How Computers Work
Processor and Main Memory
Roger Young
All rights reserved.
Even if you know nothing about electronics, you have come to the right place.
If you are wondering how microprocessors work, you have come to the right place. A microprocessor is a small processor.
If you already know something about electronics, don't be put off by the fact that the book starts out very simple and uses relays instead of transistors. You will get through the first chapter quickly. See web page 24, below, for just how complex it gets.
If you have a very fast connection (DSL or cable modem), then you can click the following link to see an easier to read (PDF) version of the book. It is 783 kilobytes, so it will take a while.
With a regular (56K) modem, it will take about 3 or 4 minutes to be displayed.
If you print this book ('How Computers Work: Processor and Main Memory') out, it will be easier to follow when it gets to large, relatively-complex diagrams.
If you would like a free electronic copy of the book ('How Computers Work: Processor and Main Memory') (152 pages) for easier reading and printing for personal use, then you can download a (pdf) file called 'bookbpdf.pdf' that almost any computer can read. Simply download the pdf file and find it with the desktop 'My Computer' icon and simply double click on the file icon. It uses Adobe Acrobat Reader. Or you can download a file called 'bookb.doc' that you can read with Microsoft Word 2000. You can download either of these files by clicking on the following link: Free Electronic Copies of the Book then clicking on the file you want to download.
You can also email me and ask for the .pdf file if you want it to be sent as an attachment to an email. Please email questions or comments to me (Roger Young) at:
young@fastchip.net
You can also reach this page with the simple (redirected) web address howcomputers.com in case you want to tell anyone about it.
Last updated: May 24, 2008
Introduction
Computers are the most complex machines that have ever been created. Very few people really know how they work. This book will tell you how they work and no technical knowledge is required. It explains the operation of a simple, but fully functional, computer in complete detail. The simple computer described consists mainly of a processor and main memory. Relays, which are explained, are used in the circuitry instead of transistors for simplicity. This book does not cover peripherals like modems, mice, disk drives, or monitors.
Did you ever wonder what a bit, a pixel, a latch, a word (of memory), a data bus, an address bus, a memory, a register, a processor, a timing diagram, a clock (of a processor), an instruction, or machine code is? Though most explanations of how computers work are a lot of analogies or require a background in electrical engineering, this book will tell you precisely what each of them is and how each of them works without requiring any previous knowledge of computers or electronics. However, this book starts out very easy and gets harder as it goes along. You must read the book starting at the first page and not skip around because later topics depend on understanding earlier topics. How far you can get may depend on your background. A junior high school science background should be enough. There is no mathematics required other than simple addition and multiplication. This is a short book, but it must be studied carefully. This means that you will have to read some parts more than once to understand them. Get as far as you can. You will be much more knowledgeable about how computers work when you are done than when you started, even if you are not able to get through the whole text. This is a technical book though it is aimed at a non-technical audience. Though this book takes considerable effort to understand, it is very easy for what it explains. After you have studied this book, if you go back and read it, it will seem simple. Good Luck!
CONTENTS
Click the page number to view the page.Each page is a few book pages.
INSTRUCTIONS . 12 . 13 . 14 . 15 . 16
PROCESSOR . 17 . 18 . 19 . 20 . 21 . 22 . 23 . 24
PROGRAMMING . 25 . 26 . 27 . 28 . 29 . 30 . 31 . 32 . 33 . 34 . 35 . 36 . 37
MISCELLANEOUS . 38
book cover
Starting in August, 2002, this book is ALSO available in 8.25" X 11" paperback book form direct from the publisher for $9.50 plus shipping and handling. The book at the publisher (AuthorHouse (was 1stBooks Library)) is at http://www.1stbooks.com/bookview/11434. The publisher is at http://www.authorhouse.com/home.aspx .
The book has a list price of $14.50 and is also available from Amazon.com (my favorite book and software supplier) and Barnes and Noble.com and can be ordered through most any bookstore.
For a great, easy-to-read, wonderfully-illustrated, introductory book on how computers work that covers all parts of a computer but isn't nearly as in depth about the processor and doesn't have any circuit diagrams, read the book 'How Computers Work' by Ron White, which is available at most libraries.
For how many other things work, see:
For more free technical books on the web: Free Tech Books
For many more free net computer books: Free Computer Web Books
For over 18,000 free online books, see: The Online Books Page from the University of Pennsylvania.
For computer architecture information, see the WWW Computer Architecture Page from the University of Wisconsin-Madison.
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