Page 42 - DCAP101_BASIC_COMPUTER_SKILLS

Rishi Chopra, Lovely Professional University Unit 3: Memory

Notes

Unit 3: Memory

CONTENTS

Objectives
Introduction
3.1 Unit of Memory
3.2 Types of Memory
3.2.1 RAM
3.2.2 ROM
3.2.3 PROM
3.2.4 EPROM
3.3 Summary
3.4 Keywords
3.5 Self-Assessment Questions
3.6 Review Questions
3.7 Further Readings

Objectives

After studying this unit, you will be able to:
• Understand the unit memory
• Discussed the various types of memory
• Explain the random access memory
• Discussed the read only memory
• Explained programmable red only memory
• Discussed about the checked memory and its components.

Introduction

CPU contains necessary circuitry for data processing controlling other components of the
computer. However, one thing it does not have built into it is the place to store programs
and data needed during data processing. CPU contains several registers for storing data and
instructions but they can store only a few bytes at a time. They are just sufficient to hold
only one or two instructions with corresponding data. If the instructions and data of a
program being executed by a CPU were to reside in secondary storage like a disk, and
fetched and loaded one by one into CPU registers as the program execution proceeded, this
would lead to the CPU being idle most of the time. This is because there is a large speed
mismatch between the rate at which CPU can process data and the rate at which data can
be transferred from disk to CPU registers. For example, a CPU can process data at a rate
of about 5 nanosecond/byte and a disk reader can read data at a speed of about 5

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