Editing Memory protection (section)

== Memory protection in different operating systems ==
Different operating systems use different forms of memory protection or separation. Although memory protection was common on most [[mainframe computer|mainframes]] and many [[minicomputer]] systems from the 1960s, true memory separation was not used in [[home computer]] operating systems until [[OS/2]] (and in <!-- Arthur from the same year (presumably) that became--> [[RISC OS]]) was released in 1987. On prior systems, such lack of protection was even used as a form of [[interprocess communication]], by sending a [[pointer (computer programming)|pointer]] between processes. It is possible for processes to access System Memory in the [[Windows 9x]] family of operating systems.<ref>{{cite web|url=http://everything2.com/title/Windows%25209x%2520does%2520not%2520have%2520true%2520memory%2520protection  |title=Windows 9x does not have true memory protection |publisher=Everything2 |date=2000-06-24 |access-date=2009-04-29}}</ref>

Some operating systems that do implement memory protection include:

* [[Unix-like]] systems (since the late 1970s), including [[Solaris (operating system)|Solaris]], [[Linux]], [[Berkeley Software Distribution|BSD]], [[macOS]], [[iOS]] and [[GNU Hurd]]
* [[Plan 9 from Bell Labs|Plan9]] and [[Inferno (operating system)|Inferno]], created at [[Bell Labs]] as Unix successors (1992, 1995)
* [[OS/2]] (1987)
* [[RISC OS]] (1987) (The OS memory protection is not comprehensive.)
* Microware [[OS-9]], as an optional module (since 1992)
* [[Microsoft Windows]] family from Windows NT 3.1 (1993)
* [[Atari]] [[MultiTOS]] (since 1991)
* Pharos<ref>{{Cite web|url=https://sourceforge.net/projects/rtospharos/|title = Pharos| date=16 December 2020 }}</ref> (since 2017)

On [[Unix-like]] systems, the <code>mprotect</code> [[system call]] is used to control memory protection.<ref>{{cite web|title=mprotect|url=http://pubs.opengroup.org/onlinepubs/009604499/functions/mprotect.html|work=The Open Group Base Specifications Issue 6|publisher=The Open Group}}</ref>