Whistle Specification Format Change
The format for a whistle specification file has changed since  v1.02.  I
am now using the standard java XML parse/unparse technology, and that
does not like tags whose name begins with a numeral.  So if
you wish to load a spec you created with v1.02 you will need to edit
the file.  A text editor is good.  Look for the specification
of the holes, it will look like this:
<Holes HoleCount="7">
    <1 Width="14.0" Offset="50" />
    <2 Width="13.0" Offset="0" />
    <3 Width="9.0" Offset="180" />
    <4 Width="13.0" Offset="0" />
    <5 Width="15.0" Offset="0" />
    <6 Width="16.0" Offset="180" />
</Holes> 
As you can see the holes have numbered tags.  Change the file by adding some 'h's:
<Holes HoleCount="7">
    <h1 Width="14.0" Offset="50" />
    <h2 Width="13.0" Offset="0" />
    <h3 Width="9.0" Offset="180" />
    <h4 Width="13.0" Offset="0" />
    <h5 Width="15.0" Offset="0" />
    <h6 Width="16.0" Offset="180" />
</Holes>
When you have loaded the specification into Whistle Calculator you can then resave it to the new format.
Whistle Calculator now only uses metric units (mm).  When you load
a whistle saved with imperial units Whistle Calculator will attempt to
perform a conversion.  You will have to load an imperial drill set
for this to work correctly.