The MCP (Master Control Program) is the operating system of the Burroughs B5000/B5500/B5700 and the B6500 and successors , including the Unisys Clearpath/MCP systems.
111-462: MCP was originally written in 1961 in ESPOL (Executive Systems Problem Oriented Language). In the 1970s, MCP was converted to NEWP which was a better structured, more robust, and more secure form of ESPOL. The MCP was a leader in many areas, including: the first operating system to manage multiple processors, the first commercial implementation of virtual memory, and the first OS written exclusively in
222-513: A Journaling file system , providing fault tolerance in case of disk failure, loss of power, etc. It is not possible to corrupt the file system (except by the operating system or other trusted system software with direct access to its lower layers) . The file system is case-insensitive and not case-preserving unless quotes are added around the name in which case it is case-sensitive and case-preserving. MCP processes are called " Jobs " and " Tasks ." A Job contains one or more tasks. Tasks within
333-491: A high-level language . In 1961, the MCP was the first OS written exclusively in a high-level language (HLL). The Burroughs Large System ( B5000 and successors) were unique in that they were designed with the expectation that all software, including system software, would be written in an HLL rather than in assembly language , which was a unique and innovative approach in 1961. Unlike IBM, which faced hardware competition after
444-427: A relational database to categorize cultural works and their images. Relational databases and metadata work to document and describe the complex relationships amongst cultural objects and multi-faceted works of art, as well as between objects and places, people, and artistic movements. Relational database structures are also beneficial within collecting institutions and museums because they allow for archivists to make
555-454: A "data element" registry, its purpose is to support describing and registering metadata content independently of any particular application, lending the descriptions to being discovered and reused by humans or computers in developing new applications, databases, or for analysis of data collected in accordance with the registered metadata content. This standard has become the general basis for other kinds of metadata registries, reusing and extending
666-772: A class-attribute-value triple. The first 2 elements of the triple (class, attribute) are pieces of some structural metadata having a defined semantic. The third element is a value, preferably from some controlled vocabulary, some reference (master) data. The combination of the metadata and master data elements results in a statement which is a metacontent statement i.e. "metacontent = metadata + master data". All of these elements can be thought of as "vocabulary". Both metadata and master data are vocabularies that can be assembled into metacontent statements. There are many sources of these vocabularies, both meta and master data: UML, EDIFACT, XSD, Dewey/UDC/LoC, SKOS, ISO-25964, Pantone, Linnaean Binomial Nomenclature, etc. Using controlled vocabularies for
777-417: A clear distinction between cultural objects and their images; an unclear distinction could lead to confusing and inaccurate searches. An object's materiality, function, and purpose, as well as the size (e.g., measurements, such as height, width, weight), storage requirements (e.g., climate-controlled environment), and focus of the museum and collection, influence the descriptive depth of the data attributed to
888-474: A file and a directory. Files are stored on named volumes, for example 'this/is/a/filename on myvol', 'myvol' being the volume name. This is device independent, since the disk containing 'myvol' can be moved or copied to different physical disk drives. Disks can also be concatenated so that a single volume can be installed across several drives, as well as mirrored for recoverability of sensitive data. For added flexibility, each program can make volume substitutions,
999-401: A file may have a guard file where the owner can specify complex security rules. Another security mechanism is that code files can only be created by trusted compilers. Malicious programmers cannot create a program and call it a compiler – a program could only be converted to be a compiler by an operator with sufficient privileges with the 'mc' make compiler operator command. The MCP implements
1110-399: A file path was inefficient and for a production environment it was found to be better to keep all files in a single directory, even though they retain the hierarchical naming scheme. Programmatically, this makes no difference. The only difference visible to users is that an entity file can have the same name as a directory. For example, "A/B" and "A/B/C" can both exist; "B" can be both a node in
1221-448: A job can run sequentially or in parallel. Logic can be implemented at the Job level, typically in the MCP's job control language WFL, to control the flow of a job. Once all tasks in a job are complete, the job itself is completed. An MCP Process goes through a life cycle from the time it enters the system until it leaves. The initial state for a Job is "Queued." There is a period of time while
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#17327721002691332-485: A key topic in efforts toward international standardization . Standards for metadata in digital libraries include Dublin Core , METS , MODS , DDI , DOI , URN , PREMIS schema, EML , and OAI-PMH . Leading libraries in the world give hints on their metadata standards strategies. The use and creation of metadata in library and information science also include scientific publications: Metadata for scientific publications
1443-408: A library might hold in its collection. Until the 1980s, many library catalogs used 3x5 inch cards in file drawers to display a book's title, author, subject matter, and an abbreviated alpha-numeric string ( call number ) which indicated the physical location of the book within the library's shelves. The Dewey Decimal System employed by libraries for the classification of library materials by subject
1554-504: A newer mechanism was introduced in the mid 1990s. In a misguided attempt at compatibility, it was named after the then-proposed C++ language construct of the same name. Because the syntax and behavior of the two differ to such a large extent, choosing the same name has only led to confusion and misunderstanding. Syntactically, 'try' statements look like 'if' statements: 'try', followed by a statement or block, followed by 'else' and another statement or block. Additional 'else' clauses may follow
1665-511: A problem with alternative approaches: Here's a new language we want you to learn, and now you need to output these additional files on your server. It's a hassle. (Microformats) lower the barrier to entry. Most common types of computer files can embed metadata, including documents, (e.g. Microsoft Office files, OpenDocument files, PDF ) images, (e.g. JPEG , PNG ) Video files, (e.g. AVI , MP4 ) and audio files. (e.g. WAV , MP3 ) Metadata may be added to files by users, but some metadata
1776-432: A processor resource and are marked as 'running'. Processes that are ready to be assigned to a processor, when there is no free processor are placed in the ready queue. Processes may be assigned a “Declared” or “Visible” priority, generally 50 as the default, but can be from 0 to 99 for user processes. System processes may be assigned the higher values. Note that this numerical priority is secondary to an overall priority, which
1887-427: A resource. Statistical data repositories have their own requirements for metadata in order to describe not only the source and quality of the data but also what statistical processes were used to create the data, which is of particular importance to the statistical community in order to both validate and improve the process of statistical data production. An additional type of metadata beginning to be more developed
1998-456: A task to be waiting is waiting on a file. When a process opens a file, and the file is not present, the task is placed in the waiting entries, noting that it is waiting on a certain file. An operator (or the user that owns the process) has the opportunity either to copy the file to the expected place, or to redirect the task to read the file from another place, or the file might even be created by an independent process that hasn't yet completed. If
2109-404: A volume name may be substituted with a primary and secondary alternate name. This is referred to as the process’ FAMILY. For instance, the assignment “FAMILY DISK = USERPACK OTHERWISE SYSPACK” stores files logically designated on volume DISK onto the volume USERPACK and will seek files first on volume USERPACK. If that search has no success, another search for the file is done on volume SYSPACK. DISK
2220-461: A year, regardless of whether or not they [ever] were persons of interest to the agency. Geospatial metadata relates to Geographic Information Systems (GIS) files, maps, images, and other data that is location-based. Metadata is used in GIS to document the characteristics and attributes of geographic data, such as database files and data that is developed within a GIS. It includes details like who developed
2331-676: Is accessibility metadata . Accessibility metadata is not a new concept to libraries; however, advances in universal design have raised its profile. Projects like Cloud4All and GPII identified the lack of common terminologies and models to describe the needs and preferences of users and information that fits those needs as a major gap in providing universal access solutions. Those types of information are accessibility metadata. Schema.org has incorporated several accessibility properties based on IMS Global Access for All Information Model Data Element Specification. The Wiki page WebSchemas/Accessibility lists several properties and their values. While
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#17327721002692442-548: Is a programming language , a superset of ALGOL 60 , that provides abilities of what would later be termed a system programming language or machine oriented high order language (mohol) , such as interrupting a processor on a multiprocessing system (the Burroughs large systems were multiprocessor systems). ESPOL was used to write the Master Control Program (MCP) on Burroughs computer systems from
2553-449: Is also listed and more information about a task may be seen with the 'Y' command. It may be that a task is waiting for operator input, which is sent to a task via the accept 'AX' command (note that operator input is very different from user input, which would be input from a network device with a GUI interface). Tasks waiting on user input or file reads would not normally be listed as waiting entries for operator attention. Another reason for
2664-438: Is an early example of metadata usage. The early paper catalog had information regarding whichever item was described on said card: title, author, subject, and a number as to where to find said item. Beginning in the 1980s and 1990s, many libraries replaced these paper file cards with computer databases. These computer databases make it much easier and faster for users to do keyword searches. Another form of older metadata collection
2775-491: Is available programmatically as a task attribute that is of type task. For example, 'myself.initiator.name' gives the name of the process that initiated the current process. GETSPACE and FORGETSPACE are the two main procedures handling memory allocation and deallocation. Memory needs to be allocated at process initiation and whenever a block is entered that uses arrays, files, etc. GETSPACE and FORGETSPACE not only handle memory space, they also allocate or deallocate
2886-457: Is available, the system maintains an idle stack. MCP libraries provide a way of sharing data and code between processes. The article on Burroughs large systems looks at the way dependent processes could be asynchronously run so that many processes could share common data (with the mechanisms to provide synchronized update). Such a family of related processes had to be written as a single program unit, processing procedures at higher lex levels as
2997-412: Is based on the task type. Processes that are directly part of the operating system, called Independent Runners, have the highest priority regardless of numeric priority value. Next come processes using an MCP lock, then Message Control Systems such as CANDE . Then Discontinued processes. Then Work Flow Language jobs. Finally come user processes. At a lower level, there is a Fine priority intended to elevate
3108-491: Is being accomplished in the national and international standards communities, especially ANSI (American National Standards Institute) and ISO (International Organization for Standardization) to reach a consensus on standardizing metadata and registries. The core metadata registry standard is ISO / IEC 11179 Metadata Registries (MDR), the framework for the standard is described in ISO/IEC 11179-1:2004. A new edition of Part 1
3219-407: Is caused, which wakes up all the processes waiting on it. Processes may wait on multiple events for any one of them to happen, including a time out. Events are fully user programmable – that is, users can write systems that use the generalized event system provided by the MCP. Processes that have terminated are marked as completed. Operationally, the status of all tasks in the system is displayed to
3330-486: Is clear that he uses the term in the ISO 11179 "traditional" sense, which is "structural metadata" i.e. "data about the containers of data"; rather than the alternative sense "content about individual instances of data content" or metacontent, the type of data usually found in library catalogs. Since then the fields of information management, information science, information technology, librarianship, and GIS have widely adopted
3441-403: Is closest to libraries on other systems – for each client a separate copy of the library is invoked and there is no data sharing between processes. Shared by all is more interesting. When a client starts up, it can run for a while until it requires the services in the library. Upon first reference of a library entry-point, the linkage is initiated. If an instance of the library is already running,
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3552-470: Is completely discrete from other elements and classified according to one dimension only. An example of a linear metadata schema is the Dublin Core schema, which is one-dimensional. Metadata schemata are often 2 dimensional, or planar, where each element is completely discrete from other elements but classified according to 2 orthogonal dimensions. The degree to which the data or metadata is structured
3663-560: Is in its final stage for publication in 2015 or early 2016. It has been revised to align with the current edition of Part 3, ISO/IEC 11179-3:2013 which extends the MDR to support the registration of Concept Systems. (see ISO/IEC 11179 ). This standard specifies a schema for recording both the meaning and technical structure of the data for unambiguous usage by humans and computers. ISO/IEC 11179 standard refers to metadata as information objects about data, or "data about data". In ISO/IEC 11179 Part-3,
3774-454: Is more work to be done. Metadata (metacontent) or, more correctly, the vocabularies used to assemble metadata (metacontent) statements, is typically structured according to a standardized concept using a well-defined metadata scheme, including metadata standards and metadata models . Tools such as controlled vocabularies , taxonomies , thesauri , data dictionaries , and metadata registries can be used to apply further standardization to
3885-608: Is most commonly used in museum contexts for object identification and resource recovery purposes. Metadata is developed and applied within collecting institutions and museums in order to: Many museums and cultural heritage centers recognize that given the diversity of artworks and cultural objects, no single model or standard suffices to describe and catalog cultural works. For example, a sculpted Indigenous artifact could be classified as an artwork, an archaeological artifact, or an Indigenous heritage item. The early stages of standardization in archiving, description and cataloging within
3996-533: Is no intelligence or "inferencing" occurring, just the illusion thereof. Metadata schemata can be hierarchical in nature where relationships exist between metadata elements and elements are nested so that parent-child relationships exist between the elements. An example of a hierarchical metadata schema is the IEEE LOM schema, in which metadata elements may belong to a parent metadata element. Metadata schemata can also be one-dimensional, or linear, where each element
4107-503: Is not desirable to have a task wait, but because of the operator-level recoverability, this is not forced and therefore makes programming much simpler. In addition to the ability to dynamically remap file (or database) requests to other files (or databases), before or during program execution, several mechanisms are available to allow programmers to detect and recover from errors. One way, an 'ON' statement, has been around for many years. Specific faults (e.g., divide by zero) can be listed, or
4218-636: Is not only on creation and capture, but moreover on maintenance costs. As soon as the metadata structures become outdated, so too is the access to the referred data. Hence granularity must take into account the effort to create the metadata as well as the effort to maintain it. In all cases where the metadata schemata exceed the planar depiction, some type of hypermapping is required to enable display and view of metadata according to chosen aspect and to serve special views. Hypermapping frequently applies to layering of geographical and geological information overlays. International standards apply to metadata. Much work
4329-508: Is not recoverable except by privileged tasks using an UNSAFE form of try. MCP thus provides a very fault-tolerant environment, not the crash-and-burn core-dump of other systems. As with file attributes, tasks have attributes as well, such as the task priority (which is assigned at compile time or execution time, or can be changed while the task is running), processor time, wait time, status, etc. These task attributes can be accessed programmatically as can file attributes of files. The parent task
4440-494: Is often automatically added to files by authoring applications or by devices used to produce the files, without user intervention. While metadata in files are useful for finding them, they can be a privacy hazard when the files are shared. Using metadata removal tools to clean files before sharing them can mitigate this risk. Metadata may be written into a digital photo file that will identify who owns it, copyright and contact information, what brand or model of camera created
4551-403: Is often created by journal publishers and citation databases such as PubMed and Web of Science . The data contained within manuscripts or accompanying them as supplementary material is less often subject to metadata creation, though they may be submitted to e.g. biomedical databases after publication. The original authors and database curators then become responsible for metadata creation, with
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4662-412: Is referred to as "granularity" . "Granularity" refers to how much detail is provided. Metadata with a high granularity allows for deeper, more detailed, and more structured information and enables a greater level of technical manipulation. A lower level of granularity means that metadata can be created for considerably lower costs but will not provide as detailed information. The major impact of granularity
4773-774: Is saved as persistent repository and describe business objects in various enterprise systems and applications. Structural metadata commonality is also important to support data virtualization. Standardization and harmonization work has brought advantages to industry efforts to build metadata systems in the statistical community. Several metadata guidelines and standards such as the European Statistics Code of Practice and ISO 17369:2013 ( Statistical Data and Metadata Exchange or SDMX) provide key principles for how businesses, government bodies, and other entities should manage statistical data and metadata. Entities such as Eurostat , European System of Central Banks , and
4884-523: Is stored in the integrated library management system, ILMS , using the MARC metadata standard. The purpose is to direct patrons to the physical or electronic location of items or areas they seek as well as to provide a description of the item/s in question. More recent and specialized instances of library metadata include the establishment of digital libraries including e-print repositories and digital image libraries. While often based on library principles,
4995-467: Is that all synchronization is provided in the library and client code does not need to worry about this level of programming at all. This results in robust code since clients can't undermine the synchronization code in the library. (Some would call this a ' Trusted Computing Initiative'.) Libraries are more sophisticated forms of libraries on other systems such as DLLs . MCP libraries can be 'shared by all', ‘shared by rununit’ or 'private'. The private case
5106-485: Is the bibliographic classification, the subject, the Dewey Decimal class number . There is always an implied statement in any "classification" of some object. To classify an object as, for example, Dewey class number 514 (Topology) (i.e. books having the number 514 on their spine) the implied statement is: "<book><subject heading><514>". This is a subject-predicate-object triple, or more importantly,
5217-466: Is the default volume name if none is specified. Each file in the system has a set of file attributes. These attributes record all sorts of meta data about a file, most importantly its name and its type (which tells the system how to handle a file, like the more limited four-character file type code on the Macintosh ). Other attributes have the file's record size (if fixed for commercial applications),
5328-462: Is the only dynamic implementation of COBOL rununits. If this was the first invocation of the library, the library would run its main program (outer block in an ALGOL program) to initialize its global environment. Once initialization was complete, it would execute a freeze, at which point all exported entry points would be made available to clients. At this point, the library's stack was said to be frozen since nothing more would be run on this stack until
5439-484: Is the use by the US Census Bureau of what is known as the "Long Form". The Long Form asks questions that are used to create demographic data to find patterns of distribution. Libraries employ metadata in library catalogues , most commonly as part of an Integrated Library Management System . Metadata is obtained by cataloging resources such as books, periodicals, DVDs, web pages or digital images. This data
5550-567: Is usually expressed as a set of keywords in a natural language. According to Ralph Kimball , metadata can be divided into three categories: technical metadata (or internal metadata), business metadata (or external metadata), and process metadata . NISO distinguishes three types of metadata: descriptive, structural, and administrative. Descriptive metadata is typically used for discovery and identification, as information to search and locate an object, such as title, authors, subjects, keywords, and publisher. Structural metadata describes how
5661-420: Is very widely collected by various national governmental organizations. This data is used for the purposes of traffic analysis and can be used for mass surveillance . Metadata was traditionally used in the card catalogs of libraries until the 1980s when libraries converted their catalog data to digital databases . In the 2000s, as data and information were increasingly stored digitally, this digital data
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#17327721002695772-420: The U.S. Environmental Protection Agency have implemented these and other such standards and guidelines with the goal of improving "efficiency when managing statistical business processes". Metadata has been used in various ways as a means of cataloging items in libraries in both digital and analog formats. Such data helps classify, aggregate, identify, and locate a particular book, DVD, magazine, or any object
5883-419: The contents and context of data or data files increases its usefulness. For example, a web page may include metadata specifying what software language the page is written in (e.g., HTML), what tools were used to create it, what subjects the page is about, and where to find more information about the subject. This metadata can automatically improve the reader's experience and make it easier for users to find
5994-503: The B5000 to the B6700. The single-pass compiler for ESPOL could compile over 250 lines per second. ESPOL was superseded by NEWP in the early 1970s. This programming-language -related article is a stub . You can help Misplaced Pages by expanding it . Meta data Metadata (or metainformation ) is " data that provides information about other data", but not the content of
6105-499: The CCO, are integrated within a Museum's Collections Management System (CMS), a database through which museums are able to manage their collections, acquisitions, loans and conservation. Scholars and professionals in the field note that the "quickly evolving landscape of standards and technologies" creates challenges for cultural documentarians, specifically non-technically trained professionals. Most collecting institutions and museums use
6216-451: The Job resides in one of several user defined Job Queues. The next state is "Scheduled" as the Job moves from a queue into memory. Tasks within a job do not wait in queue; instead going directly to the 'Scheduled' state when initiated. Once a Job or Task is started, it can transition between "Active," "Waiting" and "Scheduled" as it progresses. Once a Job or Task completes, it moves to the 'Completed' state. Running processes are those that use
6327-563: The Library of Congress Controlled Vocabularies are reputable within the museum community and are recommended by CCO standards. Museums are encouraged to use controlled vocabularies that are contextual and relevant to their collections and enhance the functionality of their digital information systems. Controlled Vocabularies are beneficial within databases because they provide a high level of consistency, improving resource retrieval. Metadata structures, including controlled vocabularies, reflect
6438-545: The Product Planning Department from 1960 to 1968. He refers to “a control program” (presumably the MCP then under development) in his book ‘Fundamental Algorithms’ in section 2.5 on Dynamic Storage Allocation , Knuth claims credit for “The “boundary-tag” method, introduced in Section 2.5, was designed by the author in 1962 for use in a control program for the B5000 computer.” Unisys stopped producing
6549-812: The assistance of automated processes. Comprehensive metadata for all experimental data is the foundation of the FAIR Guiding Principles , or the standards for ensuring research data are findable , accessible , interoperable , and reusable . Such metadata can then be utilized, complemented, and made accessible in useful ways. OpenAlex is a free online index of over 200 million scientific documents that integrates and provides metadata such as sources, citations , author information , scientific fields , and research topics. Its API and open source website can be used for metascience, scientometrics , and novel tools that query this semantic web of papers . Another project under development, Scholia , uses
6660-540: The asynchronous processes, which could still access global variables and other variables at lower lex levels. Libraries completely inverted this scenario with the following advantages: So clean and radical was the library mechanism that much system software underwent major rewrites resulting in a better structured systems and performance boosts. Libraries were introduced to MCP systems in the early 1980s, having been developed by Roy Guck and others at Burroughs . They are very much like C. A. R. Hoare 's monitors and provide
6771-563: The author is, when the document was written, and a short summary of the document. Metadata within web pages can also contain descriptions of page content, as well as key words linked to the content. These links are often called "Metatags", which were used as the primary factor in determining order for a web search until the late 1990s. The reliance on metatags in web searches was decreased in the late 1990s because of "keyword stuffing", whereby metatags were being largely misused to trick search engines into thinking some websites had more relevance in
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#17327721002696882-478: The base OS code over the years, and are now available to all customers. As such, the MCP could be considered one of the earliest open-source projects. Burroughs was not the first manufacturer to distribute source code and was a late entry to electronic computing (compared to its traditional rivals NCR, IBM, and Univac). Now that MCP runs on commodity hardware, some elements of the MCP based software suite are no longer made available in source form by Unisys. The MCP
6993-456: The block size (in multiples of records that tells the MCP how many records to read and write in a single physical IO) and an area size in multiples of blocks, which gives the size of disk areas to be allocated as the file expands. The file type indicates if the file is character data, or source code written in particular languages, binary data, or code files. Files are protected by the usual security access mechanisms such as public or private, or
7104-525: The catch-all 'anyfault' can be used. The statement or block following the 'ON' statement is recognized by the compiler as fault-handling code. During execution, if a recoverable fault occurs in scope of the 'on' statement, the stack is cut back and control transferred to the statement following it. One problem with the handling logic behind the ON statement was that it would only be invoked for program faults, not for program terminations having other causes. Over time,
7215-425: The client is then linked to that instance of the library. All clients share the same instance. Shared by rununit is a sharing mechanism in between these two sharing schemes. It was designed specifically for COBOL, where a rununit is defined as the original initiating client program and all the libraries it has linked to. Each rununit gets one instance of the library and different rununits get a different instance. This
7326-574: The components of an object are organized. An example of structural metadata would be how pages are ordered to form chapters of a book. Finally, administrative metadata gives information to help manage the source. Administrative metadata refers to the technical information, such as file type, or when and how the file was created. Two sub-types of administrative metadata are rights management metadata and preservation metadata. Rights management metadata explains intellectual property rights , while preservation metadata contains information to preserve and save
7437-428: The components of metacontent statements, whether for indexing or finding, is endorsed by ISO 25964 : "If both the indexer and the searcher are guided to choose the same term for the same concept, then relevant documents will be retrieved." This is particularly relevant when considering search engines of the internet, such as Google. The process indexes pages and then matches text strings using its complex algorithm; there
7548-741: The content is desirable. This is particularly useful in video applications such as Automatic Number Plate Recognition and Vehicle Recognition Identification software, wherein license plate data is saved and used to create reports and alerts. There are 2 sources in which video metadata is derived: (1) operational gathered metadata, that is information about the content produced, such as the type of equipment, software, date, and location; (2) human-authored metadata, to improve search engine visibility, discoverability, audience engagement, and providing advertising opportunities to video publishers. Avid's MetaSync and Adobe's Bridge are examples of professional video editing software with access to metadata. Information on
7659-762: The data itself, such as the text of a message or the image itself. There are many distinct types of metadata, including: Metadata is not strictly bound to one of these categories, as it can describe a piece of data in many other ways. Metadata has various purposes. It can help users find relevant information and discover resources . It can also help organize electronic resources, provide digital identification, and archive and preserve resources. Metadata allows users to access resources by "allowing resources to be found by relevant criteria, identifying resources, bringing similar resources together, distinguishing dissimilar resources, and giving location information". Metadata of telecommunication activities including Internet traffic
7770-464: The data, when it was collected, how it was processed, and what formats it's available in, and then delivers the context for the data to be used effectively. Metadata can be created either by automated information processing or by manual work. Elementary metadata captured by computers can include information about when an object was created, who created it, when it was last updated, file size, and file extension. In this context an object refers to any of
7881-413: The data; it is used to summarize basic information about data that can make tracking and working with specific data easier. Some examples include: For example, a digital image may include metadata that describes the size of the image, its color depth, resolution, when it was created, the shutter speed, and other data. A text document's metadata may contain information about how long the document is, who
7992-406: The departure of Gene Amdahl , Burroughs software only ever ran on Burroughs hardware due to a lack of compatible third party hardware. For this reason, Burroughs was free to distribute the source code of all software it sold, including the MCP, which was designed with this openness in mind. For example, upgrading required the user to recompile the system software and apply any needed local patches. At
8103-411: The disk space where non memory resident data may be overlaid. Memory may be SAVE (i.e., memory resident), OVERLAYABLE (i.e., virtual memory) or STICKY (meaning memory resident, but movable). They are called upon e.g. by HARDWAREINTERRUPT when a process addresses an uninitialized array or by FILEOPEN . HARDWAREINTERRUPT handles hardware interrupts and may call upon GETSPACE , IO_FINISH or
8214-467: The efforts to describe and standardize the varied accessibility needs of information seekers are beginning to become more robust, their adoption into established metadata schemas has not been as developed. For example, while Dublin Core (DC)'s "audience" and MARC 21's "reading level" could be used to identify resources suitable for users with dyslexia and DC's "format" could be used to identify resources available in braille, audio, or large print formats, there
8325-506: The file, along with exposure information (shutter speed, f-stop, etc.) and descriptive information, such as keywords about the photo, making the file or image searchable on a computer and/or the Internet. Some metadata is created by the camera such as, color space, color channels, exposure time, and aperture (EXIF), while some is input by the photographer and/or software after downloading to a computer. Most digital cameras write metadata about
8436-509: The first. During execution, if any recoverable termination occurs in the code following the 'try' clause, the stack is cut back if required, and control branches to the code following the first 'else'. In addition, attributes are set to allow the program to determine what happened and where (including the specific line number). Most events that would result in task termination are recoverable. This includes stack overflow, array access out-of-bounds, integer over/under flow, etc. Operator (or user) DS
8547-446: The focus on non-librarian use, especially in providing metadata, means they do not follow traditional or common cataloging approaches. Given the custom nature of included materials, metadata fields are often specially created e.g. taxonomic classification fields, location fields, keywords, or copyright statement. Standard file information such as file size and format are usually automatically included. Library operation has for decades been
8658-425: The following: A metadata engine collects, stores and analyzes information about data and metadata in use within a domain. Data virtualization emerged in the 2000s as the new software technology to complete the virtualization "stack" in the enterprise. Metadata is used in data virtualization servers which are enterprise infrastructure components, alongside database and application servers. Metadata in these servers
8769-463: The hardware in the early 2010s, and the operating system is now run under emulation. The MCP provides a file system with hierarchical directory structures. In early MCP implementations, directory nodes were represented by separate files with directory entries, as other systems did. However, since about 1970, MCP internally uses a 'FLAT' directory listing all file paths on a volume. This is because opening files by visiting and opening each directory in
8880-638: The information objects are data about Data Elements, Value Domains, and other reusable semantic and representational information objects that describe the meaning and technical details of a data item. This standard also prescribes the details for a metadata registry, and for registering and administering the information objects within a Metadata Registry. ISO/IEC 11179 Part 3 also has provisions for describing compound structures that are derivations of other data elements, for example through calculations, collections of one or more data elements, or other forms of derived data. While this standard describes itself originally as
8991-417: The level of contribution and the responsibilities. Moreover, various metadata about scientific outputs can be created or complemented – for instance, scite.ai attempts to track and link citations of papers as 'Supporting', 'Mentioning' or 'Contrasting' the study. Other examples include developments of alternative metrics – which, beyond providing help for assessment and findability, also aggregate many of
9102-531: The library became unfrozen, in which case clean-up and termination code would be run. When a client calls a routine in a library, that routine runs on top of the client stack, storing its locals and temporary variables there. This allows many clients to be running the same routine at the same time, being synchronized by the library routine, which accesses the data in the global environment of the library stack. Executive Systems Problem Oriented Language The Executive Systems Problem Oriented Language ( ESPOL )
9213-399: The like. BLOCKEXIT is called upon by a task exiting a block. BLOCKEXIT may in turn call FILECLOSE , FORGETSPACE or the like while cleaning up and releasing resources declared and used within that block. J_EDGAR_HOOVER is the main security guardian of the system, called upon at process start, file open, user log on, etc. GEORGE is the procedure that decides which process is
9324-434: The location the photo was taken from may also be included. Photographic Metadata Standards are governed by organizations that develop the following standards. They include, but are not limited to: Metadata is particularly useful in video, where information about its contents (such as transcripts of conversations and text descriptions of its scenes) is not directly understandable by a computer, but where an efficient search of
9435-438: The metadata application is manifold, covering a large variety of fields, there are specialized and well-accepted models to specify types of metadata. Bretherton & Singley (1994) distinguish between two distinct classes: structural/control metadata and guide metadata. Structural metadata describes the structure of database objects such as tables, columns, keys and indexes. Guide metadata helps humans find specific items and
9546-463: The metadata of scientific publications for various visualizations and aggregation features such as providing a simple user interface summarizing literature about a specific feature of the SARS-CoV-2 virus using Wikidata 's "main subject" property. In research labor, transparent metadata about authors' contributions to works have been proposed – e.g. the role played in the production of the paper,
9657-524: The metadata. Structural metadata commonality is also of paramount importance in data model development and in database design . Metadata (metacontent) syntax refers to the rules created to structure the fields or elements of metadata (metacontent). A single metadata scheme may be expressed in a number of different markup or programming languages, each of which requires a different syntax. For example, Dublin Core may be expressed in plain text, HTML , XML , and RDF . A common example of (guide) metacontent
9768-720: The model number, shutter speed, etc., and some enable you to edit it; this functionality has been available on most Nikon DSLRs since the Nikon D3 , on most new Canon cameras since the Canon EOS 7D , and on most Pentax DSLRs since the Pentax K-3. Metadata can be used to make organizing in post-production easier with the use of key-wording. Filters can be used to analyze a specific set of photographs and create selections on criteria like rating or capture time. On devices with geolocation capabilities like GPS (smartphones in particular),
9879-683: The museum community began in the late 1990s with the development of standards such as Categories for the Description of Works of Art (CDWA), Spectrum, CIDOC Conceptual Reference Model (CRM), Cataloging Cultural Objects (CCO) and the CDWA Lite XML schema. These standards use HTML and XML markup languages for machine processing, publication and implementation. The Anglo-American Cataloguing Rules (AACR), originally developed for characterizing books, have also been applied to cultural objects, works of art and architecture. Standards, such as
9990-486: The need for guaranteed handling of abnormal terminations grew. In particular, a mechanism was needed to allow programs to invoke plug-ins written by customers or third parties without any risk should the plug-in behave badly. In addition to general plug-in mechanisms, the new form of dynamic library linkage ( Connection Libraries ) allows programs to import and export functions and data, and hence one program runs code supplied by another. To accomplish such enhanced protection,
10101-549: The next one to receive CPU resources and is thus one of the few processes that uses the MoveStack instruction. A task goes through various states starting with NASCENT. At DELIVERY the event BIRTH is caused and the task's state changes to ALIVE. When PROCESSKILL is called upon, the state changes into DISEASED. When DEATH is caused the task gets put into the queue structure the MORGUE, after which all remaining resources are freed to
10212-427: The numbers themselves can be perceived as the data. But if given the context that this database is a log of a book collection, those 13-digit numbers may now be identified as ISBNs – information that refers to the book, but is not itself the information within the book. The term "metadata" was coined in 1968 by Philip Bagley, in his book "Extension of Programming Language Concepts" where it
10323-635: The object by cultural documentarians. The established institutional cataloging practices, goals, and expertise of cultural documentarians and database structure also influence the information ascribed to cultural objects and the ways in which cultural objects are categorized. Additionally, museums often employ standardized commercial collection management software that prescribes and limits the ways in which archivists can describe artworks and cultural objects. As well, collecting institutions and museums use Controlled Vocabularies to describe cultural objects and artworks in their collections. Getty Vocabularies and
10434-433: The operator are listed in the complete entries as O-DS. Tasks can also terminate due to program faults, marked as F-DS or P-DS, for faults such as invalid index , numeric overflow , etc. Completed entries can be listed by the operator with the 'C' command. Tasks waiting on a resource are listed under the waiting entries and the reason for waiting. All waiting tasks may be listed with the 'W' command. The reason for waiting
10545-426: The operator. All running and ready processes are displayed as 'Active' tasks (since the system implements preemptive multitasking , the change from ready to running and back is so quick that distinguishing ready and running tasks is pointless because they will all get a slice of the processor within a second). All active tasks can be displayed with the 'A' command. Terminated tasks are displayed as completed tasks with
10656-482: The opportunity for controlled mutual exclusion and synchronization between client processes, using MCP EVENTs and the Dahm locking technique. Libraries offer procedural entry-points to the client, which are checked for a compatible interface (all parameters and return types of imported procedures checked) before the client is linked to the library. The library and its client may be written in different languages. The advantage
10767-456: The priority of tasks that do not use their full processor slice. This allows an IO bound task to get processor time ahead of a processor bound task on the same declared priority. Processes that are waiting on other resources, such as a file read, wait on the EVENT data structure . Thus all processes waiting on a single resource wait on a single event. When the resource becomes available, the event
10878-588: The public discussions about a scientific paper on social media such as Reddit , citations on Misplaced Pages , and reports about the study in the news media – and a call for showing whether or not the original findings are confirmed or could get reproduced . Metadata in a museum context is the information that trained cultural documentation specialists, such as archivists , librarians , museum registrars and curators , create to index, structure, describe, identify, or otherwise specify works of art, architecture, cultural objects and their images. Descriptive metadata
10989-516: The purposes of discovery. The original set of 15 classic metadata terms, known as the Dublin Core Metadata Element Set are endorsed in the following standards documents: The W3C Data Catalog Vocabulary (DCAT) is an RDF vocabulary that supplements Dublin Core with classes for Dataset, Data Service, Catalog, and Catalog Record. DCAT also uses elements from FOAF, PROV-O, and OWL-Time. DCAT provides an RDF model to support
11100-485: The reason for termination, EOT for normal 'end of task', and DSed with a reason for a process failure. All processes are assigned a mix number, and operators can use this number to identify a process to control. One such command is the DS command (which stands for either Delete from Schedule, DiScontinue, or Deep Six, after the influence of Navy personnel on early computer projects, depending on who you talk to). Tasks terminated by
11211-452: The registration and administration portion of the standard. The Geospatial community has a tradition of specialized geospatial metadata standards, particularly building on traditions of map- and image-libraries and catalogs. Formal metadata is usually essential for geospatial data, as common text-processing approaches are not applicable. The Dublin Core metadata terms are a set of vocabulary terms that can be used to describe resources for
11322-542: The resource cannot be provided by the operator, the operator can DS the task as a last resort. This is different from other systems, which automatically terminate a task when a resource such as a file is not available. The MCP provides this level of operator recoverability of tasks. Other systems force programmers to add code to check for the presence of files before accessing them, and thus extra code must be written in every case to provide recoverability, or process synchronization. Such code may be written in an MCP program when it
11433-493: The search than they really did. Metadata can be stored and managed in a database , often called a metadata registry or metadata repository . However, without context and a point of reference, it might be impossible to identify metadata just by looking at it. For example: by itself, a database containing several numbers, all 13 digits long could be the results of calculations or a list of numbers to plug into an equation – without any other context,
11544-403: The system by a process called PROCESSKILL. While the task is ALIVE, MCP functions are run on top of that particular process, thus CPU resources are automatically charged to the task causing the MCP overhead. Also, much of the MCP work is being performed with that particular stack's security rights. Only before BIRTH and after DEATH does the MCP need to be operating out of some other stack. If none
11655-474: The term. In these fields, the word metadata is defined as "data about data". While this is the generally accepted definition, various disciplines have adopted their own more specific explanations and uses of the term. Slate reported in 2013 that the United States government's interpretation of "metadata" could be broad, and might include message content such as the subject lines of emails. While
11766-537: The time, this was common practice, and was necessary as it was not unusual for customers (especially large ones, such as the Federal Reserve ) to modify the program to fit their specific needs. As a result, a Burroughs Users Group was formed, which held annual meetings and allowed users to exchange their own extensions to the OS and other parts of the system software suite. Many such extensions have found their way into
11877-601: The times, origins and destinations of phone calls, electronic messages, instant messages, and other modes of telecommunication, as opposed to message content, is another form of metadata. Bulk collection of this call detail record metadata by intelligence agencies has proven controversial after disclosures by Edward Snowden of the fact that certain Intelligence agencies such as the NSA had been (and perhaps still are) keeping online metadata on millions of internet users for up to
11988-450: The typical structure of a catalog that contains records, each describing a dataset or service. Although not a standard, Microformat (also mentioned in the section metadata on the internet below) is a web-based approach to semantic markup which seeks to re-use existing HTML/XHTML tags to convey metadata. Microformat follows XHTML and HTML standards but is not a standard in itself. One advocate of microformats, Tantek Çelik , characterized
12099-439: The web page online. A CD may include metadata providing information about the musicians, singers, and songwriters whose work appears on the disc. In many countries, government organizations routinely store metadata about emails, telephone calls, web pages, video traffic, IP connections, and cell phone locations. Metadata means "data about data". Metadata is defined as the data providing information about one or more aspects of
12210-628: Was described using metadata standards . The first description of "meta data" for computer systems is purportedly noted by MIT's Center for International Studies experts David Griffel and Stuart McIntosh in 1967: "In summary then, we have statements in an object language about subject descriptions of data and token codes for the data. We also have statements in a meta language describing the data relationships and transformations, and ought/is relations between norm and data." Unique metadata standards exist for different disciplines (e.g., museum collections, digital audio files , websites , etc.). Describing
12321-472: Was the first commercial OS to provide virtual memory , which has been supported by the Burroughs large systems architecture since its inception. This scheme is unique in the industry, as it stores and retrieves compiler-defined objects rather than fixed-size memory pages, as a consequence of its overall non-von Neumann and uniformly stack-based architecture. Donald Knuth also had influence during this period, becoming consultant to Burroughs Corporation, joining
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