For infinite lives in this game, use the DOS utility
DEBUG. First backup the game to be edited, then type
the following from the DOS prompt:

ren main.dat cheater.cht
debug
a 100
mov dx,es
add dx,1000
mov es,dx 

g 108
r ip 100
ncheater.cht
l
e es:11aa 0
e es:11d1 0
Then type: w
q

Then rename CHEATER.CHT back to its previous name.