|
MCP (Burroughs Large Systems)
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. 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 a high-level language. History 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 har ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burroughs Corporation
The Burroughs Corporation was a major American manufacturer of business equipment. The company was founded in 1886 as the American Arithmometer Company by William Seward Burroughs I, William Seward Burroughs. The company's history paralleled many of the major developments in history of computing, computing. At its start, it produced mechanical adding machines, and later moved into programmable ledgers and then computers. It was one of the largest producers of mainframe computers in the world, also producing related equipment including typewriters and Printer (computing), printers. In the 1960s, the company introduced a range of mainframe computers that were well regarded for their performance running high level languages. These formed the core of the company's business into the 1970s. At that time the emergence of superminicomputers and the dominance of the IBM System/360 and 370 at the high end led to shrinking markets, and in 1986 the company purchased former competitor Sperry C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Art Of Computer Programming
''The Art of Computer Programming'' (''TAOCP'') is a comprehensive multi-volume monograph written by the computer scientist Donald Knuth presenting programming algorithms and their analysis. it consists of published volumes 1, 2, 3, 4A, and 4B, with more expected to be released in the future. The Volumes 1–5 are intended to represent the central core of computer programming for sequential machines; the subjects of Volumes 6 and 7 are important but more specialized. When Knuth began the project in 1962, he originally conceived of it as a single book with twelve chapters. The first three volumes of what was then expected to be a seven-volume set were published in 1968, 1969, and 1973. Work began in earnest on Volume 4 in 1973, but was suspended in 1977 for work on typesetting prompted by the second edition of Volume 2. Writing of the final copy of Volume 4A began in longhand in 2001, and the first online pre-fascicle, 2A, appeared later in 2001. The first published installment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Structure
In computer science, a data structure is a data organization and storage format that is usually chosen for Efficiency, efficient Data access, access to data. More precisely, a data structure is a collection of data values, the relationships among them, and the Function (computer programming), functions or Operator (computer programming), operations that can be applied to the data, i.e., it is an algebraic structure about data. Usage Data structures serve as the basis for abstract data types (ADT). The ADT defines the logical form of the data type. The data structure implements the physical form of the data type. Different types of data structures are suited to different kinds of applications, and some are highly specialized to specific tasks. For example, Relational database, relational databases commonly use B-tree indexes for data retrieval, while compiler Implementation, implementations usually use hash tables to look up Identifier (computer languages), identifiers. Data s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CANDE
CANDE (Command AND Edit) is a command line shell and text editor on the MCP (Master Control Program) operating system which runs on the Unisys Clearpath series of mainframes. Originally implemented on Burroughs large systems, it has a range of features for interacting with the operating system execution environment, focused on executing, editing and compiling programs, and creating, copying, moving, renaming, and deleting files in general. Its full name is CANDE MCS. MCS, or Message Control Subsystem is the general form of a systems program in the Burroughs architecture (other than MCP, the Master Control Program or core OS). As an MCS, CANDE is more than just an editor as it provides overall control for a network of users. The editing capabilities of CANDE are anachronistic for casual (as opposed to scripted) editing as they predate full screen and graphical editors. CANDE was also used on the Burroughs CMS (mini computer) range, with very similar syntax. In contemporary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Task (computing)
In computers, computing, a task is a unit of execution (computing), execution or a unit of work. The term is ambiguous; precise alternative terms include ''process (computing), process'', light-weight process, ''thread (computing), thread'' (for execution), ''step'', ''request–response, request'', or ''query'' (for work). In the adjacent diagram, there are task queue, queues of incoming work to do and outgoing completed work, and a thread pool of threads to perform this work. Either the work units themselves or the threads that perform the work can be referred to as "tasks", and these can be referred to respectively as requests/responses/threads, incoming tasks/completed tasks/threads (as illustrated), or requests/responses/tasks. Terminology In the sense of "unit of execution", in some operating systems, a task is synonymous with a process (computing), process, and in others with a thread (computing), thread. In non-interactive execution (batch processing), a task is a unit o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Job (computing)
In computing, a job is a unit of work or unit of execution (that performs said work). A component of a job (as a unit of work) is called a ''task (computing), task'' or a ''step'' (if sequential, as in a job stream). As a unit of execution, a job may be concretely identified with a single process (computing), process, which may in turn have subprocesses (child processes; the process corresponding to the job being the parent process) which perform the tasks or steps that comprise the work of the job; or with a process group; or with an abstract reference to a process or process group, as in Unix job control. Jobs can be started interactively, such as from a command line, or scheduled for non-interactive execution by a job scheduler, and then controlled via automatic or manual job control (computing), job control. Jobs that have finite input can complete, successfully or unsuccessfully, or fail to complete and eventually be terminated. By contrast, online processing such as by serv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Process (computing)
In computing, a process is the Instance (computer science), instance of a computer program that is being executed by one or many thread (computing), threads. There are many different process models, some of which are light weight, but almost all processes (even entire virtual machines) are rooted in an operating system (OS) process which comprises the program code, assigned system resources, physical and logical access permissions, and data structures to initiate, control and coordinate execution activity. Depending on the OS, a process may be made up of multiple threads of execution that execute instructions Concurrency (computer science), concurrently. While a computer program is a passive collection of Instruction set, instructions typically stored in a file on disk, a process is the execution of those instructions after being loaded from the disk into memory. Several processes may be associated with the same program; for example, opening up several instances of the same progra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Case-preserving
In file systems, case preservation is the preservation of the letter case (uppercase or lowercase) of letters in file names. If an attempt is made to create a file named "ThisIsAFile" on a file system that preserves letter case, the file's name will be "ThisIsAFile", rather than, for example, "thisisafile" or "THISISAFILE". In contrast, a file system that does not preserve letter case will typically store letters in file names either as all lowercase or as all uppercase, and the letter case information will thus be lost. If an attempt is made to create a file named "ThisIsAFile" on a file system that does not preserve letter case, the file's name will be "thisisafile" if letters are stored as all lowercase or "THISISAFILE" if letters are stored as all uppercase. Combinations of preservation and sensitivity Case-preserving, case-insensitive It is possible and common for a system to be case-insensitive, yet case-preserving. This combination is often considered most natural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Case-insensitive
In computers, case sensitivity defines whether uppercase and lowercase letters are treated as distinct (case-sensitive) or equivalent (case-insensitive). For instance, when users interested in learning about dogs search an e-book, "dog" and "Dog" are of the same significance to them. Thus, they request a case-insensitive search. But when they search an online encyclopedia for information about the United Nations, for example, or something with no ambiguity regarding capitalization and ambiguity between two or more terms cut down by capitalization, they may prefer a case-sensitive search. Areas of significance Case sensitivity may differ depending on the situation: * Searching: Users expect information retrieval systems to be able to have correct case sensitivity depending on the nature of an operation. Users looking for the word "dog" in an online journal probably do not wish to differentiate between "dog" or "Dog", as this is a writing distinction; the word should be matched w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journaling File System
A journaling file system is a file system that keeps track of changes not yet committed to the file system's main part by recording the goal of such changes in a data structure known as a " journal", which is usually a circular log. In the event of a system crash or power failure, such file systems can be brought back online more quickly with a lower likelihood of becoming corrupted. Depending on the actual implementation, a journaling file system may only keep track of stored metadata, resulting in improved performance at the expense of increased possibility for data corruption. Alternatively, a journaling file system may track both stored data and related metadata, while some implementations allow selectable behavior in this regard. History In 1990 IBM introduced JFS in AIX 3.1 as one of the first UNIX commercial filesystems that implemented journaling. The next year the idea was popularized in a widely cited paper on log-structured file systems. This was subsequentl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macintosh
Mac is a brand of personal computers designed and marketed by Apple Inc., Apple since 1984. The name is short for Macintosh (its official name until 1999), a reference to the McIntosh (apple), McIntosh apple. The current product lineup includes the MacBook Air and MacBook Pro laptops, and the iMac, Mac Mini, Mac Studio, and Mac Pro desktops. Macs are currently sold with Apple's UNIX-based macOS operating system, which is Proprietary software, not licensed to other manufacturers and exclusively Pre-installed software, bundled with Mac computers. This operating system replaced Apple's original Macintosh operating system, which has variously been named System, Mac OS, and Classic Mac OS. Jef Raskin conceived the Macintosh project in 1979, which was usurped and redefined by Apple co-founder Steve Jobs in 1981. The original Macintosh 128K, Macintosh was launched in January 1984, after Apple's 1984 (advertisement), "1984" advertisement during Super Bowl XVIII. A series of increment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meta Data
Metadata (or metainformation) is "data that provides information about other data", but not the content of the data itself, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive information about a resource. It is used for discovery and identification. It includes elements such as title, abstract, author, and keywords. * Structural metadata – metadata about containers of data and indicates how compound objects are put together, for example, how pages are ordered to form chapters. It describes the types, versions, relationships, and other characteristics of digital materials. * Administrative metadata – the information to help manage a resource, like resource type, and permissions, and when and how it was created. * Reference metadata – the information about the contents and quality of statistical data. * Statistical metadata – also called process data, may describe processes tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
