JXM FAQs

• What is JXM?

  JXM is a program designed to allow a computer to control an XM PCR.

• What is an XM PCR?

  An XM PCR is an XM radio that is powered and controlled over a USB connection. XMPCRs are no longer being sold by XM (as of late summer, 2004). Your best bet to find them is on eBay. If you can find one, they still work just fine with XM's service and can be subscribed just like any other radio. You can also find adapters that can make in-car XM receivers work like PCRs.

• What is XM?

  XM is a satellite broadcasting service available in the United States. For more information about XM, see the XM Radio Site.

• What does JXM require to run?

  • An XM PCR (obviously)
  • The Java Runtime Environment, version 1.4 or beyond
  • The Java Communications API (javax.comm)
  • The FTDI FT245 driver for your platform

  Note that all of these pieces must be installed correctly so that they work together. The FTDI driver must see your XM PCR, javax.comm must be installed correctly so that it sees the FTDI driver's ports, and javax.comm must be in your JRE's classpath.

• Wow, that sounds complicated. Isn't there a simpler way?

  Fortunately, it's not as complicated as it sounds. You need to install a driver for the FTDI USB-to-Serial chip that is in the XMPCR. Then...

  • If you're using a Macintosh, all you have to do is drag the application from a disk image into your Applications folder (or wherever else you want it).
  • If you're using Windows, there is an installer that will set you up.
  • If you're using FreeBSD, just install the 'audio/jxm' port.
  • If you're using Linux, just install the RPM.

  NOTE: At the moment, we are currently looking for someone to take on the Linux release engineering duties, so an RPM is not currently available.

• All I get when I start JXM is a message asking if javax.comm is installed correctly. What's wrong?

  Your JRE is not seeing your javax.comm classes. Because of the wide variety of platforms, we don't really have the bandwidth to walk everyone through it. Check the XM411 software support forum for information for your platform.

• I can't find the correct device in the device picker menu, or I don't know which device is correct. What's wrong?

  Either javax.comm is not finding the FTDI ports (if the right port isn't showing up), or you need to try them until you find the right one (if you don't know which one is the right one). Because of the wide variety of platforms, we don't really have the bandwidth to walk everyone through it. Check the XM411 software support forum for information for your platform.

• I plugged in my XM PCR but it isn't showing up in the device picker. What's wrong?

  You must restart JXM if you connect your XM PCR after it is already running. This is a limitation of javax.comm. Once it enumerates the ports (at load time), it won't re-enumerate them.

• When I quit JXM, my multi-processor Windows machine get the Blue Screen Of Death! Oh my!

  This is a known issue with older revisions of the FTDI FT232 driver for Windows 2000/XP. Make sure you are using a version of the driver whose build number is higher than 2151. Currently, this version is not yet available for download from FTDI's web site. As soon as it is, I'll put a pointer to it up here. In the meantime, the workaround is to not power down the radio or quit JXM with the radio on. Instead, yank the USB plug out of the PCR, wait for JXM to display an error and power off, then quit.