Computer systems and networks

329 Pages·2007·8.307 MB·English

by  Barry Blundell, Nawaz Khan, Aboubaker Lasebae, Muthana Jabbar

Computer Systems
and Networks

Copyright 2006 Cengage Learning, Inc. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.
SystNet-0.p65 1 11/2/2006, 2:03 PM
Copyright 2006 Cengage Learning, Inc. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.
SystNet-0.p65 2 11/2/2006, 2:03 PM

Computer Systems and Networks

Copyright © 2006 Middlesex University Press

The Cengage Learning logo is a registered trademark used herein under
license.

For more information, contact Cengage Learning, Cheriton House; North
Way, Andover, Hampshire SP10 5BE or visit us on the World Wide Web at:
http://www.cengagelearning.co.uk

All rights reserved by Cengage Learning. The text of this publication, or any
part thereof, may not be reproduced or transmitted in any form or by any
means, electronic or mechanical, including photocopying, recording, storage
in an information retrieval system, or otherwise, without prior permission of
the publisher.

While the publisher has taken all reasonable care in the preparation of this
book the publisher makes no representation, express or implied, with regard
to the accuracy of the information contained in this book and cannot accept
any legal responsibility or liability for any errors or omissions from the book
or the consequences thereof.

Products and services that are referred to in this book may be either
trademarks and/or registered trademarks of their respective owners. The
publisher and author/s make no claim to these trademarks.

British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library

ISBN 978-1-84480-639-3

British Library Cataloguing-in-
Publication Data
A catalogue record for this book is

available from the British Library
Contents
v
Series preface ix
Preface xi
About the website xiii
1 Setting the scene 1
1.1 Introduction 2
1.2 What is a computer? 2
1.3 The stored program model 6
1.4 Forms of computer hardware 8
1.5 Basic computer operation 9
1.6 Binary (number base 2) 10
1.7 Bits and bytes 13
1.8 Summary 14
1.9 Review questions 14
1.10 Feedback on activities 15
2 Logic gates and simple digital circuits 17
2.1 Introduction 18
2.2 Logic gates and truth tables 18
2.3 Combinational and sequential circuits 26
2.4 Example combinational logic circuits 30
2.5 Example sequential logic circuits 31
2.6 Hexadecimal 36
2.7 Summary 39
2.8 Review questions 39
2.9 Feedback on activities 40
3 Using and accessing memory 43
3.1 Introduction 44
3.2 Concepts and terminology 44
3.3 Addresses 45
3.4 The fetch-execute cycle 47
3.5 The connection between the processor and the main memory 48
3.6 Processor registers 50
3.7 Machine code 53
3.8 Volatile and non-volatile memory 57
3.9 Cache memory 63
3.10 Summary 64
3.11 Review questions 64
3.12 Feedback on activities 65
4 The computer: an interrupt-driven mathematical machine 67
4.1 Introduction 68
4.2 Representing positive and negative integers 68
4.3 Dealing with non-integer numbers 73
4.4 Character representation: ASCII 80
4.5 Representation of data and instructions 83
4.6 Interrupts 84
4.7 Interrupt priorities 86
4.8 Summary 90
4.9 Review questions 91
4.10 Feedback on activities 91
Copyright 2006 Cengage Learning, Inc. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.
SystNet-0.p65 5 11/2/2006, 2:03 PM
vi
5 Storage devices and data transfer issues 93
5.1 Introduction 94
5.2 Primary and secondary storage: capacity, speed and cost 94
5.3 Secondary storage using magnetisation 96
5.4 Secondary storage using optical techniques 103
5.5 Serial and parallel interfaces 105
5.6 Signal transfer 106
5.7 Summary 110
5.8 Review questions 112
5.9 Feedback on activities 112
6 Interfacing to the physical world 115
6.1 Introduction 116
6.2 Digital-to-analogue conversion 116
6.3 Analogue-to-digital conversion 119
6.4 Signals 122
6.5 Interaction devices 124
6.6 The display 129
6.7 Display metrics 135
6.8 Summary 136
6.9 Review questions 137
6.10 Feedback on activities 137
7 The central processing unit 141
7.1 Introduction 142
7.2 General processor architecture 142
7.3 The Register Transfer Language (RTL) 150
7.4 The stack 151
7.5 The overall architecture of a simple processor model 155
7.6 Summary 156
7.7 Review questions 156
7.8 Feedback on activities 157
8 Aspects of the operating system 161
8.1 Introduction 162

8.2 Basic input/output system (BIOS) 162
8.3 The reset vector 163
8.4 Operating system 164
8.5 Types of operating systems 168
8.6 Virtual memory 173
8.7 Multi-tasking 175
8.9 Summary 177
8.10 Review questions 177
8.11 Feedback on activities 178
Copyright 2006 Cengage Learning, Inc. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.
SystNet-0.p65 6 11/2/2006, 2:03 PM
vii
9 Networking computers 181
9.1 Introduction 182
9.2 Bandwidth bit-rate and latency 182
9.3 Types of network 188
9.4 Network topologies 189
9.5 The layered approach to computer communications 192
9.6 Standards 194
9.7 The OSI model 196
9.8 The TCP/IP protocol 201
9.9 Summary 206
9.10 Review questions 207
9.11 Feedback on activities 210
10 Transmission media and data communications 213
10.1 Introduction 214
10.2 Concerning signals 214
10.3 Data transmission media 228
10.4 Contention-based access (CSMA/CD) 224
10.5 Ethernet 230
10.6 The Ethernet frame 236
10.7 Token passing 237
10.8 Summary 239
10.9 Review questions 239
10.10 Feedback on activities 240
11 The Internet 243
11.1 Introduction 244
11.2 Connection-oriented and connectionless internetworking 244
11.3 Internetworking 246
11.4 Data encapsulation 251
11.5 Internet Protocol (IP) 251
11.6 Internet addressing 254
11.7 Address resolution 260
11.8 The Domain Name System (DNS) 262
11.9 Summary 263
11.10 Review questions 26 4
11.11 Feedback on activities 266
12 Routers, satellites and security 269
12.1 Introduction 270
12.2 Routers in networks 270
12.2 The process of routing 271
12.3 Satellite communications 275
12.4 Cryptography 278
12.5 Public key encryption 279
12.6 Summary 282
12.7 Review questions 282
12.9 Feedback on activities 284
Answers to review questions 287
Index 307
Copyright 2006 Cengage Learning, Inc. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.
SystNet-0.p65 7 11/2/2006, 2:03 PM
Copyright 2006 Cengage Learning, Inc. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.
SystNet-0.p65 8 11/2/2006, 2:03 PM
Series preface
The FastTrack Series
Thomson Learning and Middlesex University Press have collaborated to produce a unique
collection of textbooks which cover core, mainstream topics in an undergraduate computing
curriculum. FastTrack titles are instructional, syllabus-driven books of high quality and utility.
They are:
● For students: concise and relevant and written so that you should be able to get 100% value
out of 100% of the book at an affordable price
● For instructors: classroom tested, written to a tried and trusted pedagogy and market-
assessed for mainstream and global syllabus offerings so as to provide you with confidence in
the applicability of these books. The resources associated with each title are designed to make
delivery of courses straightforward and linked to the text.
FastTrack books can be used for self-study or as directed reading by a tutor. They contain the
essential reading necessary to complete a full understanding of the topic. They are augmented
by resources and activities, some of which will be delivered online as indicated in the text.
How the series evolved
Rapid growth in communications technology means that learning can become a global activity.
In collaboration, Global Campus, Middlesex University and Thomson Learning have produced
materials to suit a diverse and innovating discipline and student cohort.
Global Campus at the School of Computing Science, Middlesex University, combines local
support and tutors with CD-ROM-based materials and the Internet to enable students and
lecturers to work together across the world.
Middlesex University Press is a publishing house committed to providing high-quality,
innovative, learning solutions to organisations and individuals. The Press aims to provide
leading-edge ‘blended learning’ solutions to meet the needs of its clients and customers.

Partnership working is a major feature of the Press’s activities.
Together with Middlesex University Press and Middlesex University’s Centre for Learning
Development, Global Campus developed FastTrack books using a sound and consistent
pedagogic approach. The SCATE pedagogy is a learning framework that builds up as follows:
● Scope: Context and the learning outcomes
● Content: The bulk of the course: text, illustrations and examples
● Activity: Elements which will help students further understand the facts and concepts
presented to them in the previous section. This promotes students’ active participation in their
learning and in creating their understanding of the unit content
● Thinking: These elements give students the opportunity to reflect and share with their peers
their experience of studying each unit. There are review questions so that the students can
assess their own understanding and progress
● Extra: Further online study material and hyperlinks which may be supplemental, remedial or
advanced.
Copyright 2006 Cengage Learning, Inc. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.
SystNet-0.p65 9 11/2/2006, 2:03 PM