Here are the steps for installing gpsd and verifying its performance:

1. Start by making sure you can get data from your GPS, otherwise the later
steps will be very frustrating.  In this command

      stty -F /dev/ttyXXX ispeed 4800 && cat </dev/ttyXXX

replace ttyXXX with the filename of the port.  This will probably be
either /dev/ttyUSB0 or /dev/ttyS0.  When you run this command, you
should see text lines beginning with $ come to stdout (possibly after
a short initial burst of binary garbage).  If you don't see this, you
may have OS-level problems with your serial support, but more likely
have the wrong device.  Look again.

2. Make a symlink named /dev/gps to your GPS port; the command will be

     ln -s /dev/ttyXXX /dev/gps

where ttyXXX is as in step 1.

3. Build gpsd from source (skip this step if you have installed a gpsd
binary package).

You will need to have either Motif or LessTif installed in order for
xgps and xgpsspeed to build.  If you're on a Linux system, you probably
already have LessTif.  Source code is available from
<http://www.lesstif.org/>.

To build from source, run ./autogen.sh (or sh autogen.sh if the
script does not have execute permission).  Then run make: libgps.so,
gpsd, xgps, and xgpsspeed will be built. Copy the app-defaults files
xgps.ad and xgpsspeed.ad to your home directory or to the system-wide X
app-defaults directory.

4. Determine whether you need a non-NMEA driver.  Usually you will not,
but there are unusual exceptions.  Consult the hardware page at

    http://gpsd.berlios.de/hardware.html

to find out if your hardware is one of them.  If so, you may need to
specify a driver type option at gpsd startup time; if you installed 
a binary RPM, this will mean editing the gpsd init script.

5. Start gpsd on a serial or USB port that has the GPS connected to it.
If you made a /dev/gps symlink, just invoking "gpsd" as root should do it.
If you installed from an RPM, gpsd will be started for you automatically 
at boot time.

6. Once gpsd is running, telnet to port 2947.  Type "r" to start raw
and watcher modes.  You should see NMEA data (text lines beginning
with $) spewing out.  You will also see lines with a GPSD prefix;
these are sentence translations in GPSD protocol.

Note that until your GPS has acquired a fix, typing "p" to get position
will only return this:

GPSD,P=?

This response does not mean that gpsd is broken or that the GPS is not
sending data, merely that gpsd has not yet seen any *valid* position data.
You will have to wait for the GPS to acquire satellite lock.  If you have 
raw or watcher mode on it should be obvious when you get a lock.

7. Start the xgps client.  Calling it with no arguments should do the right 
thing.  You should see a GUI panel with position/velocity-time information,
and a satellite display.  The displays won't look very interesting until 
the GPS acquires satellite lock.

8. Check out the list of supported hardware at 

   http://gpsd.berlios.de/hardware.html

If your GPS isn't on the list, please send us information to add a new
line to the table.  Here's what we need:

1. Name (preferably with a URL to the vendor's product page or spec sheet).
2. Chipset.  Ideally we'd like to know both the GPS engine chip and
   the USB-to-serial chip the device uses.  80% of the time this will be
   SiRF-II + PL2303, but it's the exceptions that are interesting.
3. Interface type -- RS232, USB, CF, etc.
4. Vendor (preferably with a URL to the vendor's website).
5. gpsd type -- usually this will be 'n'.  If you had to specify a
   non-NMEA driver type to make gpsd work, give it.
6. Version of gpsd you tested with.
7. NMEA protocol version.
8. List of NMEA sentences the GPS emits.
9. Notes -- anything interesting or unusual about this GPS.

You may get some help on fields 2, 7, and 8 by running gpsprobe.  Note that
you will have to stop gpsd to do this.

We can also use updates of the latest version number known to work with
hardware already supported.