Date: Tue, 6 May 2014 20:34:49 +0000 (UTC) From: Dru Lavigne <dru@FreeBSD.org> To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r44781 - head/en_US.ISO8859-1/books/handbook/serialcomms Message-ID: <201405062034.s46KYnwS018742@svn.freebsd.org>
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Author: dru Date: Tue May 6 20:34:49 2014 New Revision: 44781 URL: http://svnweb.freebsd.org/changeset/doc/44781 Log: White space fix only. Translators can ignore. Sponsored by: iXsystems 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 Tue May 6 19:47:57 2014 (r44780) +++ head/en_US.ISO8859-1/books/handbook/serialcomms/chapter.xml Tue May 6 20:34:49 2014 (r44781) @@ -63,441 +63,435 @@ <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> - </listitem> - </varlistentry> + <listitem> + <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> - </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> + </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 - serial communication. Typically, it is a modem.</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 + serial communication. Typically, it is a modem.</para> + </listitem> + </varlistentry> - <varlistentry> - <term>RS-232</term> + <varlistentry> + <term>RS-232</term> + <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> + </listitem> + </varlistentry> + </variablelist> - <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> - </listitem> - </varlistentry> - </variablelist> + <para>When talking about communications data rates, this section + does not use the term <quote>baud</quote>. Baud refers to the + number of electrical state transitions that may be made in a + 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 + with serial hardware and cabling can safely skip this + section.</para> + + <sect2 xml:id="term-cables-null"> + <title>Serial Cables and Ports</title> + + <para>There are several different kinds of serial cables. The + two most common types are null-modem cables and standard + RS-232 cables. The documentation for the hardware should + describe the type of cable required.</para> - <para>When talking about communications data rates, this section - does not use the term <quote>baud</quote>. Baud refers to the - number of electrical state transitions that may be made in a - 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 - with serial hardware and cabling can safely skip this - section.</para> - - <sect2 xml:id="term-cables-null"> - <title>Serial Cables and Ports</title> - - <para>There are several different kinds of serial cables. The - two most common types are null-modem cables and standard - RS-232 cables. The documentation for the hardware should - describe the type of cable required.</para> + <indexterm> + <primary>null-modem cable</primary> + </indexterm> - <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> - <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> - - <table frame="none" pgwide="1"> - <title>DB-25 to DB-25 Null-Modem Cable</title> - - <tgroup cols="5"> - <thead> - <row> - <entry align="left">Signal</entry> - <entry align="left">Pin #</entry> - <entry/> - <entry align="left">Pin #</entry> - <entry align="left">Signal</entry> - </row> - </thead> - - <tbody> - <row> - <entry>SG</entry> - <entry>7</entry> - <entry>connects to</entry> - <entry>7</entry> - <entry>SG</entry> - </row> - - <row> - <entry>TD</entry> - <entry>2</entry> - <entry>connects to</entry> - <entry>3</entry> - <entry>RD</entry> - </row> - - <row> - <entry>RD</entry> - <entry>3</entry> - <entry>connects to</entry> - <entry>2</entry> - <entry>TD</entry> - </row> - - <row> - <entry>RTS</entry> - <entry>4</entry> - <entry>connects to</entry> - <entry>5</entry> - <entry>CTS</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>6</entry> - <entry>DSR</entry> - </row> - - <row> - <entry>DTR</entry> - <entry>20</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>DCD</entry> - <entry>8</entry> - <entry>connects to</entry> - <entry>20</entry> - <entry>DTR</entry> - </row> - </tbody> - </tgroup> - </table> - - <para>The next two tables show two other common - schemes.</para> - - <table frame="none" pgwide="1"> - <title>DB-9 to DB-9 Null-Modem Cable</title> - - <tgroup cols="5"> - <thead> - <row> - <entry align="left">Signal</entry> - <entry align="left">Pin #</entry> - <entry/> - <entry align="left">Pin #</entry> - <entry align="left">Signal</entry> - </row> - </thead> - - <tbody> - <row> - <entry>RD</entry> - <entry>2</entry> - <entry>connects to</entry> - <entry>3</entry> - <entry>TD</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>6</entry> - <entry>DSR</entry> - </row> - - <row> - <entry>DTR</entry> - <entry>4</entry> - <entry>connects to</entry> - <entry>1</entry> - <entry>DCD</entry> - </row> - - <row> - <entry>SG</entry> - <entry>5</entry> - <entry>connects to</entry> - <entry>5</entry> - <entry>SG</entry> - </row> - - <row> - <entry>DSR</entry> - <entry>6</entry> - <entry>connects to</entry> - <entry>4</entry> - <entry>DTR</entry> - </row> - - <row> - <entry>DCD</entry> - <entry>1</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>CTS</entry> - <entry>8</entry> - <entry>connects to</entry> - <entry>7</entry> - <entry>RTS</entry> - </row> - </tbody> - </tgroup> - </table> - - <table frame="none" pgwide="1"> - <title>DB-9 to DB-25 Null-Modem Cable</title> - - <tgroup cols="5"> - <thead> - <row> - <entry align="left">Signal</entry> - <entry align="left">Pin #</entry> - <entry/> - <entry align="left">Pin #</entry> - <entry align="left">Signal</entry> - </row> - </thead> - - <tbody> - <row> - <entry>RD</entry> - <entry>2</entry> - <entry>connects to</entry> - <entry>2</entry> - <entry>TD</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>6</entry> - <entry>DSR</entry> - </row> - - <row> - <entry>DTR</entry> - <entry>4</entry> - <entry>connects to</entry> - <entry>8</entry> - <entry>DCD</entry> - </row> - - <row> - <entry>SG</entry> - <entry>5</entry> - <entry>connects to</entry> - <entry>7</entry> - <entry>SG</entry> - </row> - - <row> - <entry>DSR</entry> - <entry>6</entry> - <entry>connects to</entry> - <entry>20</entry> - <entry>DTR</entry> - </row> - - <row> - <entry>DCD</entry> - <entry>1</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>CTS</entry> - <entry>8</entry> - <entry>connects to</entry> - <entry>4</entry> - <entry>RTS</entry> - </row> - </tbody> - </tgroup> - </table> + <table frame="none" pgwide="1"> + <title>DB-25 to DB-25 Null-Modem Cable</title> - <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> + <tgroup cols="5"> + <thead> + <row> + <entry align="left">Signal</entry> + <entry align="left">Pin #</entry> + <entry/> + <entry align="left">Pin #</entry> + <entry align="left">Signal</entry> + </row> + </thead> - <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>/dev</filename>. - There are two different kinds of entries:</para> + <tbody> + <row> + <entry>SG</entry> + <entry>7</entry> + <entry>connects to</entry> + <entry>7</entry> + <entry>SG</entry> + </row> - <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> + <row> + <entry>TD</entry> + <entry>2</entry> + <entry>connects to</entry> + <entry>3</entry> + <entry>RD</entry> + </row> - <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> + <row> + <entry>RD</entry> + <entry>3</entry> + <entry>connects to</entry> + <entry>2</entry> + <entry>TD</entry> + </row> + + <row> + <entry>RTS</entry> + <entry>4</entry> + <entry>connects to</entry> + <entry>5</entry> + <entry>CTS</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>6</entry> + <entry>DSR</entry> + </row> + + <row> + <entry>DTR</entry> + <entry>20</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>DCD</entry> + <entry>8</entry> + <entry>connects to</entry> + <entry>20</entry> + <entry>DTR</entry> + </row> + </tbody> + </tgroup> + </table> + + <para>The next two tables show two other common schemes.</para> + + <table frame="none" pgwide="1"> + <title>DB-9 to DB-9 Null-Modem Cable</title> + + <tgroup cols="5"> + <thead> + <row> + <entry align="left">Signal</entry> + <entry align="left">Pin #</entry> + <entry/> + <entry align="left">Pin #</entry> + <entry align="left">Signal</entry> + </row> + </thead> + + <tbody> + <row> + <entry>RD</entry> + <entry>2</entry> + <entry>connects to</entry> + <entry>3</entry> + <entry>TD</entry> + </row> - <para>If a terminal is connected to the first serial - port(<filename>COM1</filename>), use - <filename>/dev/ttyu0</filename> to refer to the - terminal. If the terminal is on the second serial port - (<filename>COM2</filename>), use - <filename>/dev/ttyu1</filename>, and so forth.</para> - </sect2> + <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>6</entry> + <entry>DSR</entry> + </row> + + <row> + <entry>DTR</entry> + <entry>4</entry> + <entry>connects to</entry> + <entry>1</entry> + <entry>DCD</entry> + </row> + + <row> + <entry>SG</entry> + <entry>5</entry> + <entry>connects to</entry> + <entry>5</entry> + <entry>SG</entry> + </row> + + <row> + <entry>DSR</entry> + <entry>6</entry> + <entry>connects to</entry> + <entry>4</entry> + <entry>DTR</entry> + </row> + + <row> + <entry>DCD</entry> + <entry>1</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>CTS</entry> + <entry>8</entry> + <entry>connects to</entry> + <entry>7</entry> + <entry>RTS</entry> + </row> + </tbody> + </tgroup> + </table> + + <table frame="none" pgwide="1"> + <title>DB-9 to DB-25 Null-Modem Cable</title> + + <tgroup cols="5"> + <thead> + <row> + <entry align="left">Signal</entry> + <entry align="left">Pin #</entry> + <entry/> + <entry align="left">Pin #</entry> + <entry align="left">Signal</entry> + </row> + </thead> + + <tbody> + <row> + <entry>RD</entry> + <entry>2</entry> + <entry>connects to</entry> + <entry>2</entry> + <entry>TD</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>6</entry> + <entry>DSR</entry> + </row> + + <row> + <entry>DTR</entry> + <entry>4</entry> + <entry>connects to</entry> + <entry>8</entry> + <entry>DCD</entry> + </row> + + <row> + <entry>SG</entry> + <entry>5</entry> + <entry>connects to</entry> + <entry>7</entry> + <entry>SG</entry> + </row> + + <row> + <entry>DSR</entry> + <entry>6</entry> + <entry>connects to</entry> + <entry>20</entry> + <entry>DTR</entry> + </row> + + <row> + <entry>DCD</entry> + <entry>1</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>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>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>/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 + (<filename>COM1</filename>), use + <filename>/dev/ttyu0</filename> to refer to the terminal. If + the terminal is on the second serial port + (<filename>COM2</filename>), use + <filename>/dev/ttyu1</filename>, and so forth.</para> + </sect2> <sect2> <title>Kernel Configuration</title> <para>&os; supports four serial ports by default. In the - &ms-dos; world, these are known as - <filename>COM1</filename>, - <filename>COM2</filename>, - <filename>COM3</filename>, and + &ms-dos; world, these are known as <filename>COM1</filename>, + <filename>COM2</filename>, <filename>COM3</filename>, and <filename>COM4</filename>. &os; currently supports <quote>dumb</quote> multiport serial interface cards, such as the BocaBoard 1008 and 2016, as well as more intelligent @@ -505,19 +499,18 @@ Technologies. However, the default kernel only looks for the standard COM ports.</para> - <para>To see if the kernel recognizes the serial ports, - watch for messages while the kernel is booting, or use - <command>/sbin/dmesg</command> to replay the kernel's - boot messages. Look for messages that start with the - characters <literal>uart</literal>:</para> + <para>To see if the kernel recognizes the serial ports, watch + for messages while the kernel is booting, or use + <command>/sbin/dmesg</command> to replay the kernel's boot + messages. Look for messages that start with the characters + <literal>uart</literal>:</para> <screen>&prompt.root; <userinput>/sbin/dmesg | grep 'uart'</userinput></screen> - <para>If the kernel does not recognize all of the serial - ports, configure <filename>/boot/device.hints</filename>. - When editing this file, one can comment out or completely - remove lines for devices that do not exist on the - system.</para> + <para>If the kernel does not recognize all of the serial ports, + configure <filename>/boot/device.hints</filename>. When + editing this file, one can comment out or completely remove + lines for devices that do not exist on the system.</para> <note> <para><literal>port IO_COM1</literal> is a substitution for @@ -528,11 +521,10 @@ addresses for their respective serial ports and interrupts 4, 3, 5, and 9 are fairly common interrupt request lines. Regular serial ports <emphasis>cannot</emphasis> share - interrupts on ISA-bus PCs. Multiport boards have - on-board electronics that allow all the 16550A's on the - board to share one or two interrupt request lines.</para> + interrupts on ISA-bus PCs. Multiport boards have on-board + electronics that allow all the 16550A's on the board to + share one or two interrupt request lines.</para> </note> - </sect2> <sect2> @@ -614,7 +606,8 @@ of the port will be stuck with 57600 bps.</para> <para>The initial state and lock state devices should only be - writable by <systemitem class="username">root</systemitem>.</para> + writable by <systemitem + class="username">root</systemitem>.</para> </sect2> </sect1> @@ -641,9 +634,9 @@ 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 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 @@ -668,17 +661,18 @@ 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. Instead, dumb terminals - connect to a computer that runs the needed programs.</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> + No programs can be run on these devices. Instead, dumb + terminals connect to a computer that runs the needed + programs.</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 + <para>Dumb terminals are popular in work environments where + workers do not need access to graphical applications.</para> </listitem> </varlistentry> @@ -689,9 +683,8 @@ <para>Since 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 <firstterm>terminal - emulation</firstterm> software to run on the - computer.</para> + cable and some <firstterm>terminal emulation</firstterm> + software to run on the computer.</para> <para>This configuration can be useful. For example, if one user is busy working at the &os; system's console, another @@ -703,25 +696,27 @@ &os; that can be used to work through a serial connection: &man.cu.1; and &man.tip.1;.</para> - <para>For example, to connect from a client system that runs &os; to the - serial connection of another system:</para> + <para>For example, to connect from a client system that runs + &os; to the serial connection of another system:</para> <screen>&prompt.root; <userinput>cu -l <replaceable>serial-port-device</replaceable></userinput></screen> - <para>Replace <replaceable>serial-port-device</replaceable> with the device name of - the connected serial port. These device files are called + <para>Replace <replaceable>serial-port-device</replaceable> + with the device name of the connected serial port. These + device files are called <filename>/dev/cuau<replaceable>N</replaceable></filename> on &os; versions 8.x and lower and <filename>/dev/cuad<replaceable>N</replaceable></filename> on &os; versions 9.x and higher. In either case, - <replaceable>N</replaceable> is the - serial port number, starting from zero. - This means that <filename>COM1</filename> - is <filename>/dev/cuau0</filename> or - <filename>/dev/cuad0</filename> in &os;.</para> - - <para>Additional programs are available - through the Ports Collection, such as <package>comms/minicom</package>.</para> + <replaceable>N</replaceable> is the serial port number, + starting from zero. This means that + <filename>COM1</filename> is + <filename>/dev/cuau0</filename> or + <filename>/dev/cuad0</filename> in &os;.</para> + + <para>Additional programs are available through the Ports + Collection, such as *** DIFF OUTPUT TRUNCATED AT 1000 LINES ***
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