CHAPTER 2 : PROCESSOR and MEMORY

2.1.1.3 PROCESSOR AND MEMORY

The complex procedure that transforms raw input data into useful information for output is called processing. To perform this transformation, the computer uses the processing and main memory devices, which are housed in the computer’s system unit or system cabinet. The system unit, or system cabinet, houses among other things, the electronic circuitry, called the CPU that does the actual processing and the main memory that supports processing.

The Central Processing Unit, or CPU, is the processor and is considered as the brain or heart of the computer. It reads and interprets software and coordinates the processing activities that must take place. In a microcomputer, the CPU is usually contained on a single integrated circuit or chip.

This single chip is called a microprocessor. This chip and other components necessary to make it work are mounted on a main circuit board called a system board. In larger computers, the CPU is contained on one or several circuit boards. The design of the CPU affects the processing power and the speed of the computer, as well as the amount of main memory it can use effectively.

The CPU uses the computer’s memory to hold pieces of data or information while it works with them, together with the instructions for processing these data. It operates like a chalkboard that is constantly being written on, then erased, and then written on again.

The main memory, which is also called random access memory (RAM), internal memory, or primary storage, is contained on chips mounted on the system board. The major attribute with main memory is storage capacity or size because it determines how much data can be processed at a time and how big and complex a program may be used to process it.

RAM is volatile, that is, all contents are lost when the computer’s power is shut off. To produce a copy of the data and instructions that are stored in the memory, they should be saved, before the computer is turned off, to a secondary storage device for future use.