TODAY

Tomorrow. Tom Snyder is the host for a six-hour Fourth of July celebration. Even if you've had your fill of Snyder and of Bicentennial tripe, you might stay tuned for a bit of local color: in addition to interviews with Jimmy Breslin, Las Vegas tourists and Wernher von Braun, Snyder will talk with "young people at Harvard." Ch. 4, 1 a.m.

FRIDAY

Yellow Submarine[1968]. It's hard to get very excited about things when the Dodgers are eight games out and Tony C. wallows in Pawtucket, but I suppose this Erich Segal-scripted, 7-up commercial of a Beatles movie is worth seeing. Ch. 7, 8 p.m. Color, 1 1/2 hours.

SATURDAY

Tennis From Wimbledon. Women's singles at 12:30 p.m., men's singles at 5 p.m. Ch. 4. Tape delay.

The Bridge of Frankenstein [1935]. The original, with Boris Karloff. Ch. 5, 3:30 p.m. B/W, 1 1/2 hours.

David Susskind. Tonight Susskind interviews a trained chimpanzee in a program called "A Conversation With a Chimp." Susskind and a chimp: there's your straight line, now play with it. Ch. 2. 10 p.m., 2 hours.

SUNDAY

The Big Sleep [1946]. Humphrey Bogart, Lauren Bacall, Southern California, Philip Marlowe, Raymond Chandler. Good but very confusing. Ch. 56, 6:30 p.m. B/W, 2 hours.

Jerry Williams vs. Avl Nelson. "The first" says the WCVB blurb, "in a series of exciting debates between Boston's most outstanding talkmasters." (Williams is a burly, middle-aged, old-school liberal; Nelson is a young, super ambitious libertarian.) But this will probably dissolve into a classic more-heat-than-light confrontation, especially considering the not very narrow topic of tonight's debate: "Does the 'System' work?" Ch. 5, 11 p.m. 1 hour.