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
Then rename CHEATER.CHT back to its previous name.