HBO's docudrama "Truman" opens with a close-up of feet, clad in a rather jaunty pair of black-and-white shoes, striding decisively forward. There is no hint of hesitation or turning back. Used several times throughout the film, the image is particularly apt for Harry S. Truman, 33d President of the United States.

When he left office in 1952, Truman had a measly public approval rating of 32 percent. His only guaranteed income back in Independence, Mo., was an Army pension of $112.56 a month. Truman and his wife, Bess, would get no Secret Service protection. Those, as they say, were the days. In the years since, things have changed radically, not least Truman's reputation, which has surged upward in a good many history books. This film, adapted by Tom Rickman from David McCullough's Pulitzer Prize-winning biography, catalogues the reasons for the turnabout.

The script is too often superficial as it tries to cram the events of some 35 years into a production running just under two and a quarter hours. Momentous events are reduced to sound bites. But there are two splendid performances that manage to hold the center. As Truman, Gary Sinise ("Forrest Gump," "Apollo 13") once again demonstrates his astonishing versatility, supplemented with excellent makeup. This portrayal is a driving force of flinty honesty and salty humor. Equally impressive is Diana Scarwid as Bess, a tower of common sense who observes at one point: "If you want a friend in Washington, get a dog."

The film opens in 1948 when Truman, far behind in the polls, launches his whistle-stop Presidential campaign against the Republicans and Thomas Dewey. "Give-'em-hell Harry," on the offensive against "these gluttons of privilege," asks the voters, "How many times do you have to be hit on the head before you figure out who's hitting you?" The scene shifts to 1917, when Truman joins the Army at 33, even though, as Bess says, he's "blind as a bat." After the war, he marries Bess Wallace and opens a haberdashery with a Jewish partner, who would later be instrumental in persuading Truman to recognize the new state of Israel. By the 1930's Depression, his debts are formidable. At the age of 50, he has no money and not even his own house.

The notorious political boss Tom Pendergast (Pat Hingle) sets him on a course that will eventually, with the death of Franklin D. Roosevelt, land the Trumans in the White House. The rest is turbulent history that will include the Allied defeat of Nazi Germany. From the postwar Potsdam conference with Stalin and Churchill, Truman writes to his wife, "We are three old men walking in a graveyard planning a brave new world, and we're haggling like a bunch of old women."

And then came his decision to drop atomic bombs on Japan. It remains controversial to this day. Outstanding accomplishments: the Truman Doctrine, the Marshall Plan, desegregation of the Army. Later, during the Korean War, Truman fires an American hero, Gen. Douglas MacArthur, asking "Who's the boss, the military or the people?" He barks at one of his more diplomatic advisers, "What the hell is deniability?"

A seemingly ordinary man and his wife turn out to be quite extraordinary. Mr. Sinise and Ms. Scarwid do them full and loving justice. 'Dead Ahead' 'The Grateful Dead in Concert' WNET, tomorrow at 11:10 P.M.

Actually scheduled on PBS before the recent death of Jerry Garcia, the Grateful Dead's lead guitarist and guiding spirit, this 1980 film now takes on added poignancy. At the time, one ad for the group's 15th-anniversary tour read simply: "They're not the best at what they do. They're the only ones who do what they do."

This is the Halloween night concert that concluded the tour at, of all places, Radio City Music Hall. Passers-by were said to be experiencing contact highs. The opening acoustic set is followed by two electric sets in the nearly two-hour program. Here's a reminder that this unorthodox group was made up of exceptionally fine musicians, excelling in numbers like "Ripple" and "Don't Ease Me In," in addition to Willie Dixon's blues composition "Little Red Rooster." A treat for Deadheads and anyone else interested in special moments in rock. TRUMAN HBO, tomorrow, 8 P.M. Directed by Frank Pierson and based on the book by David McCullough. Screenplay by Tom Rickman; music by David Mansfield; Paul Elliot, director of photography. Steven Marsh, production designer; Doro Bachrach, producer. An HBO Pictures and Spring Creek production. Paula Weinstein and Anthea Sylbert, executive producers. WITH: Gary Sinise (Harry S. Truman), Diana Scarwid (Bess Truman), Richard Dysart (Henry L. Stimson), Colm Feore (Charlie Ross), James Gammon (Sam Rayburn), Tony Goldwyn (Clark Clifford), Tom Pendergast (Pat Hingle), Harris Yulin (Gen. George Marshall).

Photo: Gary Sinise as Harry S. Truman in "Truman" on HBO. (D. Stevens/HBO)