* Attached Support Processor, one of the two early IBM System / 360 programs that replaces the native SPOOL facilities of OS / 360 ; the other was Houston Automatic Spooling Priority ( HASP ).

With ASP Version 3 the name was changed to Asymmetric Multiprocessor and support was added for OS / VS2 ( SVS ).

* Auxiliary Storage Pool, a group of disk drives in the IBM i ( aka OS / 400 ) operating system

Three emulators of the machine exist, ElectrEm for Windows / Linux / Mac OS X, Elkulator for Windows / DOS and the Multi-system emulator MESS.

The rise of TCP / IP during the 1990s led to a re-implementation of most of these types of support on that protocol, and AppleTalk became unsupported as of the release of Mac OS X v10. 6 in 2009.

| ATA / ATAPI-8 || ATA-8 || — || || Hybrid drive featuring non-volatile cache to speed up critical OS files || In progress

( Around 1990, OS / 2 came out with " preemptive multitasking " of DOS, an alternative to DESQview for multi-node BBS.

By 1995, many of the DOS-based BBSes had begun switching to modern multitasking operating systems, such as OS / 2, Windows 95, and Linux.

JPI first launched a MS-DOS compiler named JPI Modula-2, that later became TopSpeed Modula-2, and followed up with TopSpeed C, TopSpeed C ++ and TopSpeed Pascal compilers for both the MS-DOS and OS / 2 operating systems.

MS-DOS and Win16 subsystems ( only on i386 ) can run some applications for those platforms, and it has an OS / 2 subsystem for running CLI OS / 2 applications.

IBM contributed its Common User Access model from OS / 2's Workplace Shell.

OS / 390 or its successor, z / OS, display dates in yy. ddd format for most operations.

* On systems that support one-button mice, context menus are typically opened by pressing and holding the primary mouse button ( this works on the icons in the Dock on Mac OS X ) or by pressing a keyboard / mouse button combination ( e. g. Ctrl-mouse click in Mac OS ).

Debian GNU / Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential Linux distribution.

* Open Dylan-Host of two open source, optimizing Dylan compilers targeting Unix / Linux, Mac OS X, and Microsoft Windows

System / 370 introduced virtual memory capabilities in all models other than the very first System / 370 models ; the OS / VS1 variant of OS / 360 MFT, the OS / VS2 ( SVS ) variant of OS / 360 MVT, and the DOS / VS variant of DOS / 360 were introduced to use the virtual memory capabilities, followed by MVS, which, unlike the earlier virtual-memory operating systems, ran separate programs in separate address spaces, rather than running all programs in a single virtual address space.

At first IBM described MVS as simply a new release of OS / VS2, but it was, in fact a major rewrite.

IBM's use of " OS / VS2 " emphasized upwards compatibility: application programs that ran under MVT did not even need recompiling to run under MVS.

OS / VS1 was OS / 360 MFT within a single virtual address space ; OS / VS2 SVS was OS / 360 MVT within a single virtual address space.

However, some older operating systems ( such as OS / VS1 and OS / VS2 SVS ) and even modern ones ( such as IBM i ) are single address space operating systems that run all processes in a single address space composed of virtualized memory.

* Four new operating systems: DOS / VS ( DOS with virtual storage ), OS / VS1 ( OS / 360 MFT with virtual storage ), OS / VS2 ( OS / 360 MVT with virtual storage ) Release 1, termed SVS ( Single Virtual Storage ), and Release 2, termed MVS ( Multiple Virtual Storage ) and planned to be available 20 months later ( at the end of March 1974 ), and VM / 370 – the re-implemented CP / CMS

Existing S / 370-145 customers were happy to learn that they did not have to purchase a hardware upgrade in order to run DOS / VS or OS / VS1 ( or OS / VS2 Release 1 – which was possible, but not common because of the limited amount of main storage available on the S / 370-145 ).

" The upgrade, required to run OS / VS1 or OS / VS2, was not cost effective for most customers by the time IBM could actually deliver and install it, so many customers were stuck with these machines running MVT until their lease ended.

It was not unusual for this to be another four, five or even six years for the more unfortunate ones, and turned out to be a significant factor in the slow adoption of OS / VS2 MVS, not only by customers in general, but for many internal IBM sites as well.

In computing, 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.

In response to the impending release of OS / 2 2. 0, Microsoft developed Windows 3. 1, which included several minor improvements to Windows 3. 0 ( such as display of TrueType scalable fonts, developed jointly with Apple ), but primarily consisted of bugfixes and multimedia support.

However, with the release of Windows 95, OS / 2 began to lose market share.

The release of an open source version as well as ports to GNU / Linux and Mac OS X was announced in May 2010, but the release date of December 2011 was postponed to 30th October 2012 ( Alpha release ).

* OS X Mountain Lion, the eighth major release of OS X

The original release was textmode-only and still lacked the GUI, which was added with OS / 2 1. 1 about a year later.

Until release 2. 0 in April 1992, OS / 2 ran in 16-bit protected mode and therefore could not benefit from the Intel 80386's much simpler 32-bit flat memory model and virtual 8086 mode features.

" Warp " had originally been the internal IBM name for the release: IBM claimed that it had used Star Trek terms as internal names for past OS / 2 releases, and that this one seemed appropriate for external use as well.

Although IBM began indicating shortly after the release of Warp 4 that OS / 2 would eventually be withdrawn, the company did not end support until December 31, 2006.

There is a community of OS / 2 users and developers, along with loyal company customers, hoping that IBM will release OS / 2 or a significant part of it as open source.

Open source operating systems such as Linux have already profited from OS / 2 indirectly through IBM's release of the improved JFS file system which was ported from the OS / 2 code base.

As IBM didn't release the source of the OS / 2 JFS driver, developers ported the Linux driver back to eComStation and added the functionality to boot from a JFS partition.

In 1999, nineteen years after the first release of OS-9, Apple Computer released Mac OS 9.

IBM supports z / OS release coexistence and fallback on an " N + 2 " basis.

z / OS customers using Parallel Sysplex ( clustering ) can operate N + 2 releases ( e. g. Release 9 and Release 11, or Release 9 and Release 10 ) in mixed release configurations, in production, as long as required to complete release upgrades.

Supported software release mixing within server clusters is extremely rare among operating systems and middleware generally but routine with z / OS.

The addition of the Plus 1 added a number of new * FX and OSBYTE calls that allowed the OS to read the values from the Analogue and parallel interfaces.

EFI booting has been supported in only Microsoft Windows versions supporting GPT, the Linux kernel 2. 6. 1 and later, and Mac OS X on Intel-based Macs.

* 1704 1 August ( NS ): ( 21 July ( OS )) – During the War of the Spanish Succession, and when returning from a failed expedition to Barcelona, an Anglo-Dutch fleet, under the command of Sir George Rooke, chief commander of the Alliance Navy, began a new siege ( the eleventh siege of the town ).

OS / 2 1. 0, released in 1987, supported swapping and multitasking and allowed running of DOS executables.

A GUI, called the Presentation Manager ( PM ), was not available with OS / 2 until version 1. 1, released in 1988.

In an attempt to resolve this tension, IBM and Microsoft agreed that IBM would develop OS / 2 2. 0, to replace OS / 2 1. 3 and Windows 3. 0, while Microsoft would develop a new operating system, OS / 2 3. 0, to later succeed OS / 2 2. 0.

After an interim 1. 3 version to fix up many remaining problems with the 1. x series, IBM released OS / 2 version 2. 0 in 1992.

While OS / 2 continued to run Windows 3. 1 applications, it lacked support for anything but the Win32s subset of Win32 API ( see above ).

OSR2, OSR2. 1, and OSR2. 5 were not released to the general public ; rather, they were available only to OEMs that would preload the OS onto computers.

The same limitations affected Digital Research's FlexOS 286 version 1. 0, a derivation of Concurrent DOS 286, developed in 1986, introduced in January 1987, and later adopted by IBM for their IBM 4690 OS.

First released in 1974, MVS was extended by program products with new names multiple times, first to MVS / SE ( System Extension ), next to MVS / SP ( System Product ) Version 1, next to MVS / XA ( eXtended Architecture ), next to MVS / ESA ( Enterprise Systems Architecture ), next to OS / 390 and finally to z / OS ( when 64-bit support was added with the zSeries models ).

Several operating systems have since been constructed using this method, known as co-location, among them Lites, MkLinux, OSF / 1 and NeXTSTEP / OPENSTEP / Mac OS X.

Apple purchased NeXT on December 20, 1996 for $ 429 million and 1. 5 million shares of Apple stock, and much of the current OS X and iOS operating systems are built on the OPENSTEP foundation.

A server version of the new operating system was released as Mac OS X Server 1. 0 in 1999, and the first consumer version, Mac OS X 10. 0, in 2001.

OS / 2 1. 0 was announced in April 1987 and released in December.