TV HIGHLIGHTS

SUNDAY Nova (PBS, 8-9 p.m., check local listings for premiere and repeats) in season premiere, "Computers, Spies and Private Lives." MONDAY

Great Performances (PBS, 8-10:30 p.m.) Premieres with performance of composer-lebrettist Carlisle Floyd's "Willie Stark," a full-scale production of the pop opera, allegedly about Huey Long, featuring baritone Timothy Nolen and staged by Broadway's Hal Prince. As much a spectacle as it is an musical drama, despite fine performances by all the leads, I found it difficult to understand much of the action without libretto in hand. But all in all, this Houston Grand Opera/Kennedy Center production is landmark TV. MONDAY THROUGH FRIDAY

Two innovative daily CBS news shows premiere this week: Morning (7:30-9 a.m.) , revised version of the CBS morning news, with Diane Sawyer joining Charles Kuralt as co-anchor. And Up to the Minute (4-4:30 p.m., check local listings) this week featuring Harry Reasoner as moderator in a study of how feminism has affected men. Too much in a similar vein -- one day would have been enough. Next week Mike Wallace moderates "Morality of the New Right," with Morley Safer due to follow with a week of "Non-sexist Child Rearing."