Introduction

In the previous Block, we have touched upon the basic foundation of computers, which include concepts on von Neumann machine, instruction, execution, the digital data representation and logic circuits. In this Block we will define some of the most important component units of a computer, which are the memory unit and the inputout3ut units. In this unit we will discuss various components of the memory system of a computer system. Computer memory is organised into a hierarchy to minimise cost. Also, it does not compromise the overall speed of access. Memory hierarchy include cache memory, main memory and other secondary storage technologies. In this Unit, we will discuss the main memory, the secondary memory and high-speed memories such as cache memory, arid the memory system of microcomputer.

Objectives

After going though this Unit, you will be able to:

• describe the key characteristics of the memory system;
• distinguish among various types of random access memories;
• describe the latest secondary storage technologies;
• describe the importance of cache memory and other high-speed memories; and
• describe the different memory chips of micro computers.