- abort
A procedure that terminates a program or session
if an irrecoverable error, mistake, or malfunction occurs, or if
the system manager requests termination.
- access
The process of obtaining data from files or acquiring
the use of a device. Access implies an input/output (I/O) operation
and is used as a synonym for I/O.
- access codes
Access codes are assigned by the system manager
to accounts and by the account manager to groups, and users. Access
codes specify which users have the ability to read, write, append,
lock, or execute a given file.
- access control definitions (ACDs)
An ACD is how the owner of a file defines >who can
do what with the file. ACDs take precedence over other
access controls namely the MPE file access matrix and lockwords. The
types of access are read (R), write (W), append (A), lock (L), execute
(X), none (NONE), and read and copy the ACD permission file
(RACD).
- access method
The way in which data is moved between main storage
and input/output devices.
- access port (AP)
The MPE/iX system console interfaces the host system
through the access port (AP) located in the channel I/O (CIO) section
of the system card cage. The AP provides a user support interface
for issuing hard and soft resets through software commands from
the console. It allows a remote console to be enabled and to switch
between console and session modes.
- access rights field (ARF)
A field containing the type of memory access. It
is compared with the user's privilege level to determine if the
type of access the user is requesting (READ, WRITE, EXECUTE, or
GATEWAY) is allowed for that page of memory.
- account
A collection of users and groups. Each account has
a unique name on the system. It is the method used to organize a
system's users and files and track use of system resources such
as central processor time, online connect time, and file space.
Accounts are the principal billing entity for the use of these resources.
Every user must specify an account to access the system.
- account level security
The types of file access assigned by the system
manager to the account when it is created. The types of access are
READ, LOCK, APPEND, WRITE, and EXECUTE, abbreviated R, L, A, W,
and X respectively. They may be assigned to any user (ANY), members
of the account only (AC), or members of the group only (GU). The
types of file access permitted are the first level of system security.
The account manager may further restrict groups and users within
an account by assigning them a limited set of file access modes.
- account librarian capability (AL capability)
A capability assigned by the account manager to
a user within the account. An account librarian can be allowed special
file access to maintain specified files within the account.
- account manager capability (AM capability)
A capability assigned to one user within each account
who is then responsible for establishing users and groups.
- account member
A person who has been granted access to the system
through the use of a valid user name within an account. Account
members are created by the account manager, who defines the user
name and assigns the user appropriate capabilities and security
restrictions.
- account structure
The account structure provides organization, security,
and billing for the system. It is used to allocate system resources
such as central processor time, online connect time, and file space.
The account is the principal billing entity for the use of system
resources.
- acknowledge
To answer or reply to a polling, an address, or a message.
- acoustic modem
A data communications device. An acoustic modem
has a cradle and form-fitting rubber cups to hold a telephone handset.
The opposite of direct-connect modem.
- ACTIVE state
The status of either an input or output spoolfile
(defined differently for each). During input spooling, an ACTIVE
file is a spoolfile being created, indicating that the input spooler
is still collecting data from the input device. An ACTIVE output
spoolfile is the only file being output to a device. For example,
when the standard output device is the system printer the file being
printed is ACTIVE.
- actual file designator
The file name provided by the user. The system then
uses the file name in place of the formal file designator to accomplish
some task. The actual file designator is the file name listed in
the directory. See formal file designator.
- address
A number identifying an exact location in memory. A process can
send data to, or retrieve data from, this address.
A set of values identifying a specific peripheral (I/O) device to
the computer. The exact details on the formation of an address differ
between systems.
- address bus
The electrical conductors within a computer. They
carry addresses from the CPU to components under CPU control. The
900 Series HP 3000 address bus is 32-bits wide.
- advanced terminal processor (ATP)
An intelligent hardware interface between terminals
and the HP 3000. The ATP handles character processing and eliminates
CPU interrupts. It supports full-duplex asynchronous modems and
direct memory access of user data.
- AdvanceNet
See HP AdvanceNet.
- algorithm
A step-by-step procedure for solving a problem in
a finite amount of time.
- ALLBASE/SQL
A Hewlett-Packard database management system. It
provides both network and relational interfaces.
- allocate
To locate and reserve disk space for a particular file.
To use the ALLOCATE command to update table entries and
resolve pointers necessary for a program to execute. However, the
program is not actually loaded into memory until run time.
- alpha character
A character in the range of A through Z (or a-z).
- alphanumeric character
A character in the range of A through Z (or a-z), or 0
through 9.
- alpha test
The designation given when the reliability of a
computer system is tested by internal users. For example, internal
Hewlett-Packard users test and verify a new product before external
customer tests are conducted.
- alternate boot path
The hardware path used when booting the system from
a boot tape. See boot path.
- American National Standards Institute (ANSI)
A nongovernmental agency that establishes standards,
including those for data processing.
- American Standard Code for Information
Interchange (ASCII, USASCII)
The standard method of representing character data
(seven data bits plus one that is sometimes used for parity). This
method was established by the American National Standards Institute
(ANSI) to achieve compatibility between data devices when they are
interchanging information.
- analog
Data that varies continuously rather than in discrete
steps. When used in reference to circuits, it means those circuits
that produce an output varying as an uninterrupted function of the
input. The opposite of digital.
- append
To join all or part of one existing file to the
end of another existing file.
- application
A set of computer instructions or programs that
accomplish tasks for the end user, rather than control the computer
(that is what the operating system does). Examples of applications
include spreadsheets, word processing programs, graphics, database
management, and communications.
- application layer
Layer seven of the Open Systems Interconnection
(OSI) network model. Application layer tasks include the user interface
to remote services.
- application program
A set of computer instructions that guides the computer
through a specific set of tasks (usually for the end user). Applications
include spreadsheets, word processing, graphics, database management,
and data communication programs.
- architecture
The unique set of machine instructions, registers, and components,
as well as the way they interact, that provides the basis of the
operation of the computer's CPU.
In networking, a structured modular network design in which
different data communications tasks are assigned to different layers
or levels. See Open Systems Interconnection.
- archive mode
A DBCore mode of logging that enables both rollback
and rollforward recovery for HP SQL databases.
- archiving
Storing infrequently used or out-of-date files onto
tape and permanently removing them from the system disks at the
same time.
- arithmetic logic unit (ALU)
The part of a system that performs arithmetic and
logic operations as part of the central processing unit (CPU). The
CPU may contain one or more arithmetic logic units.
- array
An ordered collection of letters, numbers, or words
defined by the user. The computer stores the data in an array in
continuous memory.
- ASCII
American Standard Code for Information Interchange (ASCII) is the
standard method of representing character data (seven bits plus one that
can be used for parity). This method was established by the American
National Standards Institute (ANSI) to achieve compatibility between data
devices when they are exchanging information.
- assembly language
A programming language in which each operation performed by the
central processing unit (CPU) is written as a symbolic instruction.
Assembly language is a convenient means of representing machine language
(one instruction represents exactly one operation). A program known
as an assembler translates instructions written in assembly language
into machine language.
- associated device
A device associated with a user by way of the
ASSOCIATE command. Thereafter, the associated user has operator
control of the designated device until the user logs off or gives
up control of the device, or until the operator issues the
DISASSOCIATE command.
- asynchronous
A method of transmitting data serially without sending
a clock signal. Each character consists of one start bit, five to
eight data bits, an optional parity bit, and one or more stop bits.
The opposite of synchronous.
- asynchronous I/O
An I/O operation. The user process need not wait
for completion before continuing execution. There are two forms,
user asynchronous I/O and system asynchronous I/O.
- asynchronous serial communications (ASC)
A part of the fundamental operating software package for the 900
Series HP 3000. It works in conjunction with the Datacommunications
and Terminal Controller (DTC) to provide data transmission functions.
The ASC software handles handshaking between the host system and
its asynchronous devices, including character echoing, multiplexing,
and input character buffering.
- attachment unit interface (AUI)
A cable joining the local area network interface controller
(LANIC) to the media attachment unit (MAU) for coaxial cable IEEE
802.3 local area network links.
- attributes
Characteristics assigned to users, groups, and accounts
which determine what can be done in the groups and accounts, or by the
user. Attributes include file access codes and special capabilities.
They enable the computer to determine what functions it will or
will not allow a user, group, or account to perform.
- authorization group
A security feature of HP SQL. A collection of users
and groups with the same authorities within a DBEnvironment.
- automatic calling unit (ACU)
A device that automatically places a telephone call
after receiving instructions from the calling device.
- automatic in
A computer-to-PBX connection sequence. It allows
the computer to initiate an incoming connection on a specified channel
from a specified device through the PBX. No telephone number is
given; the device location (telephone number) is associated with
the given channel by an administrative process on the PBX.
- automatic master data set
A data set within a database. It contains only one
data item (the key item). It is related to at least one detail data
set. When a new search item value is added to a related detail set,
a new entry is automatically added to the master with that item
value as a key. When the last entry containing that search item
is deleted from all related child data sets, the master entry is
automatically deleted.
- automatic out
A computer-to-PBX connection sequence. It allows
the computer to initiate an outgoing connection on a specified channel
to a specified device through the PBX. No telephone number is given;
the device location (telephone number) is associated with the given
channel by an administrative process on the PBX.
- automatic restart
Main memory battery backup to automatically restart
the system after a power failure. Temporary power line interruptions
can be tolerated with no data loss and without needing to restart
the system.
- backplane
Wiring blocks or units that provide most of the
interconnecting circuits of a system. Individual printed-circuit
boards plug into the backplane. Every backplane contains multiple
card cages.
- backreference
The technique of using an asterisk (*) before a formal file
designator to indicate that it has been previously defined with the
FILE command.
- backup
The process that duplicates computer data to offline
media, such as magnetic tape. Backups protect data if a system problem
should occur.
- backup devices
System peripherals that allow you to write information
to, and read information from, backup media.
- battery backup unit
A box within the SPU that contains a battery to
supply power to main memory during a power failure.
- BASIC
Beginner's All-purpose Symbolic Instruction Code.
A computer programming language.
- batch processing
A method of submitting a job for processing. A job,
which is submitted as a single entity, can consist of multiple commands
such as program compilation and execution, file manipulation, or
utility functions. Once submitted, no further interaction between
the user and the job is necessary.
- batch access capability (BA capability)
A default capability. It is assigned to accounts and
users, allowing users to submit batch jobs.
- baud
A measure of the speed at which information travels
between devices. This signal speed is equal to the number of discrete
conditions or signal event changes per second. When one bit represents
each signal change, baud is the same as bits per second. Terminal
speed settings are the most familiar references to baud rate.
- beginning of tape (BOT)
A mark on a magnetic tape indicating where the tape
drive will start reading or writing data.
- beta test
The designation given to a product test in a limited customer
environment. For example, Hewlett-Packard tests its products at selected
external customer sites before they are publicly released.
- binary
A method of representing numbers, alphabetic characters,
and symbols in digital computers. Binary is the base two numbering
system that uses only two digits, 0's and 1's, to express numeric
quantities.
- binary coded decimal (BCD)
A decimal notation in which individual decimal digits
are each represented by a group of four bits.
- binary synchronous communications (BSC)
A data link protocol, also referred to as BISYNC.
A line control station in a data communications system.
- bit
A binary digit; the number 0 or 1 in the base 2
numbering system (0 represents OFF, and 1 represents ON). Usually
eight bits equal one byte. A bit is the smallest unit of information
in a digital computer.
- bit bucket
Computer jargon referring to a nonexistent computer
storage area. The bit bucket is used when the system-defined
$NULL file is specified in a command line as an output
file. The associated write request is accepted by MPE/iX, but no
physical output is actually performed.
- bit-oriented protocol (bop)
A communications protocol that does not recognize
a character as sequences of bits.
- bit rate
The speed at which bits are transmitted. The bit
rate is usually kilobits per second (Kb/s) or megabits per second
(Mb/s).
- bits per inch (bpi)
A measurement of data density. It expresses the
number of bits recorded per inch of recording surface.
- bits per second (bps)
A measure of transmission speed over a communications channel.
- block
A group of one or more logical records treated as
a single piece of data.
- blocked
A state of suspension for a process.
- blocked record
A physical record that contains more than one logical
record. The opposite of unblocked record.
- block mode
A terminal processing mode. It transmits groups, or blocks of
characters all at once, instead of one character at a time.
- board
A piece of fiberglass that holds integrated circuits
(ICs or chips) and contains the connections between chips. A board
is also called a card or circuit board.
- Boolean
A data type with a value that is either TRUE or
FALSE (binary 1 or 0).
- boot
The process of loading and initializing an operating
system. The term booting is derived from the phrase "pulling yourself
up by your bootstraps."
- boot path
Boot paths are used to bring up the system from disk or tape. The
primary boot path is used for booting the system from disk resident
software. The alternate boot path is used for booting the system from a
boot tape. The console boot path is used to determine if the system can
autoboot without operator intervention.
- boot ROM
Performs tests on the computer's hardware, finds
all devices that are accessible through the computer, and then loads
either a specified operating system or the first operating system
found according to a specific search algorithm.
- boot tape
A tape created by backing up the system with the
system generator (SYSGEN) utility program. The tape is then used
to reload the system. Also referred to as a system load tape. Equivalent
to MPE V/E coldload tape.
- bottleneck
A system resource that is being completely used
and is compromising system performance.
- branch
A machine instruction that alters the sequence of
instructions being executed by the CPU.
- break
An operation that interrupts (suspends or aborts) an executing
process and allows the user to initiate some other operation.
To press the Break key on the terminal or call the
CAUSEBREAK intrinsic. If a process is only suspended, it may
be resumed with the RESUME command.
- broadcast
A communication method of sending a message to all
devices on a link simultaneously.
- broadcast bus network
A network in which nodes are connected by a linear run of cable.
Messages are simultaneously transmitted to every node. Typically, the
nodes process only those messages addressed to them and ignore all other
messages. The opposite of point-to-point network.
- broadcast space
An implementation to address multiple processors
on a bus. Local broadcast address space is used when all processors
on a bus with the I/O module are to be interrupted. A global broadcast
address space is used when all processors system-wide are to be
interrupted.
- b-tree index
An index type supported by DBCore that maintains
tuples in sorted order by key value and is used for accessing a
particular tuple in a set of tuples.
- buffer
The part of a computer or device memory where data
is held temporarily until it can be processed or transmitted elsewhere.
A buffer usually refers to a memory area that is reserved for I/O
operations.
- bug
Computer industry jargon for a computer problem.
- bundled systems
A pricing option. It allows a group of products
to be purchased at a lower cost than if they were each purchased
separately.
- bus
A common group of hardware lines that are used to transmit information
between digitally based devices or components.
- bus address
A number that is part of the address used to find
a particular device. The bus address is determined by a setting
on a peripheral device that allows the computer to distinguish between
two devices connected to the same interface. A bus address is also
referred to as a device address.
- BYE
An MPE command used to terminate an interactive
session on the HP 3000.
- byte
A combination of eight consecutive bits treated
as a unit. A byte represents one letter or number. The size of memory
and disk storage is measured in bytes.
- bytes per inch (BPI)
A measurement of data density; usually for tapes.
It expresses the number of bytes recorded per inch of recording
surface.
- C
A high-level computer programming language that
can do low-level manipulations. It allows great flexibility with
type declarations.
- cable
A connector between computers and peripheral devices.
- cache
A small, high-speed memory buffer unit. The cache
is continually updated to contain recently accessed data to reduce
access time. There may be one cache or separate caches for instructions
and data. HP Precision Architecture has separate caches.
- cache miss
When an instruction or data required by the CPU
is not stored in a cache, the procedure that occurs is called a
cache miss. The required code or data is then retrieved from the
main memory modules.
- capability
A type of access right assigned to a subject (user,
group, or account) affecting what the subject can do to an object
(file, device, command) on the system.
- card
A printed circuit assembly (PCA). See board.
- card cage
The structure used to hold cards in their proper
place inside the computer. Card cage and I/O bay are
sometimes used interchangeably. However, the I/O bay usually refers
to the entire cabinet containing one or more card cages used to
store the cards that control I/O devices.
- card image
The representation of data in the standard columns found on a punched
card, which is a fixed-length record of 80 characters.
- carriage-control characters (CCTL)
Carriage-control characters determine such things
as double spacing, vertical line spacing, and page ejects.
- catalog
A file that acts as a directory of specific objects
(files, commands, messages, users, etc.) on the system.
- catenet
Several networks that are joined, or concatenated, to form a network
of networks. A catenet is also called an internetwork.
- cathode ray tube (CRT)
The video display part of a terminal or PC.
- CCITT
Comite Consultatif International Telephonique et Telegraphique
(International Telegraph and Telephone Consultative Committee); an
international standards group for establishing communication
protocols.
- central bus (CTB)
The communication path between the CPU main memory
modules and the channel I/O adapters.
- central processing unit (CPU)
The part of a system that interprets and executes machine
instructions. The central processor contains an execution unit and
a control unit. See SPU.
- channel
A path within a data communications line through
which data flows.
- channel I/O (CIO)
Input/output instructions for a channel.
- channel I/O adapter
Provides the interface between the central bus (CTB)
and the channel I/O buses. Each channel I/O adapter serves as a high
performance channel multiplexer. It provides a full direct memory access
(DMA) for all HP-IB and LAN I/O channels and synchronizes the differing
speeds and bandwidths of the CTB and channel I/O buses.
- channel I/O buses (CIB)
Provides a synchronous bidirectional data path between
the central bus (CTB) and I/O devices.
- channel number
The number assigned to the device controller board
in the I/O card cage. It is used to calculate the logical address
of the device, or device reference table (DRT) number.
- character
A letter, number, or symbol represented by one byte of data.
- character-oriented protocol
A communications protocol that uses special control characters
to relay instructions for controlling data transmission.
- character set
A series of characters to substitute for a single
character to name a group of files.
- characters per inch (cpi)
A measurement of print density of various printers.
- checksum
The combination of all binary digits in a block. The checksum is used
to verify correct transmission of the block.
- child process
A new process created by an existing process. The new process is
thereafter known to the preexisting process as its child process. The
preexisting process is called the parent process.
- chip
A slice of silicon containing an integrated circuit.
RAM, ROM, PROM, CPU, and EPROM are commonly used chips.
- CIO adapter (CA)
The interface slot number containing the adapter
for the CIO bus and central bus (CTB).
- CIO expander
The channel input/output expander provides eight
additional peripheral card slots to the SPU.
- circuit board
See board.
- circular file
A wraparound file structure that functions as a sequential file
until it is full. As records are written to a circular file, they are
appended to the tail of the file. When the file is full, the next
record causes the block at the head of the file to be deleted and all
other blocks to be logically shifted toward the head of the file.
Circular files are useful as history files when you are more
interested in information recently written to the file and less
concerned about earlier material.
A file that can be reused (DBCore nonarchive log files are
circular files).
- class
A user-defined collection of objects.
- class name
-
A label that is either unique to, or associated with, one or more
devices in the system's I/O configuration, used to reference a
particular device or class of devices. Device class names may be up
to eight alphanumeric characters long, beginning with a letter. A
single logical device may have multiple device class names. The HP
2680 Laser Printer, for example, is referred to as EPOC
(electro-photographic output for computers), PP (page
printer), or SLP (system line printer), or any other defined
name. Directing output to any of these class names sends the output
to a laser printer.
An abstract entity that can own objects in an HP SQL
DBEnvironment.
- clipping
To restrict plotting or drawing to a rectangular
portion (window) of the total available area.
- closing a file
Terminating access to a file. A file is closed by calling the
FCLOSE intrinsic or terminating process execution.
- cluster
A physical storage organization method supported
by DBCore that can help minimize disk accesses. If a relation is
clustered, the physical placement of its rows is controlled by a
key value; this key is called the cluster index key.
- COBOL
Common business-oriented language. A high-level computer language
primarily used for business applications.
- code
Code consists of the executable instructions that
make up a program or subprogram.
- code segment
The instructions to the CPU contained in a single
logical module; one or more code segments comprise a complete program
or subprogram. Code segments remain unchanged during program execution,
and may be overwritten with a new code segment once the current
segment has executed completely. In this way, programs larger than
the maximum code segment size can execute without user intervention
or a large amount of memory.
- code segment table (CST)
A table that keeps track of all code segments currently being used.
CST is used only in compatibility mode (CM) on MPE XL.
- cold dump
See memory dump.
- coldload
See system load tape.
- coldload tape
See boot tape.
- COLDSTART
See UPDATE.
- color palette
In plotting terminology, a specific set of pen colors
and line widths as defined by the pen color instructions of the
graphics system being used.
- column
A named collection of data in an HP SQL table or
view with a particular data type and size.
- command
A system-reserved word that directs the operating
system, a subsystem, or a utility program to perform a specific
operation.
- command file
A set of one or more MPE/iX commands in a file that are executed
by specifying the file name. See also HPPATH or UDC.
A set of one or more SQL or ISQL commands in a file that can be
executed with the ISQL START command.
- command interpreter (CI)
CI: A program that reads command lines entered at
the standard input device, interprets them, determines if they are
valid, and, if so, executes them.
- command line history stack
See history stack (also called
command history stack).
- command set '80 protocol (CS/80 or CS-80)
A family of mass storage devices from Hewlett-Packard
that communicate using the C/80 protocol. Examples are the HP 7911,
HP 7912, HP 7914 disk/tape drives.
- communication
The ability of one computer system to access or talk to other computer
systems by way of telecommunication devices.
- communication link
The software and hardware that moves data from the driver and card of
one computer to the driver of an adjacent computer.
- communications subsystem capability (CS)
Allows users to obtain exclusive access to a communications
device such as a DSN/RJE line or a DSN/DS line. The capability is
required to use DSN/RJE subsystems.
- compatibility
The ability of software developed for one computer
to work on another computer. See compatibility mode.
- compatibility mode (CM)
Compatibility mode provides object code compatibility between
MPE V/E-based systems and the 900 Series HP 3000. Compatibility mode
allows current Hewlett-Packard customers to move applications and data to
the 900 Series HP 3000 without changes or recompilation.
- compile
The process of changing a program written in a source
language (for example, BASIC, C, FORTRAN) into machine executable
instructions. The compiled routine is then ready to be link-edited
and then loaded into storage and run.
- compiler
A program that translates source code written by
a programmer into machine instructions. The compiler also diagnoses
and reports syntax errors found in the application program.
- completion list
A linked list of four-word entries made by a direct
memory access (DMA) I/O card before interrupting the processor.
Each DMA adapter or module (which may have more than one DMA device
associated with it) has its own completion list.
- complex instruction set computer (CISC)
A computer based on an architecture that uses microprogramming
and complex instructions.
- component name
A name identifying an object within the context
of a directory object.
- compound item
A named group of identically defined, adjacent items
within the same data entry; an array. A compound item is subdivided
into subitems.
- compression
The process of translating data into a more compact form so that it
can be transmitted more economically or efficiently.
- computer
A device that accepts information, processes it, and supplies an
output. A computer usually contains memory, a control unit, arithmetic
and logical units, and a means for input and output.
- concurrent directories
A decentralized system directory scheme. Each disk
attached to the system contains its own directory of the files on
that disk. This provides faster file access by eliminating the physical
or logical serialization of a centralized directory.
- configuration
The way in which computer and peripheral devices are programmed to
interact with each other.
The layout of the computer system, including MPE table, memory,
and buffer sizes. The configuration tells which peripheral devices
are connected to the computer and how they can be accessed. The
system is configured by the system supervisor, who works with the
Hewlett-Packard applications engineer (AE).
- connect time
The amount of time, in minutes, that a user, group, or account has
used the CPU for a session or job. It is determined by executing the MPE
REPORT command.
- console
A terminal given unique status by the operating
system. The operator uses the console to monitor and manage jobs,
sessions and resources, respond to requests, and communicate with
other user terminals. It is used to boot the system and receive
system loader error messages, system error messages, and system
status messages.
- console boot path
Used to determine if the system can autoboot without
operator intervention. See boot path.
- console command
A command that is executable only from the system console at the
= prompt (generated by pressing CTRL and the A
key on the console keyboard). Console commands cannot be distributed to
MPE users, since CTRL-A has no meaning on a standard terminal. The
logical console, however, can be moved to a standard terminal.
- console logging
A system logging event. It records console commands
in the system log file.
- console message
A message sent to the system console by the system,
an application, or a user.
- constant
A fixed value (as opposed to a variable which is
a symbol for a changing valuex).
- continuation character
An ampersand (&) character entered as the
last character of a command line. A continuation character tells
the command interpreter that the command is longer than one line
and is continuing onto a second or more subsequent lines.
- continuation line
See subline.
- control character
A member of a character set that produces action in a device rather
than printing or displaying a character. In the ASCII character set,
control characters are those in the range 0 through 31, and 127. Control
characters are generated by pressing the CTRL key and a character
key simultaneously (for example D). In documentation these two-key
sequences are shown as CTRL-D.
- control codes
Special codes contained in data sent to a peripheral
device. These codes control how the device operates.
- control program
The program responsible for handling I/O for terminals
and file storage, establishing processing priorities, maintaining
waiting lists of work in process, activating operational programs,
and performing other supervisory functions in a real-time system.
Other terms used synonymously to designate such a program are driver,
executive, monitor, kernel, and supervisor.
- control register
A 32-bit register on the register file board, used
for memory access protection, interrupt control, and processor state
control.
- control unit
A part of the CPU that regulates the execution unit
and oversees the instruction cycle.
- control-Y
A break function activated by simultaneously pressing the CTRL
key and the Y key on a terminal's keyboard. It is typically a
subsystem break and does not affect MPE commands. In documentation this
two-key sequence is shown as CTRL-Y.
- COOLSTART
See START.
- coprocessor
A special purpose processor that works with the CPU to speed up
specialized operations such as floating-point arithmetic
and graphics processing.
- coupled environment
The MPE/iX file system's use of the MPE V/E file
system in compatibility mode to perform functions that MPE/iX does
not currently handle.
- CPU time
The amount of time, in seconds, that a user, group,
or account has used the CPU. It is displayed by executing the MPE
REPORT command.
- crash
The unexpected shutdown of a program or system. If the operating
system crashes, it is called a system crash, and the system must be
rebooted.
A head crash or disk crash. This occurs when the read/write heads
on a disk drive (that normally ride on a thin cushion of air above
the disk) make physical contact with the disk surface, destroying
data and the disk track. The extent of damage to the system depends
on which disk crashed and how much of the disk was corrupted. A crash
of the system disk is serious, since it contains the directory of
user files as well as operating system programs, the I/O
configuration, and the account structure.
- CRC-CCITT
An error detection scheme defined by the Comite Consultatif
International Telephonique et Telegraphique (CCITT).
- CRC-16
An error detection scheme used in data communications.
- create volumes capability (CV capability)
The ability to define and access nonsystem domain disks with the
NEWSET command of VOLUTIL.PUB.SYS (use NEWVSET command
for private volumes on MPE V/E). Users and accounts assigned CV
capability are automatically given use volumes (UV) capability.
- cursor
A flashing rectangle or blinking underline character on a display
screen. It marks the position where text or data can be entered,
changed, or deleted.
In HP SQL, the pointer to one tuple in a set of tuples from an
application program.
- customer engineer (CE)
A Hewlett-Packard field representative responsible for the
installation, troubleshooting, and maintenance of computer
hardware and operating systems.
- custom performance consulting
Using an outside performance expert to locate and evaluate
performance problems.
- cyclic redundancy check (CRC)
An error detection scheme in which the checking character
is generated by taking the remainder after dividing all the serialized
bits in a block of data by a predetermined binary number. An equal
comparison indicates no errors, while an unequal comparison indicates
an error in the transmission.
- cylinder
A portion of a disk pack that consists of vertically
aligned tracks on each disk platter within the pack. The first track
on the first platter is directly above the first track on the second
platter, which is aligned with the first track on the third platter,
and so on. These tracks, taken together, are considered a cylinder.
Therefore, cylinder 1 refers to track 1 on each of the platters
in the disk.
- daisy wheel printer
A printer that forms characters by striking metal
or plastic images of characters against a ribbon onto paper. The
name comes from the shape of the print wheel, which looks like a
daisy.
- database (DB)
A collection of logically related data files, and
structural information about the data and/or files.
- database management system (DBMS)
A software package designed to protect the consistency
and security of data in computer-stored files (databases). It allows
a user to define a database structure and manipulate the contents by
storing, retrieving, deleting, modifying, and sorting data.
- data cache
A high-speed CPU cache implemented on the 900 Series
HP 3000. It operates in parallel with the instruction cache. Data
is transferred by load and store instructions between the general
purpose registers of the execution unit and the data cache. It is
a write-to cache, so the main memory modules are updated only as
required. See instruction cache.
- data circuit terminating equipment (DCE)
Equipment used to send information between locations, such as a modem.
DCE is also known as data communications equipment.
- data communications
The transmission of information from one computer or terminal to
another. It is sometimes shortened to datacomm.
- Datacommunications and Terminal Controller (DTC)
An MPE/iX intelligent controller, with microprocessors to handle
communications with 900 Series HP 3000 systems. Each DTC may contain
connection cards allowing access to X.25 networks, as well as connection
cards allowing asynchronous device connections.
- data communications and terminal subsystem (DTS)
The methodology used to connect all asynchronous devices to a 900
series HP 3000, except for the system console.
- data dictionary
A database used as a programmer's tool to store
information about data. It does not contain the data itself, but
describes the type, location, usage, and relationships of the data
resources of an organization.
- data endpoint
The point at which the digital multiplexer interface
(DMI) data channel protocol is terminated. Data endpoints can be
at the host computer or at the PBX. Data endpoints are classified
by the physical serial interface they would present such as terminal
or communication equipment. See data circuit-terminating
equipment and data terminal equipment.
- data entry
A task that involves entering information into a computer.
- data item
The smallest accessible data element in a database. A data item
corresponds to a column in relational database terminology.
- data link layer
Layer two of the Open Systems Interconnection (OSI)
network model. The data link layer checks for and corrects transmission
errors over the physical link.
- data recovery
The process of using special utilities to recover
data that cannot be used by the operating system from disks (due
primarily to disk addressing problems).
- data segment table (DST)
A table that identifies and provides pointer information
to all data segments, including those used by MPE and user's data
stacks. On the 900 Series HP 3000 the DST is used only in compatibility
mode (CM).
- data set
A file used in a database. There are different types
of data sets: detail, manual master, and automatic master.
- data switch
A dynamic port allocator. Allows access from any
terminal to any system that is connected (see PBX).
- data terminal equipment (DTE)
The local node or the user terminal where information
enters into and exits from a data link or the computer itself.
- DBCore/XL
The common services that HP SQL uses on the MPE/iX
operating system.
- DBEFile
The basic unit of storage used by DBCore. A DBEFile
is a file on the host operating system. DBCore stores relations
in DBEFileSets.
- DBEFileSet
A logical grouping of DBEFiles. A relation can span
DBEFiles within a DBEFileSet.
- DBEnvironment (DBE)
The scope of transactions and recovery for HP SQL
databases. A DBE is a collection of one or more databases.
- deadlock
A condition that arises when multiple processes
are waiting for resources held by other processes. A process cannot
release the resources it holds until it can acquire the resources
it is waiting for, but it cannot acquire these resources until another
process releases them.
- debug
To find and correct mistakes in a computer program.
Debug/XL is the debug facility supplied with MPE/iX. It provides
debug information at the machine instruction (object code) level. It
can be used to debug programs written in any
Hewlett-Packard-supported language, both in native mode and
compatibility mode.
- decimal code
The decimal representation of an ASCII character. For example, the
character A has the ASCII binary code value 01000001
and the decimal code value 65.
- default
A predefined value or condition that is assumed,
and used if no other value or condition is specified.
- defined volume
A member volume that is not yet physically available
to a volume set, but has its name, class assignments, and space
allocation specified on the volume set information table (VSIT)
of a system master volume. See initialized volume.
- delimiter
A special character used to mark the end of a string of characters.
Common delimiters are a comma (,), semicolon (;), equal
sign (=), or a Return.
- delta
A term used to express an incremental change. Refers
to a release of the operating system with only minor changes from
the previous release.
- dereferencing
Dereferencing substitutes the value of a variable
in place of the variable name. See explicit dereferencing and
implicit dereferencing.
- descriptor
A set of data structures that collectively represent
the characteristics of an open file. The data structures contain
the file's attributes, identification, access control, and accounting
information, and are maintained by the file system routines.
- destructive testing
A deliberate attempt to cause the system or program to fail by
including a test specifically designed for that purpose.
- detail data set
A data set in a database whose entries contain one
or more search items but not a key item. Entries with the same search
item value are chained together; this chain can be linked to entries
in master data sets that have matching key item values. A detail
data set is equivalent to a child relation that does not have a
key item.
- device
See peripheral.
- device adapter
A device that manages communications between the
computer and a peripheral device. It is the same as an I/O interface
card or a printed circuit assembly.
- device address
See bus address.
- device class
A collection of devices. The MPE/iX file system
supports a means of maintaining collections of devices.
- device configuration
See system configuration.
- device file
A physical device that the system treats as a file by writing to it or
reading from it. Examples of device files are $STDIN and
$STDLIST, the default input and output device files for
the keyboard and terminal screen, respectively.
- device independence
A characteristic of the operating system that allows users to
selectively redirect input/output from a program, session, or job with
the FILE command without regard to the nature of the device.
File equations created with the FILE command are in effect only
for the duration of the job or session in which they are defined.
- device reference table (DRT)
A table containing the logical address of disks,
tape drives, and other peripheral devices.
- device subtype
A number ranging from 0 to 15, defining a specific
device and its associated software driver. There can be several
device subtypes within one basic type. For example, a graphics terminal
and one without graphics capabilities can share the same device
type, but they are assigned different subtype numbers.
- device type
Device types are defined by a number. For example,
0 represents a moving-head disk and 16 is the class type number
assigned to line printers.
- diagnostician capability (DI capability)
A capability usually assigned only to the Hewlett-Packard
customer engineer (CE). It allows the CE to conduct certain CPU
and diagnostic tests.
- Diagnostic Support Monitor (DSM)
The online diagnostic package for the Intelligent Network
Processor (INP).
- diagnostic user interface (DUI)
A means by which a user can communicate with the diagnostic
system.
- diagnostic utility system (DUS)
A set of utilities used to diagnose a system failure. The
DUS is loaded from standalone serial storage media into the main memory
of the shutdown system.
- diagnostics
A set of programs that test for hardware faults.
- dibit
A two-bit signal unit.
- digital
A method of representing all information stored,
processed, or transferred in discrete values or symbols. For example,
the set of integers constitute a set of digital values. The opposite
of analog.
- digital multiplexed interface (DMI)
A specification for interfacing a host computer
to a private branch exchange (PBX).
- digitize
To convert a continuous function to one containing
a finite number of discrete levels.
- direct access
To read from or write to a random access device
(usually a disk) by addressing a specific logical record. Direct
record access is not possible on serial storage media (such as magnetic
tapes) since data can only be read sequentially from the first record
(or byte) to the nth record (or byte).
- direct connect modem
A data communications device. A direct connect modem
has a built-in phone jack, allowing the phone line to be plugged
directly into the modem. The opposite of acoustic modem.
- direct memory access (DMA)
A technique that allows a periperals device to gain
direct access to the main memory of the computer. This method allows
extremely high data transfer rates.
- directory
A system table showing in what group or account
each file is located, as well as its disk address, so that it can
be accessed. A directory may contain other information such as size
of the file, its creation date, any modification dates, file creator,
or file security information.
- DISCFREE
An MPE/iX utility supplying information about a
system's disk free space, transient and permanent space, and the
volumes total space capacity. The information is supplied in either
a histogram or a condensed format. Equivalent to the MPE V/E FREE5
utility.
- DISCUTIL utility
An MPE/iX utility that is used primarily to recover
data from disks that cannot be used by the operating system.
- disk
A circular plate, coated with material which holds
a magnetic charge, used to store computer data. A disk may be fixed,
removable, hard, or flexible.
- disk drive
A peripheral device that reads information from
and writes information to the disk.
- disk failure
A disk-related problem that causes a disk to be
unavailable for use.
- disk file
A file stored on disk.
- disk I/O
The electromechanical process of transferring the
code and data that are stored on disk into main memory.
- disk loaded
See mounting.
- disk pack
A set of one or more disk platters stacked inside
a plastic cylindrical container.
- disk platter
An aluminum disk coated with magnetic material.
One or more platters are mounted on a central spindle, and together
they form a complete disk pack. Information may be recorded on one
or both sides of each platter within the pack.
- disk sector
A section of a disk's surface (256 contiguous bytes).
A file is stored in one or more sectors.
- disk space
The space available on a disk to store data.
- disk status
The state of a disk recognized by the system. See MEMBER,
MASTER, LONER, SCRATCH, and UNKNOWN.
- disk swapping
The process of moving data segments from memory to disk and from disk
to memory; and for moving code segments from disk to memory.
- diskette
See flexible disk.
- dismounted
A disk not recognized by the system.
- distributed database
A database whose data is located on a number of different computers,
which may be in different geographic locations.
- distributed systems
Systems in which some or all of the processing functions are in
different places and connected by transmission facilities.
- distributed system line (DS line)
The communications line between two computers, controlled
by the distributed system network.
- distributed system network (DSN)
A system of hardware and software data communications
products spanning multiple Hewlett-Packard product lines.
- dot matrix printer
A printer in which each character is represented
by a pattern of dots.
- download
The process of transferring a block of information
from one computer system to another.
- driver
In hardware, driver refers to a circuit that is capable of
supplying specific current and voltage requirements.
In software, driver refers to a program that is capable of
controlling a specific input/output device. See control
program.
- DRT number
Device reference table number. The physical I/O
address of a device controller, displayed in the second column of
the I/O configuration table listed during the SYSDUMP dialog. An
MPE V/E index into the DRT.
- dumb terminal
A terminal which can only display and transmit data.
- DUMP
The MPE/XL ISL DUMP utility writes system main memory and
secondary storage to tape. DUMP also, optionally, attempts a software
reboot from disk.
See cold dump.
- Dump Analysis (DPAN)
See dump analysis tool (DAT)
- Dump Analysis Tool (DAT)
An MPE/iX program. It produces a formatted listing
of the contents of main memory after a system failure or shutdown.
This aids in the analysis of fatal system events such as process
hangs, system failures, or hardware failures. This tool is similar
to the MPE V dump analysis program (DPAN).
- duplex
The method of transmission that allows simultaneous
two-way communication. Duplex is usually called full-duplex. The
opposite of half-duplex.
- duplicative
To echo input operations to a corresponding display without
intervention by the operating system software.
The name of an MPE/iX command that writes to $STDLIST.
- dynamic backup
Dynamic backup means that the STORE file set and
structures are accessible for any access while the backup is taking
place. Any modifications made to the STORE file set during the backup
are logged and saved along with the data on the backup medium. On
RESTORE, the data and log file are used to recover the data to a
consistent state.
- echo
What the computer does when it sends data typed
on the keyboard back to the terminal screen. If echo is turned off,
the computer receives the data, but does not send it back, so nothing
appears on the screen.
- echoplex
A mode in the full-duplex communication channel in which any character
transmitted by a terminal is echoed back to it.
- EDIT/3000
An HP 3000 text editor, supplied with MPE/iX. It
is used to create and manipulate ASCII files.
- editor
A word processing application used to prepare, modify,
or delete text and program files. EDIT/3000 is the text editor used
with MPE/iX.
- EIA 232-C
See RS 232-C.
- EIA 422-A
See RS 422.
- electronic mail
The transmission of a message from one person to
another by way of computers.
- Electronics Industries Association (EIA)
An organization that creates North American data
communication standards.
- electrostatic discharge (ESD)
The electric charge given by the release of integrated
circuits.
- end of file (EOF)
The marker that indicates the logical end of a file.
An end-of-file marker may be a control character embedded in the
data.
- end of line (EOL)
The mechanism for indicating the end of a line.
- end of tape (EOT)
A marker on the back of a tape, sensed by the tape
drive, indicating the supply of tape is running low.
- entry
An element of information in a table, list, queue,
or other organized structure of data.
- environment file
A disk file containing the formatting specifications
for a printed page of data. These specifications, which are not
part of the data, may include the page size, character fonts, forms,
and other requirements to be used in conjunction with the Hewlett-Packard
Laser Printing System.
- erasable programmable read-only memory chip (EPROM)
An EPROM chip can be programmed, erased, and reprogrammed.
- error checking code
On an MPE/iX system, the internal memory word size
is 39 bits. There are 32 bits for data and seven bits dedicated
to error detection and correction. Single-bit errors are automatically
detected and corrected ensuring data integrity. Multi-bit errors
are automatically detected resulting in a high-priority interrupt
to the system software for appropriate action.
- error listing
A report generated by the system describing the
step by step processing of the job.
- error messages
Messages describing errors that occur during either
an interactive session or a batch job. The messages are reported
to the standard list device, which is usually a terminal (for a
session) or a line printer (for a job).
- escape key
A special terminal key that is used in combination
with other characters to give those characters different functions
that modify a session or terminal. The escape key is represented
by ESC or Escape.
- escape sequences
A sequence of characters beginning with the escape
character and used to control printers, plotters, or the display
screen.
- EXCLUSIVE access
A restriction limiting file access to one user at a time.
- execute
What the computer does when it carries out the instructions
or performs the routine indicated.
- executing state
The state of a job/session, displayed when the SHOWJOB
command is executed. Possible states are INTRO, WAIT,
EXEC*, EXEC, and SUSP.
- execution unit (EU)
The part of the CPU containing the arithmetic logic unit (ALU) and the
registers. Data is held in registers and manipulated in the ALU.
- executive
See control program.
- execution unit (EU)
The part of the CPU containing the arithmetic logic
unit (ALU) and the registers. Data is held in registers and manipulated
in the ALU.
- executor
A procedure responsible for executing an operating
system command.
- explicit dereferencing
When the command interpreter encounters an exclamation point
immediately before a variable name, it substitutes the value for the
variable name. Explicit dereferencing may be used in any MPE/iX command.
See implicit dereferencing.
- expression
A statement consisting of variables, constants,
and operators.
- extended binary-coded decimal interchange code (EBCDIC)
An 8-bit code that is an extension of binary-coded
decimal (BCD) notation. EBCDIC can represent up to 256 different
characters.
- extended code segment table (CSTX or XCST)
A table containing information about code segments
that come from users' program files and those segments that are
assigned by running a program. CSTX (or XCST) is used in MPE/iX
only in compatibility mode (CM).
- extended large addressing
MPE/iX can be implemented with either 48-bit or
64-bit virtual addressing. The 48-bit addressing provides a virtual
address space consisting of 65,000 individual spaces each 4GB (four
billion bytes) in size. This is 65,000 times larger than a typical
32-bit system.
- extent
A group of one or more contiguous sectors of disk
space allocated for a single file. Extents can be variable length;
any number of extents can exist for a given file.
- external interrupt message (EIM)
A mechanism used by a module to signal to the processor
that the module has completed a requested operation and is ready
for another.
- extra data segment capability (DS capability)
A capability assigned by the system manager to users and accounts to
use extra data segments. DS capability is normally restricted to only a
few users, since allowing many processes to use extra data segments can
easily overload the system, requiring large amounts of main memory, a
large virtual storage area on the system disk, frequent disk swapping,
or all three.
- Facility/Link
An MPE communications subsystem. It allows users to access a mainframe
computer in interactive mode using a Hewlett-Packard distributed systems
network (DSN). It is usually known as Interactive Mainframe
Facility/Link.
- FCOPY
An HP 3000 subsystem that allows the user to copy,
append, translate data from one type to another (for example, ASCII
to EBCDIC), verify, and compare files. The subsystem is activated
with the MPE/iX FCOPY command.
- fiber optics
The technology of transmitting data over communication
lines made from flexible strands of glass or plastic through which
laser beams or light from light emitting diodes are passed to transfer
data. The strands are formed into cables and can carry many more
times the amount of data than traditional copper wire.
- field replaceable unit (FRU)
An assembly that is replaced when any of its components fail.
- file
A group of related records that represents ASCII text (text files) or
binary data (such as executable code). Every file must have a file name
so the user can access the file's contents.
- file access permission
The determination whether a process may perform
a requested operation on a file. Every file in the file system has
a set of access permissions. These permissions are broken down according
to whether a file may be read, written, or executed.
- file code
A four-digit integer that identifies the special
function of a file. Users may assign a file code between 0 and 1023
to a file they create to classify it according to its purpose.
- file creation time
The time when a file is created.
- file directory
A directory maintained by the system containing
each file's name, who created it, its location, and other defining
characteristics.
- file equation
A method of equating a name with a specific device
or file. This name serves as an "alias" for another device or file
whose characteristics are defined in the file equation. The MPE/iX
FILE command is used to define the file equation. File
equations are often used to direct the input to or output from a
program, job, or session to a particular device or file.
- file identifier
A number associating a name with a file system object.
For example, when you "open" a file using its name, the operating
system returns a unique number for your use. This number is the
file identifier.
- file independence
File independence means that data files are shareable
among all the Hewlett-Packard programming languages. For instance,
an HP Pascal/iX program can read files created using any of the
other supported programming languages.
- file information display (FID)
A display of file characteristics, an error message, an error number,
and current FOPEN intrinsic parameters provided when certain
file input/output errors occur.
- file label
A descriptive entry on disk containing the file name, file code,
record size, file format, current end-of-file mark, maximum number of
records, blocking factor, number of disk sectors in use, number of
extents currently allocated, and maximum number of extents. Use the
LISTF,2 command to display the file label.
- file mark
A uniquely formatted area on a magnetic tape used
to separate files. Also referred to as a tape mark.
- file name
An MPE/iX file name is a string of up to eight alphanumeric
characters, the first of which must be an alphabetic character.
- file number
An integer value assigned by the FOPEN intrinsic that is used
to refer to a file in a user program. File numbers zero through seven are
reserved for the MPE/iX operating system.
- file pointer
A logical record pointer kept by the operating system
to indicate the next sequential record to be accessed in a file.
The pointer is set to the first record when the file is opened.
- file space
The number of sectors of disk space that a group,
or account is using. It is displayed by executing the MPE/iX
REPORT command.
- file specification
The "full" name of a file. This includes the file
name, group, and account.
- file state
The condition of a file. This can include OPEN,
READY, ACTIVE, LOCKED, or WAIT. An
OPEN file, for example, is one currently being accessed
by a user or a program.
- file system
The part of the operating system that handles access
to input/output devices, data blocking, buffering, data transfers,
and deblocking.
- firmware
A set of microcode instructions that are executable
by the CPU. These are permanently stored in read-only memory (ROM)
or writable control store (WCS).
- fixed disk
A large capacity disk that is fixed inside a disk
drive and cannot be removed.
- fixed-length record
A record that always contains the same number of
characters or words. Fixed-length records within a single file are
always the same length.
- fixed space font
A typeface in which each character occupies the
same amount of space. The space between characters is uniform for
all nonproportional fonts.
- flexible disk
A random access storage device, also called a diskette
or floppy disk. Data may be written to or read from one or both
sides with a special disk drive intended only for diskettes. Flexible
disks are often used with personal computers.
- floating-point operations per second (FLOPS)
A measurement of the speed of a processor.
- foreign tapes
A tape or tapes not created on an HP 3000.
- formal file designator
The name that commonly appears on the left side
of a file equation for the purpose of redirecting input/output to
or from a file/device, or defining the characteristics of a file/device.
This is the name that processes will refer to, rather than to the
actual file or device.
- formatting
Part of a process of preparing a disk for use.
To prepare a file to be output with a certain organization.
Formatting includes such processes as setting page length and width,
specifying printing fonts, and adding headers and footers.
- FORTRAN
Formula translator. A high-level computer programming
language often used in scientific and engineering applications.
- frame
A unit of information used in packet switching.
A frame contains no more than one packet.
- frame checking sequence (FCS)
A 16-bit sequence derived from an algorithm common to
data circuit-terminating equipment (DCE) and data terminal equipment
(DTE). The sequence is appended to each frame and used as a verification
of data transmission.
- free space map
A map of allocated and available disk sectors on
the volume set.
- full-duplex
A method of transmission that allows simultaneous
two-way communication. Full-duplex is also called duplex. It is
the opposite of half-duplex.
- fully qualified file name
A complete file description that includes the file name, the group to
which the file belongs, and the account to which the group belongs. The
fully qualified file name of the LETTER file in the PUB
group of the SYS account is expressed as
LETTER.PUB.SYS.
- function keys
Special keys on the terminal keyboard that are labelled
sequentially, F1, F2, F3, and correspond to the windows that appear
at the bottom of the terminal screen. Function keys perform various
activities.
- fundamental operating software (FOS)
The programs, utilities, and subsystems supplied
on the master installation tape (MIT) for MPE/iX.
- gate
A circuit with one or more input signals to produce
a single output of binary 1 or 0 depending on the type of logic
built into it.
- gateway
A special instruction used to increase the user's privilege level
and perform a branch. It is required to access the operating
system.
In data communications, a method used to access one type of
network from another type. A gateway is a member of two or more
networks and allows communication between the networks to which it
belongs. For example, a gateway is used to go to a local area network
(LAN) from X.25.
- general register
A 32-bit register available to all processes at all privilege levels
for general computation and data manipulation.
- Glance/XL
A software product which can help in locating and
evaluating performance problems. This is equivalent to the MPE/VE
system measurement tools.
- global
A term used to define scope. A global item is widely
accessible.
- global variable
A variable whose value is valid throughout a program,
job, or session. Global is the opposite of local, which means that
a variable is useful only in a limited area.
- Governmental Agency Hardware Certification
The testing conducted for the purpose of passing
governmental agency (FCC and VDE) and safety regulations (UL, CSA,
IEC). Tests conducted include electromagnetic compatibility, conducted
emissions, radiated emissions, and various safety tests.
- group
A group is part of an account that is used to organize the
account's files. All files must be assigned to a group, and within an
account each group has a unique name. A PUB (public) group
is established for each account when it is created. Additional groups
are created within the account, as needed, by the account
manager.
For the ALLBASE/SQL group, see authorization group.
- group-level security
The file access modes, and the types of users to
whom they are available, as specified by the account manager when
the group is created.
- group librarian capability (GL capability)
Assigned by the account manager, to a user within an account. A group
librarian can be assigned special file access modes for the maintenance
of certain files within the user's home group.
- half-duplex
Communication system or equipment capable of transmission
in either direction, but not in both directions simultaneously.
The transmission flow must be halted each time the direction of
travel is reversed. This halt is called turnaround time and typically
requires from 50 to 250 milliseconds, depending upon line length.
The halt is required to reverse the direction of the echo suppressers
in the telephone line and to allow modems to stabilize. The opposite
of full-duplex.
- handshaking
A communications protocol between devices, or between
a device and the CPU. The signals indicate that information was
received, more is on the way, or it was not received correctly.
- hard copy
The output from a printer or plotter, usually onto paper.
- hard disk
A device used to store information. A hard disk
has more storage than a floppy disk without being susceptible to
the same hazards (for example, being bent or having the media corrupted
by physical handling). A hard disk generally comes in packs consisting
of several platters instead of just one. Some disk packs can be
removed from the disk drive.
- hard reset
A method to reset the computer or a terminal. A
hard reset erases all information in memory. See soft
reset.
- hardware
All the physical components of the computer, including
the CPU cabinet, tape drives, disk drives, terminals, and other
peripherals.
- hardware installation
The process of physically connecting the hardware
of a computer system together.
- hard-wired
In a hard-wired computer, the instruction set is
implemented directly in the CPU.
- hard-wired direct connection
A direct connection between a computer and a terminal or
between two computers over a relatively short distance using copper wire
pairs, coaxial cable, or fiber optics. The signals are transmitted
in digital format.
- hard-wired terminal
A terminal directly connected to the computer system
by a length of cable.
- head
The physical mechanism on a disk or tape drive that
reads data from, and writes data to, the disk or tape. The head
on a disk drive does not normally make physical contact with the
surface of the media, but the tape head does.
- header
The first page printed when output is directed to
a line printer. It contains the session name (if designated), the
session number, logon identification, day of the week, date, and
time. It corresponds to the trailer printed as the last page of
the output.
- Help facility
An online utility providing information on all MPE
commands. Information can be accessed by topic areas and tasks.
- Hewlett-Packard (HP)
A Fortune 500 company founded by Bill Hewlett and
Dave Packard in 1939. Hewlett-Packard is a producer of computers
and headquarters is located in Palo Alto, California, U.S.A.
- Hewlett-Packard Data-Link Control II (HP-DLC-II)
A Hewlett-Packard high-level data-link (HDLC) standard that defines
the elements and procedures for a balanced, bit-oriented, Level II of the
Open Systems Interconnection (OSI) model protocol.
- Hewlett-Packard Graphics Language (HP-GL)
The graphics instruction set for Hewlett-Packard
film recorders and plotters.
- Hewlett-Packard Interface Bus (HP-IB)
The HP-IB channel consists of an HP-IB cable connected to an HP-IB
interface card that is connected to the system's backplane. It performs
protocol translation between the CPU and HP-IB. For the 900 Series HP
3000 up to six devices can be connected to a single HP-IB channel. Disk
drives, tape drives, and system printers are connected by an HP-IB which
is HP's implementation of the IEEE standard 488-1975 interface.
- Hewlett-Packard Precision Architecture (HP-PA)
A computer architecture expressly designed for performance,
extensibility, and scalability. It can be implemented on low-end
and high-end computers across a complete family of computers. Precision
Architecture incorporates reduced instruction set computer (RISC)
technology in its architecture. Advantages include fewer components
and PC boards, high reliability, and small power supplies.
- Hewlett-Packard Structured Query
Language (ALLBASE/SQL)
The Hewlett-Packard relational database management system (DBMS) that
uses the industry standard Structured Query Language (SQL).
- hexadecimal
The base 16 numbering system. The first 10 digits are 0 through 9,
and the last 6 are A through F. When a number is written in base 16 it is
preceded by a dollar sign ("$"). For example, $F3 is the hexadecimal
representation for the decimal number 243.
- hierarchical topology
A point-to-point network topology. The hierarchical topology is
sometimes used with supervisory-control application, in which large
databases exist at one node, possibly along with control programs that
are accessed by nodes lower in the hierarchy. Hierarchical topologies are
also used for distributed database applications.
- High Level Data-Link Control (HDLC)
Types of protocols that eliminate much of the handshaking
(and resultant time-consuming line turnarounds).
- histogram
A graphical representation of data.
- history stack
The history stack is a CI table that contains, by default, the 20 most
recent commands entered at the system prompt during a session. The
history stack is used with the REDO and DO commands.
To display the commands in the history stack use the LISTREDO
command.
- home group
A default group, within an account, where a user
logs on when no specific group is indicated.
- host computer
A computer running a process for a user logged onto a different
computer. For example, a user logs onto system A and then uses data
communication software to start a session with system B and run a
program. System B is the host computer.
In a network, the computer that primarily provides services such
as computation, database access, or special programs or programming
languages, to other users on the network.
- HP AdvanceNet
A family of communication products, hardware and
software, that allow HP systems to communicate with each other and
with equipment made by other vendors.
- HP Desk
Hewlett-Packard's electronic mail product.
- HPSlate
An HP 3000 screen editor used to create and manipulate files.
- HPSORT
An HP 3000 utility program that sorts records in
a file(s) and then merges the sorted files.
- HP-UX
An operating system based on AT&T Bell
Laboratories' implementation of UNIX System V and containing other
features. These features include Hewlett-Packard capabilities (such
as graphics) and those from other UNIX systems, such as 4.2 BSD
from the University of California at Berkeley. UNIX is a registered
trademark of AT&T Bell Laboratories.
- HPPATH
A predefined, user-modifiable MPE/iX variable that
controls where the system searches for command and program files.
By default these files are searched for in the user's group, followed
by the .PUB group of the user's account, followed by the .PUB group
of the .SYS account.
- IF-THEN-ELSE statement
A programming statement. When the IF condition is
true, the THEN action is performed. When the IF condition is false,
the ELSE action is performed.
- implicit dereferencing
A way of substituting the value of a variable in place of the variable
name. Implicit dereferencing is used with the CALC, IF, SETVAR,
and WHILE commands. See explicit dereferencing.
- IMAGE
A network database management system. It consists
of a set of programs and procedures used to define, create, access,
and maintain a database.
- implied RUN
The ability to run a program without explicitly using the RUN
command. In MPE/iX it is not necessary to specify
RUN EDITOR.PUB.SYS to invoke and run the EDIT/3000 program. It
is only necessary to enter EDITOR.
- independent files
Files that require only single-file consistency.
- index
In database terminology, a list of the contents
of a file, with keys or references for locating the contents. An
index facilitates data retrieval.
- indirect file
A text file containing the parameters for a STORE or
RESTORE command that you execute regularly.
- INITIAL
See system generator (SYSGEN)
- initialization state
The state of a job/session when it begins to execute on its own stack.
Indicated by EXEC* when the SHOWJOB command is
issued.
- initialize
To set to beginning values.
- initialized volume
After a member volume is defined with the NEWVOL command, it
can be made physically available to the volume set by giving it a volume
label, label table, and free space map with the INITVOL command
of VOLUTIL.PUB.SYS. See defined volumes.
- initial system loader (ISL)
ISL is the software used to bring up MPE/iX or perform a memory dump
to tape. It provides a user interface to obtain information about the
bootpath or to alter the bootpath. It is used to boot MPE/iX or perform
a memory dump to tape.
- ink-jet printer
A printer that forms characters by spraying ink
through a tiny jet onto paper.
- input
The data to be processed, or the process of transferring
data from external storage to the computer.
- input/output (I/O)
The process of, or equipment used in, transmitting
information to or from the computer.
- input priority
A number in the range of 1 (lowest priority) to
14 (highest priority) assigned to input jobs. The input priority
can be assigned by the system (default is 14) or by the user. Jobs
with an input priority less than or equal to the system jobfence
(default 8) are deferred.
- INSTALL
The MPE/iX Initial System Loader (ISL) INSTALL utility
performs a system load from tape and builds essential operating
system files and data structures on disk. Equivalent to the MPE
V/E RELOAD operation.
- instruction cache
A high-speed cache implemented on the 900 Series
HP 3000. It operates in parallel with the data cache to enhance
processing efficiency. For example, data can be loaded from the
data cache while the next instruction is fetched from the instruction
cache. See data cache.
- instruction set
The set of all possible machine instructions understood
by the computer.
- instruction unit
A part of the MPE/iX CPU to control instruction
sequencing. It executes branch instructions, maintains processor
status, and handles traps and interrupts.
- integer
A data type that is either a positive or negative
whole number, or zero.
- integer value
A sequence of digits preceded by a plus sign (+), minus sign
(-), dollar sign ($), or percent sign (%).
When neither a plus sign nor minus sign is provided, a positive number
is assumed. A dollar sign indicates a hexadecimal integer and a percent
sign indicates an octal integer.
- integrated circuit (IC)
A silicon chip on which electrical connections are
etched to form electrical components. An IC may contain as many
as 100,000 gates depending on the technology used. Chips are mounted
on boards and connected to form processing and memory functions
for a computer.
- intelligent network processor (INP)
A communications input/output board used with Hewlett-Packard
data communications products.
- intelligent terminal
A terminal that can edit, perform error checking,
and respond to programmatic instructions. An intelligent terminal
may be as simple as a CRT terminal capable of block transmissions
and minor editing, or as complex as a terminal that is fully
user-programmable.
- interactive
An interactive session allows users to enter commands
and data at the terminal and receive an immediate response. Sessions
are useful for data entry and retrieval, text editing, or program
development where direct dialog with the computer is preferred.
- interactive access capability (IA capability)
A capability assigned to accounts and users allowing
users to initiate sessions with the HELLO command.
- interactive mainframe facility (IMF)
An MPE communications subsystem allowing users to
access a mainframe computer in interactive mode using a Hewlett-Packard
distributed system network (DSN).
- interactive user
A user who enters commands at a terminal.
- interface
The connecting circuitry linking the central processor of a
computer system to its peripheral devices.
Standards that allow systems to connect to each other (for
example, RS 232-C).
- interleave
A method of writing data to a disk device that improves
data access speed.
- International Association of Hewlett-Packard
Computer Users (INTEREX)
An independent organization formed for the purpose
of exchanging techniques and ideas among users of Hewlett-Packard
computers.
- International Standards Organization (ISO)
An organization established to promote the development
of standards and to facilitate the international exchange of goods
and services. ISO created the Open Systems Interconnection (OSI),
a seven-layer approach to network architecture.
- internetwork communication
Communication between networks. See catenet.
- internetwork protocol (IP)
The network services (NS) protocol based on the
Defense Advanced Research Projects Agency's (DARPA) standard. IP
is primarily used to route messages between networks using gateways.
It provides gateway-to-gateway routing, store-and-forward service
between gateways, and message fragmentation and reassembly between
source and destination networks.
- interprocess communication (IPC)
An MPE file system facility that allows processes to
communicate with one another.
- interrupt
A signal that stops the current process and demands
immediate attention (so that it gets processed).
- intrinsic
A system routine accessible by user programs providing
interface to operating system resources and functions. Intrinsics
perform common tasks such as file access, message formatting, or
data conversion.
- intrinsic call
The method used to invoke, or call, an intrinsic
from within a program.
- I/O bay
A cabinet containing the card cages and device controller
boards for peripherals connected to the HP 3000. See card
cage.
- I/O dependent code (IODC)
Contains I/O module dependent data, and code used
by processor-dependent code (PDC) in configuring the I/O module
and booting the system.
- I/O error
A data transmission error between a computer and
peripheral. Examples of I/O errors are baud rate or parity mismatch,
and incorrect syntax in device-control instructions.
- I/O interface card
See device adapter.
- I/O path
The address of the interface hardware and the physical
path to reach a device. It is constructed top down from where the
device is physically attached to the system. The path is determined
by the CIO adapter module number, the device adapter (DA) slot number,
and the device address.
- ISQL
The interactive interface to ALLBASE/SQL, the relational
interface to ALLBASE/SQL.
- job
A job is a method of submitting multiple operating
system and utility commands for processing with a single command.
Once submitted, the job executes independently of the user's session.
Jobs are used to compile source programs, modify files, or perform
other functions not requiring user interaction. See batch
processing and stream.
- job control word (JCW)
A 16-bit logical word residing in an MPE-managed
table. It's used to control command execution within a job or a
session. See variable or MPE/iX variable.
- jobfence
A limit established to manage jobs. If a job has an input priority
higher than the jobfence, it executes. If it has an input less than
or equal to the jobfence, it does not execute.
- job file
A file that contains commands that will be executed noninteractively.
A job file begins with the JOB command and ends with the
EOJ command.
- job limit
A limit set to manage jobs. The system manager or operator can
restrict system usage by limiting the number of jobs allowed to run on
the system. If the LIMIT command is used to set the job limit to
0 (zero), no additional jobs can log onto the system.
- job listing
See listing.
- job number
A system assigned identification number given to
each job when it is submitted for processing.
- job state
A generic term for the preliminary stages, excluding
initial validation, a new job or session must pass through during
its lifespan. See executing states.
- JSMAIN
An MPE/iX process that handles the logon dialog, maintains session
tables, and creates a command interpreter (CI).
- K
Kilo (1000). In computer terminology, K is commonly
a symbol representing the number 1024, or 2 raised to the 10th power.
Frequently used as a synonym for thousand.
- K file
A recovery file created by EDIT/3000, with a name in the form
Kdddhhmm, where the first three characters (ddd) show
the Julian day, and the next four (hhmm) characters show the
time in hours and minutes when work began on the file. A new K file
is created every time a new file is created or an existing file is
loaded for editing. If a system problem occurs, the data in the new or
loaded file is saved to the K file for recovery purposes.
- kernel
A set of routines in the operating system. The kernel
is the executable code responsible for overall control of the computer's
resources, such as allocating memory, creating processes, and scheduling
programs for execution. See control program.
- key
In ALLBASE/SQL, a column used in an index definition.
- keyboard
A keyboard is attached to a terminal and is a means
of inputting data to communicate with the system.
- keyed file
A file whose records can be read in logical sequence
or directly accessed by a key associated with each record.
- keyed sequential access method (KSAM)
A file access method supported on the HP 3000 (and
included with the fundamental operating software) in which records
may be accessed either sequentially or randomly by primary or alternate
record keys.
- keyword
A word assigned a specific meaning by the operating
system, a subsystem, computer language, or utility.
- keyword parameters
Words that have special meaning to the command interpreter
and are used to modify the intent or effect of an MPE/iX command.
Keyword parameters, unlike positional parameters, may appear in
any order after a command has been entered on the command line.
An entire keyword parameter group, such as PASS=password, must
be separated from other keyword parameters
by a semicolon (;).
- KSAM64
A new KSAM file type that has the ability to support
large KSAM file sizes.
- label table
A table that contains file labels for the files
residing on the volume set.
- LAN 3000/XL LINK
Provides the hardware and communications software needed to connect
900 Series HP 3000 machines to a network for system-to-system
communication.
- LAN cables
Cables used to connect the Datacommunications and
Terminal Controller (DTC) and the system. See Thick LAN
cable and Thin LAN cable.
- language construct
A command grouping (for example, IF-ENDIF) used
to control the flow of commands.
- large file
A file whose maximum file size (the file limit)
is greater than 4GB - 64KB (4,294,901,760) bytes.
- laser printer
A printer that uses a laser to produce an image on a page.
- laser printing
A method of printing in which a rotating drum has a raster image
transferred onto it by a laser. As it rotates further, it is dusted with
a fine black plastic powder called toner which adheres to the drum where
it was struck by the laser. When the drum comes in contact with the
paper, the toner pattern is transferred onto it and the toner is melted
(fused) to make the printing permanent.
- layers
The division in network architecture models. In network architecture,
different transmission and communications tasks are assigned to each
layer. Each layer is a logically distinct module. One example of layers
is the seven-layer Open Systems Interconnection (OSI) network model
developed by the International Standards Organization (ISO).
- LDEV number
See logical device number.
- library
A file containing a set of procedures that may be
accessed by programs.
- line editor
A line editor requires you to press Return to end one line of
text and to begin another. EDIT/3000 is an example of a line
editor.
- line printer
A hardware device used for system output. A line
printer prints output one line at a time.
- link
To set up pointers and table entries for a compiled
file and its libraries. This creates an executable file that allows
a program to run.
- link access protocol (LAP)
A subset of high-level data-link control (HDLC)
protocol that governs the exchanges between a user and the access
node of a public data network. LAP uses asynchronous response mode
(ARM) of HDLC and is now used in limited applications.
- link access protocol-balanced (LAP-B)
The current version of link access protocol (LAP)
that uses asynchronous balanced mode (ABM) of high-level data-link
control (HDLC).
- link editor
See linker.
- linker
A system program. It combines one or more object
programs into one program, searches libraries to resolve user program
references, and builds an executable file. This executable file
is ready for execution through the program loader. Also referred
to as link editor.
- listing
A listing is the output of a job usually in the
form of a printed document.
- load
A machine instruction requesting the CPU to take
data from memory and place it in a register.
- loading
To prepare a program for execution by allocating
primary memory and putting the job in a queue for execution.
- local area network (LAN)
A computer network confined to a single location.
For example, connecting two or more computer systems within a single
office together creates a LAN.
- local area network interface controller (LANIC)
A hardware card that fits into the backplane of
the HP 3000 and provides a physical layer for IEEE 802.3 local area
networks.
- localizable
That quality of software or documentation that facilitates
changes to the punctuation characters, key words, and command names
to fit a particular language so that applications can be used in
different countries. The user interface is in the country's native
language.
- local mode
A standalone method of terminal operation. A terminal
is operating in local mode when it is not connected to the computer.
See remote mode.
- local network
The network to which the local node belongs.
- local node
The node where you are physically located and logged
on, and at which you enter commands.
- local system console
See system console.
- local variable
A variable that appears as a UDC or a command file
parameter. A local variable is valid only in a certain section of
code. This is the opposite of global, which has value throughout
an entire program.
- LOCKED state
The status of an output spoolfile when it is being
accessed by the SPOOK utility, and is therefore unavailable for
printing.
- lockword
A word used as a security device on files. A lockword
can be assigned to a file when it is created or renamed, and must
be supplied to regain access to the file. The word may be from one
to eight alphanumeric characters long and must begin with an alphabetic
character.
- log file
A file that maintains a record of events. Each event
is recorded in a separate log record, and is correlated with the
job or session causing the event.
- logging
The process of recording all system modifications to a tape or
disk file for the purpose of recovery or accountability. If the
system fails, the log file can be used to restore the system to its
state prior to the failure.
The process used by DBCore to record the activity of a
DBEnvironment to enable either rollback or rollforward recovery
if necessary.
- logging shutdown
A shutdown marking the end of the logging cycle.
In most cases, it is performed just prior to either system or database
backup.
- logic unit (LU)
A part of the CPU that executes arithmetic statements.
A program or set of programs providing access to a network for
an end user.
- logical device (LDEV)
The logical representation of a physical device. The representation
includes a numeric identifier and a set of parameters
that define the device and its address.
- logical device number
An LDEV number is assigned to all hardware components
of a computer system and is used for identification purposes.
- logical interchange format (LIF)
A standard format for mass storage implemented on many
Hewlett-Packard computers to aid in media transportability.
- logical record
A collection of fields or related data, treated
as a unit, residing in a file. A logical record is defined in a
user program. Its length is smaller than or equal to the length
of the physical record in which it resides.
- log off
A method of terminating a session. To log off MPE/iX,
enter the BYE or EXIT command.
- log on
A method of initiating a session. To log on to MPE/iX,
enter the HELLO command and a valid user and account name, plus
a group name if necessary, and any required passwords.
- logon group
The group accessed by defining a group name when logging on using the
HELLO command. The syntax is
username.accountname, groupname. Once the desired group
is accessed, resident files may be referenced without fully
qualifying them.
- logon identity
A security device used to verify users to the system.
A logon identity includes a valid user name and account name in
the form user.account.
- logon prompt
A system prompt (MPE/iX:) that indicates the computer is
ready to initiate a session. See prompt.
- logon session
The online interaction between a user and the computer.
The session occurs between logging on and logging off.
- logon UDC
A user-defined command (UDC) automatically executed at logon.
Specified with an OPTION LOGON statement within the UDC.
- LONER
A duplicate of a member volume currently online, or a volume
recognized by MPE/iX as a member volume but without a master volume
online. The VSCLOSE command puts all master and member volumes
of a set in the LONER state.
- machine cycle
The period of time required by a computer to perform
the most fundamental operation.
- machine instruction
The smallest resolvable piece of a code segment.
Machine instructions are used by the CPU to accomplish a single
task, such as moving an item of data to the CPU, moving it from
the CPU to memory, or performing a single calculation using data
in the CPU.
- machine language
Binary code that is executable by the CPU. All programs
must eventually be translated into machine language before they
can be processed by the computer.
- magnetic tape
A data storage media that comes on reels.
- mainframe computer
A computer that generally has a large amount of
memory and operates at high-speed, servicing multiple users and/or
batch jobs.
- main memory
The fast, volatile, random access storage containing
all currently executing code and data segments, including portions
of the operating system and any utilities in use.
- maintenance word
A protection word restricting access to certain utility functions of
a database. The creator can define a maintenance word for a database or
a database space with HPIUtil and SQLUtil.
- management information systems (MIS)
A system using equipment and certain procedures
to aid the managerial decision-making process.
- manual master data set
A data set in a database containing a key item and possibly other
data items. A manual master does not have to be linked to a detail data
set. Entries in a manual master data set must be explicitly added or
deleted (compare to automatic master data set).
- mapped file
The disk files that are mapped directly into the
virtual address space memory, bypassing the file system and I/O
routines that other disk files must use.
- mapped file access
A method of transferring data to/from a disk file by implicitly using
virtual pointers and primitive LOAD and STORE
instructions, rather than by explicitly reading/writing using file system
primitives. Mapped files are accessible by obtaining a pointer to the
file that is mapped to the user's address space.
- MASTER
The state of a disk recognized by the system as
a master volume.
- master data set
A data set with one or more data items, one of which
must be a key item. A master data set is generally used as an index
to one or more detail data sets. The two types of master data sets
are manual and automatic.
- master device
A peripheral device containing the device controller
board used to control it and other slave devices.
- master installation tape (MIT)
A tape containing the MPE/iX operating system, utilities, and
subsystems for the HP 3000. It may be either a new version of the
software, a backup of the user's system, or the original installation
tape for a new site. MIT may also refer to a particular release of
MPE.
- master/slave
A relation between two processes in which one initiates
the execution of the other, and controls all subsequent communications
between them.
- master volume
A master volume is the only volume needed to define
a volume set. It contains the configuration data, the root directory,
a free space map, file label table, and a volume label with a unique
volume set ID for the volume set. See system volume.
- mean time between failures (MTBF)
A statistic that predicts how often failures will occur.
- mean time to recovery (MTTR)
A statistic that predicts how long a certain repair service
will take.
- media
Devices capable of storing data, such as disks or
magnetic tapes.
- medium attachment unit (MAU)
A device attached to a coaxial cable for a local area network. The
MAU provides physical and electrical connection from the attachment
unit interface (AUI) cable to the coaxial cable.
- megabyte
A measure of memory or storage space equal to 1,048,576
bytes of characters.
- member volume
A volume containing a volume label indicating it
belongs to an MPE/iX volume set. It may be used by one or more volume
classes.
- memory
An area of the computer's circuitry that holds applications
and any data generated with those applications. Information held
in random access memory (RAM) is erased whenever the computer is
turned off. Information held in read-only memory (ROM) is retained
even when the computer is off.
- memory dump
The contents of memory stored on disk or tape. A
memory dump is usually used for analysis and trouble shooting.
- memory error logging
A facility that records all memory errors. It begins
automatically when the system is initialized.
- memory-mapped I/O
A configuration in which each device or I/O interface
card is assigned a set of memory locations, or memory-mapped I/O
registers.
- menu
A display on the terminal screen showing the options
available within a program. Many application programs use menus
to show the options a user can select.
- message
A unit of information sent from one device or computer to another in
a form that is understandable to the receiving device.
- message file
A special type of file with features ideal for managing
messages between processes. They also allow processes in different
jobs and sessions to communicate with one another.
- metadata
A data dictionary term that means data that describes
other data.
- microcode
Directions that define machine language instructions.
Each machine instruction is a complete microprogram. Microcode directly
controls how the hardware functions. Microcode runs in a fast memory
called a control store.
- microcomputer
A small computer, based on a microprocessor, designed
to serve one user at a time.
- microprocessor
A computer chip containing the circuitry the computer
needs to interpret and execute instructions and to perform calculations.
Some microprocessors contain a small amount of memory. The microprocessor
is the heart of every personal computer.
- millicode
The 900 Series HP 3000 utilizes millicode routines
to perform some of the more frequently executed complex tasks. Millicode
routines are sequences of instructions that can be accessed and
executed very efficiently by MPE/iX.
- million instructions per second (MIPS)
A term used to measure how fast a CPU can operate.
For example, one machine might be rated to operate at 4.5 MIPS, another
at 6.7 MIPS.
- minicomputer
A medium-sized computer that can serve many users
and peripherals.
- modem
Modulator/demodulator. A device allowing communication
between computer systems. The modem converts digital signals generated
by the sending (initiating) computer into a form that can be transmitted
by telephone (modulation). At the receiving facility, the telephone
signal is reconverted into a digital signal (demodulation) and is
input to the computer.
- module
A hardware device that sits on a bus, such as an I/O interface
card. Each has its own set of memory-mapped registers to which it
responds.
Within a software context, a piece of code.
- monitor
See control program.
- motherboard
A printed circuit assembly into which circuit boards
are plugged. The motherboard provides an organized means to transmit
data and control information/power between the components and devices
controlled by the circuit boards.
- mountable volumes
See nonsystem volumes.
- mounting
The act of making a data storage device accessible.
To physically mount the device, you load the media onto the device.
To logically mount the device, you tell the operating system which
device you want to use and it allows you access to that resource.
- multileaving remote job entry (MRJE)
A distributed system network (DSN) product that
provides a link between an HP 3000 and a mainframe computer using remote
job entry communications protocol.
- multiple RIN capability (MR capability)
The ability to use more than one RIN at a time;
for example, locking more than one file at a time.
- multiplexer (MUX)
A device or interface that allows a number of separate
input or output lines to funnel into a single computer.
- multiprocessing
The appearance of simultaneous execution of two
or more processes.
- multiprocessor
A processor that can be added to the main processor
to increase computing power.
- multiprogramming
The concurrent execution of multiple programs by
a single processing unit.
- Multiprogramming Executive (MPE)
The HP 3000 MPE V/E operating system. MPE consists
of programs that handle exchanges between HP terminals, printers,
storage devices, memory, and executing programs.
- MPE/iX
Multiprogramming executive with integrated POSIX.
The operating system for the 900 Series HP 3000 computers. MPE/iX
manages all system resources and coordinates the execution of all
programs running on the system.
- multiple RINs
Allowing an account, group, or user multiple RINs (by specifying
multiple RIN (MR) capability with the ALTACCT,
ALTGROUP, or ALTUSER commands) allows users to lock
more than one resource at a time.
- multiuser mode
The state of an ALLBASE/SQL DBEnvironment that allows
more than one user to access it concurrently. The maximum number
of users is set by the maximum transactions parameter stored in
the DBECon file.
- multiuser state
The condition of an operating system in which terminals
and the system console allow communication between the system and
its users.
- multiuser system
A system that may have more than one user actively
communicating with the system when it is in a multiuser state.
- nailed device
A device permanently assigned an LDEV number.
- native language support (NLS)
MPE/iX utilities and intrinsics that facilitate
the development of applications for users in different countries.
NLS includes such features as currency symbol handling and character
translation.
- native mode (NM)
The native run-time environment of MPE/iX. In native
mode, source code has been compiled into the native instruction
set of the 900 Series HP 3000.
- network
A group of computer systems connected so that they
can exchange information and share resources.
- network administrator capability (NA capability)
A user, selected by the system manager, who is assigned to manage the
data communications subsystem at a specified location.
- network architecture
A structured, modular design for networks.
- network boundary
The division between networks in a catenet or internetwork.
- network file transfer (NFT)
A network services (NS) user service that allows you to copy files
from one node to another interactively or programmatically.
- network interprocess communication (NetIPC)
A network services (NS) user service that allows
autonomous processes running concurrently at different nodes to
exchange information in a peer-to-peer manner.
- network layer
Layer three of the Open Systems Interconnection
(OSI) network model. Network layer tasks include determining the
routes messages take to get from one node to another.
- network map
A diagram of the links, nodes, and networks in a
catenet. A network map should include node information (system type
and resources, peripherals, amount of memory, and services supported)
and linked information (location of coaxial cables, terminators,
repeaters, attachment unit interface (AUI) cables, and media attachment
unit (MAUs).
- network remote job entry (NRJE)
A facility to provide batch systems network architecture
(SNA) communications. SNA NRJE allows users to transmit large batch
jobs and files from an HP 3000 to an IBM mainframe for processing
and to receive output and files from an IBM mainframe.
- network services (NS)
Network services (NS) software products provide
user interface to the network. They allow batch job submittals,
file transfers, virtual terminal access, and other services.
- $NEWPASS
Temporary file created automatically, typically
during compiling, to which newly generated compiled code is written.
This is a system-defined file and only one may exist during a single
job or session. When this file is closed, its name changes to
$OLDPASS.
- node
One end of a communications link or a computer system
in a network. For example, if two HP 3000 computers are connected
by a DS line, each system is considered a node.
- node manager capability (NM capability)
A capability assigned to users allowing them to
control communication subsystems at their node.
- node name
A string of up to 31 characters, not including control
characters or spaces, that uniquely identifies a node in a network
or internetwork.
- noise
Undesirable signals on a communication channel.
Noise can interfere with or distort data signals.
- nonremovable disks
Disks that cannot be removed from the disk drive.
- nonshareable device capability (ND capability)
A capability assigned to accounts and users allowing
account members to own nonshareable devices such as unspooled printers,
serial disks, private volumes (on MPE V/E), and foreign disks.
- nonsystem volumes
Volumes that do not need to be mounted for the operating
system to run. Also called mountable volumes. These volumes are
equivalent to MPE V/E private volumes.
- NS Common Services
A group of network services including network file
transfer (NFT), network interprocess communication (NetIPC), remote
process management (RPM), and virtual terminal (VT).
- $NULL
Temporary file that is empty when used as input and meaningless when
used as output (the output essentially disappears into what is referred
to as the bit bucket). When referenced as an input file
by a program, that program receives only an end-of-file mark upon first
access. When referenced as an output file, the associated write request
is accepted by MPE/iX but no physical output is actually performed.
$NULL can be used to discard unneeded output from an
executing program.
- null value
A value consisting only of binary zeros. Null values
are neither blanks nor ASCII zeros. They do not print.
- object code
Machine executable instructions. Object code is
the result of source code compilation.
- octal
The base eight numbering system, in which digits
0 through 7 are used. One octal digit can be represented by three
binary digits. Octal numbers are preceded by a percent sign (for
example, %775).
- offline state
The condition of a device when it is not available
to the system, for example, not under the direct control of the
CPU.
- $OLDPASS
Temporary file created automatically when compiling
is complete. It is used to hold compiled code. This is a system-defined
file and only one may exist during a single job or session. This
file results when the $NEWPASS file closes.
- online state
The condition of a device when it is available to
the system. An online device allows the user to interact with the
system.
- open
The act of obtaining access to a resource.
- OPEN state
The state of a file when it is being accessed by a user program or
MPE/iX. An OPEN input spoolfile occurs when data is being
collected from the input device (usually a terminal or tape drive). An
OPEN output spoolfile is the disk file being created
by the output spooler.
- Open Systems Interconnection (OSI)
A seven-layer network architecture model developed
by the International Standards Organization (ISO). In the OSI model,
transmission and communication tasks are assigned to logically distinct
modules called layers. Each layer communicates with the layer directly
above and below it, and through the layers below it to its peer
in the remote computer. The OSI model defines the seven layers as
the following:
1. physical,
2. data link,
3. network,
4. transport,
5. session,
6. presentation,
7. application.
- operating system
The software that operates the computer. It consists
of programs such as basic file and I/O manipulators. All subsystems
run upon the operating system.
- operator command
MPE/iX commands executed at the system console by the system operator.
Operator commands may be distributed to specific users at the operator's
discretion with the ALLOW, ASSOCIATE, and
JOBSECURITY commands.
- OPERATOR.SYS
The user and account that MPE/iX automatically logs on to at the
console when the system is started. OPERATOR.SYS may or may not
be assigned special capabilities. Unlike the system supervisor (who is
assigned OP capability), or the system manager (who is assigned SM
capability), there is no mnemonic that entitles the operator to execute
a special subset of commands. The operator's power and responsibilities
derive solely from control of the system console and any capabilities
assigned to it by the account manager of the SYS
account.
- optimizing compiler
A sophisticated compiler that intelligently translates high-level
language programs to object code by removing inefficiencies and
unnecessary instructions. With an optimizing compiler, a program
generally runs faster and uses less memory.
- optional parameter
A parameter that is not required when entering a
command or calling an intrinsic. In reference manuals, optional
parameters are surrounded by square brackets ([ ]).
- original equipment manufacturer (OEM)
A manufacturer of equipment that may be marketed
by another manufacturer.
- outclass priority
A value in the range of 1 to 13 used to determine
if a job's error listing prints. If the outclass priority is higher
than the system outfence, the error listing will print.
- outfence
The system outfence is a number in the range of
1 (lowest priority) to 14 (highest priority), used to control access
to the system printer. If a job does not have an output priority
higher than the system outfence (default 7), it does not print.
- output
Data transferred from internal to secondary (external)
storage in a computer. Also, the process of transferring information
from the computer to a peripheral device.
- output priority
A number in the range of 1 (lowest priority) to
13 (highest priority) assigned to an output spoolfile either by
the system (a default value) or by a user. If the output priority
is higher than the system outfence, the job's output prints.
- overflow
To exceed the capacity of a register or buffer's
storage space. When an overflow occurs, the excess data is lost.
- overwrite
To replace a disk file. If a file is saved under
a name that already exists on a disk, the new file overwrites the
old file.
- owner
In ALLBASE/SQL the user ID, group, or class name
that owns a table, view, module, or group.
- pack
A set of one or more disk platters stacked inside
a plastic cylindrical container. A pack is usually called a disk
pack. A disk pack stores data.
- packet
A unit of information passed between Levels II and III (data link
layer and network layer) of the Open Systems Interconnection
(OSI) model.
- packet assembler/disassembler (PAD)
A device that converts asynchronous character streams into packets
that can be transmitted over a packet-switching network.
- packet switching
A data communications transmission technique. Long messages are
divided into smaller packets and sent on a dynamically
allocated path to their destination.
- packet switching network
Refer to value added network.
- page
In MPE/iX a page is defined as a set of 2048 contiguous
bytes (2KB) that is used as the basic unit for memory mapping. All
swapping is done in multiples of pages.
- parallel devices
A set of backup devices to which you are able to
store information simultaneously.
- parallel interface
An interface type in which a separate line is used for each data bit
in a byte or word, and all of those bits are transferred
simultaneously.
- parameter
A value in a list of values that is passed to a
procedure. The parameter is used in calculations or operations in
the procedure.
- parent process
An existing process that creates a subsequent process,
thereafter known as the child process. A parent process may create
one or more child processes.
- parity
In computing, the condition of a bit being odd or even.
- parity checking
A form of redundancy checking during data transmittal.
An odd or even parity for a particular receiving device is selected.
The sending device checks the value of the parity bit to make sure
it's the appropriate parity for the receiving device. If the parity
is not correct, the sending device adds a 1 to the bit. The receiving
device then checks the parity of the incoming data, indicates any
parity errors, and requests retransmission of data, if necessary.
Parity checking detects the loss, or unwanted inclusion, of an odd
number of bits.
- parser
A routine that subdivides an instruction, command,
or programming statement into components that the computer system
can more easily understand and use.
- partitioning data
See subdividing data.
- Pascal
A computer language that is used for many types
of applications. It is a very flexible language that is useful when
different structures of data types are needed.
- password
A string of ASCII characters required for a user
to log on to a particular group or account. Passwords are associated
with users, groups, and accounts.
- patch
A piece of software code that corrects a defect.
- path
The course within a computer that a message takes,
typically through software protocol handlers.
- performance tuning
Essentially is a matter of locating a bottleneck
and then eliminating or reducing it.
- peripheral
A hardware device attached to and controlled by a computer, such as
a terminal, a tape or disk drive, or a printer.
- permanent file
A disk file that continues to exist even after a job or session logs
off. To delete the permanent file, it must be erased from the system with
the PURGE command or with the FCLOSE
intrinsic.
- permanent space
Disk space reserved for use by permanent structures
such as files, the label table, or the free space map.
- personal computer (PC)
A portable microcomputer usually sold with software packages
useful in word processing, financial management, storing lists, and
other general usage business/personal activities.
- physical layer
Layer one of the Open Systems Interconnection (OSI)
network model. The physical layer transmits the electrical signals
over the link.
- physical record
One or more logical records, treated as a unit when transmitted to or
from devices. The number of logical records contained in a single block
is determined by the blocking factor, specified when the file is first
created with the BUILD command or the FOPEN
intrinsic.
- physical unit (PU)
In systems network architecture (SNA), the component
that manages and monitors the resources of a node.
- pipelining
A computer design technique that gives an effective
execution rate of one instruction per cycle. Pipelining exploits
the fact that it is not necessary to wait until one instruction
has completed before the next can begin. Fetch, execute, and load/store
instructions can be executed on a three-stage pipeline.
- pixel
A contraction for picture element. Any of the tiny
elements that form a digitized picture such as on a CRT screen.
Each pixel represents the degree of brightness assigned to a point
in the picture.
- platter
A single disk coated with magnetic material. One
or more platters are mounted on a central spindle, and together
they form a disk pack. Information may be recorded on one or both
sides of each platter within the pack.
- pointer
The address of a piece of data or a data structure
used by the programmer in data manipulation.
- point-to-point network
A network in which communication travels from one
node (point) to another by a unique, unshared physical link. The
opposite of broadcast bus network.
- polling
In electronic mail or data communications, the systematic
calling of terminals to determine if messages are waiting to be
transmitted or if the terminal is ready to accept messages.
- port
An outlet from the computer used to connect the
computer to peripheral devices. A cable runs between the outlet
and the device.
- positional parameters
One or more terms, appearing in a specific order
on the command line, that modify the intent or effect of the command.
If a positional parameter is omitted, the user must supply a comma
in its place.
- power down
To turn the system power off.
- power up
To turn the system power on.
- Precision Architecture
Refer to Hewlett-Packard Precision Architecture.
- preprocessor
A component of the ALLBASE/SQL relational interface
that converts code containing SQL commands into code compatible
with the source code language.
- presentation layer
Layer six of the Open Systems Interconnection (OSI)
network model. Presentation layer tasks include manipulation of
user data such as text compression and encryptions.
- preventive maintenance (PM)
The regular housecleaning chores performed to keep the
system from suffering performance degradation and to prevent problems
from developing on the system.
- primary boot path
The primary boot path is used to boot the system
from disk resident software. See boot path.
- printed circuit assembly (PCA)
An I/O interface card. Refer to device adapter.
- priority request
The use of the optional parameter ;HIPRI in the
HELLO and JOB commands. This capability, granted to
system supervisors and system managers, allows a job to be dispatched or
a session to be initiated, overriding the current jobfence or execution
limit.
- private branch exchange (PBX)
An installed telephone exchange at a given site.
A PBX may be upgraded to handle computer data traffic.
- private volumes
See removable packs (MPE V/E only).
- privileged mode capability (PM capability)
A capability assigned to accounts, groups, or users allowing
unrestricted memory access, access to privileged CPU instructions,
and the ability to call privileged procedures. This capability overrides
MPE/iX safeguards.
- process
The unique execution of a program or procedure by
a particular user at a particular time. If several users execute
the same program, each is a separate process. Similarly, if the
same user runs several programs, each execution is also considered
a distinct process.
- process control block (PCB)
A main-memory resident table containing status information for each
process running on the system such as monitor memory management,
dispatching, the stack number, what extra segments a process is using and
their location, whether the process is waiting for a resource or waiting
for a response from another process, and other information.
- process group
A collection of processsing its name, the operating
system returns a unique number for your use. This number is the
file identifier.
- process handling capability (PH capability)
A capability optionally assigned to accounts, groups,
and users, allowing a currently executing process to create other
processes. PH capability also allows process suspension, interprocess
communication, and process deletion. Since the proliferation of
processes results in heavy system resource usage, PH capability
is typically restricted to only a few users.
- process identification number (PIN)
A number assigned to a process by MPE/iX when the
process is created. It is used internally in the process control
block (PCB) table, and during requests for system resources at the
console (when the operator responds to requests by referencing the
PIN in the REPLY command).
- process local file descriptor table
The table containing the file descriptors for each process.
There is one table per process.
- processor-dependent code (PDC)
An MPE/iX hardware routine to read and initialize the
I/O paths used for booting or rebooting the system.
- processor status word (PSW)
Processor status words control the order of instruction execution
and contain various information about the state of a process.
- program
A sequence of instructions that tells the computer
how to perform a specific task.
- program counter (PC)
A pointer in memory that points to the instruction
to be executed.
- programmable read-only memory (PROM)
A PROM chip contains programs that remain permanently
in the computer.
- programmatic sessions capability (PS capability)
A capability allowing a user to execute the STARTSESS command
and to call the STARTSESS and ABORTSESS
intrinsics.
- program-to-program communications (PTOP)
A network service that allows programs residing
on different nodes to exchange information with one another in a
master/slave relationship.
- prompt
The character(s) displayed at the terminal screen indicating that the
system is ready for a command. The MPE/iX command interpreter's prompt
may be changed by the user. The default value is a colon (:).
Subsystems have different prompts.
- protocol
A set of rules that enables two or more data processing
entities to exhange information. In networks, protocols are the
rules and conventions that govern each layer of network architecture.
They define what functions are to be performed and how messages
are to be exchanged.
- PUB group
A group, created when an account is created, whose
files are usually accessible to all users within the account.
- public data network (PDN)
A networking service. It fulfills all communications needs between
the host computer and other processes and terminals.
- PUB.SYS
The public group of the system account.
PUB.SYS is where programs and applications available to
all users of the system reside.
- purge
To delete a permanent file from the system with the PURGE
command. The PURGE command is also used to delete an account
structure entry such as a user name, group name, or an account.
- query
A data retrieval request.
- queue
A list that allows additions at one end and deletions
at the opposite end. Items in a queue are usually processed on the
first in, first out (FIFO) principle, in that the first item entered
is the first item to be processed. For example, the output produced
by a program is generally stored on disk in a queue until a printer
becomes available. As each output is printed the next in priority
is selected and processed.
- quiet mode
A session mode in which messages sent from other jobs or sessions to
a terminal are not displayed. Users control quiet mode with the
SETMSG command. To determine who is running quietly, execute the
SHOWJOB command. Those sessions not receiving messages are
indicated by the word QUIET in the third column of the listing.
A WARN message from the system console overrides quiet mode and
should be used for all critical communication, such as
informing the user of an impending system shutdown.
- random access
The direct access to data stored in a device. For
example, if a user or program requires the 17th record in a file
stored on random access media, that record may be selected for the
read/write operation without scanning the preceding 16 records.
Typical random access storage devices include main memory and disk
drives.
- random access memory (RAM)
A part of memory that contains information that is temporarily stored
in the computer. When the computer is turned off, random access memory
is erased. The opposite of read-only memory.
- read
To request and accept input data from a source.
- read-only memory (ROM)
The memory used for storing firmware. A ROM contains information
that cannot be modified and is not erased when the computer is turned
off. The opposite of random access memory.
- ready state
The condition of an input spoolfile when it is available for access by
the spooler program or user. READY output spoolfiles are
complete files waiting to be printed. They may also be manipulated with
the SPOOK utility.
- real time
An operating system feature that enables it to react
very quickly to external and internal events as they occur.
- record
A collection of fields or related data treated as
a unit, residing in a file. A contiguous group of bytes whose structure
is known by the file system.
- recognizing a disk
See mounting.
- record width
The amount of data that is transmitted to and from
a device at one time. For example, the standard record width for
terminals is 80 bytes. The record width for disk devices is 128
words.
- recursion
The ability of a procedure or function to call itself.
- redo file
An MPE/iX disk file containing the commands entered
by the user.
- reduced instruction set computer (RISC)
A computer whose architecture features a simplified,
hard-wired instruction set.
- register
An area in the CPU used for storage or mathematical
operations.
- relation
A data structure having a table-like format; also
referred to as a table in relational terminology.
- relational
A type of data model (offered by Hewlett-Packard
as ALLBASE/SQL) that stores data in independent two-dimensional
tables, thus increasing access and restructuring flexibility.
- relative I/O (RIO)
A direct file access method that allows individual
records to be deactivated. These inactive records remain on disk,
but are ignored in a logical read operation.
- relative record number
A number representing the position of a logical
record in relation to the first record in the file. The first record
is numbered either 0 or 1, depending on the subsystem or utility
being used.
- RELOAD
To coldload the entire HP 3000 system, including
all MPE files, the accounting structure, I/O configuration tables,
and user files from the backup medium. A RELOAD is normally used
when no other coldload option has succeeded. MPE/iX equivalent is
the ISL INSTALL utility.
- relocatable binary module (RBM)
The smallest unit of output from a compiler. The compiler
determines how RBMs are separated and their content may vary depending
on the compiler used. Data constants are stored in the RBM along
with the code and are non-modifiable.
- remote database
A centrally located database which users throughout
a network can access and update.
- remote job entry (RJE)
A Hewlett-Packard program, executed with the RJE
command. It provides an interface between the HP 3000 and other
computers using the IBM 2780/3780 communications protocol. RJE makes
the HP 3000 appear to be either an IBM 2780 Data Transmission Terminal
or 3780 Data Communications Terminal to the host system, and provides
a complete multiprogramming environment.
- remote mode
A mode in which a terminal transmits and receives
data from a remote (or host) computer.
- remote network
Any network in the catenet to which the local node
does not belong.
- remote node
A node that is not physically located where you
are and which you communicate with using data communication.
- remote session
A session on a different machine.
- remote system
A computer system physically separated from other
computer systems.
- remote system console
A terminal that provides remote access to the SPU
as a system console or terminal session.
- remote terminal
A terminal that is indirectly connected to the computer,
using a modem and telephone hook up.
- removable disk
A disk that can be removed from disk drives and
transported to another disk drive.
- removable packs
See private volumes.
- repeater
A data transmission device used to amplify a signal.
- report
A display of information about accounts, groups, and users, generated
with the REPORT command. The information, listed in columns,
contains both the current value and maximum limit for file space (in
sectors), CPU time (in seconds), and connect time (in minutes). System
managers may report on all groups in all accounts; account managers may
report on all groups in their own account; standard users may report on
only their logon group.
- report program generator (RPG)
A computer programming language designed to provide
report-writing functions.
- required parameter
A parameter that is required when entering a command
or calling an intrinsic. In reference manuals, required parameters
are surrounded by braces ({}).
- rerouting
Ability to reroute messages around inoperative links
in a network.
- resolution
A measure of image sharpness; it can be expressed
as a number of lines or pixels per unit length.
- resource
Any device or item used by a computer, for example,
I/O devices, disk files, or programs.
- resource identification number (RIN)
A number identifying a user-defined resource. Users
are normally allowed to lock only a single RIN, which means they may
have exclusive access to one resource at a time, such as an I/O
device, a file, or a program.
- resource sharing
A network that makes elements at each node accessible
from other nodes in the network. These elements may include disk
files, printers, magnetic tapes, terminals, and other programs.
- response center support (RCS)
An HP support agreement coverage that provides telephone
assistance with software usage and problems.
- restricting data
A way of limiting access to data by grouping data
into volumes, volume classes, and volume sets.
- restore
The process of retrieving user files from tapes
or serial disk and writing them to disk. Restoring is executed with
the RESTORE command.
- resume
To restart execution of a procedure or program after
it has been suspended.
- ring
A point-to-point network topology. The ring is a
string topology with an additional link between the end nodes. The
store-and-forward delay is half that of a string topology because
the maximum number of intervening nodes is halved. The ring topology
is suited for accessible from all nodes. Ring networks are less
vulnerable than string networks. If any one link fails, all the
nodes can still communicate by rerouting around the failure. The
opposite of string.
- rollback recovery
In ALLBASE/SQL and IMAGE database management systems,
a process that ensures all completed transactions are made permanent
and that all incomplete transactions are undone.
- rollforward recovery
A database process that reconstructs a DBEnvironment (ALLBASE/SQL)
or database (IMAGE) from backups by processing completed transactions
from a log file.
- route
The course through the network that a message takes
from a source node to a destination node. A route can pass through
intervening nodes.
- row
In ALLBASE/SQL a single occurrence of one or more
columns in a table.
- RS 232-C
The "recommended standard" electrical interface
(American National Standards Institute specification) for communication
among computers and peripherals, such as terminals and printers.
This standard specifies mechanical and electrical requirements.
It uses a standard interface in a data communications network, with
lettered pin assignments for ground, data, control, and timing circuits.
The data signaling rate is from 0 to 20,000 bps in bit-serial operation,
synchronous, and asynchronous.
- RS 422
A "recommended standard" for balanced voltage digital interface
circuits. It is used between data terminal equipment (DTE) and data
circuit-terminating equipment (DCE) or as a point-to-point
interconnection of serial binary signals between digital equipment. The
data signaling rate is up to 10 Mbit per second (Mbps).
- run
To execute a program.
- run time
The time a program is run.
- save files capability (SF capability)
The capability allowing users to save the files they
create. It is assigned by default to accounts and users.
- savepoint
A place within a DBCore transaction to which you can rollback
(partially undo) then continue with same transaction.
- scaling
To divide the graphics area into units convenient
for your application.
- scanner/parser
A routine that subdivides an instruction into components
that the operating system (or another subsystem) can more easily
understand and use.
- scratch a volume
To make data unavailable on a volume so that the volume can be
reinitialized. In effect, to delete data on a volume.
- scratch tapes
Used tapes containing information that is no longer needed.
- SCRATCH volume
A volume whose data is no longer needed that has been marked as
available for a new volume or volume set. The SCRATCHVOL command
marks the volume. The UNSCRATCHVOL unmarks the volume without
losing any data or label information, provided the disk has not been
written to.
- scrolling
The act of adding a new line of data to a video
terminal's screen by adding it to the bottom of the screen and shifting
all previous lines upward.
- search path
An MPE/iX mechanism that controls which file is opened once a command
is determined not to be a UDC nor an MPE command.
- sector
A portion of a track on a disk, and the smallest
addressable piece of the disk. MPE-formatted disks use 128-word
sectors (256 bytes).
- security
The provisions that prevent unauthorized users from entering the
system, accessing data, or using resources, programs, or
capabilities.
The provisions included in MPE to protect the system from
unauthorized use. MPE offers several means to create a secure
environment. The most basic level of security includes organizing
files into groups and users into accounts, either of which may be
assigned a password. Security also refers to the ability to read,
write, append, lock, and execute files, optionally assigned to
accounts by the system manager and to groups and users by the account
manager.
- segmented library (SL)
A file containing code segments that are shareable, general-use MPE,
utility, and subsystem procedures not unique to a particular process.
The three levels of segmented libraries are: LIB=G (group library), LIB=P
(public library), LIB=S (system library). G, P, and S refer to the
location of the CM program being run. If
program.group.account is run with LIB=G, then
SL.group.account is used. If
program.group.account is run with LIB=P, then
SL.PUB.account is used. Otherwise,
SL.PUB.SYS (LIB=S) is used. The SL resolves external procedure
calls not contained in the program itself. The group SL is available
to any user who can access the group; the public SL is available
to all account users; and the system SL is available to all system
users.
- segmenter
A subsystem of the MPE V/E operating system that
performs all execution. Its primary function is to gather and link
into segments most of the resources needed to form an executable
program file.
- self-clocking data
The transmission of data when the clock information
is part of the data.
- separator
A symbol that separates the parameters of an instruction.
Some examples of separators are commas, spaces, and semicolons.
- sequential
The order (ascending or descending) in which data
items are physically stored and accessed.
- serial
See sequential.
- serial disk
A serially-accessed disk that is configured as a
magnetic tape. Flexible diskettes, disk packs, and cartridge tape
(MPE V/E) may all be used as serial disks. They are designed to
store system data (backups), load subsystems, and to perform standalone
CPU and non-CPU diagnostics.
- serial interface
A single data line that transfers data bytes sequentially
between devices.
- server
A node unit of a network that provides a specific
service to network users.
- session
A mode in which the HP 3000 is used interactively by entering commands
and data through a terminal's keyboard and receiving immediate responses
to input. A session is initiated with the HELLO command. A
session is ended with the BYE command, or a second
HELLO command that logs the user off the first session
and onto another session.
- session layer
Layer five of the Open System Interconnection (OSI)
network model. The session layer provides the means for cooperative
presentation entities to organize and synchronize their dialog and
manage their data exchange.
- signal
The software interrupt sent to processes, informing
them of special situations or events.
- simplex
The operation of a channel only in one direction,
with no reverse capability.
- single-cycle execution
Simple, hard-wired instructions that are efficiently
pipelined to allow RISC architecture to execute an instruction on
virtually every machine cycle.
- single file consistency
Single file consistency is the preservation of the
internal state of a file. The backup system ensures that a file
is in a logically consistent state before it stores the file.
- single-user mode
A DBEnvironment startup mode that allows only one
DBE session to be active at a time.
- single-user state
A condition of the MPE/iX operating system in which
the system console provides the only communication mechanism between
the system and its user.
- single-user system
A system that can communicate with only one fixed terminal.
- slave device
A peripheral device not directly connected to the
HP 3000. A slave device does not have its own device controller,
but instead is controlled through a master device.
- small computer system interface (SCSI)
A SCSI is an interface designed to connect small
computer systems to devices such as disk storage, printers, and other
peripherals.
- softcopy
The display on a video terminal. The opposite of hardcopy.
- soft reset
A reset that initializes a variety of terminal functions
but does not reset the memory. Refer to hard reset.
- software
A set of programs, instructions, rules, and procedures concerned with
the operation of a computer. The opposite of hardware.
- software dump facility (SDF)
A facility that gives the system operator the capability
of writing all main memory to a serial storage medium. It operates
in a standalone environment (without MPE/iX), and is used following
a system failure or a system halt.
- Software Status Bulletin
A Hewlett-Packard publication supplying customers
with information on Hewlett-Packard software enhancements.
- source code
One or more files containing the language used by
programmers to write a program. It must be compiled into machine-readable
data (object code) before it can be executed by the computer.
- span
To spread related data across volume sets.
- spoolfile
A file awaiting printing. This file can reside on disk or can be moved
to tape. A spoolfile may be either OPEN, ACTIVE,
READY, or LOCKED. These states describe different
stages of the spooling process depending upon whether the file is an
input or output spoolfile.
- spool
SPOOL is an acronym for "simultaneous peripheral operations online".
Spooling allows many processes to simultaneously
write output for a single printer.
- spreadsheet
A program that allows the user to enter data into
row and column positions (known as "cells"). A spreadsheet program
provides mathematical manipulation of the values in the cells.
- stack
A data structure in which items are added at the
end of a sequential list and can only be retrieved from the same
end.
- standard input
A system-defined file that provides input for programs.
This file can be a device (for example, a keyboard or printer),
or an actual data file. The formal file designator for standard
input is $STDIN or $STDINX.
- standard output
A system-defined file that holds output from a batch
job (including the job statements and error messages). This file
can be a device (for example, a terminal screen or printer), or
an actual file. The formal file designator for standard output is
$STDLIST.
- star network
A point-to-point network topology. The star topology
is often used for centralized data collection or supervisory control.
It is also used when a central node has a large database or control
program that is accessed by the other nodes. In a star network,
there is at most one intervening node between any two nodes. Star
networks are vulnerable to failure of the central node. If the central
node fails, no network communication is possible.
- START
An initial system loader (ISL) utility, and its
options, used to start the system from disk, building the system
data structures. This utility is used to recover from a hang or
failure or to reboot the system after scheduled downtime. The
START RECOVERY option is equivalent to the MPE V/E WARMSTART
procedure, and the START NORECOVERY option is equivalent to
the MPE V/E COOLSTART procedure.
- static backup
Backup is static when the files and structures are
inaccessible during the time that they are being stored. That is,
they are locked exclusively by the backup subsystem.
- status bits or words
Bits (or words, if status words are used) that indicate
the condition of a device. The status bits or word can be checked
by a program or microcode and, based upon the value, a specific
sequence of instructions executed.
- $STDIN
A system-defined file name referring to the standard input "file"
(which can be an actual file or a device). $STDIN often refers to the
keyboard for interactive sessions and a file for batch jobs or programs.
$STDIN treats a colon (:) appearing in the first column
of input data as an end-of-file. See standard input.
- $STDINX
Same as $STDIN. However, unlike $STDIN,
$STDINX treats the colon (:) prompt appearing in the
first column of input data as part of the data file, rather than an
end-of-file indicator.
- $STDLIST
A system-defined file name referring to the standard output "file"
(which can be file or a device). $SDTLIST often refers to the
terminal for interactive sessions and the printer for batch jobs.
See standard output.
- stop bits
When two computers communicate information over
an asynchronous connection, the sending computer adds one or more
stop bits to the end of each byte that it sends. The stop bits tell
the receiving computer that an entire byte has been sent and that
a separate byte is on its way.
- storage device
A device (such as a disk pack, a disk cartridge,
a flexible disk, magnetic tape, or cartridge tape) onto which data
can be stored and subsequently retrieved.
- STORE
The process of saving HP 3000 files to tape or serial disk.
Storing is executed by using the STORE command.
A machine instruction that tells the CPU to take information from
a register and put it in memory.
- store-and-forward
A method of forwarding messages in a network. In
a store-and-forward network, a node can send a message to another
node to which there is no direct link. Intermediate nodes can forward
the message to the correct destination node. Messages can be stored
and forwarded between several nodes.
- stream
To execute a batch job by using the MPE
STREAM command.
- stress testing
To test a system by executing a maximum load, over
time, to verify that the system will continue to operate given maximum
levels of interactive and batch processing.
- string
A point-to-point network topology. The string topology
requires fewer communication links than there are computers in the
network, and requires the fewest number of links. For communication
between non-adjacent nodes, messages are stored and forwarded by
intervening nodes. If a link fails, the nodes separated by the failure
are not able to communicate.
- Structured Query Language (SQL)
The industry standard relational database language.
- subdividing data
A way of limiting access to data by grouping data
into volumes, volume classes, and volume sets.
- subline
A portion of the command line that occurs only if
the command was continued on the input line by terminating it with
an ampersand. Also referred to as a continuation line.
- subqueue priority
The priority of a job, session, or system process,
with the five system queues (A, B, C, D, or E). The subqueue priority
determines the priority of CPU usage. A lower subqueue priority
indicates a higher priority for CPU time.
- subsystem
That part of the operating system that performs
specific functions for applications (for example, IMAGE database
management system).
- supervisor
See control program.
- swapping
See disk swapping.
- switch subsystem
The MPE/iX switch subsystem determines whether code
is in native mode or compatibility mode, and automatically switches
between modes as needed while an application is running.
- synchronous
A method of transmitting data using a clock signal
to coordinate timing. The opposite of asynchronous.
- synchronous data link control (SDLC)
The protocol used in a systems network architecture
(SNA) network to transmit data over a communications link. SDCL
is a bit-oriented protocol that transmits data in frames.
- syntax
The rules governing the structure of a language or
instruction.
- syntax error
An error in an instruction due to a misspelled word,
a missing character, or improper punctuation.
- SYS account
A special account on the HP 3000, included with
the system when it is first installed. It contains all MPE files
(stored in the segmented library), supported subsystems, utility
programs, and compilers.
- system
A group of one or more CPUs that communicate through
buses without the use of data communications software.
- system asynchronous I/O
A method of performing I/O whereby a process informs
a driver or subsystem that it wants to know when data has arrived
or when it is possible to perform a write request. The driver or
subsystem maintains a set of buffers through which the process performs
I/O. System asynchronous I/O frees the process's buffers upon return
from the I/O request.
- system buffers
Any buffer used by the system to send messages to
the console.
- system call
An operating system kernel function available to
the user through a high-level language (such as COBOL, FORTRAN,
or Pascal). Also referred to as an intrinsic or
a system intrinsic.
- system catalog
A file containing UDC information for each user
and accounts using UDCs on a particular system.
- system configuration
The process of defining for the operating system
the current physical layout and workload of a particular installation.
The configuration is typically modified when new terminals, another
line printer, or a disk drive are added. The system also may be
reconfigured to assign new class names to existing devices, change
the size of the system tables or virtual memory, modify system logging,
or alter any other configuration parameter.
- system console
The terminal, usually logical device 20, the system
operator uses to monitor system activity, respond to resource requests,
and send messages to users' terminals. The console (and most of
its associated privileges and responsibilities) may be transferred
to another logical device with the CONSOLE command.
- system control panel
A panel on the computer, containing control switches
and status indicator lights.
- system crash
See crash.
- system-defined files
The files defined by MPE and made available to all
users to indicate standard input or output devices, special temporary
files, and files opened for output that do not perform an actual
write operation.
- system directory
A directory maintained by MPE that records the name,
group, and account of each permanent file on the system. The directory
contains the size of each file, its location on the disk, who may
access it, and other information.
- system disk
The disk volume, mounted as logical device 1. It
contains MPE, I/O configuration information, the accounting structure
and file directory, and utilities and subsystems. It also contains
an area reserved for virtual memory and may be used to store user
files.
- system domain
See system volume.
- system event log
See system logging.
- system failure
An internally detected error from which recovery
is not possible. Rather than continue to operate, risking data integrity,
the operating system halts the computer.
- system file directory
A directory maintained by MPE that records the name,
group, and account of each permanent file on the system. The directory
contains the size of each file, its location on the disk, who may
access it, and other information.
- System generator (SYSGEN)
The MPE/iX utility used to create or modify system
and I/O configurations; add, remove, and replace program files and
boot files; replace system libraries; generate a full system backup,
and create a boot tape to bring up an MPE/iX system with the new
configuration. Equivalent to MPE V/E SYSDUMP and INITIAL.
- system halt
The condition of MPE following a system shutdown
or system failure, indicated by no response at the system console
or to any user command.
- system image
See system configuration.
- system loader
A piece of software that brings a program into memory
and binds it to addresses before execution.
- system load tape
A system load tape, also referred to as a boot tape,
contains the system load utilities, base system files, and user
files. It is generated with the system generator (SYSGEN) utility.
Equivalent to the MPE V/E coldload tape.
- system logging
The MPE/iX system logging facility records details
of system resource requests in a series of log files on disk. The
system manager or operator can select which system events to record
such as job/session initiation/termination, program termination,
file closing, file spooling completion, and system shutdown. I/O
device failures are recorded in the system log and are used to detect
problems before they interfere with overall system operation.
- system manager
The person who manages the computer installation,
responsible for creating accounts and assigning capabilities and
resource-use limits to each user/account.
- system manager capability (SM capability)
A capability that allows execution of all commands necessary to manage
the system. This capability is usually only given to a system manager,
since that is the person responsible for the structure, security, and
overall operation of the system.
- system master volume
Any disk volume that has to be mounted for the system
to boot. This is different from nonsystem volumes, which can be
removed while the system is up and the system remains running. A
system volume is always named MPEXL_SYSTEM_MASTER.
- system measurement tools (SMT)
See Glance/XL.
- system performance
The efficiency of the system as measured by response
time and transaction throughput.
- system processor unit (SPU)
The chip in which all the processor boards and cards reside.
- system services control point (SSCP)
A focal point within a system network architecture
(SNA) network for managing the configuration, coordinating network
operator problem requests, and providing directory support and other
session services for end users of the network.
- systems network architecture (SNA)
An IBM architectural model. It defines the rules,
protocols, and procedures for communication between devices within a
network.
- systems programming language (SPL)
A programming language for the HP 3000 Series 37
through 70 that provides control of machine instructions in a code
segment. It is used for many applications, including MPE V itself. Most
SPL programs execute in MPE/iX compatibility mode.
- system startup
To load the MPE operating system from either disk or tape by bringing
a subset of the MPE initiator program into memory.
- system supervisor capability (OP capability)
A capability assigned by the system manager to the system supervisor's
user name and account. The system supervisor is responsible for
performing backups, altering the system configuration, and in general,
tuning the computer so that it continues to perform
well and meet the needs of users.
- system volume
An MPE/iX system volume set. It contains a bootable
system image and system configuration on its master volume. It is
the only volume needed to load and start the system. It is always
mounted and named MPEXL_SYSTEM_VOLUME_SET. This is equivalent to
an MPE V/E system domain.
- tape mark
The uniquely formatted area on a magnetic tape that
is used to separate files; it also may be used to delimit the end
of the tape (two file or tape marks).
- tape request
A printed message at the console asking for a backup
device to be assigned to a user.
- temporary file
A file that exists only for the duration of a session
or job.
- terminal
A hardware device connected to a computer, used
for entering and receiving data. A terminal consists of a keyboard
and a display screen.
- Text and Document Processor/V (TDP/V)
An HP 3000 line editor (with a screen editor option)
used to create, manipulate, and format ASCII text files.
- thermal printer
A printer that forms characters by heating paper.
The printer requires special heat-sensitive paper.
- ThickLAN cables
ThickLAN cables (IEEE802.3 10BASE5) are used to
connect Datacommunications and Terminal Controllers (DTCs) to the
system. Thicknet cables require a media attachment unit (MAU) for
each DTC. Use of ThickLAN cabling is most appropriate when the DTCs
are distributed throughout the facility.
- ThinLAN cables
ThinLAN cables (IEEE802.3 10BASE2) are used to connect
Datacommunications and Terminal Controllers (DTCs) to the system. Use of
ThinLAN cabling is most appropriate when the DTCs are in close proximity
to the system.
- throughput
A measurement of the amount of useful work performed
by a system in a given amount of time.
- Toolset/XL
Toolset/XL provides an integrated programming environment
for COBOL II/XL and Pascal/iX programming.
- topology
The physical structure of a network (for example,
star or ring network).
- track
A data area on disk that forms a concentric circle,
divided into sectors. One full track passes under the disk head
during each rotation of the disk.
- trailer
The last page printed every time output is directed
to a line printer. It contains the session number, session name,
logon identification, day of the week, date, and time. It corresponds
to the header printed as the first page.
- TRANSACT
A high-level programming language for MPE V and MPE/iX.
- transaction
A logical unit of work. It may consist of one or more operations,
but either all or none of them will be performed.
- transaction logging
The process of keeping track of all database operations
occurring within defined transactions. The resulting transaction
log file can be used to recover data and ensure database integrity
when a program aborts or the system crashes.
- transaction management facility
Ensures data consistency and integrity by providing transaction
locking. Transaction locking ensures that only one transaction at
a time is allowed to update given data, and all changes that are
part of a transaction must be completed before the changes are committed
to a permanent record. When a transaction abnormally ends (before
it is actually complete), the changes made from the beginning of
the transaction to the abort point are undone. The database is restored
to the state it was in just prior to the beginning of the
transaction.
- transient space
Disk space used for temporary processes such as
stacks and operating system data structures.
- translation lookaside buffer (TLB)
The translation lookaside buffer (TLB) is a high-speed
random access memory (RAM) buffer. It optimizes the task of translating
virtual addresses to physical addresses. The MPE/iX processor generates
48-bit virtual addresses and memory access is provided by 28-bit
physical (real) addresses.
- transparent
Unseen by the user. A process or action with which
the user need not be concerend.
- transport backup
Transport refers to the movement of files between
MPE V/E and MPE/iX systems using backup media. MPE/iX backup and
recovery provides a compatibility option with which an MPE V/E-compatible
tape may be created or read.
- transport layer
Layer four of the Open Systems Interconnection (OSI)
network model. The transport layer provides for transport of messages
between end-users.
- tuple
A row, record, or data entry in a DBCore relation.
- unconfiguring a device
The process of logically removing a device from the system.
- unblocked record
A physical record that contains just one logical
record. The opposite of blocked record.
- undefined-length records
See variable-length records.
- unit number
A part of an address used for devices. A number
whose meaning is software-dependent and device-dependent, but which
is often used to specify a particular disk drive in a device with
a multidrive controller.
- UNIX
An operating system developed by AT&T Bell
Laboratories. Hewlett-Packard's implementation of UNIX is called
HP-UX.
- UNKNOWN
A disk pack without a volume label recognized by MPE/iX.
- unscratch a volume
To make data available on a previously "scratched"
volume. See scratch a volume.
- UPDATE
The MPE/XL ISL UPDATE utility performs a system load from tape. It
replaces the current base system files on disk, and optionally
replaces configuration files. The ISL UPDATE CONFIG option
is equivalent to the MPE V/E COLDSTART procedure, and the
UPDATE NOCONFIG option is equivalent to the MPE V/E UPDATE
operation.
An MPE V/E coldload option that loads all files in the
PUB group of the SYS account from the backup media.
I/O configuration data, the directory, and user files are loaded from
the system disk. UPDATE is typically used to install a new version of
system software or to load MPE from another computer. Equivalent to
the MPE/XL ISL UPDATE utility UPDATE NOCONFIG
option.
- use communications subsystems capability (CS capability)
A capability assigned to accounts and users allowing
access to the MPE communications subsystems.
- user
Anyone logged onto a session, using a local or remote
terminal to interact with the computer. Each user identified by
a user and account name can access files in the logon group.
- user asynchronous I/O
A method of performing I/O whereby a process launches
an I/O request and continues to execute while the I/O is performed.
The process's buffers should not be changed or used by the process
until the system informs the process that they are free.
- user command
A set of MPE/iX commands that a user has grouped together to perform
a specific task. A user command is stored in a command file or UDC.
UDCs are first in MPE's search path for commands.
- user-defined command (UDC)
A command that executes a set of one or more commands
that the user has grouped together into a single, named procedure
file to perform a specific task. See command file.
- user-level security
The file access modes permitted the user. User-level
security must duplicate, or be a subset of, the file access permitted
the user's account and group.
- user logging
A facility that enables users and subsystems to
record additions and modifications to files. If necessary, user
logging also provides the means whereby recorded entries can be
used to recover the files themselves.
- use volumes capability (UV capability)
A capability assigned at the account and user level
allowing users to access nonsystem disk volumes.
- utility program
A program that performs specific functions such as file copying,
sorting and merging, memory dump analysis, or monitoring available
disk space.
- value added network (VAN)
A common carrier service that has been upgraded by a communications
service. Also referred to as a packet switching network.
- variable
A value that can be changed, as opposed to a constant, usually
represented by a letter or a group of alphanumeric characters.
- variable-length record
A record whose length (in bytes or words) can vary
and is defined only by a maximum allowable file size. A file with
undefined length records must have a blocking factor of one, and
is written without buffering. One of a set of records that varies
in size with respect to each other.
- VINIT
An MPE V/E volume initialization subsystem (accessed
with the VINIT command). It contains several commands for online
initialization and formatting of private volumes, serial disks,
and foreign disks. Equivalent to the MPE/XL VOLUTIL utility.
- virtual memory
MPE/iX virtual memory refers to providing programmers
with the appearance that the available memory space is many times
larger than the actual amount of main or even disk memory. MPE/iX
provides this capability by taking advantage of the system's extremely
large addressing potential.
- virtual terminal (VT)
An NS3000/XL service that provides interactive access
to other systems on a network.
- VLSI
Very large scale integrated circuit technology.
VLSI technology puts over 100,000 gates on a single chip and is
used for CPUs and memories.
- volume
A volume is one disk pack. Each volume is a member
of a volume set and contains a volume label, a label table, and
a free space map.
- volume class
Volume classes are used for the allocation and restriction
of disk space. A volume class is a logical subset or partition within
a volume set and can include any number of physical member volumes
of a volume set.
- volume name
The name given to a volume set or volume class with
the NEWSET command. The name may be assigned only by a user
with CV (create volume) capability, usually the system manager or
account manager. The volume name is an ASCII character string of
up to eight alphanumeric characters, beginning with an alphabetic
character.
- volume failure
See disk failure.
- volume management
A facility of MPE used to manage disk storage using
volumes, volume sets, and volume classes.
- volume number
A number used to specify a particular volume on
a multivolume disk drive.
- volume set
A volume set is a group of from 1 to 255 related
disk packs. One volume of the volume set must be designated as the
master volume for the set. Each volume set is assigned a name by
which it is identified and referenced. MPE/iX recognizes both system
volume sets and nonsystem or mountable, volume sets.
- volume set information table (VSIT)
A part of a master volume of a volume set containing
description and address information about volume sets.
- volume states
The states in which a volume can exist on a system.
Accessible: MASTER and MEMBER. Inaccessible: LONER, UNKNOWN, and
SCRATCH.
- volume testing
The verification that the system will continue to
operate when loaded to each individual limit, the determination
of what occurs when those limits are exceeded, and the determination
of what occurs when the system is emptied after being in a full
state.
- VOLUTIL
The MPE/iX volume utility that provides volume initialization and
maintenance, volume label and membership inquiries, and volume
space/sector status. Equivalent to the MPE V/E VINIT subsystem.
- VPLUS/V
An application designed to simplify forms design
and screen handling for interactive applications. VPLUS/V is included
in the fundamental operating software (FOS) for the 900 Series HP
3000.
- WARMSTART
The process of restarting the HP 3000 by loading
MPE V/E from the system disk. A WARMSTART is used if incompletely
processed spooled jobs and spooled files must be recovered, since
other startup options do not permit the recovery of spoolfiles.
MPE/iX equivalent is the START RECOVERY option of the ISL START
utility.
- WELCOME message
The message that appears when a user logs on to the system.
- wildcard
A symbol that represents a variety of characters. In MPE, the at sign
(@), the pound sign (#), and the question mark
(?) are used as wildcard characters. Other subsystems may use
different symbols.
- window
A portion of a file or image displayed on selected
portions of a CRT screen.
- word
A word consists of 32 bits (4 bytes) of information
in the 900 Series HP 3000. A word consists of 16 bits (2 bytes)
of information in other HP 3000 systems.
- word processor
A program that creates, stores, recalls, and edits
text (used for letters, memos, reports, and other documents).
- work around
A "scratch file" used for intermediate data storage
by a subsystem or program. It is usually purged when the subsystem
or program terminates.
- work file
A temporary file created when a text editor is invoked.
A work file is a copy of a permanent disk file. Any changes to the
work file are lost unless the user saves the updated version of
the file.
- workstation
Terminals, personal computers, or serial printers
that communicate with a host computer but have inherent processing
capabilities.
- write
What a computer does when it writes information to a device.
- write-enable
To remove write-protection, allowing data to be
written upon a floppy disk or a tape.
- write-protect
To protect stored data so that it can not be overwritten.
- write ring
A plastic ring that fits onto the inner groove of a reel-to-reel tape,
enabling you to write information onto the tape.
- XON/XOFF
An industry standard protocol used by a peripheral
device to regulate data transmission. XON starts data transmission
and XOFF stops it.
- X.25
A type of communication link that provides connection
of packet switching networks (PSNs), also known as value added networks
(VANs). X.25 links are useful for long-distance communication and
can be more economical than leased lines in some applications.