<HTML ><HEAD ><TITLE >WinModems</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="Remote Serial Console HOWTO" HREF="index.html"><LINK REL="UP" TITLE="Modem configuration" HREF="modem.html"><LINK REL="PREVIOUS" TITLE="Internal modems" HREF="modem-internal.html"><LINK REL="NEXT" TITLE="Bugs and annoyances" HREF="bugs.html"></HEAD ><BODY CLASS="SECTION" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Remote Serial Console HOWTO</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="modem-internal.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 12. Modem configuration</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="bugs.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECTION" ><H1 CLASS="SECTION" ><A NAME="MODEM-DSP" ></A >12.5. WinModems</H1 ><P >If you look at a modem, with it's small central processing unit and special-purpose digital signal processor, and then look at a modern <SPAN CLASS="ACRONYM" >PC</SPAN >, with it's large <SPAN CLASS="ACRONYM" >CPU</SPAN > and general-purpose <SPAN CLASS="ACRONYM" >DSP</SPAN > on the sound card, you may wonder if the hardware duplication of an external modem is necessary.</P ><P >A <SPAN CLASS="QUOTE" >"WinModem"</SPAN > incorporates the <SPAN CLASS="ACRONYM" >CPU</SPAN > and <SPAN CLASS="ACRONYM" >DSP</SPAN > of the modem into the slightly-enhanced fabric of a <SPAN CLASS="ACRONYM" >PC</SPAN >. They are called "WinModems" because they originally only shipped with <SPAN CLASS="PRODUCTNAME" >Microsoft <SPAN CLASS="SYSTEMITEM" >Windows</SPAN ></SPAN > device drivers. These device drivers presented the illusion of a serial port attached to a Hayes <SPAN CLASS="ACRONYM" >AT</SPAN >-style modem. For a long time only <SPAN CLASS="SYSTEMITEM" >Windows</SPAN > versions of these drivers where available. Some manufacturers now provide <SPAN CLASS="SYSTEMITEM" >Linux</SPAN > versions of their device drivers as well, these modems are jokingly called <SPAN CLASS="QUOTE" >"LinModems"</SPAN >.</P ><P >It is probably possible to use a LinModem as a <SPAN CLASS="SYSTEMITEM" >Linux</SPAN > console. At the most this would require altering the source code to dumb-down the AT command emulation of the modem and recompiling the kernel.</P ><P >Boot loaders, however, work in a very confined software environment and struggle to support a simple serial chip. Considering that some boot loaders do not even handle interrupts, handling the complex <SPAN CLASS="ACRONYM" >DSP</SPAN > of a LinModem is well beyond what is practical.</P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="modem-internal.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="bugs.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Internal modems</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="modem.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Bugs and annoyances</TD ></TR ></TABLE ></DIV ></BODY ></HTML >
