query: the supervisor program in an operating system ( os ) is also known as the

pos: Supervisory program operating systems starting with OS/360. In other operating systems, the supervisor is generally called the kernel. In the 1970s, IBM further abstracted the supervisor state from the hardware, resulting in a hypervisor that enabled full virtualization, i.e. the capacity to run multiple operating systems on the same machine totally independently from each other. Hence the first such system was called "Virtual Machine" or "VM". Supervisory program A supervisory program or supervisor is a computer program, usually part of an operating system, that controls the execution of other routines and regulates work scheduling, input/output operations, error actions, and similar functions and

pos: Kernel (operating system) hybrid kernel because the kernel itself contains tasks such as the Window Manager and the IPC Managers, with a client/server layered subsystem model. Supervisory program or supervisor is a computer program, usually part of an operating system, that controls the execution of other routines and regulates work scheduling, input/output operations, error actions, and similar functions and regulates the flow of work in a data processing system. Historically, this term was essentially associated with IBM's line of mainframe operating systems starting with OS/360. In other operating systems, the supervisor is generally called the kernel. In the 1970s, IBM further abstracted the

pos: Hypervisor operating-system-level virtualization, where all instances (usually called "containers") must share a single kernel, though the guest operating systems can differ in user space, such as different Linux distributions with the same kernel. The term "hypervisor" is a variant of "supervisor", a traditional term for the kernel of an operating system: the hypervisor is the supervisor of the supervisor, with "" used as a stronger variant of "". The term dates to circa 1970; in the earlier CP/CMS (1967) system the term "Control Program" was used instead. In their 1974 article, "Formal Requirements for Virtualizable Third Generation Architectures", Gerald J. Popek

pos: Process management (computing) part of the system executing in kernel supervisor state is called the kernel, or nucleus, of the operating system. The kernel operates as trusted software, meaning that when it was designed and implemented, it was intended to implement protection mechanisms that could not be covertly changed through the actions of untrusted software executing in user space. Extensions to the OS execute in user mode, so the OS does not rely on the correctness of those parts of the system software for correct operation of the OS. Hence, a fundamental design decision for any function to be incorporated into the OS

pos: Micro-Controller Operating Systems tool chain (i.e., C compiler, assembler, and linker-locator), µC/OS-II can be embedded as part of a product. µC/OS-II is used in many embedded systems, including: µC/OS-II is a multitasking operating system. Each task is an infinite loop and can be in any one of the following five states (see figure below additionally) Further, it can manage up to 255 tasks. However, it is recommended that eight of these tasks be reserved for µC/OS-II, leaving an application up to 247 tasks. The kernel is the name given to the program that does most of the housekeeping tasks for the operating system.

pos: Operating system types, such as 16-bit processors on a 32-bit one, or 32-bit processors on a 64-bit one. At power-on or reset, the system begins in supervisor mode. Once an operating system kernel has been loaded and started, the boundary between user mode and supervisor mode (also known as kernel mode) can be established. Supervisor mode is used by the kernel for low level tasks that need unrestricted access to hardware, such as controlling how memory is accessed, and communicating with devices such as disk drives and video display devices. User mode, in contrast, is used for almost everything else. Application programs,

pos: Process management (computing) to a fixed location in the system space. Since only system code is loaded in the system space, only system code can be invoked via a trap. When the OS has completed the supervisor call, it resets the mode bit to user mode prior to the return. -= The Kernel system concept =- The parts of the OS critical to its correct operation execute in kernel mode, while other software (such as generic system software) and all application programs execute in user mode. This fundamental distinction is usually the irrefutable distinction between the operating system and other system software. The

pos: Operating system instructions that could potentially cause disruption to the system's operation. In supervisor mode, instruction execution restrictions are typically removed, allowing the kernel unrestricted access to all machine resources. The term "user mode resource" generally refers to one or more CPU registers, which contain information that the running program isn't allowed to alter. Attempts to alter these resources generally causes a switch to supervisor mode, where the operating system can deal with the illegal operation the program was attempting, for example, by forcibly terminating ("killing") the program). Among other things, a multiprogramming operating system kernel must be responsible for managing all

pos: System call System call In computing, a system call is the programmatic way in which a computer program requests a service from the kernel of the operating system it is executed on. This may include hardware-related services (for example, accessing a hard disk drive), creation and execution of new processes, and communication with integral kernel services such as process scheduling. System calls provide an essential interface between a process and the operating system. In most systems, system calls can only be made from userspace processes, while in some systems, OS/360 and successors for example, privileged system code also issues system calls. The

pos: Blackfin of memory can be protected (with the help of the MPU). In a modern operating system or RTOS, the kernel typically runs in supervisor mode and threads/processes will run in user mode. If a thread crashes or attempts to access a protected resource (memory, peripheral, etc.) an exception will be thrown and the kernel will then be able to shut down the offending thread/process. The official guidance from ADI on how to use the Blackfin in non-OS environments is to reserve the lowest-priority interrupt for general-purpose code so that all software is run in supervisor space. Blackfin uses a variable-length

neg: Supervisor Call instruction system for the RCA Spectra 70 series computers) for the UNIVAC Series 90 mainframe line, and the B800 operating system (also developed from the TSOS operating system) for Fujitsu's mainfames, all use the LPSW instruction to exit from a Supervisor Call. In MVS/370 and later incarnations of the OS, branch and link entry points are alternatives to SVC invocations for supervisor mode routines. In MVS/SP V1R3 and later incarnations of the OS, Program Call (PC) entries have augmented SVCs for invocations of many supervisory functions by both authorized and unauthorized programs; and some functions may only be invoked by branch

neg: Loader (computing) are absolute addresses rather than offsets from the program's base address. Some well-known examples are IBM's OS/360 for their System/360 mainframes, and its descendants, including z/OS for the z/Architecture mainframes. In OS/360 and descendant systems, the (privileged) operating system facility is called IEWFETCH, and is an internal component of the OS Supervisor, whereas the (non-privileged) LOADER application can perform many of the same functions, plus those of the Linkage Editor, and is entirely external to the OS Supervisor (although it certainly uses many Supervisor services). IEWFETCH utilizes highly specialized channel programs, and it is theoretically possible to load and to

neg: Execute Direct Access Program when presented with certain XDAP channel programs. As IBM did not guarantee system security and data integrity on pre-SVS systems, an obvious circumvention was to utilize only those XDAP channel programs which did not also utilize RPS as it was the RPS-type XDAP channel programs which were confusing the SAM and PAM appendages, thereby leading to random supervisor storage overlays. Execute Direct Access Program In IBM mainframe operating systems, Execute Direct Access Program (XDAP) is a pseudo access method for accessing direct access datasets on a block by block basis. XDAP is more specifically described in the OS System Programmer's

neg: IEFBR14 that programs supplied by IBM were grouped together by function or creator and that each group shared a three-letter prefix. In OS/360, the first letter was almost always "I", and the programs produced by the Job Management group (including IEFBR14) all used the prefix "IEF". Other common prefixes included "IEB" for dataset utility programs, "IEH" for system utility programs, and "IEW" for program linkage and loading. Other major components were (and still are) "IEA" (Operating System Supervisor) and "IEC" (Input/Output Supervisor). As explained below, "BR 14" was the essential function of the program, to simply return to the operating system.

neg: Unit Control Block Unit Control Block In IBM mainframe operating systems from the OS/360 and successors line, a Unit Control Block (UCB) is a memory structure, or a "control block", that describes any single input/output peripheral device ("unit"), or an "exposure" (alias), to the operating system. Certain data within the UCB also instructs the Input/Output Supervisor (IOS) to use certain closed subroutines in addition to normal IOS processing for additional physical device control. Some other operating systems have similar structures. During initial program load (IPL) of current MVS systems, the Nucleus Initialization Program (NIP) reads necessary information from the I/O Definition File (IODF)

neg: OS/360 and successors eventually renamed OS/VS2 SVS, for Single Virtual Storage, when OS/VS2 Release 2, also known as MVS, for Multiple Virtual Storage, was introduced. SVS was intended as a stepping stone from MVT to MVS, and is only of historical interest today. In 1974 IBM released what it described as OS/VS2 Release 2 but which was really a new operating system that was upwards-compatible with OS/VS2 Release 1. The Supervisor of the new system had been largely rewritten in a new dialect of BSL, PL/S; BSL and PL/S were dialects of PL/I with extensions designed to transcribe Assembly language code, including privileged

neg: Apple GS/OS Apple GS/OS GS/OS is an operating system developed by Apple Computer for its Apple II personal computer that uses the ProDOS filing system. It provides facilities for accessing the file system, controlling input/output devices, loading and running program files, and a system allowing programs to handle interrupts and signals. GS/OS was included as a component of Apple II System Software versions 4.0 through 6.0.1. GS/OS, unlike its predecessor, is written entirely in 16-bit code and was the first true 16-bit operating system for the II. GS/OS includes a facility known as file system translators (FSTs) which allows it to support

neg: Channel I/O program terminates and returns a "no record found" status indication. In some cases the system software has the option of updating the track or cylinder number and "redriving" the I/O operation without interrupting the application program. On most systems channels operate using "real (or physical) addresses", while the channel programs are built using "virtual addresses". The operating system is responsible for "translating" these channel programs before executing them, and for this particular purpose the Input/Output Supervisor (IOS) has a special "fast fix" function which was designed into the OS Supervisor just for those "fixes" which are of relatively short duration

neg: Input/Output Supervisor Input/Output Supervisor The Input/Output Supervisor (IOS) is that portion of the control program in the IBM mainframe OS/360 and successors operating systems which issues the privileged I/O instructions and supervises the resulting I/O interruptions for any program which requests I/O device operations until the normal or abnormal conclusion of those operations. IOS has two purposes: To facilitate the handling of the I/O requests and interruptions, IOS is divided into two primary program sections (CSECTs): These primary sections are resident in main storage and provide control program support for the normal execution of channel programs. The secondary program sections (also CSECTs),

neg: Single-level store (formerly known as "i5/OS" or "OS/400"), the operating system of the IBM System i, although IBM first implemented SLS in 1978 in the System/38 and its Control Program Facility (CPF) operating system, the predecessor to IBM i. With a single-level storage the entire storage of a computer is thought of as a single two-dimensional plane of addresses, pointing to pages. Pages may be in primary storage (RAM) or in secondary storage (disk); however, the current location of an address is unimportant to a process. The operating system takes on the responsibility of locating pages and making them available for processing.

neg: Houston Automatic Spooling Priority Houston Automatic Spooling Priority The Houston Automatic Spooling Priority Program, commonly known as HASP, is an extension of the IBM OS/360 operating system and its successors providing extended support for "job management, data management, task management, and remote job entry." OS/360 included spooling routines, called "reader/interpreters" and "output writers". Each reader/interpreter was "responsible for reading one input job stream" – that is one input device. Likewise each output writer was responsible for controlling one printer or punch. Spooled data were stored in OS "temporary datasets" controlled by standard OS services. Each reader/interpreter or output writer was a separate operating system

neg: Operating system During the 1960s, IBM's OS/360 introduced the concept of a single OS spanning an entire product line, which was crucial for the success of the System/360 machines. IBM's current mainframe operating systems are distant descendants of this original system and applications written for OS/360 can still be run on modern machines. OS/360 also pioneered the concept that the operating system keeps track of all of the system resources that are used, including program and data space allocation in main memory and file space in secondary storage, and file locking during update. When the process is terminated for any reason, all

neg: Protection ring tables, or performing operations such as disabling interrupts. The idea of having two different modes to operate in comes from "" a program in supervisor mode is trusted never to fail, since a failure may cause the whole computer system to crash. Supervisor mode is "an execution mode on some processors which enables execution of all instructions, including privileged instructions. It may also give access to a different address space, to memory management hardware and to other peripherals. This is the mode in which the operating system usually runs." In a monolithic kernel, the operating system runs in supervisor mode

neg: IBM Basic assembly language and successors e.g. in Z/OS than in Z/VSE. The following fragment shows how the logic "If SEX = 'M', add 1 to MALES; else, add 1 to FEMALES" would be performed in assembler. The following is the ubiquitous Hello world program, and would, executing under an IBM operating system such as OS/VS1 or MVS, display the words 'Hello World' on the operator's console: codice_8 is an assembler macro that generates an operating system call. Because of saving registers and later restoring and returning, this small program is usable as a batch program invoked directly by the operating system Job control language (JCL)

neg: Sound card a sound card, the operating system (OS) typically requires a specific device driver, a low-level program that handles the data connections between the physical hardware and the operating system. Some operating systems include the drivers for many cards; for cards not so supported, drivers are supplied with the card, or available for download. Sound card A sound card (also known as an audio card) is an internal expansion card that provides input and output of audio signals to and from a computer under control of computer programs. The term "sound card" is also applied to external audio interfaces used for

neg: Mesosphere, Inc. May 7, 2018, the company announced that it had accumulated $125 million for their Series D round for its hybrid cloud platform. The Datacenter Operating System, also known as DC/OS, is an open-source, distributed operating system built with Apache Mesos. It was developed by Mesosphere and announced in April 2016. The difference between DC/OS and other cluster managers is the ability to provide dedicated container scheduling. The latest release, DC/OS 1.12.0, was on October 25, 2018. The term "datacenter operating system" was promoted in the paper "The Datacenter Needs an Operating System", published at the University of California, Berkeley. In

neg: Linker (computing) System/360 mainframe environments such as OS/360, including z/OS for the z/Architecture mainframes, this type of program is known as a "linkage editor". As the name implies a linkage "editor" has the additional capability of allowing the addition, replacement, and/or deletion of individual program sections. Operating systems such as OS/360 have format for executable load-modules containing supplementary data about the component sections of a program, so that an individual program section can be replaced, and other parts of the program updated so that relocatable addresses and other references can be corrected by the linkage editor, as part of the process. One

neg: BlackBerry Tablet OS with the GNU toolchain is currently in closed beta testing. The first device to run BlackBerry Tablet OS was the BlackBerry PlayBook tablet computer. A similar QNX-based operating system, known as BlackBerry 10, replaced the long-standing BlackBerry OS on handsets after version 7. BlackBerry Tablet OS BlackBerry Tablet OS is an operating system from BlackBerry Ltd based on the QNX Neutrino real-time operating system designed to run Adobe AIR and BlackBerry WebWorks applications, currently available for the BlackBerry PlayBook tablet computer. The BlackBerry Tablet OS is the first tablet running an operating system from QNX (now a subsidiary of RIM).

neg: BOS/360 were developed for systems with at least 16,384 bytes and either disks or tape drives. BOS was released in October 1965, nearly two years before OS/360, thus BOS was the only disk based operating system available at launch for a machine that was marketed as disk based. BOS consisted of the following components: The IBM 1070 Process Communication Supervisor was a dedicated process control system that ran as an extension under BOS. BOS/360 BOS/360 (Basic Operating System/360) was an early IBM System/360 operating system. BOS was one of four System/360 Operating System versions developed by the IBM General Products Division

neg: Input/Output Supervisor I/O requests. Input/Output Supervisor The Input/Output Supervisor (IOS) is that portion of the control program in the IBM mainframe OS/360 and successors operating systems which issues the privileged I/O instructions and supervises the resulting I/O interruptions for any program which requests I/O device operations until the normal or abnormal conclusion of those operations. IOS has two purposes: To facilitate the handling of the I/O requests and interruptions, IOS is divided into two primary program sections (CSECTs): These primary sections are resident in main storage and provide control program support for the normal execution of channel programs. The secondary program sections

neg: Execute Channel Program Execute Channel Program In IBM mainframe operating systems, Execute Channel Program (EXCP) is a supervisor call for low-level device access, where the programmer is responsible for providing a "channel program"—a list of device-specific commands (CCWs)—to be executed by I/O channels, control units and devices. EXCP is more specifically described in the OS System Programmer's Guide. Using EXCP, legacy devices and legacy datasets may be operated on with relatively high performance. EXCP devices are OPENed (that is, are made available to the application) by specifying MACRF=(E) in the Data Control Block (DCB). A comprehensive list of "exits" (called, in the EXCP

neg: IBM Basic assembly language and successors assembler programs was often felt to make up for this drawback, but with the advent of optimizing compilers, C for the mainframe, and other advances, assembler has lost much of its appeal. IBM continues to upgrade the assembler, however, and it is still used when the need for speed or very fine control is paramount. Another reason to use assembler is that not all operating system functions can be accessed in high level languages. The application program interface of mainframe operating systems is defined as a set of assembly language "macro" instructions, that typically invoke Supervisor Call (SVC) [on z/OS]

neg: Application Enhancer Application Enhancer Application Enhancer (APE) is a software program released by Unsanity for Apple's Mac OS X operating system. Application Enhancer provides a framework that allows third-party developers to write "haxies" for Mac OS X. It also provides a daemon to load haxies when certain applications are launched. These haxies, or plugins, are known as application enhancer modules, or APEs. Once the APE is loaded by the daemon, the module modifies the behavior of an existing application. Examples include allowing the classic Mac OS WindowShade behavior, or adding/removing Mac OS X's brushed aluminum theme to/from all applications. Application Enhancer is

neg: Disk partitioning such systems a menu at startup gives a choice of which OS to boot/start (and only one OS at a time is loaded). This is distinct from virtual operating systems, in which one operating system is run as a self-contained virtual "program" within another already-running operating system. (An example is a Windows OS "virtual machine" running from within a Linux OS.) The GUID Partition Table (Globally Unique IDentifier) is a part of the Unified Extensible Firmware Interface (UEFI) standard for the layout of the partition table on a physical hard disk. Many operating systems now support this standard. When a

neg: MIPS RISC/os MIPS RISC/os RISC/os is a discontinued UNIX operating system developed by MIPS Computer Systems, Inc. from 1985 to 1992, for their computer workstations and servers, such as the MIPS M/120 server or MIPS Magnum workstation. It was also known as UMIPS or MIPS OS. RISC/os was based largely on UNIX System V with additions from 4.3BSD UNIX, ported to the MIPS architecture. It was a "dual-universe" operating system, meaning that it had separate, switchable runtime environments providing compatibility with either System V Release 3 or 4.3BSD. MIPS OS was one of the first 32-bit operating systems for RISC-based workstation-class computers.

neg: Mobile operating system devices. /e/ mobile operating system is an open source operating system forked from the source code of LineageOS. The OS currently in its beta version covers about 49 devices.. /e/ essentially targets Android smart phone devices. The OS uses MicroG as a replacement for the Google Play Services. Flyme OS is an operating system developed by Meizu Technology Co., Ltd., an open source OS based on Google Android Open Source Project (AOSP). Flyme OS is mainly installed on Meizu Smartphones such as the MX's series; however, it also has official ROM support for a few Android devices. HTC Sense is

neg: Event Driven Executive the start that, in order to provide a successful System/7 based environment for laboratory automation in the SJRL, it would be necessary to develop a real-time, sensor-based, multitasking and multiprogramming operating system, an associated application development facility which provided not only an appropriate high level application programming language with requisite special features, e.g. sensor I/O, but also a communication interface to the large scale host computer for program development, bidirectional data transfer and data analysis. The result was the development of an operating system known as the Laboratory Automation Basic Supervisor for the System/7 (LABS/7) and an application development language.

neg: Xgrid modeled the design of Xgrid on the Zilla program, distributed with NeXT's OPENSTEP operating system application programming interface (API), which Apple owned the rights to. The company also opted to provide the client version of Mac OS X with only command-line functions and little flexibility, while giving the Mac OS X Server version of Xgrid a GUI control panel and a full set of features. Xgrid's original concept can be traced back to Zilla.app, found in the OPENSTEP operating system, created by NeXT in the late 1980s. Zilla was the first distributed computing program released on an end-user operating system

neg: Firefox OS OS specific devices for developers: Firefox OS specific devices for consumers: Firefox OS has been ported to the following devices: Firefox OS Firefox OS (project name: "Boot to Gecko", also known as "B2G") is a discontinued open-source operating system made for smartphones, tablet computers and smart TVs designed by Mozilla and external contributors. It is based on the rendering engine of the Firefox web browser, Gecko, and on the Linux kernel. It was first commercially released in 2013. Firefox OS was designed to provide a complete, community-based alternative operating system, for running web applications directly or those installed from an

neg: Supervisor Call instruction supervisory functions after thorough authorization checking by the operating system: DEBCHK (SVC 117), TESTAUTH (SVC 119), and possibly additional tests. Programs which fail any of these tests are ABENDed, that is "abnormally terminated" and immediately cease processing. Some of these tests were not available in OS/360, but were added in OS/VS1, SVS or MVS/370, but all were available in MVS/370 or subsequent releases, and are still available to this day. In OS/VS1, OS/VS2 (SVS), MVS/370 and subsequent versions of the OS, the MODESET function (SVC 107) obviated the need for many user-written SVCs as this system SVC accommodated both changes

neg: LeWa OS LeWa OS LeWa OS (Chinese: 乐蛙), also known as Music Frogs and жабка, is an operating system for smartphones, based on the Android mobile platform. Developed by Chinese company Lewa Technology, it is mainly intended for low-cost phones under 1000 yuan (around US$126). As of April 2013, there are more than 2 million users of the system, and as of July 2012, they are among the most popular third-party Android-based ROMs in China, together with MIUI and DianXin OS (also known as Tapas OS). Lewa is also the first aftermarket Android-based firmware in the world that supports the dual-SIM standby

neg: Classic Mac OS System 5. Apple rebranded the system as Mac OS in 1996, starting officially with version 7.6, due in part to its Macintosh clone program. That program ended after the release of Mac OS 8 in 1997. The last major release of the system was Mac OS 9 in 1999. Initial versions of the System Software run one application at a time. With the introduction of System 5, a cooperative multitasking extension called MultiFinder was added, which was later integrated into System 7 as part of the operating system along with support for virtual memory. By the mid-1990s, however, contemporary operating

neg: GOS (operating system) window, and will keep loading the main operating system (Windows, Linux, OSX) in the background. An icon in the Dock will tell the user when the main OS has finished booting in the background, and can be used to switch instantly to the main OS, when tasks not (yet) supported under Cloud are needed. A beta test program for Cloud version 1.0 was announced January 30, 2009. On January 3, 2009, Good OS released gOS 3.1 Gadgets (SP1), or Service pack 1, a bug-fixed version of gOS 3.0. Simultaneously, the Good OS team also launched a new official forum, as

neg: Docker (software) do with Docker. The latter, however, is a form of hardware virtualization (as opposed to OS-level virtualization) and uses Docker to deliver the guest OS image. The guest OS image is a Windows Nano Server image, which is 652 MB in size and has the same limitations of Nano Server, as well as a separate end-user license agreement. Docker (software) Docker is a computer program that performs operating-system-level virtualization, also known as "containerization". It was first released in 2013 and is developed by Docker, Inc. Docker is used to run software packages called "containers". Containers are isolated from each other

neg: Firefox OS Firefox OS Firefox OS (project name: "Boot to Gecko", also known as "B2G") is a discontinued open-source operating system made for smartphones, tablet computers and smart TVs designed by Mozilla and external contributors. It is based on the rendering engine of the Firefox web browser, Gecko, and on the Linux kernel. It was first commercially released in 2013. Firefox OS was designed to provide a complete, community-based alternative operating system, for running web applications directly or those installed from an application marketplace. The applications use open standards and approaches such as JavaScript and HTML5, a robust privilege model, and open

neg: Virtual Storage Access Method VSAM, DFSMStvs. This is an optional program that builds on VSAM RLS by adding logging and two-phase commit, using underlying z/OS system services. This permits generalised sharing of VSAM data. VSAM was introduced as a replacement for older access methods and was intended to add function, to be easier to use and to overcome problems of performance and device-dependence. VSAM was introduced in the 1970s when IBM announced virtual storage operating systems (DOS/VS, OS/VS1 and OS/VS2) for its new System/370 series, as successors of the DOS/360 and OS/360 operating systems running on its System/360 computer series. While backwards compatibility was

neg: Chrome OS Chrome OS Chrome OS is an operating system designed by Google that is based on the Linux kernel and uses the Google Chrome web browser as its principal user interface. As a result, Chrome OS primarily supports web applications. Google announced the project in July 2009, conceiving it as an operating system in which both applications and user data reside in the cloud: hence Chrome OS primarily runs web applications. Source code and a public demo came that November. The first Chrome OS laptop, known as a Chromebook, arrived in May 2011. Initial Chromebook shipments from Samsung and Acer occurred

neg: Mac OS X 10.2 last version of Mac OS X officially supported on the "Beige G3" desktop, minitower, and all-in-one systems as well as the PowerBook G3 Series (1998) also known as Wallstreet/PDQ; though later releases can be run on such Macs with the help of unofficial, unlicensed, and unsupported third-party tools such as XPostFacto. Mac OS X 10.2 Mac OS X Jaguar (version 10.2) is the third major release of Mac OS X (now named macOS), Apple's desktop and server operating system. It superseded Mac OS X 10.1 and preceded Mac OS X Panther. The operating system was released on August 23, 2002

neg: Access method access methods mentioned in this article. In the z/OS operating system, two elements provide access methods: Access method An access method is a function of a mainframe operating system that enables access to data on disk, tape or other external devices. They were introduced in 1963 in IBM OS/360 operating system. Access methods provide an application programming interface (API) for programmers to transfer data to or from device, and could be compared to device drivers in non-mainframe operating systems, but typically provide a greater level of functionality. System/360 and successor systems perform input/output using a special program for an I/O

neg: Apple GS/OS fonts, plug-in device drivers (modem, printer, etc.). A command-line development environment called APW (Apple Programmer's Workshop) is available; much like the Macintosh Programmer's Workshop. Apple GS/OS GS/OS is an operating system developed by Apple Computer for its Apple II personal computer that uses the ProDOS filing system. It provides facilities for accessing the file system, controlling input/output devices, loading and running program files, and a system allowing programs to handle interrupts and signals. GS/OS was included as a component of Apple II System Software versions 4.0 through 6.0.1. GS/OS, unlike its predecessor, is written entirely in 16-bit code and was

neg: Bochs used for operating system development (when an emulated operating system crashes, it does not crash the host operating system, so the emulated OS can be debugged) and to run other guest operating systems inside already running host operating systems. It can also be used to run older software – such as PC games – which will not run on non-compatible, or too fast computers. Bochs started as a program with a commercial license, at the price of US$25, for use as-is. If a user needed to link it to other software, that user would have to negotiate a special license.

neg: OS/360 and successors 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 heavily influenced by the earlier IBSYS/IBJOB and Input/Output Control System (IOCS) packages. It was one of the earliest 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. IBM announced three different levels of OS/360, generated from the

neg: VPS/VM code necessary to run the VPS system. Josie Bondoc wrote some of the later VPS additions, like UNIX piping. Many MVS/VM programs ran on VPS/VM, such as XEDIT, and compilers for Pascal, PL/1, C and Cobol. These MVS/VM programs ran under an OS simulation program that simulated the OS/VM supervisor calls (SVCs). Margorie Orr supervised the OS simulation program development and maintenance. Some of the programmers who wrote parts of the OS simulation package, or maintained it were Margorie Orr, Timothy Greiser, Daniel Levbre, John Coldwell Lotz, and Paul Cheffers. Michael Krugman wrote some of the early main utilities such

neg: IBM Series/1 environment (RPS) was available along with several additional high level languages for the RPS OS. The EDX operating system was originally ported from the System/7. Series/1 was also the first computer that IBM supported for Unix. Systems without an operating system were intended for users needing dedicated applications that did not require the full capabilities of either OS. Applications were built using a set of standalone programs, called the Base Program Preparation Facilities, consisting of a macro assembler, a link editor and some basic utilities. A set of modules, called Control Program Support (CPS), was linked with the application to

neg: Mac OS X Lion program necessary to synchronize a Mac with non-Apple mobile devices, as well as abandoned functionality in Exposé and Spaces. However, in an extensive review of the operating system, Ars Technica recommended Lion. They noted that it feels like it is the start of a new line of operating systems that will continue to be influenced by Apple's iOS platform. The review also compared the introduction of Lion, along with its new conventions that change traditional ways of computing, with the original Mac OS X and when it replaced the classic Mac OS. "Macworld" called Lion a "radical revision", praising the

neg: Blackfin operating systems, RTOSs and kernels like ThreadX, µC/OS-II, or NOMMU Linux. Although the MPU is referred to as a Memory Management Unit (MMU) in the Blackfin documentation, the Blackfin MPU does not provide address translation like a traditional MMU, so it does not support virtual memory or separate memory addresses per process. This is why Blackfin currently can not support operating systems requiring virtual memory such as WinCE or QNX. Blackfin supports three run-time modes: supervisor, user and emulation. In supervisor mode, all processor resources are accessible from the running process. However, when in user mode, system resources and regions

neg: Microkernel Microkernel In computer science, a microkernel (often abbreviated as μ-kernel) is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, thread management, and inter-process communication (IPC). If the hardware provides multiple rings or CPU modes, the microkernel may be the only software executing at the most privileged level, which is generally referred to as supervisor or kernel mode. Traditional operating system functions, such as device drivers, protocol stacks and file systems, are typically removed from the microkernel itself and are instead run in user space.

neg: OS/360 and successors Systems Release History, System/370 Market Chronology of Products & Services, 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 heavily influenced by the earlier IBSYS/IBJOB and Input/Output Control System (IOCS) packages. It was one of the earliest 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.

neg: HTC Dream HTC Dream The HTC Dream (also known as the T-Mobile G1 in the United States of America and parts of Europe, and as the Era G1 in Poland) is a smartphone developed by HTC. First released in September 2008, the Dream was the first commercially released device to use the Linux-based Android operating system, which was purchased and further developed by Google and the Open Handset Alliance to create an open competitor to other major smartphone platforms of the time, such as Symbian operating system, BlackBerry OS, and iPhone OS. The operating system offers a customizable graphical user interface, integration

neg: Supervisory program Supervisory program A supervisory program or supervisor is a computer program, usually part of an operating system, that controls the execution of other routines and regulates work scheduling, input/output operations, error actions, and similar functions and regulates the flow of work in a data processing system. It can also refer to a program that allocates computer component space and schedules computer events by task queuing and system interrupts. Control of the system is returned to the supervisory program frequently enough to ensure that demands on the system are met. Historically, this term was essentially associated with IBM's line of mainframe

neg: Dock (macOS) indicates if a program is not running by showing an ellipsis below its icon. If the program is running, there isn't an ellipsis on the icon. In macOS, running applications have been variously identified by a small black triangle (Mac OS X 10.0-10.4) a blue-tinted luminous dot (Mac OS X 10.5-10.7), a horizontal light bar (OS X 10.8 and 10.9), and a simple black or white dot (OS X 10.10-macOS 10.13). In macOS, however, the Dock is used as a repository for any program or file in the operating system. It can hold any number of items and resizes them

neg: MVS MVS Multiple Virtual Storage, more commonly called MVS, was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers. It was developed by IBM, but is unrelated to IBM's other mainframe operating systems, e.g., VSE, VM, TPF. First released in 1974, MVS was extended by program products with new names multiple times: At first IBM described MVS as simply a new release of OS/VS2, but it was, in fact a major rewrite. OS/VS2 release 1 was an upgrade of OS/360 MVT that retained most of the original code and, like MVT, was mainly written in assembly

neg: ISIS (operating system) ISIS (operating system) ISIS (Intel System Implementation Supervisor) is an operating system, originally developed by Ken Burgett under the new management of Bill Davidow for Intel's Intel Microprocessor Development System starting 1975, and later adopted as ISIS-II for systems with floppy drives. Communication with the user is terminal-like. Its user interface is somewhat CP/M-like, even from the program interface point of view. For file opening, the program sends the name of file and gets back a handle. Each device has a name, which is entered between a pair of colons (codice_1 and codice_2 are floppies, codice_3 is printer, etc.). Each

neg: Operating system Operating system An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by

neg: IPhone OS 1 IPhone OS 1 iPhone OS 1 is the first major release of iOS, Apple's mobile operating system. iPhone OS 1.1.5 is the latest and the last version of Apple's iPhone OS 1. This version of iOS was the first iteration of the touch-centric mobile operating system. No official name was given on its initial release; Apple marketing literature simply stated that the iPhone runs a version of Apple's desktop operating system, macOS, then known as Mac OS X. On March 6, 2008, with the release of the iPhone software development kit (iPhone SDK), Apple named it "iPhone OS" (they later

neg: Cisco Nexus switches Cisco Nexus switches The Cisco Nexus Series switches are modular and fixed port network switches designed for the data center. Cisco Systems introduced the Nexus Series of switches on January 28, 2008. The first chassis in the Nexus 7000 family is a 10-slot chassis with two supervisor engine slots and eight I/O module slots at the front, as well as five crossbar switch fabric modules at the rear. Beside the Nexus 7000 there are also other models in the Nexus range. All switches in the Nexus range run the modular NX-OS firmware/operating system on the fabric. NX-OS has some high-availability

neg: Real-time operating system common approaches to resolve this problem: General-purpose operating systems usually do not allow user programs to mask (disable) interrupts, because the user program could control the CPU for as long as it wishes. Some modern CPUs don't allow user mode code to disable interrupts as such control is considered a key operating system resource. Many embedded systems and RTOSs, however, allow the application itself to run in kernel mode for greater system call efficiency and also to permit the application to have greater control of the operating environment without requiring OS intervention. On single-processor systems, an application running in kernel

neg: Mac OS 9 Mac OS 9 Mac OS 9 is the ninth and final major release of Apple's classic Mac OS operating system. Introduced on October 23, 1999, it was promoted by Apple as "The Best Internet Operating System Ever", highlighting Sherlock 2's Internet search capabilities, integration with Apple's free online services known as iTools and improved Open Transport networking. While Mac OS 9 lacks protected memory and full pre-emptive multitasking, lasting improvements include the introduction of an automated Software Update engine and support for multiple users. Apple discontinued development of Mac OS 9 in 2001, transitioning all future development to Mac OS

neg: Security-evaluated operating system in August, 1987. The Unisys OS 2200 operating system includes an implementation of the DoD Orange Book B1, Labeled security protection level specification. OS 2200 first obtained a successful B1 evaluation in September, 1989. Unisys maintained that evaluation until 1994 through the National Computer Security Center Rating Maintenance Phase (RAMP) of the Trusted Product Evaluation Program. Security-evaluated operating system In computing, security-evaluated operating systems have achieved certification from an external security-auditing organization, the most popular evaluations are Common Criteria (CC) and FIPS 140-2. Trusted Solaris 8 was a security-focused version of the Solaris Unix operating system. Aimed primarily at the

neg: Time Sharing Option read by a card reading machine. When it was originally introduced in 1971, IBM considered time-sharing an "optional feature", as compared to standard batch processing, and hence offered TSO as an option for OS/360 MVT. With the introduction of MVS in 1974, IBM made it a standard component of their top-end mainframe operating system. "TSO/E ("Time Sharing Option/Extensions")" is a set of extensions to the original TSO. TSO/E is a base element of z/OS. Before z/OS, TSO Extensions (TSO/E) was an element of OS/390 and was a licensed program for the MVS and MVS/ESA System Products. Since all z/OS installations

neg: CP/CMS CP/CMS CP/CMS (Control Program/Cambridge Monitor System) is a discontinued time-sharing operating system of the late 60s and early 70s, known for its excellent performance and advanced features. It had three distinct versions: Each implementation was a substantial redesign of its predecessor and an evolutionary step forward. CP-67/CMS was the first widely available virtual machine architecture. IBM pioneered this idea with its research systems M44/44X (which used partial virtualization) and CP-40 (which used full virtualization). In addition to its role as the predecessor of the VM family, CP/CMS played an important role in the development of operating system (OS) theory, the

neg: History of Apple Inc. popularize the use of Wireless LAN technology to connect computers to networks. In 2001, Apple introduced Mac OS X (now known as macOS), an operating system based on NeXT's NeXTSTEP and incorporating parts of the FreeBSD kernel. Aimed at consumers and professionals alike, Mac OS X married the stability, reliability and security of Unix with the ease of a completely overhauled user interface. To aid users in transitioning their applications from Mac OS 9, the new operating system allowed the use of Mac OS 9 applications through the Classic environment. Apple's Carbon API also allowed developers to adapt their Mac

neg: Runtime system devices such as a DVD drive are active entities that a program can interact with via a runtime system. A unique application of a runtime environment (RTE) is within an operating system (OS) that "only" allows that RTE to run, meaning from boot until power-down the entire OS is dedicated to only the application(s) running within that RTE. Any other code that tries to run or any failures in the application(s) break the RTE which breaks the OS which stops all processing and requires a re-boot. If the boot is from read-only memory, an extremely secure, simple, single-mission system is

neg: OS/360 and successors meant to reduce the cost of running large networks of terminals, mainly by using communications lines much more efficiently. This is only available for IBM's virtual memory operating systems, since its mainframe software component, VTAM is only available with these operating systems. In 1977 IBM announced MVS/System Extensions, a "program product" (i.e. it cost extra money) which improved MVS performance. Descendants of MVS are still used on the latest descendants of System/360, System/390 and zSeries; it was renamed to OS/390 for System/390, and the 64-bit version for the zSeries was named z/OS. These data are taken from IBM 360 Operating

neg: BlackBerry Tablet OS BlackBerry Tablet OS BlackBerry Tablet OS is an operating system from BlackBerry Ltd based on the QNX Neutrino real-time operating system designed to run Adobe AIR and BlackBerry WebWorks applications, currently available for the BlackBerry PlayBook tablet computer. The BlackBerry Tablet OS is the first tablet running an operating system from QNX (now a subsidiary of RIM). BlackBerry Tablet OS supports standard BlackBerry Java applications. Support for Android apps has also been announced, through sandbox "app players" which can be ported by developers or installed through sideloading by users. A BlackBerry Tablet OS Native Development Kit, to develop native applications

neg: Operating system systems that have fixed deadlines use a real-time operating system such as VxWorks, PikeOS, eCos, QNX, MontaVista Linux and RTLinux. Windows CE is a real-time operating system that shares similar APIs to desktop Windows but shares none of desktop Windows' codebase. Symbian OS also has an RTOS kernel (EKA2) starting with version 8.0b. Some embedded systems use operating systems such as Palm OS, BSD, and Linux, although such operating systems do not support real-time computing. Operating system development is one of the most complicated activities in which a computing hobbyist may engage. A hobby operating system may be classified as

neg: Operating system writing applications against software platforms such as Java or Qt. These abstractions have already borne the cost of adaptation to specific operating systems and their system libraries. Another approach is for operating system vendors to adopt standards. For example, POSIX and OS abstraction layers provide commonalities that reduce porting costs. Operating system An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and

neg: Runtime system behaviors as well, and when available, the runtime system is implemented as an abstraction layer that translates the invocation of the runtime system into an invocation of the operating system. This hides the complexity or variations in the services offered by different operating systems. This also implies that the OS kernel can itself be viewed as a runtime system, and that the set of OS calls that invoke OS behaviors may be viewed as interactions with a runtime system. In the limit, the runtime system may provide services such as a P-code machine or virtual machine, that hide even the

neg: Protected mode due to the performance issues created with hardware task switches. As a result, many operating systems use both hardware and software to create a multitasking system. Operating systems like OS/2 1.x try to switch the processor between protected and real modes. This is both slow and unsafe, because a real mode program can easily crash a computer. OS/2 1.x defines restrictive programming rules allowing a "Family API" or "bound" program to run in either real or protected mode. Some early Unix operating systems, OS/2 1.x, and Windows used this mode. Windows 3.0 was able to run real mode programs in

neg: Dynamic loading to potentially gain additional functionality. Dynamic loading was a common technique for IBM's operating systems for System/360 such as OS/360, particularly for I/O subroutines, and for COBOL and PL/I runtime libraries, and continues to be used in IBM's operating systems for z/Architecture, such as z/OS. As far as the application programmer is concerned, the loading is largely transparent, since it is mostly handled by the operating system (or its I/O subsystem). The main advantages are: IBM's strategic transaction processing system, CICS (1970s onwards) uses dynamic loading extensively both for its kernel and for normal application program loading. Corrections to application

neg: Darwin (operating system) of Darwin began with NeXT's NeXTSTEP operating system (later, since version 4.0, known as OPENSTEP), first released in 1989. After Apple bought NeXT in 1997, it announced it would base its next operating system on OPENSTEP. This was developed into Rhapsody in 1997, Mac OS X Server 1.0 in 1999, Mac OS X Public Beta in 2000, and Mac OS X 10.0 in 2001. In 2000, the core operating system components of Mac OS X were released as open-source software under the Apple Public Source License (APSL) as Darwin; the higher-level components, such as the Cocoa and Carbon frameworks, remained

neg: Computer multitasking one another. This approach, which was eventually supported by many computer operating systems, is known today as cooperative multitasking. Although it is now rarely used in larger systems except for specific applications such as CICS or the JES2 subsystem, cooperative multitasking was once the only scheduling scheme employed by Microsoft Windows and Classic Mac OS to enable multiple applications to run simultaneously. Cooperative multitasking is still used today on RISC OS systems. As a cooperatively multitasked system relies on each process regularly giving up time to other processes on the system, one poorly designed program can consume all of the

neg: OS X Yosemite integrated in this release. CloudKit functions as a Mobile Backend as a Service (MBaaS) and is one method for App developers to integrate access to Apple’s iCloud servers into their apps. There is a "dark mode" in System Preferences which makes the dock and menu bar darker. Apple initiated a new public beta program for OS X, a practice not seen with its operating systems since 2000's Mac OS X Public Beta, which had preceded the release of Mac OS X v10.0. Yosemite is part of the OS X Beta Seed Program, a public program that allows the first 1

neg: Host card emulation BlackBerry bold 9900 that was first available in Thailand. released together with BlackBerry 7 OS. CyanogenMod operating system was the next known mobile device operating system to support HCE through the effort of modifying the NXP NFC stack known as libnfc-nxp, the NFC service manager, and operating system APIs by Doug Yeager. The OS APIs were adapted to include two new tag types that were called ISO_PCDA and ISO_PCDB which are also known terminal or PCD standards. This would imply that you could "read" a tag in the same manner that you could read a terminal. Microsoft has announced new

neg: System request SysRq key". Microsoft has also used SysRq for various OS- and application-level debuggers. In the CodeView debugger, it was sometimes used to break into the debugging during program execution. For the Windows NT remote kernel debugger, it can be used to force the system into the debugger. IBM 3270-type console keyboards of the IBM System/370 mainframe computer, created in 1970, had an operator interrupt key that was used to cause the operating system such as VM/370 or MVS to allow the console to give input to the operating system. System request System request (often abbreviated SysRq or Sys Req) is

neg: Macintosh Programmer's Workshop environment. MPW also included a version control system called Projector; this has been superseded by modern version control systems and is no longer supported in Mac OS X. Macintosh Programmer's Workshop Macintosh Programmer's Workshop or MPW, is a software development environment for the Classic Mac OS operating system, written by Apple Computer. For Macintosh developers, it was one of the primary tools for building applications for System 7.x and Mac OS 8.x and 9.x. Initially MPW was available for purchase as part of Apple's professional developers program, but Apple made it a free download after it was superseded by CodeWarrior.

neg: 68K/OS 68K/OS 68K/OS was a computer operating system developed by GST Computer Systems for the Sinclair QL microcomputer. It was commissioned by Sinclair Research in February 1983. However, after the official launch of the QL in January 1984, 68K/OS was rejected, and production QLs shipped with Sinclair's own Qdos operating system. GST later released 68K/OS as an alternative to Qdos, in the form of an EPROM expansion card, and also planned to use it on single-board computers based on the QL's hardware. The operating system was developed by Chris Scheybeler, Tim Ward, Howard Chalkley and others. The few ROM cards that

neg: Dir (command) Dir (command) In computing, codice_1 (directory) is a command used for computer file and directory listing, specifically in the command line interface (CLI) of the operating systems CP/M, MP/M<ref name="MP/M_1981_UG"></ref>, DOS, OS/2, Singularity, Microsoft Windows, ReactOS, AROS and in the DCL command line interface used on VMS, RT-11 and RSX-11. The command is also supplied with OS/8 as a CUSP (Commonly-Used System Program) and available in the open source MS-DOS emulator DOSBox. codice_1 is not a Unix command; Unix has the analogous codice_3 command instead. The Linux operating system, however, has a codice_1 command that "is equivalent to codice_5; that

neg: Execute Channel Program code which allows the appendages developed for earlier, pre-MVS instances of the OS, specifically for EXCP, to function largely as before and thereby to appear to be in TCB mode, for which these appendages were originally designed. This distinction can complicate conversion of certain "roll-your-own" access methods and applications to MVS. Execute Channel Program In IBM mainframe operating systems, Execute Channel Program (EXCP) is a supervisor call for low-level device access, where the programmer is responsible for providing a "channel program"—a list of device-specific commands (CCWs)—to be executed by I/O channels, control units and devices. EXCP is more specifically described

neg: Panvalet Panvalet Computer Associates Panvalet® (also known as CA-Panvalet) is a revision control and source code management system for mainframe computers such as the IBM System z and IBM System/370 running the z/OS and z/VSE operating systems. Unlike open-source solutions such as CVS, SVN or Mercurial, Panvalet is a closed source, proprietary system for versioning and control of source code such as Microsoft Visual SourceSafe on personal computers. It uses a client-server model where users check-out files to change and check them back into the repository when finished. Panvalet can be used to manage program source code, JCL, and object module

neg: Macintosh Macintosh operating systems. The first versions initially had no name but came to be known as the "Macintosh System Software" in 1988, "Mac OS" in 1997 with the release of Mac OS 7.6, and retrospectively called "Classic Mac OS". In 2001, Apple released Mac OS X, a modern Unix-based operating system which was later rebranded to simply OS X in 2012, and then macOS in 2016. The current version is macOS Mojave, released on September 24, 2018. Intel-based Macs are capable of running non-Apple operating systems such as Linux, OpenBSD, and Microsoft Windows with the aid of Boot Camp or

neg: Post-PC era accessory they can be docked upon. While Google already produces the Android operating system used by many tablets and smartphones, it also introduced Chrome OSan operating system designed for personal computing built around its popular Chrome web browser, in 2009. Primarily shipping on netbooks known as Chromebooks, Chrome OS is designed for users who frequently use web applications and cloud-based services (such as Google's own Play and Drive)all of its "applications" are web applications, and the OS itself formerly used only a fullscreen web browser as its shell until an update in 2012, which introduced a desktop environment closer to

neg: Interrupts in 65xx processors execution to resume where expected. Alternatively, a may be inserted as a signature "placeholder," in which case no program counter adjustment will be required. The fact that and double-increment the program counter before pushing it to the stack facilitates the technique of treating them as supervisor call instructions, as found on some mainframe computers. The usual procedure is to treat the signature as an operating system service index. The operating system or handler would retrieve the value of the program counter pushed to the stack, decrement it and read from the resulting memory location to get the signature. After converting

neg: Internet OS Internet OS An Internet operating system, or Internet OS, is any type of operating system designed to run all of its applications and services through an Internet client, generally a web browser. The advantages of such an OS would be that it would run on a "thin client", allowing cheaper, more easily manageable computer systems; it would require all applications to be designed on cross-platform, open standards; and would not tie a user's applications, documents, and preferences to a single computer, but rather place them in the Internet cloud. The Internet OS has also been promoted as the perfect type

neg: SDSF SDSF The System Display and Search Facility (SDSF) component of IBM's mainframe operating system, z/OS, is an interactive user interface that allows users and administrators to view and control various aspects of the mainframe's operation and system resources. Some of the information displayed in SDSF includes Batch job output, Unix processes, scheduling environments, and status of external devices such as printers and network lines. SDSF is primarily used to access the batch and system log files and dumps. When it was a field-developed program offering, SDSF was known as the SPOOL Display and Search Facility The word "SPOOL" was changed

neg: OS-9 operating system functions System management utilities General utilities OS-9's notion of processes and I/O paths is quite similar to that of Unix in nearly all respects, but there are some significant differences. Firstly, the file system is not a single tree, but instead is a forest with each tree corresponding to a device. Second, OS-9 does not have a Unix-style fork() system call—instead it has a system call which creates a process running a specified program, performing much the same function as a fork-exec or a spawn. Additionally, OS-9 processes keep track of two "current directories" rather than just one;

neg: OS/360 Object File Format OS/360 Object File Format The OS/360 Object File Format is the standard object module file format for the IBM DOS/360, OS/360 and VM/370, Univac VS/9, and Fujitsu BS2000 mainframe operating systems. In the 1990s, the format was given an extension with the XSD-type record for the MVS Operating System to support longer module names in the C Programming Language. This format is still in use by the z/VSE operating system (the follow-on to the DOS/360 Operating System). In contrast, it has been superseded by the GOFF file format on the MVS Operating System (the follow-on to the OS/360 Operating System)

neg: Basic direct access method Basic direct access method Basic Direct Access Method, or BDAM is an access method for IBM's OS/360 and successors computer operating systems on System/360 and later mainframes. BDAM "consists of routines used in retrieving data from, and storing data onto, direct access devices." BDAM is available on OS/360, OS/VS2, MVS, z/OS, and related high-end operating systems. "Basic", in IBM terminology, indicates a lower-level access method that deals with data sets in terms of physical blocks and does not provide either read-ahead, called "anticipatory buffering", or "synchronization" — that is, the user program has to explicitly wait for completion of each

neg: ZFS (z/OS file system) available for z/OS 1.1 and OS/390 2.10. Beginning with z/OS 1.3, zFS is included as a standard feature and is being actively developed. ZFS (z/OS file system) z/OS File System (zFS) is a POSIX-style hierarchical file system for IBM's z/OS operating system for z System mainframes, a successor to that operating system's HFS. zFS technology was first released in 1995 as the Local File System, a lower layer of the DCE Distributed File System. It was available on MVS/ESA V5R2.2 and all OS/390 releases. DFS/LFS was provided as a part of the DCE feature, not part of the base operating

neg: File system write an identifying media label to the tape before use, and even this can be automatically written by software when a new tape is used for the first time. Another concept for file management is the idea of a database-based file system. Instead of, or in addition to, hierarchical structured management, files are identified by their characteristics, like type of file, topic, author, or similar rich metadata. IBM DB2 for i (formerly known as DB2/400 and DB2 for i5/OS) is a database file system as part of the object based IBM i operating system (formerly known as OS/400 and i5/OS),