218 lines
3.6 KiB
HTML
218 lines
3.6 KiB
HTML
<HTML
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><HEAD
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><TITLE
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>WinModems</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="Modem configuration"
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HREF="modem.html"><LINK
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REL="PREVIOUS"
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TITLE="Internal modems"
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HREF="modem-internal.html"><LINK
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REL="NEXT"
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TITLE="Bugs and annoyances"
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HREF="bugs.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="modem-internal.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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>Chapter 12. Modem configuration</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.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="MODEM-DSP"
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></A
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>12.5. WinModems</H1
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><P
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>If you look at a modem, with it's small central processing
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unit and special-purpose digital signal processor, and then look at
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a modern <SPAN
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CLASS="ACRONYM"
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>PC</SPAN
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>, with it's large <SPAN
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CLASS="ACRONYM"
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>CPU</SPAN
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>
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and general-purpose <SPAN
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CLASS="ACRONYM"
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>DSP</SPAN
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> on the sound card, you may
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wonder if the hardware duplication of an external modem is
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necessary.</P
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><P
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>A <SPAN
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CLASS="QUOTE"
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>"WinModem"</SPAN
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> incorporates the
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<SPAN
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CLASS="ACRONYM"
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>CPU</SPAN
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> and <SPAN
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CLASS="ACRONYM"
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>DSP</SPAN
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> of the modem into
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the slightly-enhanced fabric of a <SPAN
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CLASS="ACRONYM"
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>PC</SPAN
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>. They are
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called "WinModems" because they originally only shipped with
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<SPAN
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CLASS="PRODUCTNAME"
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>Microsoft <SPAN
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CLASS="SYSTEMITEM"
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>Windows</SPAN
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></SPAN
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> device
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drivers. These device drivers presented the illusion of a serial
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port attached to a Hayes <SPAN
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CLASS="ACRONYM"
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>AT</SPAN
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>-style modem. For a
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long time only <SPAN
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CLASS="SYSTEMITEM"
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>Windows</SPAN
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>
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versions of these drivers where available. Some manufacturers now
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provide <SPAN
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CLASS="SYSTEMITEM"
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>Linux</SPAN
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> versions of
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their device drivers as well, these modems are jokingly called
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<SPAN
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CLASS="QUOTE"
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>"LinModems"</SPAN
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>.</P
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><P
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>It is probably possible to use a LinModem as a <SPAN
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CLASS="SYSTEMITEM"
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>Linux</SPAN
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> console. At the most this would
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require altering the source code to dumb-down the AT command
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emulation of the modem and recompiling the kernel.</P
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><P
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>Boot loaders, however, work in a very confined software
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environment and struggle to support a simple serial chip.
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Considering that some boot loaders do not even handle interrupts,
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handling the complex <SPAN
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CLASS="ACRONYM"
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>DSP</SPAN
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> of a LinModem is well
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beyond what is practical.</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="modem-internal.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.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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>Internal modems</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="modem.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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>Bugs and annoyances</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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> |