Purnel's Auto-Reverse Defence

Purnel's Auto-Reverse Defence is a defence system from the Marvel Comics portion of the Generation 1 continuity family.

Purnel's Auto-Reverse Defence (abbreviated to PARD), invented by Professor Purnel, makes Decepticons nice and Autobots nasty.

PARD can reverse computer-controlled instructions to missiles the world over! Any weapons launched at allied countries returned to sender! The merest touch and the power of PARD floors the entire world in seconds! Of course, until properly targetted and programmed, it will not affect man-made technology!Professor Purnel, "To a Power Unknown!"

Fiction

Marvel comics continuity

Professor Purnel had been developing PARD at a secret research facility in the United Kingdom for at least five years before its first successful test. Intended to direct missiles back at their senders, he ensured that the test signal would not affect man-made technology though it interfered with the systems of the two warring factions of earthbound Cybertronians instead, causing the Autobots to attack humans and the Decepticons to apologise and try to fix things.

As the Transformers attempted to track down the source of the signal, Purnel uncovered a rat in his own house—his assistant Zeke Heilmann was a spy who intended to steal PARD. Heilmann floored Purnel with a stool and set fire to the control room, stealing the core of PARD and a nearby Porsche to escape. Unfortunately for Heilmann, Starscream caught up with them, and in the ensuing battle both PARD and Heilmann were destroyed by one of Jazz's heat-seeking missiles. To a Power Unknown!