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:

 ren e:\fire.exe cheater.cht
 debug e:\cheater.cht
 For invulnerability, type: e 30cb eb 8
 For infinate magic, type: e 201a 90 90 90 90 90 90
 w
 q

 Then rename CHEATER.CHT back to its previous name.