Page 11 - iPrime_V2.2_class3
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Processing Device

                 A computer converts the input into  meaningful information
                 through the processing device. The CPU (Central Processing

                 Unit) is the processor. It is known as the brain of a computer
                 that  does all the  calculations, runs  all the  programs  and
                 manages all the operations. The CPU is a chip that is placed
                                                                                                CPU      CPU box
                 inside the CPU box.
                 The working of a CPU can be shown with the help of the following block diagram:





                               INPUT Unit                      ALU                     OUTPUT Unit






                                                          Control Unit





                                                          Memory Unit



                                                               CPU


                 Arithmetic Logic Unit (ALU)


                 The ALU does arithmetic calculations like addition, subtraction, multiplication,
                 division and so on. It also does logical comparisons like greater than, less than,
                 equal to and so on.

                 Control Unit (CU)

                 The CU coordinates  between  all the parts of the  CPU. The CU gets data  and
                 instructions from the memory unit and passes them to ALU in a step-by-step

                 manner.
                 Memory Unit (MU)


                 The MU stores data and instructions given to the computer and the result of the
                 processing.

                 Output Devices

                 A computer displays the results of the processed data through the output devices.
                 Some of the output devices are monitor, printer, speakers, etc.



                                                                                           A Computer System        9
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