mvBase Glossary

Numerics
4mm DAT tape drive	A type of tape drive that uses DAT (Digital Audio Tape) technology to store large quantities of data in a small tape cartridge.
8mm tape drive	A type of tape drive that uses eight millimeter videotape technology to store large quantities of data in a small tape cartridge. 8mm cartridges are slightly larger and hold more data than 4mm DAT cartridges.
A
A-item	A data definition item used by the ACCESS processor to define the structure of data in the data section of a file.
Abort	The termination of a computer function in the event of a hardware or software malfunction.
ABS	Absolute Binary Segment. An area of disk-drive frames containing the system object code that the machine executes.
ACCESS (INFO/ACCESS)	The information retrieval language of the MultiValue system.
Access time	The time taken to reference a piece of information.
Account	A group of files and verbs defined by a Master Dictionary (MD). A user gains access to an account when logging on.
Address	A way of referencing a memory location or a part of a disk.
ADF	Adapter Description File. A MS-DOS file that resides on the Reference diskette. It contains information about the boards in the slots of the machine.
Administrator	Maintains the system for the benefit of users. Administration may take place at the operating system level, the applications level, or both.
Administration Utility	The utility used to administer tasks such as configuration, and setting environment variables.
Algorithm	A set of rules for solving a task.
Alphanumeric	A string of characters which can contain any combination of letters, numbers and symbols.
AM	Abbreviation for Attribute Mark.
AMC	Attribute mark count, or attribute number.
ANSI	An acronym for American National Standards Institute.
Applications	Software programs that perform specific tasks such as accounting, stock control, etc.
Argument	The particular occurrence of a parameter.
Array (or Matrix)	A whole set of variables identified by a single name.
ASCII	‘American Standard Code for Information Interchange.’ One of the standards used to represent alphanumeric characters.
Asynchronous	A means of communication between terminals and the computer, sometimes referred to as ‘async.’
Attribute	A structure that contains one or more data values. Attributes can be subdivided to comprise MultiValues and multiple subvalues. An attribute is analogous to a "field" used on other systems.
Attribute mark	A system delimiter used to separate attributes. It is ASCII value 254 (hexadecimal FE).
Authorization	The process by which the mvBase Server confirms the quantity of licenses and the maximum number of simultaneous connections.
B
Background	The foreground task has the highest priority in a situation where several tasks are run concurrently at a terminal. The other tasks are known as background tasks.
Back up	The means of copying the database to be able to recover its contents in the event of a hardware or software malfunction.
Backup Media (or Medium)	Any device, such as a tape drive or diskette, that serves for data backup.
Base	The frame ID of the first group of a file. It is specified by Attribute 2 of a File Definition item.
Base FID	The first of a block of frames making up a file.
BASIC	An abbreviation of ‘Beginners All-Purpose Symbolic Instruction Code,’a popular and easy-to-learn programming language. BASIC consists of a language compiler and a run-time package. mvBase uses a customized version of BASIC called mvBASIC.
Batch	A method of processing data in which work is grouped together in batches for processing, rather than each item being worked on individually in an interactive way.
Baud	The capacity of a communications line, often synonymous with bits per second. Terminals and printers typically operate at a speed of 9600 baud.
Binary	A method of representing numbers to the base of two using the numbers ‘0’ and ‘1’.
Bit	Contraction of the words ‘binary digit.’ This is the lowest level of data storage in the computer, each bit being represented as either a ‘0’ or a ‘1’.
Boolean	A system of mathematical logic dealing with classes, propositions, on-off circuits, etc.
Boot	The process of loading the operating system into main memory to make the computer ready to use.
Boot diskette	A diskette that contains operating system software (or any software) that the computer uses to run itself.
Bootstrap	The process of starting a computer from powerup.
Buffer	A place where information can be stored temporarily.
Bug	An error of programming logic.
Byte	A character of data made up of eight bits.
C
CD-ROM	Compact Disk-Read Only Memory. A storage and distribution medium used for digitized data, including software.
Channel	Another name for ‘port,’ the connection on the computer that links to peripheral devices.
Checksum	A method of data verification involving calculations of the data, which are then compared to stored values for the same data.
Coldstart	The procedures undertaken once the initial program load has taken place. See Boot.
Command	The verb of a statement.
COM port	A serial port on the back of the computer. Most systems have two Com ports, usually referred to as COM1 and COM2. Some systems have no Com ports.
Concatenate	To link two strings end to end.
Connect time	The length of time that a user is connected to the system.
Connection	Consists of a data channel and a command channel between the client application and the designated line on a specific server.
Console	A special terminal that displays system messages and is used for administrative tasks such as starting up and shutting down the system.
Contiguous	Next to or near in time or sequence.
Control characters	Normal keyboard letters, numbers, or symbols, which are entered while the CTRL key is held down. These characters do not usually print.
Controller	A hardware board that resides in one of the expansion slots in the computer and provides an interface to a device.
Conversions	Instructions stored in attribute 7 of attribute definition items. These instructions convert output data to formats (such as time, date, decimals, etc.) different from internal storage. Applied after selection-criteria.
Correlative	A processing function enabling values to be computed at run time rather than being held as a data element on the database. A derived value.
CPS	An abbreviation of ‘characters per second.’
CPU	The central processing unit.
CRT	Cathode-Ray-Terminal. A user terminal with a video screen and keyboard. Also called a Video Display Terminal or Unit.
Cursor	The means of indicating the position on a terminal at which the next input/output is expected.
D
Daisy chain	A way of connecting devices in which each device is connected to the devices next to it, like links in a chain.
D-pointer	A dictionary item (D-item) that defines a file.
Data	Information of any type.
Database	Collection of logically related data that is organized for efficient storage and retrieval. A database might consist of a group of files or a single file.
Data file	A fourth-level file that is associated with a dictionary on the previous level. The data file contains the raw data whereas the dictionary defines the structure of the data.
Data dictionary	A necessary requirement of any database system, which enables the structure and form of the database to be defined.
Data processing	The input, output and processing of information.
Deadlock	Also known as deadly embrace. A situation where two or more processes control information needed by the other in such a way that no process can proceed.
Deadly embrace	Also known as Deadlock. A situation where two or more processes control information needed by the other in such a way that no process can proceed.
Debug	The process of removing errors of logic from a program.
Debugger	A software tool to aid in determining the corrections to program logic to be made. It allows programs to be executed step by step and information, such as the contents of variables, to be displayed.
Default	The action taken or value used by the system unless otherwise specified. A default value is one that the computer uses (pre-programmed) in cases where user-defined parameters are prompted for, but not supplied.
Degradation	A slowing down in the response from a computer as it is given more work to perform.
Delimiter	Special characters used to separate data. System delimiters separate subvalues, values, and attributes.
Deskside machine	Any of the large system models that are designed to stand upright on the floor.
Desktop machine	Any of the small system models that are designed to fit on top of the user’s desk.
Device driver	Enables the operating system to support hardware devices such as disk drives, tape drives, and I/O controllers.
Diagnostics	A series of routines designed to locate hardware or software errors.
DICT	Abbreviation for dictionary.
Dictionary	A file structure for defining the structure of data.
Diskette	A small, removable disk made of a tough, flexible plastic and coated with a magnetizable substance. Often used for data transport or storage.
Disks	Magnetic media shaped like circular discs which are used for storing information.
Dump	To write the contents of internal (disk) storage to backup storage (tape).
E
EBCDIC	A character code commonly used in mainframe computers.
Editor	The processor that permits on-line interactive modifications to any item in the data base. It is the normal input processor for writing PROCS, programs, etc.
End user	The person who ends up using the computer.
Enqueue	The process of placing something into a sequence or linked list called a queue.
Extended file space	Frames linked to primary file space containing items that are larger than about 85 percent of the frame size.
F
FID	A contraction of the words ‘frame ID’ denoting the logical address of the frame on the disk.
File	A logical structure that associates a set of items.
File Area	The location in which MultiValue data is stored in files, also known as the data area. The first file in this area is the SYSTEM Dictionary. The frame ID of the first frame of the SYSTEM Dictionary is listed under the heading SYSBASE in the report produced by the WHAT command.
Fileload	To install a MultiValue database from tape to the disk. This process starts the spooler and links all user workspace.
File-save	To copy a MultiValue database from disk to tape. The resulting tape can also be called a filesave.
File system	A combination of directories and files.
File dictionary	A file structure that points to a data file on the next level and defines its contents. If a file dictionary is not associated with a data file, then it points to itself.
Firmware	A series of operating instructions (software) fixed in ROM (Read Only Memory). ROM is a hardware ‘chip’ on a PCB (Printed Circuit Board).
Floppy diskette	A flexible single disk used for storing information.
Foreground	The task that has the highest priority in a situation where several tasks are run concurrently at a terminal. The other tasks are known as background tasks.
Formatting	The process of preparing a disk to receive data. All new disks must be formatted. If a disk does not need formatting, it is because someone else has already done it for you. Most types of formatting destroy any data that may already be on the disk.
Form queue	A logical print queue that permits the association of a particular form with one or more printers.
Frame	Fixed length unit of storage; 2048 bytes. Each frame is numbered (called a frame ID or FID), thus giving the system direct access to that particular frame.
Frame ID (FID)	Frame IDentification. Used to identify each frame. See Frame.
Function	A process that returns a single value.
Function key	A key that performs a special function.
G
GFE	An abbreviation of ‘Group Format Error,’ an error condition within a group of data frames.
Global variable	A variable that is available to all users of a program.
Group	Group of items whose item-IDs hash to the same group number. A file initially consists of a set of contiguous frames as indicated by the modulo. Individual groups can overflow into secondary allocation when the primary frames become full.
H
Handshaking	A term which indicates that two processes involved in some kind of communication have a means of controlling and confirming the receipt of data sent by each other.
Hard copy	Printed output from a computer.
Hard disk drive	A non-removable disk drive, located either inside the computer or in a separate cabinet, that can hold large quantities of software and data.
Hardware	The physical computer equipment.
Hashing	The processing of an item-ID by an algorithm to locate the position of data in a file.
Hexadecimal (hex)	The base-16 numbering system, used to represent binary numbers. One hex digit represents four binary digits.
Holdfile	A temporary file used to store a print file.
Host adapter	Another term for DTC Board.
I
INFO/ACCESS	A database language processor that accepts English-like query statements and produces formatted reports on the terminal display or the printer.
Initialize	To reset the system or process to its starting point.
Interface	A link between systems or processes. Can be either software or hardware.
Interoperability	Refers to the ability within mvBase to access, read and write information from within the host operating system (Windows). Specific interoperability features are defined for COM ports and for Telnet clients which connect via the mvTelnet Server. Once defined, interoperability features are implemented and processed within the MultiValue environment.
Interpreter	A software program that translates a program (in source- or part-compiled form) into machine code instructions which are then executed.
Interrupt (vector)	A temporary suspension of computer activities caused for a variety of reasons. An asynchronous hardware event that the boards in the system use to communicate with the CPU.
I/O	An abbreviation of the term ‘input/output,’ which relates to the way in which data can be input to or output from the computer.
IRQ level	A numbering scheme that prioritizes the interrupt vectors.
IRQ vector	See Interrupt (vector).
Item	A data structure comprised of an item-ID and attributes. Items make up a file and are variable in length. Same as record on other systems.
Item-ID	The key used to access any item. The unique name given to each item in a file, by which the item is stored and retrieved.
Item-list	A set of items grouped for processing by a specified command. Explicit item-lists are part of the ACCESS input sentence. Implicit item-lists are created by the SELECT, SSELECT, and GLIST commands.
J
Job	A specific function made up of one or more programs run one after another.
Justification	A method to format output data by aligning it on the left or right.
K
K	Symbol for kilo-a thousand, and an abbreviation for kilobyte. Using binary notation, this works out to 1024 bytes. Typical Windows documentation uses K, not KB (as in 1024K). Note, however, that Windows Explorer uses KB to indicate file size (in kilobytes).
Kilobyte	A kilobyte of memory-1024 bytes.
Kernel	The part of the operating system tha t manages hardware and low level functions. Same as MONITOR.
Key	The code by which a record is retrieved from the database.
L
Label	An identifier made up of alphanumeric characters.
Language	The command set for user interaction with a processor.
Line	Comprises a serial port (hardware) and the control structure on the system (software) which manages the transmitting and receiving of data according to various protocols. Lines are numbered sequentially, starting with line 0.
Linkage	The first 12 bytes of a frame used to define forward and backward links to other frames.
Lint	Describes a portion of frame contents. After the end-of-group mark, the frame contains characters left over from the frame's previous use. These characters are known as lint.
Load	To read in code or data (to disk) from backup storage (tape).
Local variable	A variable that is only available to the specific user running the program.
Logical tape unit	A number that identifies a tape drive, floppy diskette drive or virtual tape file as an mvBase tape unit. LTU is a code-level, logical term. The operative term for such units is mvBase tape unit.
Logical unit number	A number that identifies a device on a SCSI bus.
Logoff	The process of ending a working session on the computer. May also be called Logout.
Login	To gain access to a computer system via an account name and optional password.
Logon	The process of gaining access to the computer.
Loop	A series of program instructions which may be executed more than once before the program continues.
M
Machine code	A programming language using 0s and 1s only and, therefore the lowest level programming language available.
Main memory	Memory is both ROM (Read Only Memory) and RAM (Random Access Memory). RAM is the space within the computer where information is stored while being actively worked on. RAM is a function of SIMMs (Single In-line Memory Modules).
Master Dictionary	The master file of any account on the system. It contains definition items for all verbs, INFO/ACCESS keywords, Procs, and files accessible to an account.
Matrix	A whole set of variables identified by a single name.
MAXFID	The highest frame address on disk.
Mbyte	One million bytes. Typically used to define the size of disk storage.
MD or M/DICT	Abbreviations for Master Dictionary.
Mega	A term meaning ‘million.’
Megabyte	An amount of data equal to 1024KB, or 1,048,576 bytes.
Memory (RAM)	RAM (Random Access Memory) is the physical hardware
Microcomputer	A small computer, capable of handling more than one user.
Millisecond	A thousandth of a second.
Minicomputer	The next stage up from microcomputers, both in size and the number of users it can handle-often up to 12 or even 64 terminals.
Minor number	A number that indicates bus specific information about a SCSI device, such as the logical unit number.
Modifier	An optional part of an ACCESS sentence that controls the output.
Modulo	The number of groups allocated for a file; it represents an area of contiguous disk space. Modulo is specified at the time a file is created and is based upon an estimate of the number of characters that will be contained in the file.
Monitor	The part of the operating system that controls access to the CPU and handles the transfer of data from main memory to input and output devices. Same as KERNEL.
Mount point	The directory entry (path) from which a file system is accessed.
MS-DOS	An operating system widely used on IBM-compatible personal computers.
Multiuser mode	The normal operating mode of the system. When the system is in multi-user mode, users can login at any of the terminals that the system administrator has configured.
Multiprocessor	A type of computer that has two or more processors. Multiprocessor systems are much more powerful than similar single processor systems.
MultiValue	Refers to application software and/or operating systems derived from Pick-based database technology. The MultiValued database can contain more than one sortable, listable value within a field (attribute), adding significantly to the power and flexibility of the database application. MultiValue technology includes several other characteristic features and architecture which are described in other Rocket documentation.
N
Null	A lack of information as opposed to a zero or blank (space bar).
Numeric	Comprising numbers only.
O
Object code	Machine executable instructions.
OEM	An abbreviation for ‘Original Equipment Manufacturer’ and relates to someone who incorporates major components or subsystems from other manufacturers into their own system.
Online	The position of being connected to a system.
Operating system	Software that controls how the computer performs its basic functions. Also known as O/S.
Option	A single ACCESS character code enclosed in parentheses that may be used instead of a modifier. Denotes the provision of additional facilities.
Orderly shutdown	A shutdown in which the system is allowed to close files, terminate programs, and finish whatever its is doing before being shut down.
Overflow	A pool of available frames from which to draw when the primary frames in a group are full.
Overflow Table	A table that keeps track of available frames that can be used to expand the storage of a group.
P
Parallel printer	A printer that receives bits of data from the computer in parallel. The parallel interface is faster than a serial interface.
Partition	A portion of a disk that the operating system handles as if it were a separate disk. A disk can have several partitions, or one partition that includes the entire disk.
Password	A secret word that enables the user and only the user to access an account or perform a procedure.
Path	The path describes the route the operating system follows from the root through the hierarchical structure to locate a folder, directory or file. A path typically comprises these elements: [drive:] \ [directories] \ [folder] \ filename
PC	A computer system that handles only one user.
PCB	Primary Control Block. A system table that tracks the user’s status; one user per port.
Peripheral device	Various hardware devices connected to the computer, such as terminals, tape drives, floppy diskette drives, printers, modems, etc.
Permissions	A permission is a rule associated with an object, such as a file, directory, or printer shared on a network; it can be assigned to local groups, global groups and individual users. A permission is distinct from a right, which applies to the system as a whole. Permissions and rights are "granted."
Phantom process	A process that does not have a line linked to it.
Physical	Physically installed on the system.
PIB	Abbreviation for ‘Primary Input Buffer,’ the buffer in PROCs through which all data from the keyboard passes.
POB	Abbreviation for ‘Primary Output Buffer,’ used in PROCs.
Pointer	A dictionary item that forms a link to an absolute disk address or to a file by using its name.
Port	A connection on the computer, typically for a printer or terminal.
Port monitor	A process that controls one or more serial lines.
Port services	A classification of behavior of a port on a port monitor.
Primary control block	See PCB.
Primary space	The contiguous frames allocated to a file when it is created.
Privilege level	The degree of security that limits the activities on an account. In the MultiValue environment, privilege levels include SYS0, SYS1, SYS2 and SYS3. In the Windows environment, privilege is a common synonym of permission, but permission is the preferred term.
Proc	A stored procedure of one or more steps. Also, the processor that executes stored procedures (PROC).
Process	A set of workspace and other control structures which contain the current state of a series of ongoing tasks (verbs, programs, etc.), in most part invisible to the user although there are many commands that allow the user to control and manipulate them. Each process is independent of all other processes on the system.
Processor	A collection of codes or programs.
Program	A sequence of instructions, written in the programming language, to perform a given task.
Protocol	A series of rules for defining the exchange of data.
Q
Q-pointer	File synonym dictionary item (Q-item) that renames a file or points to a file in another account.
R
RAM	Random Access Memory—the physical memory of the computer system.
Record	A conventional data processing term indicating a logical entity in a file. Analogous to item.
Reference diskette	An MS-DOS diskette that contains a program and data files which allow the user to configure the hardware installed on the system.
Reset	The same process as initialization.
Rights	A right is a rule associated with the system as a whole, granted to local groups, global groups, and users. It allows them to perform certain actions on the system. This is distinct from permissions, which are associated with objects.
Routine	A small number of program instructions.
Runoff	A text-formatting utility.
S
Scroll	The process of displaying the next or previous screen of information.
SCSI	An abbreviation for Small Computer System Inteface. SCSI is a specification of mechanical, electrical, and functional standards for connecting peripheral devices (such as disk and tape drives) to a computer.
SCSI controller number	The number that identifies the SCSI host in a system.
SCSI device ID	A number that uniquely identifies a device on a SCSI bus.
Secondary space	Frames linked to primary file space to contain overflow item storage.
Segment mark	The system delimiter (ASCII 255) designating the end of an item.
Separation	The number of frames in a group in a file.
Serial printer	A printer that receives data from the computer serially. A serial printer uses the same type of port as terminals and modems.
Server	1. A computer system which provides services to other computers (called clients). 2. The specific component within mvBase that contains the MultiValue database and associated architecture and processes.
Service agreement	A contract that entitles the customer to have the system serviced at no charge for a specified period of time.
Service engineer	A knowledgeable technician who is responsible for addressing system problems.
SIB	Abbreviation for Secondary Input Buffer, used in PROCs.
Single-user mode	The operating mode of the system in which only the system console is active. No other users can log in when the system is in single-user mode.
SOB	Abbreviation of Secondary Output Buffer, used in PROCs.
Software	Computer programs.
Sort	The means of placing information in a specified sequence according to the contents of particular parts of a record.
Source code	Instructions written by the programmer that are translated into object code.
Spooler	A system process that handles all printer operations.
Spooling	A technique for temporarily storing output on disk.
Stack	A small area of memory allocated for holding data where information added to the stack pushes down the information already held.
Statement	A complete syntax element used to invoke a processor.
Subroutine	A series of instructions performed frequently that can be executed anywhere within a main program and, once performed, enable the main program to continue from the instruction immediately following the branch instruction.
Subvalue	A structural subdivision of a value. Values can comprise one of more subvalues.
Subvalue mark	The system delimiter (ASCII 252) that designates the end of a subvalue.
SVM	Abbreviation for Subvalue Mark.
Syntax	The rules for the formulation of program and ACCESS statements.
System	A term often used as synonymous with the computer, or the computer and its peripherals.
System delimiters	ASCII characters that separate subvalues, values, attributes, and items.
SYSTEM dictionary	The master file of the system at the top of the file hierarchy. It holds Account Definition items that define all accounts on the system.
System privileges	Restrictions of an account or a user’s ability to access certain parts of the system.
T
Tape	Magnetic tape in which the supply and take-up reels are contained in a small plastic case, which in turn is mounted onto a tape unit when data is to be read from or written to the tape inside. This includes Digital Audio Tape (DAT) and Digital Linear Tape (DLT). This also includes half-inch tape, where the supply and take-up reels are not contained in a small plastic case (cartridge).
TCL	Abbreviation for ‘Terminal Control Language,’ the command language. The TCL processor handles most of the user’s communication with the computer, passing control to other system processors whenever appropriate. In most cases control is returned to TCL when other processing is completed.
TCP/IP	Transport Control Protocol/Internet Protocol. A standard format for transmitting data in packets from one computer to another over a network connection. TCP deals with the construction of data packets, and IP routes them from machine to machine.
Terminal	Video Display Terminal or Unit. Could be the same as a CRT. An input/output device with which a user communicates directly with a computer system. Terminals typical comprise a keyboard and a display device.
Timeslice	The number of milliseconds of processing given to each task during its processing cycle.
Transfer rate	The rate at which information is transferred between peripheral devices, including disks and tapes, and main memory.
U
Uniprocessor	A system that uses a single processor. Most small computers (and many large ones) are Uniprocessor systems.
UPS	An abbreviation for Uninterruptible Power Supply. A UPS supplies AC power to the system during a power failure.
User (or End-user)	The person for whom the product was developed.
User-ID	A unique name given to a user to enable him/her to access the computer system.
User process	A part of the mvBase system that handles all user activity. Each terminal is connected to the computer by a serial port which, in turn, is linked to a user process.
V
Validation	The process of checking data to ensure its accuracy.
Value (multi/sub)	A structural subdivision of an attribute. If an attribute contains more than one value, each of these values is called a MultiValue. A MultiValue, in turn, may contain more than one value called subvalue.
Value mark	The system delimiter (ASCII 253) that designates the end of a value.
Variable	A data element that can be assigned a number of values.
VDT (or VDU)	Video Display Terminal or Unit. Same as a CRT.
Verb	An entry in the master dictionary that transfers control to a processor or to system code.
Viewpoint	A terminal emulation that allows the user to operate the terminal in use as if it were a CRT supplied by ADDS.
Virtual	A term used to indicate the parts of the system that the user (or the user’s program) perceives as physical hardware, that are actually operating system analogs.
Virtual memory	A way of overcoming the limitations of RAM size by using the hard disk as an extension of physical memory.
Virtual Tape File (VTF)	A file on the host operating system that functions and is used in the same manner as a physical tape device. Data can be read from, written to, and stored in virtual tape files as with physical tape devices.
Virtual Memory Storage File	An allocation of disk space on a Windows operating system for use as the MultiValue environment (the ABS area, processes, file space, overflow, etc.). mvBase allows up to 50 virtual memory storage files.
VM	Abbreviation for Value Mark.
W
Wildcard	A character that indicates any character is acceptable in its position in a string comparison.
Workspace	An area of disk of memory set aside for work associated with a specific task or user.
Workstation	1. A specific class of computer. 2. The component within mvBase which manages client connections for devices such as those connecting via COM ports, Windows printers and Telnet clients connecting via the mvTelnet Server.