Help


[permalink] [id link]
+
Page "X86 memory segmentation" ¶ 0
from Wikipedia
Edit
Promote Demote Fragment Fix

Some Related Sentences

real and mode
The taxonomic structure of the true finch family, Fringillidae, has been fairly disputed in the past, with some upranking the Hawaiian honeycreepers ( Drepanidinae ) as family Drepanididae and / or uniting the cardueline and fringilline finches as tribes ( Carduelini and Fringillini ) in one subfamily ; the euphonious finches ( Euphoniinae ) were thought to be tanagers due to general similarity in appearance and mode of life until their real affinities were realized.
All Windows and DOS-based applications at the time were real mode, running over the protected mode kernel by using the virtual 8086 mode, which was new with the 80386 processor.
Microsoft did not change all of the Windows code to 32-bit ; parts of it remained 16-bit ( albeit not directly using real mode ) for reasons of compatibility, performance, and development time.
Windows Me was criticised for stability issues, and for lacking real mode DOS support, to the point of being referred to as the " Mistake Edition " or " Many Errors.
Additionally, there was a performance penalty involved in accessing extended memory from real mode, as noted below.
The MMU and protection mechanisms are enabled only in case of protected mode ( except for the segment overrun protection ) keeping them disabled in real mode of operation.
By design, the 286 could not revert from protected mode to the basic 8086-compatible " real mode " without a hardware-initiated reset.
When Intel designed the 286, it was not designed to be able to multitask real-mode applications ; real mode was intended to be a simple way for a bootstrap loader to prepare the system and then switch to protected mode.
) The difficulty lay in the incompatibility of old DOS ( real mode ) programs with protected mode.
In protected mode, memory management and interrupt handling were done differently than in real mode.
In addition, DOS programs would not be allowed to access or modify data and code segments that did not belong to them as they could in real mode.
* LOADALL – Undocumented 80286 / 80386 instruction that allowed access to all available memory in real mode.
The 80386 featured three operating modes: real mode, protected mode and virtual mode.
The all new virtual 8086 mode ( or VM86 ) made it possible to run one or more real mode programs in a protected environment, although some programs were not compatible.
This was an embedded version of the i386SX which did not support real mode and paging in the MMU.

real and segment
the Commission on Race and Housing concluded that `` there is no reason to believe that real estate men are either more or less racially prejudiced, on the whole, than any other segment of the American population ''.
is in C. In other words, every point on the line segment connecting x and y is in C. This implies that a convex set in a real or complex topological vector space is path-connected, thus connected.
It can then be shown that a real number r is constructible if and only if, given a line segment of unit length, a line segment of length | r | can be constructed with compass and straightedge.
The GIOVE Mission segment operated by European Satellite Navigation Industries is exploiting the GIOVE-A / B satellites to provide experimental results based on real data to be used for risk mitigation for the IOV satellites that will follow on from the testbeds.
The new medium proved very useful for political and military interests when it came to reaching a broad segment of the population and creating consent or encouraging rejection of the real or imagined enemy.
If there are multiple page or segment tables, there are multiple virtual address spaces and concurrent applications with separate page tables redirect to different real addresses.
Since the real numbers can be used to represent points along an infinitely long line, this implies that a line segment of length 1, which is a part of that line, has the same number of points as the whole line.
In the final minute of the segment, the 3D Homer ends up in a real world, live-action Los Angeles.
This business segment provides institutions with services such as capital raising and financial advisory services including mergers and acquisitions advisory, restructurings, real estate and project finance, and corporate lending.
After being introduced, guests for the interview segment were escorted from backstage by a woman in formal dress dubbed by production staff and listed in the credits as " Ms. Smythe " (" Miss Smythe " until the late 1980s ), always followed by her real name.
Letterman easily adapted to these restrictions for his CBS show: the Viewer Mail segment was continued under the name CBS Mailbag, and the actor playing Larry " Bud " Melman continued his antics under his real name, Calvert DeForest.
Data was then written just as it would on a real CGA ( i. e. the video display was updated by writing to segment B800h ) with only minor changes due to the different memory interlacing structure.
In real mode, the 16-bit segment selector is interpreted as the most significant 16 bits of a linear 20-bit address, called a segment address, of which the remaining four least significant bits are all zeros.
While real mode segments are always 64 KiB long, the practical effect is only that no segment can be longer than 64 KiB, rather than that every segment must be 64 KiB long.
Because there is no protection or privilege limitation in real mode, even if a segment could be defined to be smaller than 64 KiB, it would still be entirely up to the programs to coordinate and keep within the bounds of their segments, as any program can always access any memory ( since it can arbitrarily set segment selectors to change segment addresses with absolutely no supervision ).
Therefore, real mode can just as well be imagined as having a variable length for each segment, in the range 1 to 65536 bytes, that is just not enforced by the CPU.
With the release of the 386, protected mode could be exited by loading the segment registers with real mode values, disabling the A20 line and clearing the PE bit in the CR0 register, without the need to perform the initial setup steps required with the 286.
In real mode each logical address points directly into physical memory location, every logical address consists of two 16 bit parts: The segment part of the logical address contains the base address of a segment with a granularity of 16 bytes, i. e. a segments may start at physical address 0, 16, 32, ..., 2 < sup > 20 </ sup >- 16.

real and is
The box is internally wired so the door can never be opened without setting off a screeching klaxon ( `` It's real obnoxious '' ).
In addition to the authentication and acknowledgment procedures which precede and follow the sending of the go messages, again in special codes, each message also contains an `` internal authenticator '', another specific signal to convince the recipient that he is getting the real thing.
Now the detective must save his own skin by informing on the girl he loves, who is also the real murderer.
In order to exonerate himself, he is compelled to find the real criminal, who happens to be his girl friend.
To perpetuate wealth control led by small groups of individuals who played no role in its creation prevents those with real initiative from coming to the fore, and is basically anti-democratic.
Harris J. Griston, in Shaking The Dust From Shakespeare ( 216 ), writes: `` There is not a word spoken by Shylock which one would expect from a real Jew ''.
The basic truth in the reactionary response is to be found in its realistic assumption of the primacy of the real over the ideational.
Yet he is right when he claims in his autobiography that he drew the real features of the man, his tender and selfless motives and his rugged fearless strength.
One is that there sometimes are real although inadequate compensations in growing old.
Our problem, therefore, is to devise processes more modest in their aspirations, adjusted to the real world of sovereign nation states and diverse and hostile communities.
That is how the real routine of resistance goes on, and its strength is directly proportionate to the number of insignificant people who can let themselves be taken to pieces, piece by piece, without quitting.
The progress reported by the advisory committee is real.
The only real problem is to devise a plan whereby the owners of the above-water land can develop their property without the public losing its underwater land and the right to its development for public use and enjoyment.
`` A better position for negotiations is the real point of this speech.
Bostitch, Inc. is approximately half way through a 10-year exemption of their real estate tax.
But Albania is merely a symptom of a real malaise between China and Russia.
But this is not the real problem ; ;
And fashion is the real king here.
one who is thoroughly human, who affects no dignity, and who is endowed with real ability, genuine worth, and sterling honesty -- all dedicated to secure the best interests of the country he has loved and served so long.
This is being done both by the revaluation of real property and by seeking out forms of personal property hitherto neglected or ignored.
Rhode Island law specifies that all real estate is taxable in the town in which it is situated.
Command's new Brahms Second is a major effort to make a record that sounds like a real orchestra rather than a copy of one.

0.363 seconds.