Hexcheat:
 For cheats, use the DOS utility DEBUG. First backup 
 your game to be edited, then type the following from 
 the DOS prompt:
 
 ren tt.exe cheater.cht
 debug cheater.cht
 For infinite lives, type: e eec4 90 90 90 90
 for infinite bombs, type: e e88a 90 90 90 90
 For infinite fuel,  type: e edea 90 90 90 90
 Then type: w
 q