Hardware manual

compare it to this version: v2.27 February 2011 .
1.3 New in Recent Versions
For a full revision history going back to the time I started maintaining this HOWTO, see the source file (in
linuxdoc format): (cvs) Serial-HOWTO.sgml
TO do: explain use of udev for serial port for setting names and permissions. Fix dead links.•
2.27 Feb. 2011: The serial port is still widely used in embedded systems, etc., and is not really
obsolete. Better definition of input, output. Deleted devfs names such as tts.
•
2.26 Nov. 2010 Changed EIA-232 to RS-232. PCI-e bus is serial. No serial port on new PCs. I
incorrectly wrote in this update that the serial port was obsolete and that this HOWTO is now mainly
of historical interest.
•
2.25 Jan. 2007 picocom. devfs is obsolete. ser2net. Revised parts on drivers as modules vs. built into
kernel. Serial Programming wikibook.
•
1.4 Related HOWTO's, etc. about the Serial Port
Modems, Text-Terminals, some printers, and other peripherals often used the serial port. Get these HOWTOs
from the nearest mirror site as explained above.
Modem-HOWTO is about installing and configuring modems•
Printing-HOWTO has info for serial printers using old lpr command•
LPRng-HOWTO (not a LDP HOWTO, may come with software) has info for serial printing for "Next
Generation" lpr
•
Serial Programming is a wiki-book on the Internet•
Serial-Programming-HOWTO helps you write C programs that read and write to the serial port
and/or check/set its state. A version written by Vern Hoxie but not submitted to LDP is at Internet
section.
•
Text-Terminal-HOWTO is about how they work, how to install configure, and repair them. It
includes a section on "Make a Terminal the Console" which is useful for using a remote terminal to
control a server (via the serial port).
•
Remote-Serial-Console-HOWTO is about making a text-terminal be the console so it can
display boot-time messages, etc.
•
1.5 Feedback
Please send me any suggestions, correction or additional material. Tell me what you don't understand, or what
could be clearer. You can reach me via email at mailto:[e-mail].
1.6 What is a Serial Port?
The conventional serial port (not the newer USB port, or Firewire port) is a very old I/O (Input/Output) port.
Until around 2006, most new desktop PC's had one, and old PC's from the 1990's sometimes had 2 of them.
Most laptops gave up them before the desktops did. Macs (Apple Computer) after mid-1998 only had the
USB port. However, it's possible, to put a conventional serial port device on the USB bus which is on all
modern PCs.
Serial HOWTO
1.2 New Versions of this Serial-HOWTO 7