The AMS PDA is a mobile device developed by the AMS agency for its members. Introduced in The House of the Dead 4, it would be put to use again in The House of the Dead 4: Special and House of the Dead: Scarlet Dawn.
The PDA is depicted as a silver-and-black-colored device with numerous buttons, a joystick, and what appears to be a camera lens on the top right corner. It is equipped with a blinking red light when threats are detected. The word "AMS" is found below the screen.While escaping the creature-infested European AMS headquarters, agent James Taylor introduced the PDA to newcomer Kate Green when they encounter a fork in their path. The PDA identified the left path as safer than the right; it is ultimately the player's decision on where to go.The agents later encountered Justice, a massive four-armed creature in the AMS sewers. The PDA scanned Justice (and all further bosses), marking body parts as either "No Damage" or "Weak Point"; the latter, in this case, was Justice's tongue.
Finding the city in ruins, James received a message on his PDA from Caleb Goldman, the deceased financier of the DBR Corporation and Dr. Curien's financier. Goldman revealed his responsibility for the outbreak and that a nuclear missile launch would commence in an hour.
James and Kate raced to Goldman's headquarters, managing to halt the launch but faced with Goldman's final creation: The World. The PDA listed its weakpoint as "UNKNOWN". Realizing that the World kept growing when killed, James set his PDA to self-destruct and sacrificed himself in the resulting explosion, finally killing the creature.In Special, the PDA functions the same. As with the World, it couldn't identify the Magician's weakpoints (though it's most likely from Kate's PDA, since G's would easily recognize the Magician's weakpoint).
The PDA's abilities are relatively unchanged. Its appearance is reminiscent of modern smartphones, featuring a large touchscreen. Kate and partner Ryan Taylor also have red and black cases, respectively. When encountering a revived Chariot, Kate uses the PDA's camera to identify its weakpoint. The PDA can also be used to unlock doors.