Welcome to my nightmare.  Since you obtained a copy of this program, you
must be almost as crazy as I am.  This program is intended to process
cassette tapes for the Atari classic computers.  The audio should be
recorded with a sound card.  The wave file can then be converted to a .cas
file.  The .cas file can be loaded by the classic Atari through the SIO2PC
interface.  All of this is explained in detail in the documentation, which
cost me a lot of time to write.  So please read it sometime.