A universal method and system for downloading game software to ROM based legacy gaming machines, activating selected games and providing new services. The method includes a ROM emulator for replacing the game program image and an NVRAM emulator for swapping the game context and critical meters accordingly. The method includes detection of the state of the current game activity such as to activate a new game only at an authorized time, when no player is playing a game or is carded-in for example. The system includes emulation of the original peripherals fitted to the legacy gaming machine such as to offer extended functionality and services. The universal method and system therefore prolongs the useful life of legacy machines which otherwise would be prematurely retired.