Functional units of computer system,control unit and arithmetic logic section

FUNCTIONAL UNITS OF A COMPUTER SYSTEM Digital computer systems consist of three distinct units. These units are as follows: Input unit Central Processing unit Output unit these units are interconnected by electrical cables to permit communication between them. This allows the computer to function as a system. Input Unit A computer must receive both data and program statements to function properly and be able to solve problems. The method of feeding data and programs to a computer is accomplished by an input device. Computer input devices read data from a source, such as magnetic disks, and translate that data into electronic impulses for transfer into the CPU. Some typical input devices are a keyboard, a mouse, or a scanner. Central Processing Unit The brain of a computer system is the central processing unit (CPU). The CPU processes data transferred to it from one of the various input devices. It then transfers either an intermediate or final result of the CPU to one or more output devices.

CONTROL SECTION The control section directs the flow of traffic (operations) and data. It also maintains order within the computer. The control section selects one program statement at a time from the program storage area, interprets the statement, and sends the appropriate electronic impulses to the arithmetic-logic and storage sections so they can carry out the instructions.

ARITHMETIC-LOGIC SECTION The arithmetic-logic section performs arithmetic operations, such as addition, subtraction, multiplication, and division. Through internal logic capability, it tests