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Extra Segment
x86 memory segmentation is a term for the kind of memory segmentation characteristic of the Intel x86 computer instruction set architecture. The x86 architecture has supported memory segmentation since the original Intel 8086 (1978), but ''x86 memory segmentation'' is a plainly descriptive retronym. The introduction of memory segmentation mechanisms in this architecture reflects the legacy of earlier 80xx processors, which initially could only address 16, or later 64 KB of memory (16,384 or 65,536 bytes), and whose instructions and registers were optimised for the latter. Dealing with larger addresses and more memory was thus comparably slower, as that capability was somewhat grafted-on in the Intel 8086. Memory segmentation could keep programs compatible, relocatable in memory, and by confining significant parts of a program's operation to 64 KB segments, the program could still run faster. In 1982, the Intel 80286 added support for virtual memory and memory prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Segmentation
Memory segmentation is an operating system memory management technique of dividing a computer's primary memory into segments or sections. In a computer system using segmentation, a reference to a memory location includes a value that identifies a segment and an offset (memory location) within that segment. Segments or sections are also used in object files of compiled programs when they are linked together into a program image and when the image is loaded into memory. Segments usually correspond to natural divisions of a program such as individual routines or data tables so segmentation is generally more visible to the programmer than paging alone. Segments may be created for program modules, or for classes of memory usage such as code segments and data segments. Certain segments may be shared between programs. Segmentation was originally invented as a method by which system software could isolate software processes ( tasks) and data they are using. It was intended to in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overlapping Realmode Segments
Overlap may refer to: * In set theory, an overlap of elements shared between sets is called an intersection, as in a Venn diagram. * In music theory, overlap is a synonym for reinterpretation of a chord at the boundary of two musical phrases * Overlap (railway signalling), the length of track beyond a stop signal that is proved to be clear of obstructions as a safety margin * Overlap (road), a place where multiple road numbers overlap * Overlap (term rewriting), in mathematics, computer science, and logic, a property of the reduction rules in term rewriting systems * Overlap add, an efficient convolution method using FFT * Overlap coefficient, a similarity measure between sets * Orbital overlap, important concept in quantum mechanics describing a type of orbital interaction that affects bond strength * Overlap, publisher of the light novel series '' Arifureta: From Commonplace to World's Strongest'' Overlapping can refer to: * "Reaching over", term in Schenkerian theory, see Schen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segment Descriptors
In memory addressing for Intel x86 computer architectures, segment descriptors are a part of the segmentation unit, used for translating a logical address to a linear address. Segment descriptors describe the memory segment referred to in the logical address. The segment descriptor (8 bytes long in 80286 and later) contains the following fields: # A segment base address # The segment limit which specifies the segment size # Access rights byte containing the protection mechanism information # Control bits Structure The x86 and x86-64 segment descriptor has the following form: : What the fields stand for: ; Base Address : Starting memory address of the segment. Its length is 32 bits and it is created from the lower part bits 16 to 31, and the upper part bits 0 to 7, followed by bits 24 to 31. ; Segment Limit : Its length is 20 bits and is created from the lower part bits 0 to 15 and the upper part bits 16 to 19. It defines the address of the last accessible data. The length i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protected Mode Segments
Protection is any measure taken to guard something against damage caused by outside forces. Protection can be provided to physical objects, including organisms, to systems, and to intangible things like civil and political rights. Although the mechanisms for providing protection vary widely, the basic meaning of the term remains the same. This is illustrated by an explanation found in a manual on electrical wiring: Some kind of protection is a characteristic of all life, as living things have evolved at least some protective mechanisms to counter damaging environmental phenomena, such as ultraviolet light. Biological membranes such as bark on trees and skin on animals offer protection from various threats, with skin playing a key role in protecting organisms against pathogens and excessive water loss. Additional structures like scales and hair offer further protection from the elements and from predators, with some animals having features such as spines or camouflage servi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
