Update printing chapter to talk about USB printers.

Submitted by:	"Ted Mittelstaedt" <tedm@toybox.placo.com>
This commit is contained in:
Murray Stokely 2004-06-13 02:31:21 +00:00
parent 85a8be4912
commit 6677691ad4
Notes: svn2git 2020-12-08 03:00:23 +00:00
svn path=/head/; revision=21152

View file

@ -280,8 +280,8 @@
<sect4 id="printing-ports">
<title>Ports and Cables</title>
<para>Nearly all printers you can get for a PC today support one
or both of the following interfaces:</para>
<para>Printers sold for use on PC's today generally come
with one or more of the following three interfaces:</para>
<itemizedlist>
<indexterm>
@ -289,13 +289,16 @@
<secondary>serial</secondary>
</indexterm>
<listitem>
<para><emphasis>Serial</emphasis> interfaces use a serial
port on your computer to send data to the printer. Serial
<para><emphasis>Serial</emphasis> interfaces, also known
as RS232C or RS232D, or COM ports, use a serial port
on your computer to send data to the printer. Serial
interfaces are common in the computer industry and cables
are readily available and also easy to construct. Serial
interfaces sometimes need special cables and might require
you to configure somewhat complex communications
options.</para>
options. Most PC serial ports have a maximum
transmission rate of 115200 bps, which makes printing
large graphic print jobs with them impractical.</para>
</listitem>
<indexterm>
@ -305,7 +308,8 @@
<listitem>
<para><emphasis>Parallel</emphasis> interfaces use a
parallel port on your computer to send data to the
printer. Parallel interfaces are common in the PC market.
printer. Parallel interfaces are common in the PC market
and are faster than RS232 serial.
Cables are readily available but more difficult to
construct by hand. There are usually no communications
options with parallel interfaces, making their
@ -319,19 +323,42 @@
<quote>Centronics</quote> interfaces, named after the
connector type on the printer.</para>
</listitem>
<indexterm>
<primary>printers</primary>
<secondary>USB</secondary>
</indexterm>
<listitem>
<para>USB interfaces, named for the Universal Serial
Bus, can run at even faster speeds than parallel or
RS232 serial interfaces. Cables are simple and cheap.
USB is superior to RS232 Serial and to Parallel for
printing, but it is not as well supported under UNIX
systems. A way to avoid this problem is to purchase a
printer that has both a USB interface and a Parallel
interface, as many printers do.</para>
</listitem>
</itemizedlist>
<para>In general, serial interfaces are slower than parallel
interfaces. Parallel interfaces usually offer just
<para>In general, Parallel interfaces usually offer just
one-way communication (computer to printer) while serial
gives you two-way. Newer parallel ports (EPP and ECP) and printers
and USB gives you two-way. Newer parallel ports (EPP and
ECP) and printers
can communicate in both directions under FreeBSD when a
IEEE1284 compliant cable is used.</para>
<indexterm><primary>PostScript</primary></indexterm>
<para>Usually, the only time you need two-way communication with
the printer is if the printer speaks &postscript;. &postscript;
printers can be very verbose. In fact, &postscript; jobs are
<para>Two-way communication to the printer over a parallel
port is generally done 1 of two ways. The first method
uses a custom built printer driver for FreeBSD that speaks
the proprietary language used by the printer. This is
common with inkjet printers and can be used for reporting
ink levels and other status information. The second
method is used when the printer supports
&postscript;.</para>
<para>&postscript; jobs are
actually programs sent to the printer; they need not produce
paper at all and may return results directly to the computer.
&postscript; also uses two-way communication to tell the