Physical and Logical Memory

Replies

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  anandkumarjha

  Whats In Name

  Please explain me clearly the concept of physical and logical memory in computer?

  suppose any application wants its one one instruction to be executed by the CPU,then it says to CPU about it.Further CPU checks for that application's size. Suppose that application has the size from 1 to 250.the only thing what that application knows is that its size is of 250,that is its ligical memory
  whereas when the CPU checks for the memory space available for that application to occur,it finds that the main memory ranging from 1 to 500 is already alloted for the other works which CPU is taking care of,so what it does is it allots the memory ranging from 501 to 750 for that application.that'a the physical memory.
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  Reya

  It was rightly explained by anand..
  Say an application needs something computed by the CPU. That application says to the CPU, "I'm going to send you 500 pieces of data, so I need a space in the memory that is 500 pieces of data big." So the CPU takes a look at the memory. Initially there is room for 10,000 pieces of data, but because there are other processes already running the first 1 - 2,000 pieces are already taken up. The CPU says to himself from piece 2,000 to 2,500 is were all new data is going to go.
  
  
  
  The physical memory is the address from 2,000 to 2,500.
  
  Now the application doesn't realize that there are other processes that the CPU is taking care of. All it sees is the data 1- 500 pieces stored in the memory. This is logical memory.
  
  When the application wants to run a piece of data of the 1-500, its says to the CPU run the piece 130. In reality 130 is not even a space in the memory that the CPU has set out for the application. Because remember it was originally 2,000-2500 that was set aside for the application. Piece 130 according to the applications logical memory is in reality piece 2130 in the physical memory. So when the CPU is receiving instructions from the application it has to translate the logical memory in to the physical memory and then back into the logical when replying to the application.
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  Whats In Name

  So,they are the same memory space; just different from different perspective,right?
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  rishi0922

  Well I wan't to know that is execution of any program or software depends upon the logical memory ?
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  Reya

  i didnt get you..