Doom Cheats...
All Items on Map
Enter the code 'LEFT SHIFT, RIGHT SHIFT, RIGHT SHIFT, RIGHT, UP, B, B, LEFT, RIGHT SHIFT' on the map screen.
All Weapons + 500 Ammo
Enter the code 'A, LEFT, A, B, A, RIGHT, A, C, A' on the map screen.
God Mode
Enter the code 'UP, RIGHT, A, B, A, DOWN, A, LEFT SHIFT, LEFT SHIFT' on the map screen.
Invincibility
Enter the code 'Up, Right, A, B, A, Down, A, LS(2)' on the map screen.
Larger Screen
Enter the code 'UP, RIGHT, LEFT SHIFT, UP, RIGHT, RIGHT, RIGHT SHIFT, A, LEFT' at the map.
Note: reboot to change the screen size.
Level select
Enter the code 'LEFT SHIFT, UP, C, C, RIGHT SHIFT, DOWN, A, LEFT, LEFT' at the map screen.
Note: reboot to select any level.
Reveal entire Map
Enter the code 'LEFT SHIFT, RIGHT SHIFT, RIGHT SHIFT, A, LEFT, LEFT, UP, A, C' on the map screen.
Walls on Map
Enter the code 'LS, RS(2), A, Left(2), Up, A, C' on the map screen.
All Items on Map...