After starting a game, press [Ctrl]+K and that will give you access to
the Map Editor and Senario commands to alter game play. 

Code           Result
-----------------------
Y            - Reveal Map
[Shift]+F1   - Create Unit
[Shift]+F2   - Technological Discovery
[Shift]+F3   - Switch sides/set view
[Shift]+F4   - Change/set energy credits
[Shift]+F5   - Change Year
[Shift]+F6   - Kill Opponent
[Shift]+F7   - View replay
[Shift]+F8   - View Movies
[Shift]+F9   - Edit Faction Diplomacy

Click on the menu option and select scenario and you will get a complete
listing of all cheats and how to access them in the game.