CompuServe Messages

I am new to C++, so this may be a dumb questions, but what the heck… I have some C functions that I have used for eons to handle tasks I need frequently. I am now getting into my first TCL program, and figured I'd just bring along my standard "support.c" file. Everything compiled fine. However, when I placed a call to a function in that file, my link said that the function was undefined. I solved the problem simply by changing the name of the file from "support.c" to "support.cp" and typecasting a few places where C++ says that it can't implicitely convert from (void *) to (char *). My questions are: 1) Why does changing the file to *.cp fix the problem? I know that this makes it use the C++ compiler instead of the C compiler, but why does that make any difference to the linker here? 2) Why can't C++ convert from (void *) to (char *) without typecasting? I thought that void matched any type, or is that no longer true in C++? Is there another way to indicate "a pointer of any type"? – Burt