Talk:Memory protection

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untitled[edit]

Cite on "first OS w/mem protection were variants of unix", kthx. Or: I roll to disbelieve.


I thinking of removing as the accuracy of this statement is somewhat questionable. Jatos 21:10, 15 April 2007 (UTC)

Work on This article[edit]

Having read this article I think need todo some *major* work. Now, I know a lot about memory protection, as I have done a lot of research into memory protection, as I am looking into writing an OS.

Thinks I going to add

- Information on a global and local descriptor tables on the x86 and x64 archs
- List of OSs that do and don't use memory protection (as requested by Demanator)

If anyone else is browsing and knows the subject I could do with some help. In particular, I would glad if someone could put information on non x86/Intel/AMD x64 arch's, and cite it! My knowledge is on the whole architecture specific.

Finally I have stubbed the article to draw attention. Jatos 21:15, 15 April 2007 (UTC)


Ok, I have added a section on OSs using memory protection. Section still needs work. I intend to add more details about what forms of memory protection different OSs use.

Boy, I think I have my work cut out on this article. Jatos 22:00, 15 April 2007 (UTC)

Virtual Memory[edit]

Only the first paragraf of four under the heading "Paging" is about memory protection. The rest describes virtual memory and no matter how good introduction it is to virtual memory it doesnt help when you are reading about Memory protection.

I suggest removing the last three paragrafs and include only a reference to virtual memory. As for Segementing, IIRC its only a different kind of Virutal Memory and in this aspect working the same way as Paging. I'm not all certain in this case though. I belive that Hennessy, Patterson "Computer architecture. A quantitativ aproach" broach the subject in more detail but copy is unfortunatly not avaible right now. Patterson, Hennessy "Computer Organization & design 2nd Edition" only writes around one paragraf on the subject


Firstly, the four tildes would be useful, so people can tell you posted this comment

Virtual memory is in everyway relevant to memory protection, as it is an essential part of some memory protection implemention, most notable that of the x86 and Intel based 64bit architectures.

That said, I will be editing this article amongst other things to make this more clear.

Jatos 21:07, 15 April 2007 (UTC)

The IBM 360 had memory protection without virtual memory. Peter Flass (talk) 23:58, 8 May 2012 (UTC)

O/S list with memory protecton[edit]

Can we please add this list to the article ? The type of memory protection for each would also be valuable info. StuRat 18:40, 23 March 2006 (UTC)

I am going to start seriously working on this article, as I have a lot of knowledge on the subject. I will add some information in this area.

Jatos 21:09, 15 April 2007 (UTC)

good[edit]

most helpful for what i was looking for :-) —The preceding unsigned comment was added by Denmanator (talkcontribs) 09:44, 5 December 2006 (UTC).

true memory protection in home computer operating systems[edit]

This was available from the start with linux (arguably a home computer operating system) so that is well before 2001. —Preceding unsigned comment added by 124.178.167.46 (talk) 11:12, 8 July 2010 (UTC)

And OS/2 in 1987. I'm changing the article. Memory protection on a home system was impossible until it had hardware support. Peter Flass (talk) 23:53, 8 May 2012 (UTC)

Protection keys[edit]

This mechanism was introduced in the System/360 architecture — Was this the first appearance? I don't know enough history to say.

and heavily used by System z operating systems — I guess this is unarguable. Not as heavily today as in earlier systems, since z/OS uses several different methods, but still used quite a bit.

Todays mainframes are essentially immune to hacker attacks. It is assumed, protection keys are a major contributor. — Is the first assertion true? Even if so, does the second follow? assumed by who? Peter Flass (talk) 12:24, 6 July 2012 (UTC)