While surfing the Web, Slevinsky saw printed-paper models of arcade machines, each about the size of a Game Boy. Since he had already created an operating system for small microcontroller computers, he wondered: Why not build a functional mini arcade? He started by adapting the software to play classics such as Tetris, Space Invaders, and Breakout. Next, he needed power. Two 1.5-volt AAA batteries could support 13 hours of game play yet lacked the juice to run a tiny, five-volt LED screen. Retail power supply circuits couldn't handle the voltage conversion—they all blew up—so he eventually made his own.