VECTOR: Asteroids cheat (again)

I hate to re-post this, but I only got one reply last
time and it didn't solve the issue.  I have a customer
who REALLY wants his Asteroids to have the score cheat
that is mentioned on so many web sites as being in the
original version of the ROMs.  Unfortunately, neither
he nor I can make it work.  I've tried both original
and version 2 roms in the original hardware and even
tried it in MAME and could not seem to make it work
anywhere.  Does anyone know for sure that this cheat
exists and if so, how to go about doing it?  I
appreciate anyone's help in figuring this out.

Thanks,
-Chris