The internal structure of a computer looks like above:
Input unit links the external environment with the computer system. Data and instruction must be entered to the computer before performing any competition. Data or instructions can be entered through input devices
eg. Key board, or any other input devices.
Input unit transferred this data into binary coded in short input unit performs the following function:
The job of output unit it is just the viewers of that any input unit it provides information reasons of computation to the output of the world. Output unit links the computer with the external world. A computer prepares results in binary code. Output unit converts these results into human acceptable forms. Inshort perform the following functions.
Before actual processing start, data & instructions entered to the computer must be stored inside the computer. Similarly, results produced by the computer are required to be stored before being passed to the output unit. The intermedial result produced by the computer must also be stored for further processing. Inshort the function of storage unit:
- It stores all the data to be process.
- It stores intermedial results.
- It stores final result are realize an output device.
ALU is the place where actual execution of the instructions takes places during the processing operations. All calculations & comparisons are made in the ALU. The data and instructions stored in the primary storage are transphered as where required. Intermedial results are also transphered back to the ALU for the final processing. After completion of processing the final results are send to storage units from ALU.
Number of arithmetic & logical operation that a computer can perform is determined by the design to perform the four basic arithmetic operations. They are +,-,*,/. The logic operations like <,=,>.
ALU dose not know what should be done with the data likewise, output unit dose not know when the result should be displayed. By selecting, interning and seeing to the execution of the program the CU is able to maintain order and direct the operations of the entire system CU doesn’t perform any actual processing on data yet it is known as a central nervous system for the comforts of the computer.
It manages co-ordinates the entire system.