There was a undergraduate course about Compiler and Automata. When I took this course, I needed to make a simulation program that was Mealy Machine simulation. I did this in 1997 during fall semaster. I made this using C under DOS system.
You can try to use it in DOS-mode. If you know what the Mealy Machine is, you should know how it operate.
Source Code is available below.
Mealy_Machine(ZIP file) source
Minimizer(ZIP file) sourceMealy Machine Simulator. 
