Editing Expanded memory (section)

==Similar concepts==
Other platforms have implemented the same basic concept – additional memory outside of the main address space – but in technically incompatible ways:
*[[Expanded storage]] was a feature on IBM mainframes providing additional memory outside of the main system memory, first introduced with the IBM 3090 high-end mainframe series in 1985.<ref>{{Cite journal |last1=Sakaki |first1=M. |last2=Samukawa |first2=H. |last3=Honjou |first3=N. |date=1988 |title=Effective utilization of IBM 3090 large virtual storage in the numerically intensive computations of ab initio molecular orbitals |url=https://ieeexplore.ieee.org/document/5387596 |journal=IBM Systems Journal |volume=27 |issue=4 |pages=528–540 |doi=10.1147/sj.274.0528 |issn=0018-8670|url-access=subscription }}</ref> Expanded storage could not be directly addressed by applications; an MVS feature known as "window services" enabled applications to allocate movable windows to expanded storage within their own address space. There was also a "data mover" feature which could be invoked to move data between main memory (central storage) and expanded storage; later, an "Asynchronous Data Mover Facility" (ADMF) was introduced, which enabled applications to request data to be moved between the two in the background, while they performed other processing. By the mid-1990s, expanded storage had ceased to be a physically separate memory, and had become merely a logical division within the system memory enforced by firmware; but it was not until the November 2016 release of z/VM 6.4 that IBM finally removed all support for expanded storage from its mainframe operating systems.<ref>{{Cite web |date= 29 August 2006|title=IBM: Configuring Storage |url=https://www.vm.ibm.com/perf/tips/storconf.html |access-date=2023-05-03 |website=www.vm.ibm.com |language=en-US}}</ref>
*[[Address Windowing Extensions]] (AWE) is a conceptually similar feature in Microsoft Windows, used to enable 32-bit applications to access more memory than the 2–4GB that can fit in a 32-bit address space. Although still supported by current versions of Windows, its use has been superseded by 64-bit applications, which can access >4GB of memory directly.
*[[Virtual memory]] creates the illusion of available memory using, for instance, [[disk storage]].