IT Peak

This is the manipulating part of the CPU, Where actual data processing occurs. All calculations and comparisons take place in this section. The data and instructions, stored in the primary storage prior to processing and transferred as and when needed to the ALU where processing takes place. No processing is done in the primary storage unit. Intermediate results generated in the ALU are temporarily transferred back to the primary storage until needed at a later time. Data may thus move from primary storage to ALU and back again to storage many times before the processing is over ALU are designed to perform the four basic arithmetic operations add, subtract, multiply, divide, and logical operations or comparisons such as less than, equal to, or greater than. Because of these calculations and comparisons ALU is called the accountant of the computer. Ater the completion of processing, the final results which are stored in the storage unit are released to an output device. Decision making capabilities of the computer is achieved by capacity of ALU.