Spark when key is turned to the off position?

What if u don`t run a ballast resistor, and it does it ??
All Chrysler ECUs that I have tested do the one spark thing,at voltage collapse to the coil . I imagine all standard coils do that if the negative side is rapidly interrupted. I mean It's just like the points are being opened right? The ECU is just an amp for the pick-up, and a current breaking system; a glorified, maintenance free, set of points, that don't suffer from premature point-bounce.