mirror of https://github.com/tLDP/LDP
updated
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@ -1,6 +1,6 @@
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<?xml version="1.0"?>
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<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
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"http://docbook.org/xml/4.1.2/docbookx.dtd" [
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"docbook/docbookxx.dtd" [
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<!ENTITY howto "http://www.tldp.org/HOWTO/">
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<!ENTITY mini-howto "&howto;/mini/">
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<!ENTITY howto-host "www.tldp.org">
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@ -25,8 +25,8 @@
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<revhistory>
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<revision>
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<revnumber>2.9</revnumber>
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<date>2004-03-03</date>
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<revnumber>2.10</revnumber>
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<date>2007-11-28</date>
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<authorinitials>esr</authorinitials>
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<revremark>
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Minor updates.
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@ -34,6 +34,14 @@
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</revision>
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<!--
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<revision>
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<revnumber>2.9</revnumber>
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<date>2004-03-03</date>
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<authorinitials>esr</authorinitials>
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<revremark>
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Minor updates.
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</revremark>
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</revision>
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<revision>
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<revnumber>2.8</revnumber>
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<date>2003-10-04</date>
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@ -196,12 +204,12 @@ from lack of a good mental model of what is really going on.</para>
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<para>I'll try to describe in clear, simple language how it all works. The
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presentation will be tuned for people using Unix or Linux on PC-class
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hardware. Nevertheless, I'll usually refer simply to ‘Unix’
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here, as most of what I will describe is constant across platforms and
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across Unix variants.</para>
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machines. Nevertheless, I'll usually refer simply to ‘Unix’
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here, as most of what I will describe is constant across different machines
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and across Unix variants.</para>
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<para>I'm going to assume you're using an Intel PC. The details differ
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slightly if you're running an Alpha or PowerPC or some other Unix box, but
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slightly if you're running an PowerPC or some other kind of computer, but
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the basic concepts are the same.</para>
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<para>I won't repeat things, so you'll have to pay attention, but that
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@ -220,8 +228,8 @@ periodically.</para>
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periodically posted to <ulink url="news:comp.os.linux.help">
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comp.os.linux.help</ulink> and <ulink url="news:comp.os.linux.announce">
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comp.os.linux.announce</ulink> and <ulink url="news:news.answers">
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news.answers</ulink>. They will also be uploaded to various Linux WWW and
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FTP sites, including the LDP home page.</para>
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news.answers</ulink>. They will also be uploaded to various websites,
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including the Linux Documentation Project home page.</para>
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<para>You can view the latest version of this on the World Wide Web via the URL
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<ulink
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@ -229,8 +237,9 @@ url="&howto;Unix-and-Internet-Fundamentals-HOWTO/index.html">
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http:&howto;Unix-and-Internet-Fundamentals-HOWTO/index.html</ulink>.
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</para>
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<para>This document has been translated into <ulink
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url="http://theta.uoks.uj.edu.pl/~gszczepa/gszczepa/esr1iso2.htm">Polish</ulink>.</para>
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<para>This document has been translated into: <ulink
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url="http://theta.uoks.uj.edu.pl/~gszczepa/gszczepa/esr1iso2.htm">Polish</ulink><ulink
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url="http://es.tldp.org/Manuales-LuCAS/doc-fundamentos-unix-internet/fundamentos.htm">Spanish</ulink>.</para>
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</sect2>
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<sect2 id="feedback"><title>Feedback and corrections</title>
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@ -348,11 +357,12 @@ that Unix isn't good enough for you.)</para>
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<para>Once the kernel starts, it has to look around, find the rest of the
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hardware, and get ready to run programs. It does this by poking not at
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ordinary memory locations but rather at <firstterm>I/O ports</firstterm> —
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special bus addresses that are likely to have device controller cards
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listening at them for commands. The kernel doesn't poke at random; it has
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a lot of built-in knowledge about what it's likely to find where, and how
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controllers will respond if they're present. This process is called
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ordinary memory locations but rather at <firstterm>I/O ports</firstterm>
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— special bus addresses that are likely to have device controller
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cards listening at them for commands. The kernel doesn't poke at random;
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it has a lot of built-in knowledge about what it's likely to find where,
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and how controllers will respond if they're present. This process is
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called
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<firstterm>autoprobing</firstterm><indexterm><primary>autoprobing</primary></indexterm>.</para>
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<para>Most of the messages you see at boot time are the kernel autoprobing
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@ -673,8 +683,8 @@ goes on in your machine, you should learn how all of them work.</para>
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<para>The five kinds of memory are these: processor registers, internal (or
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on-chip) cache, external (or off-chip) cache, main memory, and disk. And
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the reason there are so many kinds is simple: speed costs money. I have
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listed these kinds of memory in decreasing order of access time and
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increasing order of cost. Register memory is the fastest and most
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listed these kinds of memory in increasing order of access time and
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decreasing order of cost. Register memory is the fastest and most
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expensive and can be random-accessed about a billion times a second, while
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disk is the slowest and cheapest and can do about 100 random accesses a
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second.</para>
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@ -920,23 +930,25 @@ accented and other special characters needed by users of other languages.
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Even British English has trouble with the lack of a pound-currency
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sign.</para>
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<para>There have been several attempts to fix this problem. All use the extra
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high bit that ASCII doesn't, making it the low half of a 256-character set.
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The most widely-used of these is the so-called ‘Latin-1’ character set
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(more formally called ISO 8859-1). This is the default character set for
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Linux, HTML, and X. Microsoft Windows uses a mutant version of Latin-1
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that adds a bunch of characters such as right and left double quotes in
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places proper Latin-1 leaves unassigned for historical reasons (for a
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scathing account of the trouble this causes, see the <ulink
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<para>There have been several attempts to fix this problem. All use the
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extra high bit that ASCII doesn't, making it the low half of a
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256-character set. The most widely-used of these is the so-called
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‘Latin-1’ character set (more formally called ISO 8859-1).
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This is the default character set for Linux, older versions of HTML, and X.
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Microsoft Windows uses a mutant version of Latin-1 that adds a bunch of
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characters such as right and left double quotes in places proper Latin-1
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leaves unassigned for historical reasons (for a scathing account of the
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trouble this causes, see the <ulink
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url="http://www.fourmilab.ch/webtools/demoroniser/">demoroniser</ulink>
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page).</para>
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<para>Latin-1 handles western European languages, including English,
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French, German, Spanish, Italian, Dutch, Norwegian, Swedish, Danish.
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However, this isn't good enough either, and as a result there is a whole
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series of Latin-2 through -9 character sets to handle things like Greek,
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Arabic, Hebrew, Esperanto, and Serbo-Croatian. For details, see the <ulink
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url="http://www.utia.cas.cz/user_data/vs/documents/ISO-8859-X-charsets.html">
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French, German, Spanish, Italian, Dutch, Norwegian, Swedish, Danish, and
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Icelandic. However, this isn't good enough either, and as a result there
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is a whole series of Latin-2 through -9 character sets to handle things
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like Greek, Arabic, Hebrew, Esperanto, and Serbo-Croatian. For details,
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see the <ulink
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url="http://czyborra.com/charsets/iso8859.html">
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ISO alphabet soup</ulink> page.</para>
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<para>The ultimate solution is a huge standard called Unicode (and its
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@ -946,7 +958,8 @@ Cyrillic, Armenian, Hebrew, Arabic, Devanagari, Bengali, Gurmukhi,
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Gujarati, Oriya, Tamil, Telugu, Kannada, Malayalam, Thai, Lao, Georgian,
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Tibetan, Japanese Kana, the complete set of modern Korean Hangul, and a
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unified set of Chinese/Japanese/Korean (CJK) ideographs. For details, see
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the <ulink url="http://www.unicode.org/">Unicode Home Page</ulink>.</para>
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the <ulink url="http://www.unicode.org/">Unicode Home Page</ulink>. XML
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and XHTML use this character set.</para>
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</sect2>
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</sect1>
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@ -1265,7 +1278,7 @@ including Linux, the latter behavior can be selected by setting the
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set-group-ID on the directory (chmod g+s).</para>
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</sect2>
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<sect2><title id="fsck">How things can go wrong</title>
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<sect2 id="fsck"><title>How things can go wrong</title>
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<para>Earlier it was hinted that file systems can be fragile things.
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Now we know that to get to a file you have to hopscotch through what may be
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@ -1381,7 +1394,7 @@ Today, Unix shells and the Lisp that lives inside the Emacs editor are
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probably the most important pure interpreted languages.</para>
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</sect2>
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<sect2><title>P-code languages</title>
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<sect2 id="pcode"><title>P-code languages</title>
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<para>Since 1990 a kind of hybrid language that uses both compilation and
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interpretation has become increasingly important. P-code languages are
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@ -1677,3 +1690,4 @@ fill-column:75
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compile-command: "mail -s \"Unix and Internet Fundamentals HOWTO update\" submit@en.tldp.org <Unix-and-Internet-Fundamentals-HOWTO.xml"
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End:
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-->
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