(1) For Cryptographic Support,
see message authentication code (MAC).
(2) For communications, see medium
access control (MAC).
machine characteristic
Values
defined in the computer.
machine interface (MI)
The
interface, or boundary, between the operating system and the Licensed Internal
Code.
machine language
A language that
can be used directly by a computer without intermediate
processing.
machine object
A program object
that has no defined storage form; the object is defined internally to the
machine. The machine aspect is not available to the user.
Contrast with data
object.
machine storage pool
A storage
pool used by the machine and certain highly shared programs, whose size is
specified in the system value QMCHPOOL.
macro
(1) See
macroinstruction.
(2) In REXX, a program that performs
certain operations, such as text editor operations, in
applications.
macroinstruction
A single
instruction that represents a set of
instructions.
magnetic ink
An ink that contains
particles of a magnetic substance whose presence can be detected by magnetic
sensors.
magnetic-ink character recognition
The
identification of characters by sensing magnetic
ink.
magnetic storage device controller
The I/O
controller card in the card enclosure that controls the operation of the disk,
diskette, and tape devices.
magnetic stripe reader
A device,
attached to a display station, that reads data from a magnetic stripe on a
badge before allowing an operator to sign
on.
magnetic tape drive
A technique
for moving and controlling magnetic
tape.
magnetic tape subsystem
A tape
unit that includes the logic interface hardware necessary to operate with a
system unit.
magnetic tape unit
A device for
reading or writing data from or to magnetic tape.
mail
The distribution objects and
documents referred to by a mail log.
mailbox
A collection of pointers
to message objects that are addressed to a single
entity.
mail details
In the OfficeVision
program, information related to a mail item, such as the date received,
authors, and due date.
mail exchange (MX) record
A record in
the Domain Name System (DNS) that indicates which host handles mail for a
particular domain.
mail log
In the OfficeVision
program, a record of all the electronic and printed mail that an office user
has sent or received.
mail log usage
In the
OfficeVision program, a measure of the number of times a document is referred
to by a user.
mail report
In the OfficeVision
program, a list of information about each mail item, but not a list of the
contents. The OfficeVision program can create several types of mail
reports. For example, mail items sorted by date, mail items received
between two dates, and action items sorted by date or
assignee.
mail server framework (MSF)
A set of
user exit points and application program interfaces (APIs) that embody an
abstract design for solutions to a number of related communications
problems.
mail subset
In the OfficeVision
program, a set of mail selected by status from the entire mail log. For
example, new mail.
main distribution frame (MDF)
In the
CallPath licensed program, a series of quick-connection blocks, supported on a
frame, that allows trunk lines and telephones to be connected to the 9722
Redwood system.
main function
In the C language,
a function that has the identifier main. Each program must have exactly
one function named main. The main function is the first user function
that gets control when a program starts to
run.
mainline module
A sequence of
instructions called by a program in the main path after it is
compiled.
main program
(1) The highest level
program involved in a run unit.
(2) The first program to
receive control when a program is run. See also
subprogram.
main storage
All addressable
storage where programs are run. Synonymous with
memory. See also control storage. Contrast
with auxiliary
storage.
main storage dump space
A section
of storage reserved on the disk unit that is used as a place to save main
storage for recovery and debugging.
main storage pool
A division of
main storage, which allows the user to reserve main storage for processing a
job or group of jobs, or to use the pools defined by the system.
Contrast with auxiliary storage
pool.
main storage - TS queue
A dynamic
storage area managed by CICS under the temporary storage facility. Data
in main storage is not kept from one CICS run to the next. Contrast
with auxiliary storage - TS queue.
maintenance
In Backup Recovery
and Media Services, the tasks that must be performed on a routine basis to
perform cleanup activities and other Backup Recovery and Media Services
functions. Examples of maintenance are tape expiration, recovery
analysis reports, and media movement.
main window
In VisualAge RPG, a
window that is an immediate child of the
desktop.
major/activity token
In OSI, the
session-layer token that controls activities and major synchronize
operations.
major synchronization point
In OSI,
a session-layer synchronization point that usually represents a logically
significant piece of work. Major synchronization points are a confirmed
service. Contrast with minor synchronization
point.
major synchronize
In OSI, a
confirmed service provided by the session layer that enables peer application
entities to synchronize the exchange of data. For example, an
application entity can send data followed by a major synchronize request;
its peer sends back a major synchronize response, which indicates that it has
received all of the data that was sent up to the major synchronize
request. The major synchronization function also marks a recovery point
in the data stream. Contrast with minor
synchronize.
major tick
In Business Graphics
Utility, a mark on an axis that denotes character grid units on a
chart. See also minor tick.
make
In VisualAge RPG, the
process by which all of the components are compiled and assembled to create a
VRPG application.
managed object
In OSI, a resource
that is subject to management--such as a layer entity, a connection, or a
line--as viewed from a systems management
perspective.
managed system
A system in the
network that is managed by a central site system. Typically these
systems have no skilled operations personnel present and run unattended on
off-shift hours.
Managed System Services
An IBM
licensed program that enables a system to be managed by a central site ES/9000
system running the IBM NetView Distribution Manager program. Managed
System Services enables objects and program temporary fixes (PTFs) to be sent
or retrieved, PTFs to be applied, programs to be run, and the central site
system to control an initial program load (IPL) of the
system.
management
In OSI, a synonym for
systems management.
management application
In OSI, a
synonym for systems management
application.
management association
In OSI, a
synonym for network management
association.
Management Central
A suite of
systems management functions that is an integrated part of AS/400 Operations
Navigator. Management Central provides the base for managing multiple
systems.
management collection
An object within
the OS/400 operating system that includes the data for a number of
collections. The collections begin when the collector is started and
continue until the collection is either ended or cycled. The
system-recognized identifier for the object type is *MGTCOL.
management domain
(1) In OSI, a
synonym for network management domain.
(2) In OSI X.400, a
set of one or more message transfer agents and zero or more user agents that
make up a system capable of handling messages and is managed by either an
administration or private company.
management information
In OSI,
information--associated with a managed object--that is operated on
by management protocols to control and monitor that object. See also
managed object.
Management Information Base (MIB)
(1) A database
containing the information pertinent to network management. The
database is conceptually organized as a tree.
(2) In System Manager,
units of managed information that specifically describe an aspect of a system,
such as the system name, hardware number, or communications
configuration. A collection of related MIB objects is defined as a
MIB.
management protocols
In OSI,
protocols for use in systems
management.
management services
In SNA, one
of the types of network services in control points and physical units.
Management services is the service provided to assist in the management of SNA
networks, such as problem management, performance and accounting management,
configuration management, and change management.
manager
(1) The part of a distributed
management application that issues requests and receives notifications;
that is, uses the services of one or more agents.
(2) In DCE Remote Procedure Call
(RPC), a set of remote procedures that implement the operations of an RPC
interface and that can be dedicated to a given type of object. See also
object and RPC interface.
(3) In the OSI Communications
Subsystem licensed program, a synonym for managing process.
(4) See also SystemView
manager.
manager entry point vector
In DCE
Remote Procedure Call (RPC), the entry point vector used by the run-time code
on the server side to dispatch incoming remote procedure calls. See
entry point vector and
manager.
manager list
In OSI, a list that
an agent maintains of the managing processes that are--or are eligible to
become--managers of that agent.
manager node
In OSI, a node that
provides a managing process.
managing process
In OSI, the part
of a systems management application that monitors and controls the resources
of an agent process. In OSI Communications Subsystem, the managing
process can send operator commands to--and receive event reports
from--its agent processes. Synonymous with
manager. See also systems management
application. Contrast with
agent.
mandatory entry field
A field in
which an operator must enter at least one
character.
mandatory fill field
A field that
an operator must leave blank, or must fill in
completely.
manual answer
In data
communications, a line type that requires operator actions to receive a call
over a switched line. Contrast with automatic
answer.
manual call
In data
communications, a line type requiring operator actions to place a call over a
switched line. Contrast with automatic
call.
manual connection
A Virtual
Private Network (VPN) connection in which all of the parameters of a manual
connection must be set up manually. Manual connections do not
automatically refresh the keys that maintain data security. Contrast
with dynamic connection.
Manufacturing Automation Protocol (MAP)
In OSI,
a specification developed by industrial users to provide a common set of
protocols to allow communications between computers and factory floor
equipment in the manufacturing environment. It is based on a subset of
the open systems interconnection (OSI) standard.
MAP
See Manufacturing
Automation Protocol (MAP).
mapped address
A bidirectional
mapping of one address to another.
mapped conversation
In advanced
program-to-program communications (APPC), a temporary connection between an
application program and an APPC session in which the system provides all the
information on how the data is formatted. Contrast with basic
conversation.
mapping
A representation of one
thing to another.
mapping object
A function of AFP
Utilities that maps a database field value to an object
name.
mapping table
An object that
contains a set of hexadecimal characters used to map data from one character
set and code page to another. For example, unprintable characters can
be mapped to blanks, and lowercase alphabetic characters can be mapped to
uppercase characters.
map set
A group of one or more
maps for use with CICS basic mapping support
(BMS).
margin A
The margin between the
7th and 8th character positions of a reference format for a COBOL source
program line.
margin B
The margin between the
11th and 12th character positions of a reference format for a COBOL source
program line.
margin C
The margin between the
6th and 7th character positions of a reference format for a COBOL source
program line.
margin L
The margin immediately
to the left of the leftmost character position of a reference format for a
COBOL source program line.
margin R
The margin immediately
to the right of the rightmost character position of a reference format for a
COBOL source program line.
margin text
Notes written in the
margins on the top, bottom, left, or right of a
document.
marker
(1) In the GDDM function, a
symbol centered on a point. Line charts may use markers to indicate the
plotted points.
(2) In hardware, reflective material
placed on magnetic tape to indicate the beginning or ending of the recording
area.
marshaling
In DCE Remote
Procedure Call (RPC), the process by which a stub converts local arguments
into network data and packages the data for transmission. Contrast with
unmarshaling.
mask
(1) A pattern of characters that
is used to control the keeping, deleting, or testing of portions of another
pattern of characters.
(2) In DCE Security, a technique used
to establish maximum permissions that can then be applied to individual access
control list (ACL) entries.
(3) A pattern or template that you
apply to an Internet Protocol (IP) address to specify which bits are
significant and which bits are irrelevant.
masquerade NAT (network address translation)
A TCP/IP function
that allows a user to translate multiple Internet Protocol (IP) addresses to
another single IP address. Masquerade NAT is used to hide one or more
IP addresses on an internal network behind an IP address that will be made
public. Traffic can initiate from the private internal addresses
only. See also network address translation (NAT) and
static NAT (network address translation).
master file
A collection of
permanent information, such as a file of customer
addresses.
master key
See host master
key.
master name server
A name server
that provides secondary name servers with domain
data.
master profile
In Client Access,
a file that contains the session profiles and keyboard profiles for a
user's work station function session.
master replica
In the DCE Cell
Directory Service (CDS), the first instance of a specific directory in the
namespace. After copies of the directory have been made, a different
replica can be designated as the master, but only one master replica of a
directory can exist at a time. CDS can create, update, and delete
object entries and soft links in a master
replica.
master sort table
A
system-supplied table that contains sort information required for sorting
double-byte characters. This table is maintained by the character
generator utility function of the Application Development ToolSet licensed
program.
match fields
In RPG primary or
secondary multifile processing, fields within a record type that are to be
used for checking the order of a single file, or for matching records of one
file with those of another file.
matching record (MR) indicator
An
indicator used in calculation or output specifications to indicate operations
that are to be performed only when records match in primary and secondary
files.
match level
In RPG, the value (M1
through M9) assigned to the match field. The match level identifies
fields by which records are matched during primary or secondary multifile
processing.
matrix
An arrangement in rows and
columns.
MAU
See multistation access
unit (MAU).
maximize
A choice that, when
selected, enlarges the window to its largest possible
size.
maximum transmission unit (MTU)
The largest
possible unit of data that can be sent on a given physical medium in a single
frame. For example, the maximum transmission unit for Ethernet is 1500
bytes.
maybe semantics
In DCE Remote
Procedure Call (RPC), a form of idempotent semantics that indicates that the
caller neither requires nor receives any response or fault indication for an
operation, even though there is no guarantee that the operation was
completed. An operation with maybe semantics is implicitly idempotent
and lacks output parameters. See at-most-once semantics,
broadcast semantics, and idempotent
semantics.
Mb
See
megabit.
MBCS
See multibyte character
set.
Mbps
Megabits per
second.
MCA
See message channel
agent (MCA).
MDF
See main distribution
frame (MDF) or multiple device file
(MDF).
MDT
See modified data tag
(MDT).
media
In Backup Recovery and
Media Services, an individual physical tape cartridge or tape reel, or
removable storage device available for use by the AS/400 system. This
media is grouped into media classes for management, tracking, and statistical
analysis.
media access method
The method
for determining which device has access to the transmission medium at any
time. See also transmission
medium.
media class
In Backup Recovery
and Media Services, a user-defined name used to identify the type and
characteristics of the physical media to be managed as a group for backup,
archive, or recovery operations. Each media class is distinguished by
attributes, such as format or capacity, that are used by the AS/400
system.
media inventory
In Backup
Recovery and Media Services, a library that contains information about media
that has been enrolled in Backup Recovery and Media Services. The media
inventory contains information such as volume serial identifier, expiration
date, creation date, and location. Media in the media inventory is used
for backup, archive, and recovery operations.
medialess
Pertaining to a
personal computer or work station that does not have a diskette or tape drive
or a hard disk.
medialess programmable work station
A
programmable work station that does not contain a diskette or tape drive or a
hard disk. Cooperative processing is done through a shared folder on
the AS/400 system.
media library device (MLD)
A tape
storage device that contains one or more tape drives, tape cartridges, and a
part (carriage and picker assembly) for moving tape media between the
cartridge storage slots and the tape
drives.
media management
In Backup
Recovery and Media Services, the overall control, cataloging, and tracking of
removable media by status, storage location, container placement, and contents
by volume from creation to expiration. Backup Recovery and Media
Services tracks only enrolled volumes. Tapes and other media are
managed by media class and individual volumes within the class. Both
active and expired media are tracked by volume serial
number.
media origin
One of the four
corners of the physical medium (usually paper) where printing
begins.
media policy
In Backup Recovery
and Media Services, a policy that defines the default values used for
management of a media class. A user can have multiple media policies
(one for each media class) to define such things as the move policy used for
this media class, the type of retention, the use of save files, and the number
of copies to be made. Values for a media policy are inherited from the
system policy and can be overridden by the media policy or by the user at the
control group level.
media set
(1) In Backup Recovery and
Media Services, a multivolume tape group created as a result of a backup
operation or archive operation. Media sets are managed as a group to
provide consistent management of single and multivolume output and to provide
integrity in cases where an individual volume in a media set is expired in
advance of the remaining volumes.
(2) In software distribution and
installation on AS/400, a multivolume CD-ROM, CD-R, or tape group created for
the purpose of distributing a selection of software to customers for
installation on to the system. Some media sets, for example, a system
software release upgrade media set, may consist of a collection of smaller
media sets, each containing a specialized selection of the Licensed Internal
Code, licensed programs, the operating system, and program temporary fixes
needed to operate the system and use it to do
business.
medium
The disk, tape, or
diskette used to store information in a save or restore
operation.
medium access control (MAC)
For local
area networks, the method of determining which device has access to the
transmission medium at any time.
medium attachment unit
See
transceiver.
medium convergence
In the DCE
Cell Directory Service (CDS), a setting that controls the degree to which CDS
attempts to keep all replicas of a directory consistent. Medium
convergence means CDS makes one attempt to immediately propagate an update to
all replicas of the directory in which a change was made. See high
convergence and low
convergence.
meeting notice
In the
OfficeVision program, a document that is mailed to meeting invitees to inform
them of a meeting.
megabit
(1) For processor storage,
real and virtual storage, and channel volume, 220 or 1 048 576
bits.
(2) For disk storage capacity and
communications volume, 1 000 000 bits.
megabyte
A unit of measure for
storage capacity. For main storage,
1 megabyte equals 1 048 576 bytes (1024 x 1024); for
auxiliary storage (disk, diskette, and tape),
1 megabyte equals 1 000 000 bytes (1000 x
1000).
member
Different sets of data,
each with the same format, within one database file. See also
source member.
memory
In Client Access,
program-addressable storage from which instructions and other data can be
loaded directly into registers for subsequent processing. See also
main storage.
memo slip
In the OfficeVision
program, additional information attached to a mail
item.
menu
A displayed list of items
from which a user can make a selection. The system-recognized
identifier for the object type is *MENU.
menu bar
The area containing
keywords at the top of a display that gives a user access to actions available
for that display. After a user requests a choice in the menu bar, a
pull-down menu is shown below the menu
bar.
menu-bar field
In DDS, a panel
element that contains a numeric field containing one or more menu-bar choice
keywords.
menu-bar separator
In DDS, a
panel element that contains a horizontal line that appears directly below a
menu bar.
menu-bar switch key
A key that
alternates the cursor between the menu bar and that application
display.
menu security
A function of the
operating system that controls which system resources are available to
users. Menu security restricts a user to a single menu or a sequence of
menus that are defined in the user profile.
merge
(1) To insert records
throughout a single output file.
(2) To combine overrides for a file
from the first call level up to and including a greater call level, producing
the override to be applied when the file is
used.
merge file
In COBOL, the
temporary file that contains all the records to be merged by a MERGE
statement. The merge file is created and can be used only by the merge
function.
mesh-connected session network
A
configuration where every network node has a control point-to-control point
session to every other network node. As the number of network nodes
increases, the number of CP-to-CP sessions increases
dramatically.
message
(1) A communication sent from
a person or program to another person or program.
(2) In OSI Message Services, a piece
of electronic mail in the format of the X.400 CCITT standard. An
X.400 message can be an AS/400 document, note, message, or file.
(3) In OfficeVision, a short
communication of no more than 202 characters in length sent from one user to
one or more other users. A message is place in the mail log of the
recipient, even if the recipient is not signed on.
(4) In MQSeries message queuing
applications, a communication sent from a program to another program.
(5) In Smalltalk, the mechanism by
which one object requests the services of another object. The message
identifies the method that the object will use to perform the request.
(6) In system programming,
information intended for the system
operator.
message authentication code (MAC)
In
Cryptographic Support, the first 4 bytes from the last 8-byte block of
ciphertext produced when encrypting a message using cipher block chaining,
that is added to the end of the plaintext message from which it was created
and used to detect whether the message was changed during
transmission.
message authentication key
In
Cryptographic Support, a data encrypting key used to encrypt data to produce a
message authentication code.
message channel
In MQSeries
distributed message queuing, a mechanism for moving messages from one queue to
another. A message channel comprises two message channel agents and a
communications link.
message channel agent (MCA)
In
MQSeries, a program that transmits prepared messages from a transmission queue
to a communications link, or from a communications link to a destination
queue.
message description
Information
describing a particular message.
message descriptor
In MQSeries,
control information that is carried as part of an MQM
message.
message envelope
The information
associated with a message aside from attachments and
recipients.
message file
(1) An object that
contains message descriptions. The system-recognized identifier for the
object type is *MSGF.
(2) In CICS, the file holding
the text of all CICS messages.
message handling system (MHS)
In OSI
X.400, a collection of message transfer agents and user agents that
provide support for sending and receiving
messages.
message help
More information
about a message, such as the message type, severity, and date and time
sent.
message identifier
A
seven-character code that identifies a predefined message, and is used to get
the message description from a message file. See predefined
message.
message line
An area on the
display where messages are displayed.
message object
An abstraction of
the data structures or system objects that store mail server framework message
information.
message priority
In MQSeries, an
attribute of a message that can affect the order in which messages on a queue
are retrieved and whether a trigger event is
generated.
message protocol data unit (MPDU)
In OSI,
the elements in Protocol 1 (P1) that are used between message transfer agents
(MTAs).
message queue
(1) A list on which
messages are placed when they are sent to a user ID or device
description. The system-recognized identifier for the object type is
*MSGQ.
(2) In interprocess
communications, a mechanism that allows a process to communicate with other
processes by sending messages to a process, receiving messages from a process,
or performing control operations on a
process.
Message Queue Interface (MQI)
The
programming interface provided by the MQSeries message queue managers.
This programming interface allows application programs to access message
queuing services.
message queuing
A programming
technique in which each program within an application communicates with the
other programs by putting messages on
queues.
message reference key
A key
assigned to every message on a message waiting line. This key is used
to remove a message from a message waiting line, to receive a message, and to
reply to a message.
message severity
See
severity.
message store (MS)
A component that
is usually associated with the local delivery exit. The message store
provides application program interfaces (APIs) for maintaining mailboxes, and
it provides pointers to message objects.
message subfile
A subfile where
the records are messages from a program message
queue.
message transfer agent (MTA)
In OSI
X.400, one of two basic parts of electronic mail. A message
transfer agent is a program that accepts the mail from user agents, delivers
messages to user agents, and forwards messages to other MTAs. See also
user agent (UA).
message transfer state
In BSC, a
condition in which a bid exchange was completed and data can be
transmitted.
message transfer system (MTS)
In OSI
X.400, a collection of message transfer agents. A message
transfer system provides the means by which user agents can exchange
messages.
message type
A value used to
define the type of data sent for a distribution to a recipient. The
message types supported on a system are defined when the mail server framework
is configured. The value associated with the message type must be a
unique type value.
message unit identifier (MUID)
In SNA, a
number that uniquely identifies a distribution message unit throughout its
existence. A message unit exists for only one hop, from one system to
the adjacent system.
messaging
A method for
communication between programs. Messaging can be synchronous or
independent of time.
metaclass
A class of
classes. Contrast with parent class, which is a class from
which instance methods are inherited.
metadata
In databases, data that
describes data objects.
metafile
A file containing a
series of attributes that set color, shape, and size, usually of a picture or
a drawing. Using a program that can interpret these attributes, a user
can view the assembled image.
metaphor
A word, phrase, or
visual representation that denotes or depicts one object or idea but suggests
a likeness or analogy with another object or
idea.
metatable
In the OSI
Communications Subsystem licensed program, the machine-readable form of an
abstract syntax. The metatable is generated by the Abstract Syntax
Checker and used by the OSI COmmunications Subsystem presentation layer to
encode and decode data being exchanged.
method
In object-oriented
programming, an operation that an object can perform. An object can
have many methods. See also HTTP
method.
method binding signature
A
hexadecimal value that contains the method signature (obtained from the
signature bank), inheritance level, slot, and signature of the method's
class. The method binding signature is added to the Interface
Definition Language (IDL) source file by the signature
emitter.
method pointer
A special OS/400
pointer type. A method pointer on a single class. Method
pointers are not guaranteed to be persistent between multiple
jobs.
method procedure
A function or
procedure, written in an arbitrary programming language, that implements a
method of a class.
method signature
A hexadecimal
value obtained from an AS/400 and placed in a signature bank on the
workstation. The signature bank uniquely identifies a method.
Method signatures are added to the Interface Definition Language (IDL) source
file by the signature emitter. Method signatures are added in the form
of a binding signature. See also class
signature.
metric
A measurement of a
particular characteristic of a program's performance.
MFM
See modified frequency
modulation (MFM).
MHS
See message handling
system (MHS).
MI
See
machine interface (MI).
MIB
See Management
Information Base (MIB).
Micro Channel architecture
Hardware
that is used for PS/2 Models 50 computers and above to provide better growth
potential and performance characteristics when compared with the original
personal computer design.
microfiche
A photographic
negative containing reduced images of pages of a document, arranged in a grid
pattern.
Microsoft Windows
Pertaining to a
Microsoft Corporation program that provides a graphical user interface for
DOS.
microswitch
A switch operated by
the movement of some part of the machine.
migrate
(1) To move to a changed
operating environment, usually to a new release or version of a system.
(2) To move data from one hierarchy
of storage to another.
Migrate'N'Grow
An offering of
migration solution options that assist users with the migration of data from
their System/36 or System/38 systems to AS/400 systems. The migration
solution options available provide varying amounts of software and service
assistance.
migration
(1) The process of moving
data and source from one computer system to another without converting the
data.
(2) A storage management operation
where selected data is physically moved from system auxiliary storage pools
(ASPs) to user ASPs.
MIME
See Multipurpose
Internet Mail Extensions
(MIME).
minimally consistent
In the
Distributed Computing Environment (DCE), pertaining to an object that
satisfies various conditions set forth in the definition of its
class.
minimize
A choice that reduces
the window to its smallest possible size and removes all the windows
associated with that window from the
display.
minor synchronization point
In OSI,
a session-layer synchronization point that represents a less significant piece
of work than a major synchronization point. Minor synchronization
points are an unconfirmed service. Contrast with major
synchronization point.
minor synchronize
In OSI, a
service provided by the session layer that enables peer application entities
to mark recovery points in the flow of data being exchanged in case they need
to resynchronize the data stream. Contrast with major
synchronize.
minor tick
In Business Graphics
Utility, one of the marks located between major ticks on an axis of a
chart. See also major
tick.
mirrored pair
Two units that
contain the same data and are referred to by the system as one logical
unit.
mirrored protection
A function
that protects data by duplicating all disk data in an auxiliary storage pool
(ASP) to another disk unit (mirrored unit) in the same ASP. If a disk
failure occurs, the system keeps running, using the operational mirrored unit
of the mirrored pair until the disk unit is repaired or replaced. See
also mirrored pair and mirrored unit. Contrast
with checksum protection and device parity
protection.
mirrored unit
One half (one of
the units) of a mirrored pair of units.
mirroring
The process of writing
the same data to two disk units within the same auxiliary storage pool at the
same time. The two disk units become a mirrored pair, allowing the
system to continue when one of the mirrored units fails. See also
mirrored pair, mirrored unit, and mirrored
protection.
mixed-byte character set
A set of
characters that contain both single-byte characters and double-byte
characters. For example, a file might contain characters from a
single-byte coded character set (such as code page 00290) and characters from
a double-byte coded character set (such as code page
00300).
mixed CCSID
A mixed-byte (single
byte and double byte) encoding scheme. CCSID 05026 is an example of a
mixed CCSID. CCSID 05026 contains both single-byte code page 00290 and
double-byte code page 00300.
mixed chart
In the GDDM function,
the combination of more than one type of chart in a business chart. For
example, the overlaying of a line chart on a bar
chart.
mixed data
In DB2 UDB for AS/400,
data that is associated with both a single-byte character set and a
double-byte character set.
mixed data string
In DB2 UDB for
AS/400, a character string that can contain both single-byte and double-byte
characters.
mixed list
A list of unlike
values for a parameter that accepts a set of separately defined values.
An example of a mixed list is a list of user names that embeds another
list. Contrast with simple
list.
Mixed Object:Document Content Architecture
The
architecture that provides a single interface definition allowing objects from
different products to be interchanged so that the data can be edited,
presented, or manipulated by processes of varying characteristics and
intent.
mixed-release support
An approach
to managing software delivery that makes it possible for IBM-supplied
distribution media to deliver entire (or parts of) licensed programs at
existing releases with or without a new release of OS/400. Existing
licensed programs that are enabled for mixed releases but that have no new
function are not rebuilt. They are not renewed with a new release of
the operating system. Similarly, optionally installable parts of
licensed programs that are enabled for mixed releases are not rebuilt or are
not renewed with each new release of its base licensed program. Enabled
licensed programs that remain at earlier releases are compatible and function
with the new release of the operating
system.
mixed string
A character string
that consists of both single-byte character set (SBCS) data and bracketed
double-byte character set (DBCS) data.
MLD
See media library device
(MLD).
MNCS
See multinational
character set (MNCS).
mnemonic
A symbol or abbreviation
chosen to help the user remember the significance or meaning of the
symbol. For example, CRTUSRPRF is a mnemonic for the Create User
Profile command.
mnemonic-name
In COBOL, a
user-defined word that is associated in the Environment Division with a
specific channel-name, switch-name, or unit-name.
mode
(1) A method of operation in
which the actions that are available to a user are determined by the state of
the system.
(2) The state or setting of a program or
device.
(3) The session limits and common
characteristics of the sessions associated with advanced-program-to-program
communications (APPC) devices managed as a unit with a remote location.
(4) In the OSI Communications Subsystem
licensed program, a set of parameter values that are proposed for use when an
association or connection is being established. The mode specifies the
services needed from one or more layers. See application
mode, network QOS mode, and transport
mode.
mode description
A system object
created for advanced-program-to-program communications (APPC) devices that
describes the session limits and the characteristics of the session, such as
the maximum number of sessions allowed, maximum number of conversations
allowed, the pacing value for incoming and outgoing request or response units,
and other controlling information for the session. The
system-recognized identifier for the object type is
*MODD.
model configuration
In Client
Access, the set of files, created by the Client Access administrator, that
define a set of common characteristics for a set of Client Access
users. Model configurations can be used as a base for defining user
configurations.
model file
In performance, a
complete representation of a system. It includes both the system
configuration and the set of workloads running on the
configuration.
model output file
A file that
contains sample output of a function.
model system
As AS/400 system
that manages the fix (PTF) levels for each of the systems in a network by
comparing what fixes are available on the model system with a specific
endpoint system.
model-unique Licensed Internal Code (MULIC)
The
Licensed Internal Code shipped with the system hardware that provides support
for that model. MULIC is a complex instruction set computer (CISC)-only
function. See also Licensed Internal Code and
feature-unique Licensed Internal Code
(FULIC).
modem (modulator/demodulator)
A device
that converts digital data from the computer to an analog signal to send it
over a communications line (modulator) and converts the communications signal
received to data for the computer (demodulator). See also data
circuit-terminating equipment (DCE).
mode-2 character
In the GDDM
function, a graphics character (symbol), characterized by an unchanging size,
constructed from picture elements. Contrast with mode-3
character; see also hardware
character.
mode-3 character
In the GDDM
function, a graphics character (symbol), characterized by a variable size and
shape, constructed from lines and curves. Contrast with mode-2
character; see also hardware
character.
modification level
A distribution
of additional function or fixes to a program since the previous release or
modification. A new release is shipped at modification 0. See
also release, version, and
VxRxMx.
modified data tag (MDT)
An
indicator, associated with each input or output field in a displayed record,
that is automatically set on when data is typed into the field. The
modified data tag is maintained by the display file and can be used by the
program using the file.
modified frequency modulation (MFM)
(1) Variation
in the amplitude and frequency of the write signal.
(2) Pertains to the
number of bytes of storage that can be stored on the recording media.
Synonymous with double-density recording.
modular program design
A design
in which multiple programs do a function (normally one program per
function). Modular program design applies to both batch and interactive
processing.
module
(1) An independent unit that
is part of a total structure.
(2) An OS/400 object that can be a
collection of one or more procedures and one or more definitions for external
or internal variables. This object results from the compiling of source
code.
(3) In online education, a unit of
instruction that is part of an education course.
(4) In OSI, one or more instances of
the use of the ASN.1 notation for type and value definitions,
represented in ASN.1 module notation.
(5) In the Integrated Language
Environment (ILE) model, the object that results from compiling source
code. A module cannot be run. To be run, a module must be bound
into a program. See also bind. Contrast with
program.
module width
In AFP Utilities,
the basic element width used in a bar code. The actual code element may
be a module width or a multiple of a module
width.
modulo check
A calculation
performed on values entered into a system by an operator. This
calculation is designed to detect most common typing errors. See also
modulus.
modulus
In communications, a
number, such as a positive integer, in a relationship that divides the
difference between two related numbers without leaving a remainder. For
example, 9 and 4 have a modulus of 5 (9 - 4 = 5; 4 - 9 = -5; and 5
divides both 5 and -5 without leaving a
remainder).
modulus 10 checking/modulus 11 checking
(1) A method
for verifying data.
(2) Formulas used
to calculate the check digit for a self-check
field.
monitor mode
In BSC, the mode
during which the communications adapter is looking for synchronization
characters.
monocase table
A table used to
convert lowercase letters to uppercase letters. The actual process of
character conversion is called monocasing.
monochrome
Consisting of a single
color.
monospace
(1) One space.
(2) Referring to a character set,
that uses one space in a preset width for each character. Contrast with
proportional spacing.
mount
In Network File System
(NFS), to make remote file systems on NFS servers
accessible.
mouse
A device with one or more
push buttons used to position a pointer on the display without using the
keyboard. It allows a user to select a choice or function to be
performed or to perform operations on the display, such as dragging or drawing
lines from one position to another.
mouse button
A mechanism on a
mouse that a user presses to select choices or start
actions.
move policy
In Backup Recovery
and Media Services, a policy that defines the movement of media between or
among storage locations, and the length of time the media is to remain at each
location. After the move is specified in the move policy, the media is
returned to the user-specified home location. A move policy can be used
with any media policy.
MPDU
See message protocol
data unit (MPDU).
MPS
See multiple port
sharing (MPS).
MPTN
See Multiprotocol
Transport Networking (MPTN).
MQI
See Message Queue
Interface (MQI).
MQSeries
(1) An IBM licensed program
that provides message queueing services. It is part of the MQSeries set
of products.
(2) The set of IBM products that
enable programs to talk to each other across a network of unlike components,
using a simple and consistent application programming interface, the
MQI.
MR indicator
See matching
record (MR) indicator.
MRJE
See multileaving remote
job entry (MRJE).
MS
See
message store (MS).
MSF
See mail server
framework (MSF).
MSG file
In VisualAge RPG, a file
containing the application messages. The file is created from the
message source file during the make process. See also
make.
MTA
See message transfer
agent (MTA).
MTS
See message transfer
system (MTS).
MTU
See maximum transmission
unit (MTU).
MUID
See message unit
identifier (MUID).
MULIC
See model-unique
Licensed Internal Code
(MULIC).
multibyte character set
A
computer representation of a character set in which each character is
represented by one or more bytes. A multibyte character set allows many
thousands of characters to be represented in a single character set.
Common multibyte character sets include PC-mixed, host-mixed and extended UNIX
coded character set.
multicast address
(1) A type of IP
address. A multicast address identifies a group of interfaces and lets
all of the systems that are in that group receive the same packet of
information. The interfaces of a single system can belong to many
different multicast groups.
(2) See group
address.
multifunction input/output processor (MFIOP)
A server
processor that as a unit contains more than one processor function such as a
diskette controller, a storage device controller, and a communications
controller.
multihomed host
In the Internet
Protocol (IP), a host that is connected to more than one network. Also
referred to as dual-homed host.
multihoming
For TCP/IP, the
ability to specify multiple interfaces per line description. The AS/400
system can have multiple hosts on the same network over the same
communications line or multiple hosts on different networks over the same
communications line.
multileaving remote job entry (MRJE)
The
fully synchronized, two-directional transmission of a variable number of data
streams between two computers using binary synchronous
communications.
multilingual support
Support that
includes more than one national language on a system. See also
national language support (NLS).
multimedia
Material presented in
a combination of text, graphics, video, animation, and
sound.
multinational character set (MNCS)
(1) A set of
graphic characters that support the languages within a specific language
group.
(2) On AS/400,
character set 697 and code page 500 are implied when speaking about the
MNCS.
multiple axis chart
In the GDDM
function, a chart in which more than one horizontal or vertical axis, or both,
are used. See also secondary
axis.
multiple bar chart
In the GDDM
function, a form of bar chart in which the bars at a given horizontal axis
value are placed side by side.
multiple chart
In the GDDM
function, two or more charts appearing together on the work station or
page. Multiple charts can be of the same type or different types and
can be constructed from one or more sets of
data.
multiple-choice selection field
A field
that contains a fixed number of choices arranged in a list in which one or
more selections can be made.
multiple-choice selection list
A field
that contains a potentially scrollable list of choices in which one or more
selections can be made.
multiple column editing
In the
OfficeVision program, a method of editing that allows the user, if using the
PC text-assist function, to edit text displayed in more than one
column.
multiple device file (MDF)
(1) A device
file in which the maximum number of program devices is greater than
one.
(2) In RPG, any
work station (WORKSTN) file with one of the keywords ID, IND, NUM, or
SAVDS. Such a file can access more than one device, and devices of
various types.
multiple DOS sessions
An OS/2
operating system service that coordinates the concurrent operation of separate
virtual DOS machines.
multiple letters merge
In the
OfficeVision program, a type of data/text merge that produces a separate
printed document for each record selected. See also column list
merge and direct
merge.
multiple-line entry field
In
VisualAge RPG, an entry field that allows the user to enter multiple lines of
text.
multiple line report
In the
OfficeVision program, a type of data/text merge that produces one document
containing several lines of information from each data record in the data
file. Contrast with column list merge and multiple
letters merge.
multiple occurrence data structure
In RPG,
a data structure that appears more than once in a
program.
multiple operating systems
A primary
operating system with one or more operating systems that coexist on the same
system. For example, AS/400 Advanced 36 Model 436 can have OS/400 as
its primary operating system that coexists with one or more AS/400 Advanced 36
machines running SSP as secondary operating
systems.
multiple port sharing (MPS)
An
arrangement for short-hold mode operation in which both the first call and a
reconnection call (recall) for a population of DTEs are directed to any
available port within a port
group.
multiple-selection field
In
Client Access, a list from which a user can choose one or more
items.
multiple text columns
In the
OfficeVision program, an arrangement of text in a document that appears as
more than one column across the page, similar to the columns in a
newspaper.
multiple up
The printing of more
than one page on a single surface of a sheet of
paper.
multiple virtual DOS machines (MVDM)
See
multiple DOS sessions.
multiplexer
A device that takes
several input signals and combines them into a single output signal in such a
manner that each of the input signals can be
recovered.
multiplexing
In OSI, the
technique of using a single network connection by multiple Transport Layer
connections so that multiple associations can share the same line.
Multiplexing is available only for transport classes 2 and
4.
multipoint
In data
communications, pertaining to a network that allows two or more stations to
communicate with a single system on one
line.
multipoint line
A line or circuit
connecting several stations. Contrast with point-to-point
line.
multiprocess installation
The process
of installing two or more licensed programs at the same
time.
multiprocessor
A computer
including two or more processors that have common access to a main
storage.
multiprotocol transport networking (MPTN)
A
networking architecture that allows application programs using common
upper-layer protocols and expecting the same transport services to communicate
over transport networks that may use protocols different from the transport
network the programs were designed to use. For example, socket
application programs that were originally designed to communicate over a
TCP/IP transport network can, using MPTN support, communicate over an SNA
transport network.
Multipurpose Internet Mail Extensions (MIME)
An
Internet standard for multimedia e-mail, including graphics, audio, and
fax.
multistation access unit (MAU)
In the
IBM Token-Ring Network, a wiring concentrator that can connect up to eight
lobes to a ring.
multitasking
A mode of operation
that provides for concurrent performance, or interleaved processing of two or
more tasks. (I) (A)
multithread
A process that has
multiple active threads. Multithread can also be called
multithread capable.
multithreaded
In Java, pertaining
to the description of a program that is designed to have parts of its code run
concurrently. See also
thread.
multithreading
A general purpose
programming technique that reduces the complexity and overhead of concurrent
programming. It is a required component to accommodate Java and Lotus
Domino Server.
multithread test
In CICS, this
type of test involves several concurrently active transactions. Whether
the new function can coexist with other related functions is tested.
Contrast with single-thread
test.
multivolume file
A file that
occupies more than one diskette or tape.
mutex
(1) A synchronization function
that is used to allow multiple jobs or processes to serialize their access to
shared data.
(2) In the Distributed Computing
Environment (DCE), a read-write lock that grants access to a single thread at
any time. A mutex is often used to ensure that shared variables are
always seen by other threads in a consistent way.
(3) An abstraction that allows two or
more threads to cooperate in a MUTual EXclusion protocol that allows safe
access to shared resources. See also mutual exclusion
lock.
mutual exclusion (mutex)
See
mutex.
mutual exclusion lock
In
software, a method for preventing two separately running pieces of code from
interfering with each other's use of a particular data object. For
example, if one thread is running a function that modifies a shared data
structure, the application may need to prevent other threads from
simultaneously attempting to read the data before the changes are
complete.