Cheat mode: 
Press [Esc] to pause game play. Press C and type one 
of the following codes at the password prompt to activate 
the corresponding cheat function. The word "Outstanding" 
will be spoken to confirm correct code entry.

Effect                   Code
Maximum fuel, armor      13593 
Invincibility            14214 
Mission select           17357 
Maximum weapons          25245 
All missions completed   33124