It compiled flawlessly with the 3.0 compiler. It needs a new project
created to work with 4.0.

Unfortunately, only the 4.0 compiler knows how to talk to a Pocket PC
2003 device.

So you can compile easily with the 3.0 compiler but it's a manual
job to copy the file onto the device and run it. No debuggers etc.

In short use the 3.0 compiler or set up a new project. If you want to
do extensive development then sorting out 4.0 would be worthwhile. 

Would it be possible to use the RAM disk for the memory mapped file?
If so does the RAM disk have a fixed name on all devices? New machines
have enough RAM, it's just getting access to it.

Bryce