MICKEY ON GUARD: The Disney empire isn't entirely ignoring the frenzied rush of other media giants into new technologies. . . . Walt Disney Computer Software Inc. stands to benefit from the growing home video and computer game industry. But Disney moguls say the studio is more interested in telling wonderful tales than in finding new ways to show them (Valley Business, page 10). Some say that's because Disney hasn't done very well in this area--especially given its hold on the American psyche.