I was watching an old movie ("The Five Pennies"), and at one point while on stage surrounded by audio gear Danny Kaye reaches down and takes a plug out of a receptacle on a box clearly labeled "110V AC" and plugs into into another labeled "220V DC," with the expected flash and bang.
Is this a case of Hollywood taking license for dramatic effect, or were the same recepts. used for 110 and 220 at one time? Just when did the various NEMA plug configuration in use today originate?
