Today’s News, Tomorrow’s Television : One more ‘Young Rider’ signs on; witness the birth of a new Nickelodeon show; watch out for Tim and Daphne Reid

SERIES

Don Franklin has been set to join the ensemble cast of “The Young Riders,” the ABC series about the young men who rode for the Pony Express in the 1860s and which recently won a Western Heritage Award. Franklin, a regular on “Knightwatch,” will play Noah Dixon, a freeborn black liberally raised by his parents on the family’s prosperous Texas ranch, where he was educated by white teachers.

“Tim and Daphne,” a one-hour syndicated talk program starring the husband-and-wife acting duo of Tim and Daphne Maxwell Reid, will debut in September on King World Productions’ Research and Development Network. If the show is popular on the test network’s 21 cable stations, it probably will go into production this year for national syndication.

Nickelodeon will explore the early days of television, circa 1950, to witness the creation of a mythical comedy-variety show in “The Sam Arnold Show.” The new series, from “The Days and Nights of Molly Dodd” producer Karen Stevens, is scheduled to premiere in January.

English college mates and comedy team Stephen Fry and Hugh Laurie will co-star in a new TV edition of P.G. Wodehouse’s “Jeeves and Wooster,” airing on PBS beginning Nov. 11. In addition to the offbeat five-hour comedy series on PBS, Fry and Laurie’s BBC series “A Bit of Fry and Laurie” will be cablecast on the Bravo network starting Sept. 22. MINISERIES

David McCallum plays a world-famous symphony conductor who becomes the target of a hate campaign by his ex-wife, Diana Rigg, in “Mother Love,” a four-part BBC production airing as a PBS’ “Mystery!” presentation Oct. 25. For her performance, “Mystery” host Rigg won a BAFTA award in England, the British equivalent of a combined Emmy and Oscar. MOVIES

Principal photography has begun in Vancouver, British Columbia, on “Deadly Intentions ... Again?,” an ABC movie starring Joanna Kerns and Harry Hamlin based on the ABC miniseries “Deadly Intentions.” The two-hour thriller, about a paroled man who was jailed for plotting the murder of his first wife, is scheduled to air during the 1990-91 season.

Three NBC movies planned for the 1990-91 season: Candace Cameron, Chad Allen, Josh Saviano and Danica McKellar will star in “Camp Cucamonga,” a madcap comedy about a co-ed summer camp. In the crime drama “Cops and Robbers,” Ray Sharkey is involved in the largest bank robbery in U.S. history, which was committed by cops. “Deadly Medicine” is the true story of a pediatrician who suspects that her best friend, a trustworthy nurse, may be a baby killer.

John Lithgow recently returned from Kenya, where he starred as an adventure writer who fights to stop the senseless slaughter of African elephants for profit in “The Last Elephant”--formerly titled “The Ivory Hunters”--a TNT movie premiering Aug. 20. The film co-stars Isabella Rossellini as an environmentalist and James Earl Jones as an African police inspector. SPORTS

Prime Ticket Network will produce “A Midsummer Night’s Magic,” Magic Johnson’s annual all-star basketball game to benefit the United Negro College Fund, for NBC. Michael Jordan, Isiah Thomas, Dominique Wilkins, Karl Malone, Spud Webb, Reggie Miller, Danny Manning and Kurt Rambis are all scheduled to play in the goodwill event, which airs Aug. 11 on NBC. EDUCATION

CNBC has made its “Smart Series” brochures, first diitributed only at consumer conventions, available to viewers as part of a consumer-education drive. The first brochure, “Send Help,” contains step-by-step tips on what to do in the event of an automobile emergency. Viewers can obtain brochures bys bytacting their local cable operators.