If you have a savegame slot named "_Wampa__Stompa" the code will always work on any savegame slot! The code just needs the name to have been there sometime in your Cheat Device session. I believe that something gets triggered in the Cheat Device codes or game that lets you use the codes after this has been done, so this code is the Cheat Device equivalent.

CONTROLS MUST STILL BE SET TO "Traditional", BUT THIS CODE CAN BE USED ON ANY SAVEGAME SLOT!

AT-ST In Battle of Hoth: Press Left on the Control Pad and the right C button simultaniously and press Up on the pad. Scroll through your camera angles to get to an over-the-shoulder view of an AT-ST. Use the control pad to move around and UP to fire your AT-ST turrets. Anything that gets in your way the AT-ST faces, even your snowspeeder which you can still control via the Control Stick.

Wampas In Escape From Echo Base: You must be playing on a MEDIUM or higher difficulty for the Wampas In Escape From Echo Base. Use the same code/procedure as the AT-ST. The Wampas have a similiar control scheme as well.

Snowtroopers, Imperial Guards, Robots, etc.: You can become a Snowtrooper only in Escape From Echo Base. This time you should press Right on the Control Pad and the right C Button simultaniously. Switch your camera views to find the character that you activated! Controls for these characters: Up, left, and right on the control pad to move and down to fire your blaster/robotic limbs (case depending).

Remember this: You can still control Dash Rendar via the Control Stick!