See basic
telecommunications access method (BTAM).
Btu
See British thermal unit
(Btu).
Btu/hr
British thermal unit per
hour. An English unit of measure for heat produced in one
hour.
buffer
(1) A routine or an area of
storage that corrects for the different speeds of data flow or timings of
events, when transferring data from one device to another.
(2) A portion of storage used to hold
input or output data temporarily.
build
In the Application
Development Manager feature of the Application Development ToolSet licensed
program, the procedure that processes a part into a
program.
build process
In the Application
Development Manager feature of the Application Development ToolSet licensed
program, the procedure that determines which parts of an application have
changed, and based on the relationship between those parts, compiles them in
the correct order.
build report
In the Application
Development Manager feature of the Application Development ToolSet licensed
program, a report that describes the results of the build process. This
report can be printed or viewed on a
display.
built-in function
(1) In C and CL, a
predefined function, such as a commonly used arithmetic function or a function
necessary to high-level language compilers (for example, a function for
manipulating character strings or converting data). It is automatically
called by a built-in function reference.
(2) In REXX, a function
that is supplied by a language. These functions, defined as part of the
REXX language, include character manipulation, conversion, and information
functions.
built-in function reference
In CL, a
built-in function name, having an optional, and possibly empty, argument list
that holds the value returned by the built-in
function.
bullet
A heavy-dot symbol used to
call attention to an item in a list or a printed
passage.
bundle
A group of journal entries
that are deposited together by the system.
burst
In AFP support, to separate
continuous-forms paper into separate sheets.
bus
One or more conductors used
for transmitting signals or power.
bus expansion
An AS/400 expansion
unit that attaches to an AS/400 system unit for the purpose of increasing the
number of buses on the system and which allows for additional I/O processor
cards to be attached.
bus extension card (BEC)
The bus
extension driver card or the bus extension receiver
card.
bus extension driver (BED) card
The
card, connected by a cable to a bus extension receiver (BER) card, that is
used to route data from one card enclosure to another card enclosure.
The direction of data can be from the processing unit to an input/output
processor in one of the card enclosures, or from an input/output processor in
one of the card enclosures to the processing unit. See also bus
extension receiver (BER)
card.
bus extension receiver (BER) card
The
card, connected by a cable to a bus extension driver (BED) card, that is used
to route data from one card enclosure to another card enclosure. The
direction of data can be from the processing unit to an input/output processor
in one of the card enclosures, or from an input/output processor in one of the
card enclosures to the processing unit. See also bus extension
driver (BED) card.
Business Conferencing
See
Ultimedia Business
Conferencing.
business graphics
See
graphics.
Business Graphics Utility (BGU)
The IBM
licensed program that can be used to design, plot, display, and print business
charts.
business intelligence
Software products
and services that are used to gather, manage, analyze, and disseminate
information for making strategic business decisions.
business management
In System
Manager, the discipline that encompasses inventory management, security
management, financial administration, business planning, and management
services for all enterprise-wide information
systems.
bus-level partitioning
The dedicated
allocation of an entire bus and all accompanying resources (input/output
processors and input/output devices) to a particular logical partition.
Contrast with IOP-level partitioning.
button
(1) A mechanism on a pointing
device, such as a mouse, used to request or start an action.
(2) A graphical mechanism in a window
that, when selected, results in an action. An example of a button is a
list button that when selected produces a list of choices.
(3) A graphical device that
identifies a choice. See also radio button and push
button.
bypass plug
Allows power to flow
through an unused outlet in the power control
compartment.
byte
(1) The smallest unit of storage
that can be addressed directly.
(2) A group of 8 adjacent bits.
In the EBCDIC coding system, 1 byte can represent a character. In the
double-byte coding system, 2 bytes represent a
character.
bytecode
Intermediate code that
is generated by the Java compiler. The code must be interpreted or
translated to run on a specific platform or processor.