"Hyphenate" is one of Hollywood's most fashionable new nouns. It describes someone -- most often, a writer-producer -- who wears two professional hats simultaneously.

Writers-producers Richard Levinson and William Link are two of the saviest and best hyphenates in televisionland, and in "Stay Tuned" they examine the "producer" side of their hypens in fascinating and instructive detail. But they are less successful at illuminating the other side of their hyphens, at taking us into their lives as TV writers.

Levinson and Link began their joint career as writers, scribbling away during their shared boyhood in Philadelphia. They made a living from their TV scripts for almost 10 years before adding "producer" to their titles in 1960. But this decade is given short shrift in "Stay Tuned." The impression is left that almost anyone could waltz into Hollywood and strike it rich as a writer.

The pair's debut as producers, "My Sweet Charlie," became the top-rated movie that had been made for television when it was broadcast in 1970. Levinson and Link soon followed it with "Columbo" and such accomplished television films as "That Certain Summer," "The Execution of Private Slovik," "The Gun" and "They Storyteller." Each of these is the subject of a chapter in "Stay Tuned," and is distinctive enough to provide the book with a new focus for each chapter.

"My Sweet Charlie" is the springboard for a discussion of TV movies. "Columbo" serves the same purpose for TV series, and the subsequent films elicit treatises about (respectively) controversy in television, the docudrama, pressure groups and TV violence. The debuting points outlined on these subjects by Levinson and Link are reasonable but somewhat predictable. Fortunately, they are accompanied by a wealth of fresh anecdotes.

We learn that "My Sweet Charlie" -- an ode to interracial understanding -- was made with an all-white film crew and with considerable hostility between the black costar and his white colleagues, that a studio executive suggested Tina Sinatra and Harry Belafonte for the "Charlie" roles that eventually were played by Patty Duke and Al Freeman Jr., that Duke was threatened with a trumped-up drug charge while shooting the film. The authors' travels with "Charlie" are presented in the format of a daily journal -- a technique that tells us much more about a producer's routines than any how-to textbook could. A similar account of one day in a composite producer's life works well in the "Columbo" chapter, where we also follow the adventures of Peter Falk as star and would-be director.

The most amusing and revealing story in the book relates a confrontation between the authors and two academics who were called in by ABC to make sure all bases were covered in the network's presentation of "That Certain Summer," the authors' landmark drama about a homosexual father. The professional watchdogs applauded the "oral sex symbolism . . . and the clitoral implications" of the script -- features the authors did not realize they had written. But the professors also strongly urged the addition of a homophobic character as a nod toward "balance." For the most part, Levinson and Link resisted. But they did add a line in which the father told his son that he would not have chosen homesexuality had he been given a choice -- a concession that Levinson and Link later deeply regretted. This is one of the rare passages in "Stay Tuned" that bears on writers' concerns as much as producers'.

The authors are not afraid to admit mistakes and naivete. But they also concentrate on their worthiest productions -- which are inherently less characteristic of commercial television than, say, "Mannix," one of their early creations. Joe Mannix, viewers may recall, was not exactly a flower child. Yet Levinson and Link do not connect him to their discussion of TV violence. Similarly, they mention only once "a dreadful series called 'Jerico,'" which they co-created. Apparently they have even forgotten how to spell it, according to other sources that list it as "Jericho."

Despite the juiciness of the stories, a dry and abstract tone occasionally nestles over the narrative. It is attributable to the fact that Levinson and Link speak as one voice. There isn't a hint of disagreement between them, and there is no explanation of how they divide their labor. Either they are creative Siamese twins or they are clamming up about their differences. Because such differences might very will help them do their jobs, especially in the screenwriting process, the absence of any commentary on the subject is disappointing.

Still, as a producers' chronicle, "Stay Tuned" will entertain TV watchers of all stripes and mesmerize potential producers. On the basis of the remarkable programs they have created (most recently "Crisis at Central High"), we should be grateful that Levinson and Link seem inseparable. It's questionable whether either of them alone -- or anyone -- could hack his way through the video jungle described in "Stay Tuned" and still mangage to produce such superlative television.