Unlock Select Mode:
     Use  the  tuner  to  point to the following numbers at one second
intervals between each one: 1, 9, 7, 9, 0, 9, 0 and 6.

A sound will confirm correct entry of the code. 

Unlock Full Screen Mode:
     Get 55,000 Command Points to unlock Full Screen mode.

Desperado Mode:
     Complete mission 23 on Veteran difficulty to unlock Desperado mode.