A _very_ quick look suggests that a Makefile might be overkill.

At the top of the BbSerial.c file are two commented out lines. Try uncommenting them;

Quote:
static char *serial_version = "5.05c";
static char *serial_revdate = "2001-07-08";

The comment out the line that includes the missing header file'

Quote:
##include "BbVersion.h"

and see if you can compile that;

Quote:
gcc BbSerial.c -o BbSerial.o