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Ibm Mainframe Utility Programs
This article discusses support programs included in or available for OS/360 and successors. IBM categorizes some of these programs as utilities and others as service aids; the boundaries are not always consistent or obvious. Many, but not all, of these programs match the types in utility software. The following lists describe programs associated with OS/360 and successors. No DOS, TPF or VM utilities are included. History/Common JCL Many of these programs were designed by IBM users, through the group SHARE, and then modified or extended by IBM from versions originally written by a user. These programs are usually invoked via Job Control Language (JCL). They tend to use common JCL DD identifiers (in the OS, now z/OS operating systems) for their data sets: Dataset utilities IDCAMS IDCAMS ("Access Method Services") generates and modifies Virtual Storage Access Method (VSAM) and Non-VSAM datasets. IDCAMS was introduced along with VSAM in OS/VS; the "Access Method" reference deri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OS/360 And Successors
OS/360, officially known as IBM System/360 Operating System, is a discontinued batch processing operating system developed by IBM for their then-new System/360 mainframe computer, announced in 1964; it was influenced by the earlier IBSYS/IBJOB and Input/Output Control System (IOCS) packages for the IBM 7090/7094 and even more so by the PR155 Operating System for the IBM 1410/ 7010 processors. It was one of the earliestJust a few years after Atlas Supervisor, Burroughs MCP and GECOS operating systems to require the computer hardware to include at least one direct access storage device. Although OS/360 itself was discontinued, successor operating systems, including the virtual storage MVS and the 64-bit z/OS, are still run and maintain application-level compatibility with OS/360. Overview IBM announced three different levels of OS/360, generated from the same tapes and sharing most of their code. IBM eventually renamed these options and made some significant design changes: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mainframe Sort Merge
The Sort/Merge utility is a mainframe program to sort records in a file into a specified order, merge pre-sorted files into a sorted file, or copy selected records. Internally, these utilities use one or more of the standard sorting algorithms, often with proprietary fine-tuned code. Mainframes were originally supplied with limited main memory by today's standards and the amount of data to be sorted was frequently very large. Because of this, unlike more recent sort programs, early Sort/Merge programs placed great emphasis on efficient techniques for sorting data on secondary storage, typically tape or disk. In 1968 the OS/360 Sort/Merge program provided five different "sequence distribution techniques" that could be used depending on the number and type of devices available. Prior to the System/370, all IBM mainframe operating systems included sort/merge utilities. With the announcement of virtual storage operating systems, DOS/VS and OS/VS, IBM unbundled much of the software ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VTOC
In the IBM System/360Including the successors S/370 through z/Architecture storage architecture, the Volume Table of Contents (VTOC), is a data structure that provides a way of locating the data sets that reside on a particular DASD volume. With the exception of the ''IBM Z compatible disk layout''The VTOC for an IBM Z compatible minidisk has a VTOC with up to three datasets, each containing a Linux File system. in Linux on Z, it is the functional equivalent of the MS/PC DOS File Allocation Table (FAT), the Windows NT Master File Table (MFT), and the equivalent structure in, e.g., a Linux file system.While the VTOC only needs to associate names directly with storage allocations, a Linux file system has an indirect association via inodes. The VTOC is not used to contain any IPLTEXTHowever, the IPL text on cylinder 0 track 0 does read and use the VTOC. and does not have any role in the IPL process, therefore does not have any data used by or functionally equivalent to the MBR. It l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supervisor Call Instruction
A supervisor, or lead, (also known as foreman, boss, overseer, facilitator, monitor, area coordinator, line-manager or sometimes gaffer) is the job title of a lower-level management position that is primarily based on authority over workers or a workplace. A supervisor can also be one of the most senior in the staff at the place of work, such as a professor who oversees a PhD dissertation. Supervision, on the other hand, can be performed by people without this formal title, for example by parents. The term supervisor itself can be used to refer to any personnel who have this task as part of their job description. An employee is a supervisor if they have the power and authority to do the following actions (according to the Ontario Ministry of Labour): # Give instructions and/or orders to subordinates. # Be held responsible for the work and actions of other employees. If an employee cannot do the above, legally, they are probably not a supervisor, but in some other category, su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of technical limitations of computer systems at the time it was invented, ASCII has just 128 code points, of which only 95 are , which severely limited its scope. All modern computer systems instead use Unicode, which has millions of code points, but the first 128 of these are the same as the ASCII set. The Internet Assigned Numbers Authority (IANA) prefers the name US-ASCII for this character encoding. ASCII is one of the List of IEEE milestones, IEEE milestones. Overview ASCII was developed from telegraph code. Its first commercial use was as a seven-bit teleprinter code promoted by Bell data services. Work on the ASCII standard began in May 1961, with the first meeting of the American Standards Association's (ASA) (now the American Nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standalone Program
A stand-alone program, also known as a freestanding program, is a computer program that does not load any external module, library function or program and that is designed to boot with the bootstrap procedure of the target processor – it runs on bare metal. In early computers like the ENIAC without the concept of an operating system, standalone programs were the only way to run a computer. Standalone programs are usually written in or compiled to the assembly language for the specific hardware. Later standalone programs typically were provided for utility functions such as disk formatting. Also, computers with very limited memory used standalone programs, i.e. most computers until the mid-1950s, and later still embedded processors. Standalone programs are now mainly limited to SoC's or Microcontrollers (where battery life, price, and data space are at premiums) [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Programming
Systems programming, or system programming, is the activity of programming computer system software. The primary distinguishing characteristic of systems programming when compared to application programming is that application programming aims to produce software which provides services to the user directly (e.g. word processor), whereas systems programming aims to produce software and software platforms which provide services to other software, are performance constrained, or both (e.g. operating systems, computational science applications, game engines, industrial automation, and software as a service applications). Systems programming requires a great degree of hardware awareness. Its goal is to achieve efficient use of available resources, either because the software itself is performance critical or because even small efficiency improvements directly transform into significant savings of time or money. Overview The following attributes characterize systems programming: * The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assembly Language
In computer programming, assembly language (or assembler language, or symbolic machine code), often referred to simply as Assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence between the instructions in the language and the architecture's machine code instructions. Assembly language usually has one statement per machine instruction (1:1), but constants, comments, assembler directives, symbolic labels of, e.g., memory locations, registers, and macros are generally also supported. The first assembly code in which a language is used to represent machine code instructions is found in Kathleen and Andrew Donald Booth's 1947 work, ''Coding for A.R.C.''. Assembly code is converted into executable machine code by a utility program referred to as an ''assembler''. The term "assembler" is generally attributed to Wilkes, Wheeler and Gill in their 1951 book ''The Preparation of Programs for an Electronic Digital Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Return Address (computing)
In computer programming, a return statement causes execution to leave the current subroutine and resume at the point in the code immediately after the instruction which called the subroutine, known as its return address. The return address is saved by the calling routine, today usually on the process's call stack or in a register. Return statements in many programming languages allow a function to specify a return value to be passed back to the code that called the function. Overview In C and C++, return ''exp''; (where ''exp'' is an expression) is a statement that tells a function to return execution of the program to the calling function, and report the value of ''exp''. If a function has the return type void, the return statement can be used without a value, in which case the program just breaks out of the current function and returns to the calling one. In Pascal there is no return statement. (However, in newer Pascals, the Exit(''exp''); can be used to return a value imm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEFBR14
IEFBR14 is an IBM mainframe utility program. It runs in all IBM mainframe environments derived from OS/360, including z/OS. It is a placeholder that returns the exit status zero, similar to the true command on UNIX-like systems. Purpose Allocation (also called Initiation) On OS/360 and derived mainframe systems, most programs never specify files (usually called datasets) directly, but instead reference them indirectly through the Job Control Language (JCL) statements that invoke the programs. These data definition (or "DD") statements can include a "disposition" (DISP=...) parameter that indicates how the file is to be managed — whether a new file is to be created or an old one re-used; and whether the file should be deleted upon completion or retained; ''etc''. IEFBR14 was created because while DD statements can create or delete files easily, they cannot do so without a program to be run due to a certain peculiarity of the Job Management system, which always requires t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Access Storage Device
A direct-access storage device (DASD) (pronounced ) is a secondary storage device in which "each physical record has a discrete location and a unique address". The term was coined by IBM to describe devices that allowed random access to data, the main examples being drum memory and hard disk drives. Later, optical disc drives and flash memory units are also classified as DASD. The term DASD contrasts with sequential access storage device such as a magnetic tape drive, and unit record equipment such as a punched card device. A record on a DASD can be accessed without having to read through intervening records from the current location, whereas reading anything other than the "next" record on tape or deck of cards requires skipping over intervening records, and requires a proportionally long time to access a distant point in a medium. Access methods for DASD include sequential, partitioned, indexed, and direct. The DASD storage class includes both fixed and removable media ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patch (Unix)
The computer tool patch is a Unix program that updates text files according to instructions contained in a separate file, called a ''patch file''. The patch file (also called a ''patch'' for short) is a text file that consists of a list of differences and is produced by running the related diff program with the original and updated file as arguments. Updating files with patch is often referred to as ''applying the patch'' or simply ''patching'' the files. History The original patch program was written by Larry Wall (who went on to create the Perl programming language) and posted to mod.sources (which later became comp.sources.unix) in May 1985. A variant of the program (but not the only one) is part of the GNU project and is maintained by the FSF. Usage context Developed by a programmer for other programmers, patch was frequently used for updating source code to a newer version. Because of this, many people came to associate patches with source code, whereas patches can in fact b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
