SUNDAY `Common Ground' (CBS, 9-11 p.m.): First of a two-part drama based on the school desegregation struggles of the '60s and '70s - fertile ground for past TV scripts. Jane Curtain, Richard Thomas, and C.C.H. Pounder star in a story about three Boston families with markedly different reactions to an explosive period in that city's history. (See preview coming in this section on Friday). `The Old Man and The Sea' (NBC, 9-11 p.m.): Adaptation of Ernest Hemingway's short, penetrating novel about a stubborn fisherman's ``Moby Dick''-like battle with a huge fish - and maybe with himself. As the old man, Anthony Quinn plays an epic and merciless role that Spencer Tracy once valiantly grappled with. MONDAY The Oscars (ABC, 9 p.m. to conclusion): ``Driving Miss Daisy'' and ``Born on the Fourth of July'' were the top vote-getters as nominees for the 62nd Annual Academy Awards, airing live from the Los Angeles Music Center. Lots of foreign films are contenders on this year's edition of a show considered by many - despite self-congratulatory excesses - the most electric of its genre. `Firing Line' special (PBS, 9-11 p.m.): Sometimes debates can make for strange ideological bedfellows. Joining George McGovern to argue on the pro side of ``Resolved: Drugs Should Be Legalized'' is William F. Buckley, Jr., a leading voice among a somewhat surprising number of conservatives who favor legalization. TUESDAY `Common Ground' (CBS, 9-11 p.m.): Part 2 (final).