Info about physical and linear memory

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Thunder

Info about physical and linear memory

Post by Thunder »

Hello,
Could someone give me links to tutorials or manuals about PHYSICAL AND LINEAR MEMORY DIFFERNCES AND TRANSLATING.

About pmode segmentation and similar stuff :)

Bye. Thanks
slacker

Re:Info about physical and linear memory

Post by slacker »

im not 100% sure but...........


physical memory is all the addressable memory.

its not "linear memory", its "linear addressing"

a linear address contains a segment and offset like:
take the address 0x50:0x00
a linear address that would point to 0x50:0x00 is 0x500.

lin address = (segment * 10) + offset
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Re:Info about physical and linear memory

Post by Pype.Clicker »

one usually uses the term of "linear address" to refer the input of the paging process, and "physical address" to refer to the output of the paging process.

If the paging is disabled, the linear address (which is also the output of the segmentation translation) is used directly as physical address ...

For the sake of completeness, the segment:offset address used in ASM programming is called "logical address" or sometimes "effective address" when one want to refer to the fact the CPU has already performed a few calculation to produce an offset out of [eax+ebx*4+12], for instance.
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