updated

LDP/howto/docbook/HOWTO-INDEX/howtoChap.sgml

@@ -4635,7 +4635,7 @@ How to change your Linux system so it uses UTF-8 as text encoding. </Para>
 Unix-and-Internet-Fundamentals-HOWTO</ULink>,
 <CiteTitle>The Unix and Internet Fundamentals HOWTO</CiteTitle>
 </Para><Para>
-<CiteTitle>Updated: Nov 2007</CiteTitle>.
+<CiteTitle>Updated: Jan 2010</CiteTitle>.
 Describes the working basics of PC-class computers, Unix-like
 operating systems, and the Internet in non-technical language. </Para>
 </ListItem>

LDP/howto/docbook/HOWTO-INDEX/osSect.sgml

@@ -44,7 +44,7 @@ requirements, and some resources. </Para>
 Unix-and-Internet-Fundamentals-HOWTO</ULink>,
 <CiteTitle>The Unix and Internet Fundamentals HOWTO</CiteTitle>
 </Para><Para>
-<CiteTitle>Updated: Nov 2007</CiteTitle>.
+<CiteTitle>Updated: Jan 2010</CiteTitle>.
 Describes the working basics of PC-class computers, Unix-like
 operating systems, and the Internet in non-technical language. </Para>
 </ListItem>

LDP/howto/docbook/Unix-and-Internet-Fundamentals-HOWTO.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0"?>
-<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
+<!DOCTYPE article PUBLIC 
+    "-//OASIS//DTD DocBook XML V4.1.2//EN" 
     "docbook/docbookxx.dtd" [
 <!ENTITY howto		"http://www.tldp.org/HOWTO/">
 <!ENTITY mini-howto	"&howto;/mini/">
@@ -24,6 +25,17 @@
   </author>
 
    <revhistory>
+      <revision>
+         <revnumber>2.11</revnumber>
+         <date>2010-01-05</date>
+         <authorinitials>esr</authorinitials>
+          <revremark>
+            Notice that it's mostly 64 bits now.  Update the sections
+	    on booting and running programs to describe X.
+         </revremark>
+      </revision>
+
+<!--
       <revision>
          <revnumber>2.10</revnumber>
          <date>2007-11-28</date>
@@ -33,7 +45,6 @@
          </revremark>
       </revision>
 
-<!--
       <revision>
          <revnumber>2.9</revnumber>
          <date>2004-03-03</date>
@@ -237,9 +248,14 @@ url="&howto;Unix-and-Internet-Fundamentals-HOWTO/index.html">
 http:&howto;Unix-and-Internet-Fundamentals-HOWTO/index.html</ulink>.
 </para>
 
-<para>This document has been translated into: <ulink
+<para>This document has been translated into: the following languages: <ulink
-url="http://theta.uoks.uj.edu.pl/~gszczepa/gszczepa/esr1iso2.htm">Polish</ulink><ulink
+url="http://theta.uoks.uj.edu.pl/~gszczepa/gszczepa/esr1iso2.htm">Polish</ulink>
-url="http://es.tldp.org/Manuales-LuCAS/doc-fundamentos-unix-internet/fundamentos.htm">Spanish</ulink>.</para>
+<ulink
+url="http://es.tldp.org/Manuales-LuCAS/doc-fundamentos-unix-internet/fundamentos.html
+">Spanish</ulink>
+<ulink
+url="http://docs.comu.edu.tr/howto/fundementals-howto.html">Turkish</ulink> 
+</para>
 
 </sect2>
 <sect2 id="feedback"><title>Feedback and corrections</title>
@@ -264,20 +280,21 @@ resources.</para>
 <sect1 id="anatomy"><title>Basic anatomy of your computer</title>
 
 <para>Your computer has a processor chip inside it that does the actual
-computing.  It has internal memory (what DOS/Windows people call <quote>RAM</quote>
+computing.  It has internal memory (what DOS/Windows people call
-and Unix people often call <quote>core</quote>; the Unix term is a folk memory from
+<quote>RAM</quote> and Unix people often call <quote>core</quote>; the Unix
-when RAM consisted of ferrite-core donuts).  The processor and memory live
+term is a folk memory from when RAM consisted of ferrite-core donuts).  The
-on the
+processor and memory live on the
 <firstterm>motherboard</firstterm><indexterm><primary>motherboard</primary></indexterm>,
 which is the heart of your computer.</para>
 
-<para>Your computer has a screen and keyboard.  It has hard drives and a
+<para>Your computer has a screen and keyboard.  It has hard drives and an
-CD-ROM and maybe a floppy disk.  Some of these devices are run by
+optical CD-ROM (or maybe a DVD drive) and maybe a floppy disk.  Some of
-<firstterm>controller cards</firstterm> that plug into the motherboard and
+these devices are run by <firstterm>controller cards</firstterm> that plug
-help the computer drive them; others are run by specialized chipsets
+into the motherboard and help the computer drive them; others are run by
-directly on the motherboard that fulfill the same function as a controller
+specialized chipsets directly on the motherboard that fulfill the same
-card.  Your keyboard is too simple to need a separate card; the controller
+function as a controller card.  Your keyboard is too simple to need a
-is built into the keyboard chassis itself.</para>
+separate card; the controller is built into the keyboard chassis
+itself.</para>
 
 <para>We'll go into some of the details of how these devices work later.  For
 now, here are a few basic things to keep in mind about how they work
@@ -341,7 +358,7 @@ system.</para>
 
 <para>The loader does this by looking for a
 <firstterm>kernel</firstterm><indexterm><primary>kernel</primary></indexterm>,
-loading it into memory, and starting it.  When you boot Linux and see
+loading it into memory, and starting it.  If you Linux and see
 "LILO" on the screen followed by a bunch of dots, it is loading the kernel.
 (Each dot means it has loaded another <anchor id="diskblock"/><firstterm>disk
 block</firstterm> of kernel code.)</para>
@@ -365,7 +382,15 @@ and how controllers will respond if they're present.  This process is
 called
 <firstterm>autoprobing</firstterm><indexterm><primary>autoprobing</primary></indexterm>.</para>
 
-<para>Most of the messages you see at boot time are the kernel autoprobing
+<para>You may or may not be able to see any of this going on.  Back when
+Unix systems used text consoles, you'd see boot messages scroll by on your
+screen as the system started up.  Nowawadays, Unixes often hide the boot
+messages behind a graphical splash screen. You may be able to see them by
+switching to a text console view with the key combination Ctrl-Shift-F1. If
+this works, you should be able to switch back to the graphical boot screen
+with a different Ctrl-Shift sequence; try F7, F8, and F9.</para>
+
+<para>Most of the messages emitted boot time are the kernel autoprobing
 your hardware through the I/O ports, figuring out what it has available to
 it and adapting itself to your machine.  The Linux kernel is extremely good
 at this, better than most other Unixes and <firstterm>much</firstterm> better
@@ -378,7 +403,8 @@ a critical mass of users.</para>
 boot process; it's just the first stage (sometimes called <firstterm>run
 level 1</firstterm>).  After this first stage, the kernel hands control to a
 special process called &lsquo;init&rsquo; which spawns several housekeeping
-processes.</para>
+processes. (Some recent Linuxes use a different program called
+&lsquo;upstart&rsquo; that does similar things)</para>
 
 <para>The init process's first job is usually to check to make sure your disks
 are OK.  Disk file systems are fragile things; if they've been damaged by a
@@ -399,35 +425,40 @@ daemons your system starts may vary, but will almost always include a print
 spooler (a gatekeeper daemon for your printer).</para>
 
 <para>The next step is to prepare for users.  Init starts a copy of a
-program called <command>getty</command> to watch your console (and maybe
+program called <command>getty</command> to watch your screen and keyboard
-more copies to watch dial-in serial ports).  This program is what issues
+(and maybe more copies to watch dial-in serial ports).  Actually, nowadays
-the <command>login</command> prompt to your console.  Once all daemons and
+it usually starts multiple copies of <command>getty</command> so you have
-getty processes for each terminal are started, we're at <firstterm>run level
+several (usually 7 or 8) virtual consoles, with your screen and keyboards
-2</firstterm>.  At this level, you can log in and run programs.</para>
+connected to one of them at a time.  But you likely won't see any of these,
+because one of your consoles will be taken over by the X server (about
+which more in a bit).</para>
 
-<para>But we're not done yet.  The next step is to start up various daemons
+<para>We're not done yet.  The next step is to start up various daemons
-that support networking and other services.  Once that's done, we're at
+that support networking and other services. The most important of these is
-<firstterm>run level 3</firstterm> and the system is fully ready for
+your X server.  X is a daemon that manages your display, keyboard, and
-use.</para>
+mouse.  Its main job is to produce the color pixel graphics you normally
+see on your screen.</para>
+
+<para>When the X server comes up, during the last part of your machine's
+boot process, it effectively takes over the hardware from whatever virtual
+console was previously in control.  That's when you'll see a graphical
+login screen, produced for you by a program called a <firstterm>display
+manager</firstterm>.</para>
 
 </sect1>
 <sect1 id="login"><title>What happens when you log in?</title>
 
-<para>When you log in (give a name to <command>getty</command>) you
+<para>When you log in, you identify yourself to the computer. On modern
-identify yourself to the computer.  It then runs a program called
+Unixes you will usually do this through a graphical display manager. But
-(naturally enough) <command>login</command>, which takes your password and
+it's possible to switch virtual consoles with a Ctrl-Shift key sequence and
-checks to see if you are authorized to be using the machine.  If you
+do a textual login, too. In that case you go through the
-aren't, your login attempt will be rejected.  If you are, login does a few
+<command>getty</command> instance watching that console tto call the
-housekeeping things and then starts up a command interpreter, the
+program <command>login</command>.</para>
-<firstterm>shell</firstterm>.  (Yes, <command>getty</command> and
-<command>login</command> could be one program.  They're separate for
-historical reasons not worth going into here.)</para>
 
-<para>Here's a bit more about what the system does before giving you a shell
+<para>You identify yourself to the display manager or
-(you'll need to know this later when we talk about file permissions).
+<command>login</command> with a login name and password.  That login name
-You identify yourself with a login name and password.  That login name is
+is looked up in a file called /etc/passwd, which is a sequence of lines
-looked up in a file called /etc/passwd, which is a sequence of lines each
+each describing a user account.</para>
-describing a user account.</para>
 
 <para>One of these fields is an encrypted version of the account password
 (sometimes the encrypted fields are actually kept in a second /etc/shadow
@@ -465,21 +496,17 @@ your personal files will live.  Finally, your account entry also sets your
 the command interpreter that <command>login</command> will start up to
 accept your commmands.</para>
 
+<para>What happens after you have successfully logged in depends on how you
+did it. On a text console, <command>login</command> will launch a shell
+and you'll be off and running.  If you logged in through a display
+manager, the X server will bring up your graphical desktop and you will
+be able to run programs from it &mdash; either through the menus, or
+through desktop icons, or through a <firstterm>terminal
+emulator</firstterm> running a <firstterm>shell</firstterm>.</para>
+
 </sect1>
-<sect1 id="running-programs"><title>What happens when you run programs from the shell?</title>
+<sect1 id="running-programs"><title>What happens when you run programs
-
+after boot time?</title>
-<para>The shell is Unix's interpreter for the commands you type in; it's
-called a shell because it wraps around and hides the operating system
-kernel.  It's an important feature of Unix that the shell and kernel are
-separate programs communicating through a small set of system calls. 
-This makes it possible for there to be multiple shells, suiting different
-tastes in interfaces.</para>
-
-<para>The normal shell gives you the &lsquo;$&rsquo; prompt that you see
-after logging in (unless you've customized it to be something else).  We
-won't talk about shell syntax and the easy things you can see on the screen
-here; instead we'll take a look behind the scenes at what's happening from
-the computer's point of view.</para>
 
 <para>After boot time and before you run a program, you can think of your
 computer as containing a zoo of processes that are all waiting for
@@ -499,16 +526,34 @@ are known as <firstterm>system calls</firstterm>.</para>
 <para>Normally all I/O goes through the kernel so it can schedule the
 operations and prevent processes from stepping on each other.  A few
 special user processes are allowed to slide around the kernel, usually by
-being given direct access to I/O ports.  X servers (the programs that
+being given direct access to I/O ports.  X servers are the most common
-handle other programs&rsquo; requests to do screen graphics on most Unix boxes)
+example of this.</para>
-are the most common example of this.  But we haven't gotten to an X server
+
-yet; you're looking at a shell prompt on a character console.</para>
+<para>You will run programs in one of two ways: through your X server
- 
+or through a shell.  Often, you'll actually do both, because you'll
+start a terminal emulator that mimics an old-fashioned textual console,
+giving you a shell to run programs from. I'll describe what happens
+when you do that, then I'll return to whaty happens when you run a program
+through an X menu or desktop icon.</para>
+
+<para>The shell is called the shell because it wraps around and hides the
+operating system kernel.  It's an important feature of Unix that the shell
+and kernel are separate programs communicating through a small set of
+system calls.  This makes it possible for there to be multiple shells,
+suiting different tastes in interfaces.</para>
+
+<para>The normal shell gives you the &lsquo;$&rsquo; prompt that you see
+after logging in (unless you've customized it to be something else).  We
+won't talk about shell syntax and the easy things you can see on the screen
+here; instead we'll take a look behind the scenes at what's happening from
+the computer's point of view.</para>
+
 <para>The shell is just a user process, and not a particularly special one.
 It waits on your keystrokes, listening (through the kernel) to the keyboard
-I/O port.  As the kernel sees them, it echoes them to your screen.  When
+I/O port.  As the kernel sees them, it echoes them to your virtual console or
-the kernel sees an &lsquo;Enter&rsquo; it passes your line of text to the
+X terminal emulator.  When the kernel sees an &lsquo;Enter&rsquo; it passes
-shell. The shell tries to interpret those keystrokes as commands.</para>
+your line of text to the shell. The shell tries to interpret those
+keystrokes as commands.</para>
 
 <para>Let's say you type &lsquo;ls&rsquo; and Enter to invoke the Unix
 directory lister. The shell applies its built-in rules to figure out that
@@ -530,6 +575,16 @@ start a game of Quake, for example.  Or, suppose you're hooked up to the
 Internet.  Your machine might be sending or receiving mail while
 <command>/bin/ls</command> runs.</para>
 
+<para>When you're running programs through the X server rather than a shell
+(that is, by choosing an application from a pull-down menu, or
+double-clicking a desktop icon), any of several programs associated with
+your X server can behave like a shell and launch the program. I'm going to
+gloss over the details here because they're both variable and unimportant.
+The key point is that the X server, unlike a normal shell, doesn't go to
+sleep while the client program is running &mdash; instead, it sits between
+you and the client, passing your mouse clicks and keypresses to it and
+fulfilling its requests to point pixels on your display.</para>
+
 </sect1>
 <sect1 id="devices"><title>How do input devices and interrupts work?</title>
 
@@ -619,7 +674,7 @@ network connection.</para>
 <para>An operating system that can routinely support many simultaneous
 processes is called <quote>multitasking</quote>.  The Unix family of operating
 systems was designed from the ground up for multitasking and is very good
-at it &mdash; much more effective than Windows or the old Mac OS, which
+at it &mdash; much more effective than Windows or the old Mac OS, which both
 had multitasking bolted into them as an afterthought and do it rather poorly.
 Efficient, reliable multitasking is a large part of what makes Linux
 superior for networking, communications, and Web service.</para>
@@ -854,10 +909,10 @@ logical calculations.  When people write about computers having bit sizes
 (calling them, say, <quote>32-bit</quote> or <quote>64-bit</quote> computers), this is what
 they mean.</para>
 
-<para>Most computers (including 386, 486, and Pentium PCs) have a word size
+<para>Most computers now have a word size of 64 bits.  In the recent past
-of 32 bits.  The old 286 machines had a word size of 16.  Old-style
+(early 2000s) many PCs had 32-bit words. The old 286 machines back in the
-mainframes often had 36-bit words.  The AMD Opteron, Intel Itanium, and the
+1980s had a word size of 16.  Old-style mainframes often had 36-bit
-Alpha from what used to be DEC and is now Compaq have 64-bit words. </para>
+words.</para>
 
 <para>The computer views your memory as a sequence of words numbered from
 zero up to some large value dependent on your memory size. That value is
@@ -869,7 +924,7 @@ nightmares.</para>
 <sect2 id="numbers"><title>Numbers</title>
 
 <para>Integer numbers are represented as either words or pairs of words,
-depending on your processor's word size.  One 32-bit machine word is the
+depending on your processor's word size.  One 64-bit machine word is the
 most common integer representation.</para>
 
 <para>Integer arithmetic is close to but not actually mathematical
@@ -880,9 +935,9 @@ notation.  The highest-order bit is a <firstterm>sign
 bit</firstterm><indexterm><primary>sign bit</primary></indexterm> which
 makes the quantity negative, and every negative number can be obtained from
 the corresponding positive value by inverting all the bits and adding one.
-This is why integers on a 32-bit machine have the range
+This is why integers on a 64-bit machine have the range
--2<superscript>31</superscript> to 2<superscript>31</superscript> - 1.
+-2<superscript>63</superscript> to 2<superscript>63</superscript> - 1.
-That 32nd bit is being used for sign; 0 means a positive number or zero, 1
+That 64th bit is being used for sign; 0 means a positive number or zero, 1
 a negative number.</para>
 
 <para>Some computer languages give you access to <firstterm>unsigned
@@ -917,12 +972,13 @@ six-character string only takes up two memory words.  For an ASCII code
 chart, type &lsquo;man 7 ascii&rsquo; at your Unix prompt.</para>
 
 <para>The preceding paragraph was misleading in two ways.  The minor one is
-that the term &lsquo;octet&rsquo; is formally correct but seldom actually used; most
+that the term &lsquo;octet&rsquo; is formally correct but seldom actually
-people refer to an octet as
+used; most people refer to an octet as
-<firstterm>byte</firstterm><indexterm><primary>byte</primary></indexterm> and
+<firstterm>byte</firstterm><indexterm><primary>byte</primary></indexterm>
-expect bytes to be eight bits long.  Strictly speaking, the term &lsquo;byte&rsquo; is
+and expect bytes to be eight bits long.  Strictly speaking, the term
-more general; there used to be, for example, 36-bit machines with 9-bit
+&lsquo;byte&rsquo; is more general; there used to be, for example, 36-bit
-bytes (though there probably never will be again).</para>
+machines with 9-bit bytes (though there probably never will be
+again).</para>
 
 <para>The major one is that not all the world uses ASCII.  In fact, much of
 the world can't &mdash; ASCII, while fine for American English, lacks many
@@ -961,6 +1017,10 @@ unified set of Chinese/Japanese/Korean (CJK) ideographs. For details, see
 the <ulink url="http://www.unicode.org/">Unicode Home Page</ulink>.  XML
 and XHTML use this character set.</para>
 
+<para>Recent versions of Linux use an encoding of Unicode called UTF-8.  In
+UTF, characters 0-127 are ASCII.  Characters 128-255 are used only in
+sequences of 2 through 4 bytes that identify non-ASCII characters.</para>
+
 </sect2>
 </sect1>
 <sect1 id="disk-layout"><title>How does my computer store things on disk?</title>
@@ -1690,4 +1750,3 @@ fill-column:75
 compile-command: "mail -s \"Unix and Internet Fundamentals HOWTO update\" submit@en.tldp.org <Unix-and-Internet-Fundamentals-HOWTO.xml"
 End:
 -->
-