|
Job Control Block
In computing, job control refers to the control of multiple tasks or jobs on a computer system, ensuring that they each have access to adequate resources to perform correctly, that competition for limited resources does not cause a deadlock where two or more jobs are unable to complete, resolving such situations where they do occur, and terminating jobs that, for any reason, are not performing as expected. Job control has developed from the early days of computers where human operators were responsible for setting up, monitoring and controlling every job, to modern operating systems, which take on the bulk of the work of job control. Even with a highly sophisticated scheduling system, some human intervention is desirable. Modern systems permit their users to stop and resume jobs, to execute them in the foreground (with the ability to interact with the user) or in the background. Unix-like systems follow this pattern. History It became obvious to the early computer develope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and software. Computing has scientific, engineering, mathematical, technological, and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology, and software engineering. The term ''computing'' is also synonymous with counting and calculation, calculating. In earlier times, it was used in reference to the action performed by Mechanical computer, mechanical computing machines, and before that, to Computer (occupation), human computers. History The history of computing is longer than the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Job Queue
In system software, a job queue ( batch queue, input queue), is a data structure maintained by job scheduler software containing jobs to run. Users submit their programs that they want executed, "jobs", to the queue for batch processing. The scheduler software maintains the queue as the pool of jobs available for it to run. Multiple batch queues might be used by the scheduler to differentiate types of jobs depending on parameters such as: * job priority * estimated execution time * resource requirements The use of a batch queue gives these benefits: * sharing of computer resources among many users * time-shifts job processing to when the computer is less busy * avoids idling the compute resources without minute-by-minute human supervision * allows around-the-clock high utilization of expensive computing resources Any process that comes to the CPU should wait in a queue. See also * Command pattern * Command queue * Job scheduler *Priority queue In computer science, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unisys
Unisys Corporation is a global technology solutions company founded in 1986 and headquartered in Blue Bell, Pennsylvania. The company provides cloud, AI, digital workplace, logistics, and enterprise computing services. History Founding Unisys’ history dates back to 1873 with E. Remington & Sons and the introduction of the first commercially viable typewriter to use the QWERTY keyboard layout. Over a hundred years later, the company became known as Unisys in 1986 through the merger of Mainframe computer, mainframe corporations Sperry Corporation, Sperry and Burroughs Corporation, Burroughs, with Burroughs buying Sperry for $4.8 billion. The new company's name was chosen from over 31,000 submissions in an internal competition when Christian Machen submitted the word "Unisys", which was composed of parts of the words "united", "information", and "systems". The merger was the largest in the computer industry at the time and made Unisys the second-largest computer company wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rexx
Rexx (restructured extended executor) is a high-level programming language developed at IBM by Mike Cowlishaw. Both proprietary and open-source software, open source Rexx interpreter (computing), interpreters exist for a wide range of computing platforms, and compilers exist for IBM mainframe computers. Rexx is used for scripting language, scripting, application software, application macro (computer science), macros and Software development, application development. As a general purpose scripting language, Rexx is considered a precursor to Tcl and Python (programming language), Python. Rexx is supported in a variety of environments. It is the primary scripting language in some operating systems including OS/2, MVS, VM (operating system), VM, AmigaOS and is used for macros in some software including SPF/PC, XEDIT#PC and Unix adaptations, KEDIT, The Hessling Editor, THE and ZOC (software), ZOC. With an engine installed, Rexx can be used for scripting and macros in programs that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CLIST
CLIST (Command List) (pronounced "C-List") is a procedural programming language for TSO in MVS systems. It originated in OS/360 Release 20 and has assumed a secondary role since the availability of Rexx in TSO/E Version 2. The term CLIST is also used for command lists written by users of NetView. In its basic form, a CLIST program (or "CLIST" for short) can take the form of a simple list of commands to be executed in strict sequence (like a DOS batch file (*.bat) file). However, CLIST also features If-Then-Else logic as well as loop constructs. CLIST is an interpreted language. That is, the computer must translate a CLIST every time the program is executed. CLISTs therefore tend to be slower than programs written in compiled languages such as COBOL, FORTRAN, or PL/1. (A program written in a compiled language is translated once to create a "load module" or executable.) CLIST can read/write MVS files and read/write from/to a TSO terminal. It can read parameters from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Sharing Option
Time Sharing Option (TSO) is an interactive time-sharing environment for IBM mainframe operating systems, including OS/360 MVT, OS/VS2 (SVS), MVS, OS/390, and z/OS. Use In computing, time-sharing is a design technique that allows many people to use a computer system concurrently and independently—without interfering with each other. Each TSO user is isolated; it appears to each one that they are the only user of the system. TSO is most commonly used by mainframe system administrators and programmers. It provides: * A text editor * Batch job support, including completion notification * Debuggers for some programming languages used on System/360 and later IBM mainframes * Support for other vendors' end-user applications, for example for querying IMS and DB2 databases TSO interacts with users in either a line-by-line mode or in a full screen, menu-driven mode. In the line-by-line mode, the user enters commands by typing them in at the keyboard; in turn, the system interp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command Language
A command language is a language for job control in computing. It is a domain-specific and interpreted language; common examples of a command language are shell or batch programming languages. These languages can be used directly at the command line, but can also automate tasks that would normally be performed manually at the command line. They share this domain—lightweight automation—with scripting languages, though a command language usually has stronger coupling to the underlying operating system. Command languages often have either very simple grammars or syntaxes very close to natural language, making them more intuitive to learn, as with many other domain-specific languages. See also * Command-line interface * In the Beginning... Was the Command Line * Batch processing * Job (computing) Notes External linksA longer definition. Programming language topics {{Prog-lang-stub РЩУж ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interactive Computing
In computer science, interactive computing refers to software which accepts input from the user as it runs. Interactive software includes commonly used programs, such as word processors or spreadsheet applications. By comparison, non-interactive programs operate without user intervention; examples of these include compilers and batch processing applications that are pre-programmed to run independently. Interactive computing focuses on real-time interaction ("dialog") between the computer and the operator, and the technologies that enable them. If the response of the computer system is complex enough, it is said that the system is conducting social interaction; some systems try to achieve this through the implementation of social interfaces. The nature of interactive computing as well as its impact on users, are studied extensively in the field of computer interaction. History of interactive computing systems Ivan Sutherland is considered the father of interactive computi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batch Processing
Computerized batch processing is a method of running software programs called jobs in batches automatically. While users are required to submit the jobs, no other interaction by the user is required to process the batch. Batches may automatically be run at scheduled times as well as being run contingent on the availability of computer resources. History The term "batch processing" originates in the traditional classification of methods of production as job production (one-off production), batch production (production of a "batch" of multiple items at once, one stage at a time), and flow production (mass production, all stages in process at once). Early history Early computers were capable of running only one program at a time. Each user had sole control of the machine for a scheduled period of time. They would arrive at the computer with program and data, often on punched paper cards and magnetic or paper tape, and would load their program, run and debug it, and carry off thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Punched Card
A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widely used for data processing, the control of automated machines, and computing. Early applications included controlling weaving looms and recording census data. Punched cards were widely used in the 20th century, where unit record equipment, unit record machines, organized into data processing systems, used punched cards for Input (computer science), data input, data output, and data storage. The IBM 12-row/80-column punched card format came to dominate the industry. Many early digital computers used punched cards as the primary medium for input of both computer programs and Data (computing), data. Punched cards were used for decades before being replaced by magnetic storage and terminals. Their influence persists in cultural references, sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Job Control Language
Job Control Language (JCL) is a scripting language used on IBM mainframe operating systems to instruct the system on how to run a batch processing, batch job or start a subsystem. The purpose of JCL is to say which programs to run, using which files or devices for input or output, and at times to also indicate under what conditions to skip a step. Parameters in the JCL can also provide accounting information for tracking the resources used by a job as well as which machine the job should run on. There are two distinct IBM Job Control Languages: * one for the operating system lineage that begins with DOS/360 and whose latest member is z/VSE; and * the other for the lineage from OS/360 to z/OS, the latter now including Job Entry Subsystem 2/3, JES extensions, #Job Entry Control Language, Job ''Entry'' Control Language (JECL). They share some basic syntax rules and a few basic concepts, but are otherwise very different. The VM (operating system), VM operating system does not have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batch Processing
Computerized batch processing is a method of running software programs called jobs in batches automatically. While users are required to submit the jobs, no other interaction by the user is required to process the batch. Batches may automatically be run at scheduled times as well as being run contingent on the availability of computer resources. History The term "batch processing" originates in the traditional classification of methods of production as job production (one-off production), batch production (production of a "batch" of multiple items at once, one stage at a time), and flow production (mass production, all stages in process at once). Early history Early computers were capable of running only one program at a time. Each user had sole control of the machine for a scheduled period of time. They would arrive at the computer with program and data, often on punched paper cards and magnetic or paper tape, and would load their program, run and debug it, and carry off thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
