Turbo mode (Galaxian)
 
 During demonstration mode, press Select(32) to add to the "Credits"
 total in the bottom right corner of the screen. Now the number "32"
 should be displayed at this time. Hold Select and press Start to
 begin the game in turbo mode. 
 
 Hard difficulty level (Galaxian)
 
 Beat level 9. Then during the next demonstration mode, press
 Triangle. Then on the options screen, a "Rank" selection will now be
 available. Select this choice to access the new "Hard" setting.
 
 Color trail mode (Galaxian)
 
 Obtain a high score of at least 30,000 points. Then during the next
 demonstration mode, press Triangle. Now highlight the "Test" option
 and press X. Highlight the "Dip Sw" option and press X. Press Up to
 enable switch 6. The game will now begin with all ships leaving
 colored trails. 
 
 Alternate tracks (Pole Position 2)
 
 Press Triangle to display the options menu. Then, select "Test" and
 press Triangle when the "Test" screen appears. Now select "Dip Sw" to
 display the DIP switch screen. Press Up to enable switch 1 in the
 left box. Return to the options screen and select the "Game" option.
 Press Triangle after the game loads and select the new "Course"
 option. All four tracks will now have a new layout. Note: The "Test"
 track is now a straightaway. 
 
 Bonus machine (The Tower Of Druaga)
 
 In the Museum, hold L1 + R1 and press Up, Right, Down, Left, Up,
 Right, Down, Left, Up, Right, Down, Left. If you entered the code
 correctly, a pickaxe symbol will appear in the bottom left corner of
 the screen. Now move forward in the Tower Of Druaga area of the
 museum until a brick wall appears. Press X to open the wall to reveal
 another Tower Of Druaga machine and an FMV sequence related to the
 game. 
 
  Game Shark Codez:
 
                 
  Dig Dug                       
                 
  Infinite Lives P1             
  80125418 0004
                 
  Score Modifier P1 (Small)     
  80125414 ????
                 
  Score Modifier P1 (Large)     
  80125416 ????
                 
  Infinite Lives P2             
  8012547C 0004
                 
  Score Modifier P2 (Small)     
  80125478 ????
                 
  Score Modifier P2 (Large)     
  8012547A ????
                 
  Galaxian                      
                 
  Infinite Lives (Both Players) 
  8010EC04 0005
                 
  Score Modifier P1 (Small)     
  8010EA44 ????
                 
  Score Modifier P1 (Large)     
  8010EA46 ????
                 
  Score Modifier P2 (Small)     
  8010EA48 ????
                 
  Score Modifier P2 (Large)     
  8010EA4A ????
                 
  Infinite Credits              
  8010EC0C 0009
                 
  Ms. Pac-Man                   
                 
  Infinite Lives P1             
  80135960 0004
                 
  Score Modifier P1 (Small)     
  80135978 ????
                 
  Score Modifier P1 (Large)     
  8013597A ????
                 
  Infinite Lives P2             
  80135964 0004
                 
  Score Modifier P2 (Small)     
  8013597C ????
                 
  Score Modifier P2 (Large)     
  8013597E ????
                 
  Infinite Credits              
  80135840 0009
                 
  Eat All Ghosts All The Time   
  80187728 0000
  8018772A 0000
  80187754 0000
  80187756 0000
  80187780 0000
  80187782 0000
  801877AC 0000
  801877AE 0000
                 
  Phozon                        
                 
  Infinite Lives P1             
  30168D4C 0005
                 
  Score Modifier P1 (Small)     
  80168CF4 ????
                 
  Score Modifier P1 (Large)     
  80168CF6 ????
                 
  Infinite Lives P2             
  30168D4D 0005
                 
  Score Modifier P2 (Small)     
  80168CFC ????
                 
  Score Modifier P2 (Large)     
  80168CFE ????
                 
  Infinite Credits              
  80168AE4 0009
                 
  Pole Position 2               
                 
  Infinite Time                 
  8013551E 7000
                 
  Lap Time Always Below 0.01    
  80135532 0000
  80135530 0000
  8013552E 0000
  8013552C 0000
                 
  Speed Modifier                
  30132E8D 00??
                 
  Infinite Credits              
  80132D2A 0900
                 
  Tower of Druaga               
                 
  Infinite Lives P1             
  8016664A 0004
                 
  Score Modifier P1 (Small)     
  8016664C ????
                 
  Score Modifier P1 (Large)     
  8016664E ????
                 
  Infinite Lives P2             
  80166696 0004
                 
  Score Modifier P2 (Small)     
  80166698 ????
                 
  Score Modifier P2 (Large)     
  8016669A ????
                 
  Infinite Time (Both Players)  
  8015F464 4E20
                 
  Infinite Keys (Both Players)  
  8015F530 0001
                 
  Infinite Credits              
  8015F480 0009