Here's what I came up with as far as documentation.  First, I'm mainly a
  windows person... ewww.. but, as such.. some things are probably not
  solved optimally.

  --- 
  Getting the Comm API working on an Ipaq
  Thomas O'Connell (thomas@cc.gatech.edu)

  For the most part, things go pretty much according to the documents
  provided by: http://www.interstice.com/~kevinh/linuxcomm.html

  I'll just cover the gotchas:

  1) Getting Java itself to run:  This was actually the most complicated
  part (for me).  You can download a JRE 1.3 from Blackdown for the ARM
  processor, but no JDK.  But you can tease a javac, jar, javah, etc.. out
  of a tools.jar file from some other distro(i went with an i386 linux
  sdk, same version as the JRE), and writing scripts to emulate the
  behaviors (and adding tools.jar to your classpath).

  Example:  
  javac is: 
  #! /bin/sh
  java com.sun.tools.javac.Main $@

  The rest can be created similarily.  I kept pulling as many as those out
  until the .configure of rxtx stopped complaining.  

  - include files: in addition to pulling tools.jar from another linux
  jdk, I brought over the <jdk>\include files too.  Dumped it in the
  <j2re1.3.1> directory.

  - sim link: in the j2re1.3.1 directory, I created a jre sub directory,
  and beneath that I sym linked a j2re1.3.1\jre\lib to j2re1.3.1\lib.
  Also, both my JDK_HOME and JAVA_HOME were set to the j2re1.3.1 location.


  After all this, the rxtx package built correctly.  I added jcl.jar to my
  classpath as well.  

  Your mileage may vary here, since I'm doing this all from recollection.
  I imagine I'll have to reformat at some point and pay more attention the
  next time I have to set it up.  Lots of trial and error here, and I'm no
  script kiddie.. I imagine some of this could be fixed up internally.


  2) Killing getty -  So there's the console terminal running on the comm
  port.  You need to be able to kill this in order for the comm port to be
  released.  Since you don't want to entirely kill getty (since,
  networking is often flaky on these things), I just changed the
  /etc/inittab with regards to getty.

  Changed: T0:2:respawn:/sbin/getty -L tts/0 115200 vt100
  To: T0:2:boot:/sbin/getty -L ttySA0 115200 vt100

  This keeps the ipaq from respawning getty everytime you kill it, but
  does activate it upon boot.  


  3) Fixing RXTXCommDriver.java.   Based on OS, the code tried to find the
  serial ports.  This will fail because of a naming convention that
  Intimate/?Debian? uses for the com ports.  Need to add a prefix that
  includes ttySA.  By default the code looks like:


          if(osName.equals("Linux"))
          {
                  String[] Temp = {
                  "ttyS" // linux Serial Ports
                  };
                  CandidatePortPrefixes=Temp;
          }

  4) Cable:  The hotsync cable that the ipaq comes with is a null modem
  cable.  compaq does sell a RS-232 cable for the hotsync port, if you're
  trying to control a serial device like me.  $26 though..

  -- 
  Thomas O'Connell               Georgia Institute of Technology
  Aware Home Lab ManagerCollege of Computing
  www.cc.gatech.edu/fce/ahri           www.cc.gatech.edu/~thomas