Table Of ContentMII!.LENNIUM EDITION
by John Rizzo
and
K. Daniel Clark
About the Authors
John Rizzo is an author and consultant
as well as the editor and publisher of
MacWindows, the Web Site for
Macintosh Windows Integration
(http://www. macwindows. com). He fre
quently writes for Macworld,
MacAddict, MacFixlt.com, CNET.com,
and other publications. Rizzo is a former
columnist for MacWeek and MacUser
magazines and was an editor for
MacUser magazine for seven years. Rizzo
has been a Mac user since 1984 and has
been writing about Mac technology
since 1987.
K. Daniel Clark began his career in the
graphic design industry in 1982 creating
logos and other print materials for small
businesses. In 1989, Dan joined MacUser
magazine where he illustrated computer
technology (this is also where he and
John first met and began to write and
illustrate this book). Dan has spent the
last seven years running his own business
developing technical illustrations and
informational graphics for national mag
azines, advertising agencies, and manu
facturers. Dan is now developing techni
cal animations for the Internet and looks
forward to the many information-design
challenges that our ever-changing busi
ness and technology environment
presents.
How the
Mac Works
Millennium Edition
Millennium Edition
John Rizzo and K. Daniel Clark
A division of Macmillan Computer Publishing, USA
20 I W. I 03rd Street
Indianapolis, IN 46290
How the Mac Works, Millennium Edition
Copyright © 2000 by Que!
Associate Publisher Greg Wiegand
Executive Editor Beth Millett
Acquisitions Editor Heather Banner Kane
Development Editors Sarah Robbins & Nicholas J. Goetz
Managing Editor Thomas F. Hayes
Project Editor Karen S. Shields
Copy Editor Megan Wade
Indexer Kelly Castell
Proofreader Maribeth Echard
Technical Editor Terry Rawlings
Illustrator K. Daniel Clark
Team Coordinator Julie Otto
Book Designers Dan Armstrong & Anne Jones
Production Mike Poor & Trina Wurst
All rights reserved. No part of this book shall be reproduced, stored in a retrieval system, or transmitted by any means, elec
tronic, mechanical, photocopying, recording, or otherwise, without written permission from the publisher. No patent liability is
assumed with respect to the use of the information contained herein. Although every precaution has been taken in the prepa
ration of this book, the publisher and authors assume no responsibility for errors or omissions. Nor Is any liability assumed for
damages resulting from the use of the information contained herein.
International Standard Book Number: 0-7897-2428-6
Library of Congress Catalog Card Number: 00-101759
Printed in the United States of America
First Printing: October, 2000
02 01 00 4 3 2
Trademarks
All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized. Que
cannot attest to the accuracy of this information. Use of a term in this book should not be regarded as affecting the validity of
any trademark or service mark. iMac, iBook, and Macintosh are trademarks of Apple Computer, Inc.
Warning and Disclaimer
Every effort has been made to make this book as complete and as accurate as possible, but no warranty or fitness is implied.
The information provided is on an "as is" basis. The author(s) and the publisher shall have neither liability nor responsibility to
any person or entity with respect to any loss or damages arising from the information contained in this book.
For my wife, Christine, who
takes the time out of her own
work to help support me with
mine.
-John Rizzo
For my family. They graciously
give me the tools, the talent,
and the freedom to do my
best.
-K. Daniel Clark
vi TABLE OF CONTENTS
Introduction xi Chapter 11 0 -
4
How a Cache Works
r
Part I : Inside the Mac
Chapter 12
How a RAM Disk Works 78
Chapter 1
,..
Inside the iMac 4 /82
Part 4: Disl< Storag~
Chapter 2
Inside the Power Mac 8 Chapter 13
•
Chapter 3 How a Floppy-Disk Drive Works 86
Inside the PowerBook and iBook 12 Chapter 14
How a Hard-Disk Drive Works 90
Part 2: Mac OS 16
Chapter 15
How Optical and Zip Storage Works 96
Chapter 4
How Startup Works 20
Part 5: Getting Information
Chapter 5
In and Out 104
How the Mac OS Works 26
Chapter 6 Chapter 16
How the Finder Works 36 How USB Works 108
Chapter 17
Part 3: Processor and
How FireWire Works 112
Memory 44
Chapter 18
How the Keyboard, Mouse, and
Chapter 7
Trackpad Work 116
Binary Numbers and Transistors 48
Chapter 19
Chapter 8
How SCSI Works 122
How the Processor Works 52
Chapter 20
Chapter 9
How Expansion Slots Work 126
How RAM Works 60
Chapter 21
Chapter 10
How Multimedia \Xlorks 136
How Virtual Memory Works 68
-
-
-
-
e
Part 6: Display 148 Part 8: Printing and
Publishing 204
Chapter 2~
How QuickDraw Works 152 I
Chapter 30
Chapter 23 How Printers Work 208
How Aqua Works 160
Chapter 31
Chapter 24 How PostScript Works 214
Hmv a CRT Display Works 164
Chapter 32
Chapter 25 How Print Publishing Works 218
How Flat-Panel Displays Work 168
Chapter 33
How Web Publishing Works 226
Part 7: Networks and the
index 232
Internet 174
Chapter 26
HO\-v Mac OS Networks 178
Chapter 27
How Networks Work 182
Chapter 28
How Wireless Networks Work 192
Chapter 29
How Internet Connections Work 196
viii
Foreword
MANY
people view computers as no more than a useful tool. In the same ·way that a micrmvave oven
helps them defrost or reheat food, a computer helps them write reports or create a presentation. They
neither think about nor care about how a computer actually works, any more than they think about how
it is that a microwave oven performs its magic. And in both cases, if the device should ever fail to work
as expected, it will be up to someone else to fix it.
Simply by the fact that you have picked up this book, I am betting that the previous paragraph does not
describe you. Instead, you are someone who is intrigued by the prospect of discovering more about your
Mac and gaining the power that comes with this knowledge. Congratulations. You came to the right
place. How the Mac Works, Millennium Edition takes you on a guided tour of the inner workings of your
computer.
How the Mac Works is not a book of tips and hints. lt has a different goal: to give you a deeper level of
understanding of what's behind all the tips and hints that other books talk about. It accomplishes this
without resorting to the jargon that is too often understood only by people who already know what is
being explained. Instead, it relies on clear, easy-to-follow prose and gorgeously rendered 30 illustrations.
Learning about how computers work is a bit like peeling away the layers of an onion. A deeper level of
understanding is always waiting to be revealed at the next layer. How the Mac \Xlorks, Millennium Edition
takes you several layers deeper than you might have previously gone. For example, if you have ever got
ten an "out of memory" error, you might know several things to do that can fix it. You might know to
quit unnecessary open applications, increase the amount of virtual memory, or (if the problem occurs
often enough) buy and install more RAM. But do you know what RAM really is? Or exactly what hap
pens when a program is "loaded into RAM" when it is launched? Or how virtual memory can trick the
Mac into thinking it has more memory than it really does? This is the sort of knowledge that How the
Mac Works Millennium Edition gives you.
1
Do you know why SCSI-2 is faster than ordinary SCSI? Or what happens when you format a disk? Or
how putting your finger on a trackpad gets the mouse cursor to move? Again, How the Mac Works,
Millennium Edition gives you the inside scoop.
As a long-time Mac troubleshooter, I assure you that this is exactly the type of knowledge that is invalu
able when trying to solve problems that elude the quick fixes you might have already learned. Beyond
this practical value, How the Mac Works, Millennium Edition offers another benefit. When studying na
ture, some people find wonder and beauty in what cannot be explained. They revel in the mystery of it
all. Others find that the true beauty is in understanding what can be explained, from the intricacies of
the genetic code to the mechanisms of natural selection. Computer users follow a similar dichotomy. If
you count yourself in the latter group, then start reading How the Mac \X/orks, Millennium Edition and dis
cover the sense of wonder behind the Mac that you use every day.
Ted Landau
Ted Landau is the author of Sad Macs Bombs, and Other Disasters and runs the MacFixit.com Web site.
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