Does the priority antenna direct a line straight toward the main board before sweeping clockwise?
The antenna can face in any direction. Here's a crappy image I tossed together in paint:


Assuming the antenna is facing the direction of the arrow priority would be resolved in the order indicated.

That said, I strongly suggest you ignore the priority rules (except in case of resolving ties) and resolve priority in the order: Power ups -> Move 3 -> Move 2 -> Move 1 -> Backup -> Turns. Agains resolve at the priority of the move they are copying. This will make your game go much faster, and won't appreciably change the game play... If you program spam cards, resolve them first, then take your turn as normal (this includes virus!)