The tank uses  (2) four-way joysticks. Like battlezone, it has the normal movements for a dual stick tank game.  However it has (2) more special moves. Pushing both joysticks left to left  and right to right at the same time causes the tank to rear up (do a "wheellie"). In this position, you can fire a nuclear blast. You return to normal play by pressing the sticks together or just by waiting for it to disengage (just a few moments). The second special move is executed if both joysticks are pushed to the right or left, the tank rolls in that direction ,and allows firing.

Thanks Mitch for these pointers