Pause the game and type "JUNKYARD" and press 'RETURN'. You are now invincible. Use any of the following keys:
'RETURN'--toggles cheat mode on and off
'D'------------make all locks disappear
'Z'---------------------Warp to level 3
'X'---------------------Warp to level 4
'C'---------------------Warp to level 5
'V'---------------------Warp to level 6
'B'---------------------Warp to level 7
'N'---------------------Warp to level 8
'M'---------------------Warp to level 9
'F7'--Increase size of screen and speed
'F10'-------------Make the border flash