Although its more than 622 years away by their count, Iranians must deal with millennium issues in about 32 days. Iran's 20-year-old breach with the United States has come back to haunt it in the form of the Y2K computer bug, an obscure legacy of western technological domination. Islamic Iran's unique solar calendar may read year 1378, but it must grapple nonetheless with the feared after-effects of a Western computer short-cut timed to the start of the next Christian millennium. Most at risk, say Iranian engineers, is the large installed base of aging U.S. technology, largely dating back to before the 1979 Islamic Revolution. Much of it involves so-called embedded systems, monitors and controllers largely hidden from view and long-forgotten.