1) Get a recent kernel. I'm using an SL-5600 myself, so I grabbed the latest
Sharp ROM. In any case, you need a 2.4.18 based kernel. Make sure you have a 
console/terminal program installed (get one from 
http://www.killefiz.de/zaurus/ if you don't). Now, type:

uname -a

and check the output. It should say something like "Linux zaurus 
2.4.18-rmk7-pxa3-embedix" and some more data. Note the kernel version number: 
2.4.18.

2) Get the serial_cs driver from 
http://www.iral.com:88/~albertr/zaurus/misc/serial_cs.o.gz
IE might corrupt the file, so use something else to download it.

3) Become root, and extract and place the serial_cs.o file with the rest of 
your kernel modules (/lib/modules/your_kernel_version/)
Make sure you don't have another serial_cs.o lying around in that directory or 
it's subdirectories.
Give it the right permissions:
chown root:root serial_cs.o
chmod 755 serial_cs.o

4) Make sure the module is not loaded: 

rmmod serial_cs

5) Navigate to /etc/pcmcia/ and open serial.opts in an editor. Modify the line 
SERIAL_OPTS="" to SERIAL_OPTS="115200", and save the file.

6) Now, load the module:

modprobe serial_cs

It should be loaded without any complaints.

7) insert your GPS CF card. It should light up faintly and then go dark again. 
Check if all wend well:

cardctl status

should note your card, probaly in status [suspended]. Time for a wakeup call!

cardctl resume

Let's see the current configuration:

cardctl config

This should give you some info on the CF cards communication interface.

8) Run Cumulus, and go into the settings dialog (SHIFT-S). Go to the GPS tab, 
and select /dev/ttyS3 as your device and 4800 baud as the speed. 


That's all folks!