Invincibility:
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 16017,44 
Set number of lives:
Load or reset the game, then execute the following BASIC command before running or restarting the program. Note: X represents the desired number of lives. 

POKE 10430,X 
Set number of lives (alternate):
Load or reset the game, then execute the following BASIC command before running or restarting the program. Note: X represents the desired number of lives. 

POKE 10435,X