The Unix and Internet Fundamentals HOWTO

Eric Raymond


Revision History
Revision 2.14Revised by: esr
More minor corrections.
Revision 2.13Revised by: esr
Minor corrections.
Revision 2.122010-07-31Revised by: esr
Add Farsi translation link. Note that ISA is dead.
Revision 1.01998-10-29Revised by: esr
Initial revision.

This document describes the working basics of PC-class computers, Unix-like operating systems, and the Internet in non-technical language.

Table of Contents
1. Introduction
1.1. Purpose of this document
1.2. New versions of this document
1.3. Feedback and corrections
1.4. Related resources
2. Basic anatomy of your computer
3. What happens when you switch on a computer?
4. What happens when you log in?
5. What happens when you run programs after boot time?
6. How do input devices and interrupts work?
7. How does my computer do several things at once?
8. How does my computer keep processes from stepping on each other?
8.1. Virtual memory: the simple version
8.2. Virtual memory: the detailed version
8.3. The Memory Management Unit
9. How does my computer store things in memory?
9.1. Numbers
9.2. Characters
10. How does my computer store things on disk?
10.1. Low-level disk and file system structure
10.2. File names and directories
10.3. Mount points
10.4. How a file gets looked up
10.5. File ownership, permissions and security
10.6. How things can go wrong
11. How do computer languages work?
11.1. Compiled languages
11.2. Interpreted languages
11.3. P-code languages
12. How does the Internet work?
12.1. Names and locations
12.2. The Domain Name System
12.3. Packets and routers
12.4. TCP and IP
12.5. HTTP, an application protocol
13. To Learn More