Secret Decoder Wheel
To fly from location to location, the rocket pack must be filled with a very specific amount of fuel. Too much or too little will cause the hero to overshoot or fall short of the target, and as a result plunge to his death. The player could determine the correct amount of fuel for a starting/destination pair using this "secret decoder wheel", included with the original game package. This element of the game was actually a form of copy protection. The idea was that since the wheel was included with the game and couldn't easily be duplicated, only legitimate purchasers of the game could successfully use the game.
Because the wheel needed to be used for every trip the Ranger made, it got heavy use. As a result, the wheel often fell apart (the front part of the wheel became separated from the back) after several games. The wheels could still be used, but it was more difficult when they weren't connected. Therefore, some users constructed tables that included all of the codes needed to travel from one location to another. These tables eventually made their way to bulletin board systems and (later) the Internet and used as a tool for pirated versions of the game.
Version
This is scan of Amiga - PAL version (UK release) of Secret Decoder Wheel. There is a US version, but the numbers are much different than the UK release.
Thanks to ~ Danny Albrecht ~ for codewheel source scans.
The Game
Rocket Ranger is a 1988 action adventure developed and published by Cinemaware. The game's setting is based in the World War II era, allowing the player to control a US Army scientist and setting out to stop Nazi Germany from winning the war. The Rocket Ranger moniker stems from the Rocket Pack the player uses over the course of the game. Like many Cinemaware games, Rocket Ranger draws its inspiration from Hollywood, and likely The Rocketeer comics. This title pays homage to the many 1950s sci-fi serials, using the look and feel of the serials, including action-packed cut-scenes and an art treatment loyal to the futuristic visions of that era. It also features the cliché elements of that era, including a dashing, courageous hero and a beautiful, voluptuous damsel in distress in need of rescue.