WORTH NOTING ON TV

FRIDAY Homicide Squad (NBC, 10-11 p.m.): Tom Brokaw anchors an unusually candid and personal look at the grisly business of solving a murder case, as he unfolds the lives and work of detectives at the Houston Police department. The action is gritty, dramatic, and unstaged, a window on a big national crime problem. SUNDAY The Tragedy of Flight 103 (HBO, 9-10:30 p.m.): Even if it isn't quite ``The Inside Story'' claimed by its subtitle, this fact-based drama - starring Ned Beatty, Peter Boyle - does probe deeply into the much-debated 1988 terrorist bombing of an airplane over Scotland. Intensive research went into the production - reflected in the tough policy questions raised by the script about terrorism and public safety.

MONDAY 1990 Billboard Music Awards (Fox, 8-10 p.m.): From rock to country, the top recording acts of the year - picked by pop music's industry magazine - are saluted by an impressive list of performers. Yes, it's another awards show, but with this difference: It's all based on the sales charts maintained by Billboard - so the choices, in effect, are your own.

The Dreamer of Oz (NBC, 9-11 p.m.): ``The L. Frank Baum Story'' - though true - is fully as exotic as the fantasy land author Baum created in his enduring tales: A man who failed at many ventures, in 1900 he gambled his small remaining stake on one strange children's book - ``The Wonderful Wizard of Oz.'' John Ritter stars as Baum in this family drama about Baum's life and unique imagination.

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