251 lines
4.0 KiB
HTML
251 lines
4.0 KiB
HTML
<HTML
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><HEAD
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><TITLE
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>Advanced Power Management</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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REL="HOME"
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TITLE="Remote Serial Console HOWTO"
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HREF="index.html"><LINK
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REL="UP"
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TITLE="Bugs and annoyances"
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HREF="bugs.html"><LINK
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REL="PREVIOUS"
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TITLE="Boot loaders are vulnerable to line noise"
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HREF="bugs-bootloadernoise.html"><LINK
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REL="NEXT"
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TITLE="Modems and overseas telecommunications requirements"
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HREF="bugs-international.html"></HEAD
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><BODY
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CLASS="SECTION"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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LINK="#0000FF"
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VLINK="#840084"
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ALINK="#0000FF"
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><DIV
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CLASS="NAVHEADER"
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><TABLE
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SUMMARY="Header navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>Remote Serial Console HOWTO</TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="bugs-bootloadernoise.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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>Appendix A. Bugs and annoyances</TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="bugs-international.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="SECTION"
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><H1
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CLASS="SECTION"
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><A
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NAME="BUGS-APM"
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></A
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>A.10. <SPAN
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CLASS="PRODUCTNAME"
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>Advanced Power Management</SPAN
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></H1
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><P
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><SPAN
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CLASS="ACRONYM"
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>APM</SPAN
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> allows control of the power from
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software. This can be a blessing and a curse.</P
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><P
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>The blessing is that the machine can be cleanly and totally
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shut down remotely. You may want to do this if the remote site is
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maintaining their power supply.</P
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><P
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>The curse is that once powered down the machine will not
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start up again until the <B
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CLASS="KEYCAP"
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>Power</B
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> button is
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physically pressed. Some machines have a <SPAN
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CLASS="ACRONYM"
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>BIOS</SPAN
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> or
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motherboard setting to defeat this unhelpful behaviour.</P
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><DIV
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CLASS="CAUTION"
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><A
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NAME="CAUTION-SHUTDOWN"
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></A
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><P
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></P
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><TABLE
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CLASS="CAUTION"
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WIDTH="100%"
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BORDER="0"
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><TR
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><TD
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WIDTH="25"
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ALIGN="CENTER"
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VALIGN="TOP"
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><IMG
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SRC="../images/caution.gif"
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HSPACE="5"
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ALT="Caution"></TD
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><TH
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ALIGN="LEFT"
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VALIGN="CENTER"
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><B
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>Errors when typing <B
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CLASS="COMMAND"
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>shutdown</B
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> are worse
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with <SPAN
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CLASS="ACRONYM"
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>APM</SPAN
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></B
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></TH
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></TR
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><TR
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><TD
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> </TD
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><TD
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ALIGN="LEFT"
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VALIGN="TOP"
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><P
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>Be careful not to confuse <B
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CLASS="COMMAND"
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>shutdown -r
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now</B
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>, which cleanly reboots the machine, with
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<B
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CLASS="COMMAND"
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>shutdown -h now</B
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>, which cleanly powers down the
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machine. Someone will need to physically press the
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<B
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CLASS="KEYCAP"
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>Power</B
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> button if you choose wrongly.</P
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></TD
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></TR
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></TABLE
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></DIV
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><P
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>If you are serious about remote site computing then you
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should investigate remote power switches from companies like <A
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HREF="http://www.wti.com/"
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TARGET="_top"
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>Western Telematic</A
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>, <A
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HREF="http://www.servertech.com/"
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TARGET="_top"
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>Server Technology</A
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> and many
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others. Some models include built-in terminal servers, built-in
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modems and <SPAN
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CLASS="ACRONYM"
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>RS-232</SPAN
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> lines to simulate a
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<SPAN
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CLASS="ACRONYM"
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>UPS</SPAN
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> input power failure (and thus shut the
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<SPAN
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CLASS="SYSTEMITEM"
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>Linux</SPAN
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> system down cleanly
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before removing power).</P
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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SUMMARY="Footer navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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><A
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HREF="bugs-bootloadernoise.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="index.html"
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ACCESSKEY="H"
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>Home</A
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></TD
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><TD
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WIDTH="33%"
|
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ALIGN="right"
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VALIGN="top"
|
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><A
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HREF="bugs-international.html"
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ACCESSKEY="N"
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>Next</A
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></TD
|
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></TR
|
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><TR
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><TD
|
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WIDTH="33%"
|
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ALIGN="left"
|
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VALIGN="top"
|
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>Boot loaders are vulnerable to line noise</TD
|
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><TD
|
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WIDTH="34%"
|
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ALIGN="center"
|
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VALIGN="top"
|
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><A
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HREF="bugs.html"
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ACCESSKEY="U"
|
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>Up</A
|
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></TD
|
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><TD
|
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WIDTH="33%"
|
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ALIGN="right"
|
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VALIGN="top"
|
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>Modems and overseas telecommunications requirements</TD
|
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></TR
|
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></TABLE
|
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></DIV
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></BODY
|
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></HTML
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> |