WORTH NOTING ON TV

SATURDAY US Open Golf (ABC, 1:30-6 p.m., ET): All 18 holes of Round 3 in the 89th version of this durable event are covered live from the Oak Hill Country Club in Rochester, N.Y., by Jim McKay and others, with an overview by Jack Nicklaus. SUNDAY US Open Golf (ABC, 2-6:30 p.m., ET): The event ends with live coverage of Round 4.

MONDAY Firing Line Special Debate (PBS, 9-11 p.m.): ``Resolved: The Cold War Is Not Coming to an End.'' You could scarcely choose more politically antagonistic sides than the ones debating this question: William F. Buckley, Jr. and John Tower vs. George McGovern and Gary Hart.

TUESDAY Seaway (PBS, 10-11 p.m.): When the St. Lawrence River and the Great Lakes were linked by a seaway 30 years ago, it was supposed to become a commercial marvel - one of the world's greatest shipping centers. Today, it's considered something of a flop, with less than half its capacity used. A TV crew traveled the seaway's whole length - Duluth, Minn., to the Atlantic - to see how this controversial system operates and to shoot some splendid scenery in the bargain.

WEDNESDAY Timeline (PBS, 8:30-9 p.m.): In the old ``You Are There'' tradition of ``covering'' history - a potentially hokey but often fascinating production device - ``Vikings'' takes a TV news crew back to 1066 and all that, as William the Conqueror's invasion ends the very short-lived Saxon triumph after the Battle of Stamford Bridge in Britain.

Please check local listings for all programs, especially on PBS.