You might want to take a look at the documentation that comes with your compiler regarding getchar and putchar(). My compiler at least rightly assumes that it doesn't know what the hardware configuration and I/O ports is, and doesn't do ANYTHING with these functions besides RET.

You might have to write the lowlevel serial function to map getchar() with a serial read, and serial write for putchar().

And as Michael bluntly suggests, a teeny tiny bit of searching will help you out there. Take a look also at the tutorials which cover both polled and interrupt driven serial I/O.

Dennis