Enter MONEYBAGS as a password.
Enter one of the following passwords to unlock the corresponding feature. Note: The map password will unlock full city maps that are rated "excellent". They are accessible only after a time period is selected in Free mode, then a city map (topography) to chosen. The message "Excellent map. The best map of this age. Reference it for your own city." will appear.
Use the following trick to get a higher population in Challenge mode. Save the game then select the "Quit Game" button. Choose "Yes" then you select the "Challenge" tab. Load your game. Usually your population will increase a lot (depending on the era), then it may decrease somewhat. Note: Sometimes your population will go down a bit then go up a lot.