Logical memory & Physical memory..??

• Say an application needs something to be 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