Go to the ProntoProNG forum and search for posts on memory issues. There are a few folks on that forum who understand how Prontos treat memory. Apparently, the nominal size of a pcf (or icf) file has little to do with how much memory the Pronto device uses because it translates graphics and other information using its own compression algorithms. In ProntoPro it is possible to determine the true memory requirement using the simulator, but, since iPronto has no simulator, I don't know how you would get to it. My experience is that you can save quite a bit of memory by using png files instead of bmps.