Hewlett-Packard said it will purchase Voodoo, a producer of high-end computers favored by gamers, for an undisclosed sum–as well as create a new unit for gaming–marking the firm’s first notable effort to compete in the profitable PC-gaming space. Voodoo, of Calgary, Alberta, makes PCs with high-performance processors and top-of-the-line graphics cards, making them ideal for running computer video games.