I have 5 different C files and i Main.c program separately. In the Project diaglog box i have added all these files. For Target Options i have selected Large 64kCode ROM size and memory model Large. And selected output as hex. Upon building the target file, I get warning messages. 1. Unresolved external symbol 2. reference made to unresolved external sysmbol 3. ignored for overlay process. i dont know how to eliminate this messages. Please help me.