This application is fairly straight-forward, but, unfortunately, it requires the mame source.  

Download the srouce code for the mame version you will be using.  Locate the file that contains the default input port
definitions (inptport.c for mame .105, it was recently moved and I don't know the old location).  Take this file,
rename it to "source.txt" and drop it in this folder.  Now run src-std.exe.  Bam you are done!  


You'll very rarely have to use this utility.  Only when mame's core defaults are changed or when a new type of input port
are added to you have to worry about the defaults being off.  With that being said, they WERE changed around .104u3 so if
you are using an older version of mame you'll need to generate one, otherwise use the one included.  