MPE/iX Glossary of Terms and Acronyms HP 3000 MPE/iX Computer Systems Edition 3 Manufacturing Part Number: 32650-90887 E0300 U.S.A.
Notice The information contained in this document is subject to change without notice. Hewlett-Packard makes no warranty of any kind with regard to this material, including, but not limited to, the implied warranties of merchantability or fitness for a particular purpose. Hewlett-Packard shall not be liable for errors contained herein or for direct, indirect, special, incidental or consequential damages in connection with the furnishing or use of this material.
Contents 1. Glossary of Terms 2.
Contents 4
Preface This manual is written to serve a wide range of users of the MPE/iX documentation set, from the occasional MPE/iX user, to the experienced system manager. NOTE MPE/iX, Multiprogramming Executive with Integrated POSIX, is the latest in a series of forward-compatible operating systems for the HP 3000 line of computers. In HP documentation and in talking with HP 3000 users, you will encounter references to MPE XL, the direct predecessor of MPE/iX. MPE/iX is a superset of MPE XL.
1 Glossary of Terms This chapter contains a glossary of terms defining many Hewlett-Packard-specific and industry-wide computer terms. The term appears in bold type in the left column. The definition for the term appears in the right column. If a term has more than one definition, they are listed in numerical sequence. The numbering does not imply order of importance.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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).
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms the file and less concerned about earlier material. 2. A file that can be reused (DBCore nonarchive log files are circular files). class A user-defined collection of objects. class name 1. 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.
Glossary of Terms 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 1. 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. 2. A set of one or more SQL or ISQL commands in a file that can be executed with the ISQL START command.
Glossary of Terms 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.
Glossary of Terms 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 CTRLD.
Glossary of Terms 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 1.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 2. 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.
Glossary of Terms 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).
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 2. 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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 .
Glossary of Terms 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.
Glossary of Terms 2. 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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 1. The process of recording all system modifications to a tape or disk file for the purpose of recovery or accountability.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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).
Glossary of Terms 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.
Glossary of Terms 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 1. The provisions that prevent unauthorized users from entering the system, accessing data, or using resources, programs, or capabilities. 2. The provisions included in MPE to protect the system from unauthorized use. MPE offers several means to create a secure environment.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
Glossary of Terms 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.
2 Acronyms and Abbreviations Below is a listing of many commonly used acronyms and abbreviations, each followed by the complete non-abbreviated term it represents. A definition for each acronym and abbreviation can be found in the glossary of terms in chapter 1 of this book.
Acronyms and Abbreviations CCTL carriage control CE customer engineer CI command interpreter CIB channel I/O buses CIO channel I/O CISC complex instruction set computer CM compatibility mode COBOL common business-oriented language cpi characters per inch CPU central processing unit CRC cyclic redundancy check CRT cathode ray tube CS communications subsystems capability CS/80 or CS-80 command set '80 protocol CST code segment table CSTX or XCST extended code segment table CTB ce
Acronyms and Abbreviations DTS data communications and subsystem terminal DUI diagnostic user interface DUS diagnostic utility system EBCDIC extended binary coded decimal interchange code ECC error checking code EIA Electronics Industries Association EIM external interrupt message EOF end-of-file EOL end-of-line EOF end-of-tape EPROM erasable programmable read-only memory ESD electrostatic discharge EU execution unit FCS frame checking sequence FID file information display FLO
Acronyms and Abbreviations I/O input/output IODC I/O-dependent code IP internetwork protocol IPC interprocess communication IPSW interrupt processor status word ISL initial system loader ISO International Standards Organization ISR interruption space register IVA interrupt vector address JCW job control word K kilo KSAM Keyed Sequential Access Method LAN local area network LANIC local area network interface controller LAP link access protocol LAP-B link access protocol-balanc
Acronyms and Abbreviations NLS native language support NFT network file transfer NM native mode or node manager capability NRJE network remote job entry NS network services OEM original equipment manufacturer OP system supervisor capability OSI Open Systems Interconnection PAD packet assembly and disassembly PBX private branch exchange PC personal computer or program counter PCA printed circuit assembly PCB process control block PCR parent-child relationship PDC processor depen
Acronyms and Abbreviations SDLC synchronous data link control SF save file capability SL segmented library SM system manager capability SMT system measurement tools SNA systems network architecture SPL System Programmming Language SPOOL simultaneous peripheral operations online SQL Structured Query Language SSCP system services control point SYSGEN system generator TDP/V Text and Document Processor TLB translation lookaside buffer UDC user defined command USASCII American Stand
