svn commit: r42985 - head/en_US.ISO8859-1/books/handbook/serialcomms
Dru Lavigne
dru at FreeBSD.org
Thu Oct 17 17:08:29 UTC 2013
Author: dru
Date: Thu Oct 17 17:08:29 2013
New Revision: 42985
URL: http://svnweb.freebsd.org/changeset/doc/42985
Log:
White space fix only. Translators can ignore.
To be followed by a quick typo fix.
Modified:
head/en_US.ISO8859-1/books/handbook/serialcomms/chapter.xml
Modified: head/en_US.ISO8859-1/books/handbook/serialcomms/chapter.xml
==============================================================================
--- head/en_US.ISO8859-1/books/handbook/serialcomms/chapter.xml Thu Oct 17 15:42:25 2013 (r42984)
+++ head/en_US.ISO8859-1/books/handbook/serialcomms/chapter.xml Thu Oct 17 17:08:29 2013 (r42985)
@@ -59,30 +59,36 @@
<sect1 id="serial">
<title>Serial Terminology and Hardware</title>
- <para>The following terms are often used in serial commnications:</para>
- <variablelist>
- <varlistentry>
- <term><acronym>bps</acronym></term>
+ <para>The following terms are often used in serial
+ commnications:</para>
+ <variablelist>
+ <varlistentry>
+ <term><acronym>bps</acronym></term>
<listitem>
- <para>Bits per Second<indexterm><primary>bits-per-second</primary></indexterm> (<acronym>bps</acronym>) is the rate
- at which data is transmitted.</para>
+ <para>Bits per
+ Second<indexterm><primary>bits-per-second</primary></indexterm>
+ (<acronym>bps</acronym>) is the rate at which data is
+ transmitted.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><acronym>DTE</acronym></term>
<listitem>
- <para>Data Terminal Equipment<indexterm><primary>DTE</primary></indexterm>
- (<acronym>DTE</acronym>) is one of two endpoints in a
- serial communication. An example would be a computer.</para>
+ <para>Data Terminal
+ Equipment<indexterm><primary>DTE</primary></indexterm>
+ (<acronym>DTE</acronym>) is one of two endpoints in a
+ serial communication. An example would be a
+ computer.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><acronym>DCE</acronym></term>
<listitem>
- <para>Data Communications Equipment<indexterm><primary>DCE</primary></indexterm>
- (<acronym>DTE</acronym>) is the other endpoint in a
+ <para>Data Communications
+ Equipment<indexterm><primary>DCE</primary></indexterm>
+ (<acronym>DTE</acronym>) is the other endpoint in a
serial communication. Typically, it is a modem.</para>
</listitem>
</varlistentry>
@@ -92,8 +98,9 @@
<listitem>
<para>The original standard which defined hardware serial
- communications. It has since been renamed to
- <acronym>TIA</acronym>-232<indexterm><primary>RS-232C cables</primary></indexterm>.</para>
+ communications. It has since been renamed to
+ <acronym>TIA</acronym>-232<indexterm><primary>RS-232C
+ cables</primary></indexterm>.</para>
</listitem>
</varlistentry>
</variablelist>
@@ -104,7 +111,6 @@
period of time, while <acronym>bps</acronym> is the
<emphasis>correct</emphasis> term to use.</para>
-
<para>To connect a modem or serial terminal to a &os; system, a
serial port on the computer and the proper cable to connect to
the serial device are needed. Users who are already familiar
@@ -119,372 +125,372 @@
RS-232 cables. The documentation for the hardware should
describe the type of cable required.</para>
- <indexterm>
- <primary>null-modem cable</primary>
- </indexterm>
-
- <para>A null-modem cable passes some signals, such as
- <quote>Signal Ground</quote>, straight through, but
- switches other signals. For example, the
- <quote>Transmitted Data</quote> pin on one end goes to the
- <quote>Received Data</quote> pin on the other end.</para>
-
- <para>A null-modem cable can be constructed for use with
- terminals. The following table shows the RS-232C <link
- linkend="serialcomms-signal-names">signal names</link>
- and the pin numbers on a DB-25 connector. While the
- standard calls for a straight-through pin 1 to pin 1
- <emphasis>Protective Ground</emphasis> line, it is often
- omitted. Some terminals work using only pins 2, 3, and
- 7, while others require different configurations than
- the examples shown below.</para>
+ <indexterm>
+ <primary>null-modem cable</primary>
+ </indexterm>
- <table frame="none" pgwide="1">
- <title>DB-25 to DB-25 Null-Modem Cable</title>
+ <para>A null-modem cable passes some signals, such as
+ <quote>Signal Ground</quote>, straight through, but
+ switches other signals. For example, the
+ <quote>Transmitted Data</quote> pin on one end goes to the
+ <quote>Received Data</quote> pin on the other end.</para>
+
+ <para>A null-modem cable can be constructed for use with
+ terminals. The following table shows the RS-232C <link
+ linkend="serialcomms-signal-names">signal names</link>
+ and the pin numbers on a DB-25 connector. While the
+ standard calls for a straight-through pin 1 to pin 1
+ <emphasis>Protective Ground</emphasis> line, it is often
+ omitted. Some terminals work using only pins 2, 3, and
+ 7, while others require different configurations than
+ the examples shown below.</para>
- <tgroup cols="5">
- <thead>
- <row>
- <entry align="left">Signal</entry>
- <entry align="left">Pin #</entry>
- <entry></entry>
- <entry align="left">Pin #</entry>
- <entry align="left">Signal</entry>
- </row>
- </thead>
+ <table frame="none" pgwide="1">
+ <title>DB-25 to DB-25 Null-Modem Cable</title>
- <tbody>
- <row>
- <entry>SG</entry>
- <entry>7</entry>
- <entry>connects to</entry>
- <entry>7</entry>
- <entry>SG</entry>
- </row>
+ <tgroup cols="5">
+ <thead>
+ <row>
+ <entry align="left">Signal</entry>
+ <entry align="left">Pin #</entry>
+ <entry></entry>
+ <entry align="left">Pin #</entry>
+ <entry align="left">Signal</entry>
+ </row>
+ </thead>
- <row>
- <entry>TD</entry>
- <entry>2</entry>
- <entry>connects to</entry>
- <entry>3</entry>
- <entry>RD</entry>
- </row>
+ <tbody>
+ <row>
+ <entry>SG</entry>
+ <entry>7</entry>
+ <entry>connects to</entry>
+ <entry>7</entry>
+ <entry>SG</entry>
+ </row>
- <row>
- <entry>RD</entry>
- <entry>3</entry>
- <entry>connects to</entry>
- <entry>2</entry>
- <entry>TD</entry>
- </row>
+ <row>
+ <entry>TD</entry>
+ <entry>2</entry>
+ <entry>connects to</entry>
+ <entry>3</entry>
+ <entry>RD</entry>
+ </row>
- <row>
- <entry>RTS</entry>
- <entry>4</entry>
- <entry>connects to</entry>
- <entry>5</entry>
- <entry>CTS</entry>
- </row>
+ <row>
+ <entry>RD</entry>
+ <entry>3</entry>
+ <entry>connects to</entry>
+ <entry>2</entry>
+ <entry>TD</entry>
+ </row>
- <row>
- <entry>CTS</entry>
- <entry>5</entry>
- <entry>connects to</entry>
- <entry>4</entry>
- <entry>RTS</entry>
- </row>
+ <row>
+ <entry>RTS</entry>
+ <entry>4</entry>
+ <entry>connects to</entry>
+ <entry>5</entry>
+ <entry>CTS</entry>
+ </row>
- <row>
- <entry>DTR</entry>
- <entry>20</entry>
- <entry>connects to</entry>
- <entry>6</entry>
- <entry>DSR</entry>
- </row>
+ <row>
+ <entry>CTS</entry>
+ <entry>5</entry>
+ <entry>connects to</entry>
+ <entry>4</entry>
+ <entry>RTS</entry>
+ </row>
- <row>
- <entry>DTR</entry>
- <entry>20</entry>
- <entry>connects to</entry>
- <entry>8</entry>
- <entry>DCD</entry>
- </row>
+ <row>
+ <entry>DTR</entry>
+ <entry>20</entry>
+ <entry>connects to</entry>
+ <entry>6</entry>
+ <entry>DSR</entry>
+ </row>
- <row>
- <entry>DSR</entry>
- <entry>6</entry>
- <entry>connects to</entry>
- <entry>20</entry>
- <entry>DTR</entry>
- </row>
+ <row>
+ <entry>DTR</entry>
+ <entry>20</entry>
+ <entry>connects to</entry>
+ <entry>8</entry>
+ <entry>DCD</entry>
+ </row>
- <row>
- <entry>DCD</entry>
- <entry>8</entry>
- <entry>connects to</entry>
- <entry>20</entry>
- <entry>DTR</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
+ <row>
+ <entry>DSR</entry>
+ <entry>6</entry>
+ <entry>connects to</entry>
+ <entry>20</entry>
+ <entry>DTR</entry>
+ </row>
- <para>The next two tables show two other common
- schemes.</para>
+ <row>
+ <entry>DCD</entry>
+ <entry>8</entry>
+ <entry>connects to</entry>
+ <entry>20</entry>
+ <entry>DTR</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
- <table frame="none" pgwide="1">
- <title>DB-9 to DB-9 Null-Modem Cable</title>
+ <para>The next two tables show two other common
+ schemes.</para>
- <tgroup cols="5">
- <thead>
- <row>
- <entry align="left">Signal</entry>
- <entry align="left">Pin #</entry>
- <entry></entry>
- <entry align="left">Pin #</entry>
- <entry align="left">Signal</entry>
- </row>
- </thead>
+ <table frame="none" pgwide="1">
+ <title>DB-9 to DB-9 Null-Modem Cable</title>
- <tbody>
- <row>
- <entry>RD</entry>
- <entry>2</entry>
- <entry>connects to</entry>
- <entry>3</entry>
- <entry>TD</entry>
- </row>
+ <tgroup cols="5">
+ <thead>
+ <row>
+ <entry align="left">Signal</entry>
+ <entry align="left">Pin #</entry>
+ <entry></entry>
+ <entry align="left">Pin #</entry>
+ <entry align="left">Signal</entry>
+ </row>
+ </thead>
- <row>
- <entry>TD</entry>
- <entry>3</entry>
- <entry>connects to</entry>
- <entry>2</entry>
- <entry>RD</entry>
- </row>
+ <tbody>
+ <row>
+ <entry>RD</entry>
+ <entry>2</entry>
+ <entry>connects to</entry>
+ <entry>3</entry>
+ <entry>TD</entry>
+ </row>
- <row>
- <entry>DTR</entry>
- <entry>4</entry>
- <entry>connects to</entry>
- <entry>6</entry>
- <entry>DSR</entry>
- </row>
+ <row>
+ <entry>TD</entry>
+ <entry>3</entry>
+ <entry>connects to</entry>
+ <entry>2</entry>
+ <entry>RD</entry>
+ </row>
- <row>
- <entry>DTR</entry>
- <entry>4</entry>
- <entry>connects to</entry>
- <entry>1</entry>
- <entry>DCD</entry>
- </row>
+ <row>
+ <entry>DTR</entry>
+ <entry>4</entry>
+ <entry>connects to</entry>
+ <entry>6</entry>
+ <entry>DSR</entry>
+ </row>
- <row>
- <entry>SG</entry>
- <entry>5</entry>
- <entry>connects to</entry>
- <entry>5</entry>
- <entry>SG</entry>
- </row>
+ <row>
+ <entry>DTR</entry>
+ <entry>4</entry>
+ <entry>connects to</entry>
+ <entry>1</entry>
+ <entry>DCD</entry>
+ </row>
- <row>
- <entry>DSR</entry>
- <entry>6</entry>
- <entry>connects to</entry>
- <entry>4</entry>
- <entry>DTR</entry>
- </row>
+ <row>
+ <entry>SG</entry>
+ <entry>5</entry>
+ <entry>connects to</entry>
+ <entry>5</entry>
+ <entry>SG</entry>
+ </row>
- <row>
- <entry>DCD</entry>
- <entry>1</entry>
- <entry>connects to</entry>
- <entry>4</entry>
- <entry>DTR</entry>
- </row>
+ <row>
+ <entry>DSR</entry>
+ <entry>6</entry>
+ <entry>connects to</entry>
+ <entry>4</entry>
+ <entry>DTR</entry>
+ </row>
- <row>
- <entry>RTS</entry>
- <entry>7</entry>
- <entry>connects to</entry>
- <entry>8</entry>
- <entry>CTS</entry>
- </row>
+ <row>
+ <entry>DCD</entry>
+ <entry>1</entry>
+ <entry>connects to</entry>
+ <entry>4</entry>
+ <entry>DTR</entry>
+ </row>
- <row>
- <entry>CTS</entry>
- <entry>8</entry>
- <entry>connects to</entry>
- <entry>7</entry>
- <entry>RTS</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
+ <row>
+ <entry>RTS</entry>
+ <entry>7</entry>
+ <entry>connects to</entry>
+ <entry>8</entry>
+ <entry>CTS</entry>
+ </row>
- <table frame="none" pgwide="1">
- <title>DB-9 to DB-25 Null-Modem Cable</title>
+ <row>
+ <entry>CTS</entry>
+ <entry>8</entry>
+ <entry>connects to</entry>
+ <entry>7</entry>
+ <entry>RTS</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
- <tgroup cols="5">
- <thead>
- <row>
- <entry align="left">Signal</entry>
- <entry align="left">Pin #</entry>
- <entry></entry>
- <entry align="left">Pin #</entry>
- <entry align="left">Signal</entry>
- </row>
- </thead>
+ <table frame="none" pgwide="1">
+ <title>DB-9 to DB-25 Null-Modem Cable</title>
- <tbody>
- <row>
- <entry>RD</entry>
- <entry>2</entry>
- <entry>connects to</entry>
- <entry>2</entry>
- <entry>TD</entry>
- </row>
+ <tgroup cols="5">
+ <thead>
+ <row>
+ <entry align="left">Signal</entry>
+ <entry align="left">Pin #</entry>
+ <entry></entry>
+ <entry align="left">Pin #</entry>
+ <entry align="left">Signal</entry>
+ </row>
+ </thead>
- <row>
- <entry>TD</entry>
- <entry>3</entry>
- <entry>connects to</entry>
- <entry>3</entry>
- <entry>RD</entry>
- </row>
+ <tbody>
+ <row>
+ <entry>RD</entry>
+ <entry>2</entry>
+ <entry>connects to</entry>
+ <entry>2</entry>
+ <entry>TD</entry>
+ </row>
- <row>
- <entry>DTR</entry>
- <entry>4</entry>
- <entry>connects to</entry>
- <entry>6</entry>
- <entry>DSR</entry>
- </row>
+ <row>
+ <entry>TD</entry>
+ <entry>3</entry>
+ <entry>connects to</entry>
+ <entry>3</entry>
+ <entry>RD</entry>
+ </row>
- <row>
- <entry>DTR</entry>
- <entry>4</entry>
- <entry>connects to</entry>
- <entry>8</entry>
- <entry>DCD</entry>
- </row>
+ <row>
+ <entry>DTR</entry>
+ <entry>4</entry>
+ <entry>connects to</entry>
+ <entry>6</entry>
+ <entry>DSR</entry>
+ </row>
- <row>
- <entry>SG</entry>
- <entry>5</entry>
- <entry>connects to</entry>
- <entry>7</entry>
- <entry>SG</entry>
- </row>
+ <row>
+ <entry>DTR</entry>
+ <entry>4</entry>
+ <entry>connects to</entry>
+ <entry>8</entry>
+ <entry>DCD</entry>
+ </row>
- <row>
- <entry>DSR</entry>
- <entry>6</entry>
- <entry>connects to</entry>
- <entry>20</entry>
- <entry>DTR</entry>
- </row>
+ <row>
+ <entry>SG</entry>
+ <entry>5</entry>
+ <entry>connects to</entry>
+ <entry>7</entry>
+ <entry>SG</entry>
+ </row>
- <row>
- <entry>DCD</entry>
- <entry>1</entry>
- <entry>connects to</entry>
- <entry>20</entry>
- <entry>DTR</entry>
- </row>
+ <row>
+ <entry>DSR</entry>
+ <entry>6</entry>
+ <entry>connects to</entry>
+ <entry>20</entry>
+ <entry>DTR</entry>
+ </row>
- <row>
- <entry>RTS</entry>
- <entry>7</entry>
- <entry>connects to</entry>
- <entry>5</entry>
- <entry>CTS</entry>
- </row>
+ <row>
+ <entry>DCD</entry>
+ <entry>1</entry>
+ <entry>connects to</entry>
+ <entry>20</entry>
+ <entry>DTR</entry>
+ </row>
- <row>
- <entry>CTS</entry>
- <entry>8</entry>
- <entry>connects to</entry>
- <entry>4</entry>
- <entry>RTS</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
+ <row>
+ <entry>RTS</entry>
+ <entry>7</entry>
+ <entry>connects to</entry>
+ <entry>5</entry>
+ <entry>CTS</entry>
+ </row>
- <note>
- <para>When one pin at one end connects to a pair of pins
- at the other end, it is usually implemented with one
- short wire between the pair of pins in their connector
- and a long wire to the other single pin.</para>
- </note>
+ <row>
+ <entry>CTS</entry>
+ <entry>8</entry>
+ <entry>connects to</entry>
+ <entry>4</entry>
+ <entry>RTS</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <note>
+ <para>When one pin at one end connects to a pair of pins
+ at the other end, it is usually implemented with one
+ short wire between the pair of pins in their connector
+ and a long wire to the other single pin.</para>
+ </note>
- <para>The above designs seem to be the most popular. In
- another variation, SG connects to SG, TD connects to RD,
- RTS and CTS connect to DCD, DTR connects to DSR, and
- vice-versa.</para>
-
- <indexterm><primary>RS-232C cables</primary></indexterm>
-
- <para>A standard serial cable passes all of the RS-232C
- signals straight through. The <quote>Transmitted
- Data</quote> pin on one end of the cable goes to the
- <quote>Transmitted Data</quote> pin on the other end.
- This is the type of cable used to connect a modem to
- the &os; system, and is also appropriate for some
- terminals.</para>
+ <para>The above designs seem to be the most popular. In
+ another variation, SG connects to SG, TD connects to RD,
+ RTS and CTS connect to DCD, DTR connects to DSR, and
+ vice-versa.</para>
+
+ <indexterm><primary>RS-232C cables</primary></indexterm>
+
+ <para>A standard serial cable passes all of the RS-232C
+ signals straight through. The <quote>Transmitted
+ Data</quote> pin on one end of the cable goes to the
+ <quote>Transmitted Data</quote> pin on the other end.
+ This is the type of cable used to connect a modem to
+ the &os; system, and is also appropriate for some
+ terminals.</para>
<para>Serial ports are the devices through which data is
transferred between the &os; host computer and the
terminal. This section describes the kinds of ports that
exist and how they are addressed in &os;.</para>
- <para>Several kinds of serial ports exist. Before
- purchasing or constructing a cable, make sure it will
- fit the ports on the terminal and on the &os;
- system.</para>
-
- <para>Most terminals have DB-25 ports. Personal computers
- may have DB-25 or DB-9 ports. A multiport serial card may
- have RJ-12 or RJ-45 ports.</para>
-
- <para>See the documentation that accompanied the hardware
- for specifications on the kind of port or visually verify
- the type of port.</para>
-
- <para>In &os;, each serial port is accessed through an
- entry in <filename class="directory">/dev</filename>.
- There are two different kinds of entries:</para>
-
- <itemizedlist>
- <listitem>
- <para>Call-in ports are named
- <filename>/dev/ttyu<replaceable>N</replaceable></filename>
- where <replaceable>N</replaceable> is the port number,
- starting from zero. Generally, the call-in port is
- used for terminals. Call-in ports require that the
- serial line assert the Data Carrier Detect
- (<acronym>DCD</acronym>) signal to work
- correctly.</para>
- </listitem>
-
- <listitem>
- <para>Call-out ports are named
- <filename>/dev/cuau<replaceable>N</replaceable></filename>.
- Call-out ports are usually not used for terminals, but
- are used for modems. The call-out port can be used if
- the serial cable or the terminal does not support the
- carrier detect signal.</para>
- </listitem>
- </itemizedlist>
-
- <para>If a terminal is connected to the first serial
- port(<devicename>COM1</devicename>), use
- <filename>/dev/ttyu0</filename> to refer to the
- terminal. If the terminal is on the second serial port
- (<devicename>COM2</devicename>), use
- <filename>/dev/ttyu1</filename>, and so forth.</para>
- </sect2>
+ <para>Several kinds of serial ports exist. Before
+ purchasing or constructing a cable, make sure it will
+ fit the ports on the terminal and on the &os;
+ system.</para>
+
+ <para>Most terminals have DB-25 ports. Personal computers
+ may have DB-25 or DB-9 ports. A multiport serial card may
+ have RJ-12 or RJ-45 ports.</para>
+
+ <para>See the documentation that accompanied the hardware
+ for specifications on the kind of port or visually verify
+ the type of port.</para>
+
+ <para>In &os;, each serial port is accessed through an
+ entry in <filename class="directory">/dev</filename>.
+ There are two different kinds of entries:</para>
+
+ <itemizedlist>
+ <listitem>
+ <para>Call-in ports are named
+ <filename>/dev/ttyu<replaceable>N</replaceable></filename>
+ where <replaceable>N</replaceable> is the port number,
+ starting from zero. Generally, the call-in port is
+ used for terminals. Call-in ports require that the
+ serial line assert the Data Carrier Detect
+ (<acronym>DCD</acronym>) signal to work
+ correctly.</para>
+ </listitem>
+
+ <listitem>
+ <para>Call-out ports are named
+ <filename>/dev/cuau<replaceable>N</replaceable></filename>.
+ Call-out ports are usually not used for terminals, but
+ are used for modems. The call-out port can be used if
+ the serial cable or the terminal does not support the
+ carrier detect signal.</para>
+ </listitem>
+ </itemizedlist>
+
+ <para>If a terminal is connected to the first serial
+ port(<devicename>COM1</devicename>), use
+ <filename>/dev/ttyu0</filename> to refer to the
+ terminal. If the terminal is on the second serial port
+ (<devicename>COM2</devicename>), use
+ <filename>/dev/ttyu1</filename>, and so forth.</para>
+ </sect2>
<sect2>
<title>Kernel Configuration</title>
@@ -635,109 +641,110 @@
connected network. This section describes how to use terminals
with &os;.</para>
- <para>The original &unix; systems did not have consoles.
- Instead, users logged in and ran programs through terminals
- that were connected to the computer's serial ports.</para>
-
- <para>The ability to establish a login session on a serial port
- still exists in nearly every &unix;-like operating system
- today, including &os;. By using a terminal attached to an
- unused serial port, a user can log in and run any text program
- that can normally be run on the console or in an
- <command>xterm</command> window.</para>
-
- <para>Many terminals can be attached to a &os; system. An older
- spare computer can be used as a terminal wired into a more
- powerful computer running &os;. This can turn what might
- otherwise be a single-user computer into a powerful multiple
- user system.</para>
-
- <para>&os; supports three types of terminals:</para>
+ <para>The original &unix; systems did not have consoles.
+ Instead, users logged in and ran programs through terminals
+ that were connected to the computer's serial ports.</para>
+
+ <para>The ability to establish a login session on a serial port
+ still exists in nearly every &unix;-like operating system
+ today, including &os;. By using a terminal attached to an
+ unused serial port, a user can log in and run any text program
+ that can normally be run on the console or in an
+ <command>xterm</command> window.</para>
+
+ <para>Many terminals can be attached to a &os; system. An older
+ spare computer can be used as a terminal wired into a more
+ powerful computer running &os;. This can turn what might
+ otherwise be a single-user computer into a powerful multiple
+ user system.</para>
+
+ <para>&os; supports three types of terminals:</para>
+ <term><acronym>Dumb terminals</acronym></term>
+ <term>Computers Acting as Terminals</term>
- <variablelist>
- <varlistentry>
- <term><acronym>Dumb terminals</acronym></term>
- <listitem>
- <para>Dumb terminals are specialized hardware that connect to
- computers over serial lines. They are called
- <quote>dumb</quote> because they have only enough
- computational power to display, send, and receive text. No
- programs can be run on these devices. Dumb terminals
- connect to a computer that has all the power to run text
- editors, compilers, email, games, and so forth.</para>
-
- <para>There are hundreds of kinds of dumb terminals made by
- many manufacturers, and just about any kind will work with
- &os;. Some high-end terminals can even display graphics,
- but only certain software packages can take advantage of
- these advanced features.</para>
-
- <para>Dumb terminals are popular in work environments where
- workers do not need access to graphical applications.</para>
- </listitem>
- </varlistentry>
+ <variablelist>
+ <varlistentry>
+ <listitem>
+ <para>Dumb terminals are specialized hardware that connect
+ to computers over serial lines. They are called
+ <quote>dumb</quote> because they have only enough
+ computational power to display, send, and receive text.
+ No programs can be run on these devices. Dumb terminals
+ connect to a computer that has all the power to run text
+ editors, compilers, email, games, and so forth.</para>
+
+ <para>There are hundreds of kinds of dumb terminals made
+ by many manufacturers, and just about any kind will work
+ with &os;. Some high-end terminals can even display
+ graphics, but only certain software packages can take
+ advantage of these advanced features.</para>
+
+ <para>Dumb terminals are popular in work environments
+ where workers do not need access to graphical
+ applications.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
- <term>Computers Acting as Terminals</term>
<listitem>
- <para>If a dumb terminal has
- just enough ability to display, send, and receive text,
- any spare computer can be a dumb terminal. All that is
- needed is the proper cable and some <emphasis>terminal
+ <para>If a dumb terminal has just enough ability to
+ display, send, and receive text, any spare computer can
+ be a dumb terminal. All that is needed is the proper
+ cable and some <emphasis>terminal
emulation</emphasis> software to run on the
- computer.</para>
+ computer.</para>
- <para>This configuration can be useful. For example, if one
- user is busy working at the &os; system's console, another
- user can do some text-only work at the same time from a
- less powerful personal computer hooked up as a terminal to
- the &os; system.</para>
-
- <para>There are at least two utilities in the base-system of
- &os; that can be used to work through a serial connection:
- &man.cu.1; and &man.tip.1;.</para>
-
- <para>To connect from a client system that runs &os; to the
- serial connection of another system, use:</para>
-
- <screen>&prompt.root; <userinput>cu -l <replaceable>serial-port-device</replaceable></userinput></screen>
-
- <para>Where <quote>serial-port-device</quote> is the name of a
- special device file denoting a serial port on the system.
- These device files are called
- <devicename>/dev/cuau<replaceable>N</replaceable></devicename>.</para>
+ <para>This configuration can be useful. For example, if one
+ user is busy working at the &os; system's console, another
+ user can do some text-only work at the same time from a
+ less powerful personal computer hooked up as a terminal to
+ the &os; system.</para>
+
+ <para>There are at least two utilities in the base-system of
+ &os; that can be used to work through a serial connection:
+ &man.cu.1; and &man.tip.1;.</para>
+
+ <para>To connect from a client system that runs &os; to the
+ serial connection of another system, use:</para>
+
+ <screen>&prompt.root; <userinput>cu -l <replaceable>serial-port-device</replaceable></userinput></screen>
+
+ <para>Where <quote>serial-port-device</quote> is the name of
+ a special device file denoting a serial port on the
+ system. These device files are called
+ <devicename>/dev/cuau<replaceable>N</replaceable></devicename>.</para>
- <para>The <quote>N</quote>-part of a device name is the serial
- port number.</para>
+ <para>The <quote>N</quote>-part of a device name is the
+ serial port number.</para>
- <note>
- <para>Note that device numbers in &os; start from zero and
- not one. This means that <devicename>COM1</devicename> is
- <filename>/dev/cuau0</filename> in &os;.</para>
- </note>
+ <note>
+ <para>Note that device numbers in &os; start from zero and
+ not one. This means that <devicename>COM1</devicename>
+ is <filename>/dev/cuau0</filename> in &os;.</para>
+ </note>
- <note>
- <para>Some people prefer to use other programs available
- through the Ports Collection, such as <filename
- role="package">comms/minicom</filename>.</para>
- </note>
- </listitem>
- </varlistentry>
+ <note>
+ <para>Some people prefer to use other programs available
+ through the Ports Collection, such as <filename
+ role="package">comms/minicom</filename>.</para>
+ </note>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term>X Terminals</term>
<listitem>
- <para>X terminals are the most sophisticated kind of terminal
- available. Instead of connecting to a serial port, they
- usually connect to a network like Ethernet. Instead of
- being relegated to text-only applications, they can display
- any X application.</para>
-
- <para>This chapter does <emphasis>not</emphasis> cover the
- setup, configuration, or use of X terminals.</para>
- </listitem>
- </varlistentry>
- </variablelist>
+ <para>X terminals are the most sophisticated kind of
+ terminal available. Instead of connecting to a serial
+ port, they usually connect to a network like Ethernet.
+ Instead of being relegated to text-only applications, they
+ can display any X application.</para>
+
+ <para>This chapter does <emphasis>not</emphasis> cover the
+ setup, configuration, or use of X terminals.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
<sect2 id="term-config">
<title>Configuration</title>
@@ -968,69 +975,70 @@ ttyu5 "/usr/libexec/getty std.19200"
Here is a list of common symptoms and some suggested
fixes.</para>
- <para>If no login prompt appears, make sure the terminal is plugged in and powered up. If
- it is a personal computer acting as a terminal, make sure it
- is running terminal emulation software on the correct serial
- port.</para>
-
- <para>Make sure the cable is connected firmly to both the
- terminal and the &os; computer. Make sure it is the
- right kind of cable.</para>
-
- <para>Make sure the terminal and &os; agree on the
- <acronym>bps</acronym> rate and parity settings. For a
- video display terminal, make sure the contrast and
- brightness controls are turned up. If it is a printing
- terminal, make sure paper and ink are in good supply.</para>
-
- <para>Make sure that a <command>getty</command> process is
- running and serving the terminal. For example, to get a
- list of running <command>getty</command> processes with
- <command>ps</command>, type:</para>
-
- <screen>&prompt.root; <userinput>ps -axww|grep getty</userinput></screen>
-
- <para>There should be an entry for the terminal. For example,
- the following display shows that a
- <command>getty</command> is running on the second serial
- port, <devicename>ttyu1</devicename>, and is using the
- <literal>std.38400</literal> entry in
- <filename>/etc/gettytab</filename>:</para>
*** DIFF OUTPUT TRUNCATED AT 1000 LINES ***
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