For cheats in this game, use the DOS utility DEBUG. First backup your
 game to be edited, then type the following from the DOS prompt:
 
 For the CGA version of this game, type:
 ren ckcga.exe cheater.cht
 debug cheater.cht
 For Invulnerability, type:
 e 1a0a 0
 
 For infinite lives, type:
 e 1bc9 0
 e 12d5 eb
 Then type:
 w
 q
 
 For the EGA version of this game, type:
 ren ckega.exe cheater.cht
 debug cheater.cht
 For invulnerability, type:
 e 1a2c 0
 
 For infinite lives, type:
 e 1bc9 0
 e 12d5 eb
 Then type:
 w
 q
 
 For the [MGA] (VGA? MCGA?) version of this game, type:
 ren ckmga.exe cheater.cht
 debug cheater.cht
 For invulnerability, type:
 e 1a0a 0
 
 For infinite lives, type:
 e 1ba7 0
 e 12d1 eb
 Then type:
 w
 q
 
 Then rename CHEATER.CHT back to its previous name.