The machine does not allow modifications to its ROM (because it has an O in the middle), but the team was able to use a technique called return-oriented programming to modify how the machine executes existing code, taking the bits they want and, ultimately, devising a way to re-program its behavior by simply inserting a cartridge into a slot -- presumably after blowing on it for good luck.

ENGADGET: Hang your head, Sequoia e-voting machine; you've been hacked again