This extension contains two buttons on the view docGUI. 

One allows you to enter a point and then based on a from and to datum, 
it returns the transformed coordinates. 

The other button transforms the shapes of all active themes from one datum to another. 

See the description portion of each script to familiarize yourself with 
how each script works before running any of them. This updated extension 
prevents you from trying to convert between NAD27 and NAD83, since 
ArcView is not the tool to use to do that type of conversion. 

Requires: A file called datum.par in your HOME directory. If the 
file is not found, the extension will build it for you. The contents 
of the file can be found in the Script Editor document called 'Datum Parameters'.