It says something about the first two "Godfather" movies that even the hype for "The Godfather, Part III" has its fascinating side. The proof of this particular pudding is a Home Box Office special called "The Godfather Family: A Look Inside," which premieres tonight at 7.

The special will be repeated several times this month, including a playdate on Christmas Day, when "Godfather III" is set to open in theaters. HBO will also be showing the first two films: "The Godfather" on Dec. 18 at 8 p.m., and "Part II," Dec. 19 at 8.

Perhaps a word of protest should be sounded whenever Hollywood gets away with passing off publicity as entertainment. On Sunday night, for example, NBC is offering a "special" celebrating the less-than-legendary partnership of actor Robert Redford and director Sydney Pollack, a one-hour ad for their forthcoming film "Havana."

If HBO's "Godfather" documentary has the same craven aims, it nevertheless earns its hour upon the screen. The program includes such priceless, previously unseen footage as Marlon Brando's wardrobe test, with the actor experimenting with some of the makeup tricks he would later use as Vito Corleone.

We also get to see Al Pacino's screen test for the role of Michael Corleone, a part that director Francis Ford Coppola says Paramount executives did not want him to play. As a result, Coppola had to test actors like Martin Sheen as well, and one can see even from a glimpse of Sheen's screen test what a disaster that would have been. James Caan, who got the part of Sonny, also tested for Michael.

Robert De Niro, who didn't appear until the second "Godfather" film (as the young Vito -- more casting to which Coppola says Paramount objected), auditioned for the role of Sonny in the first film. His screen test is amusingly explosive, his long hair tied in a bun at the back of his head.

Actors suggested by Paramount, Coppola says, included Redford and Ryan O'Neal. Imagine.

The "Godfather" films have achieved such mythic stature that virtually all the preserved marginalia in "Godfather Family" seems riveting. Coppola recalls, as he has before, how skeptical Paramount was about the project, how each day Coppola thought he would be fired, how he almost had to smuggle Brando into the film over executive misgivings and objections.

Paramount produced this hour; is it surprising Coppola is allowed to be so critical? No, because the company regime has changed since "The Godfather" was filmed. Current Paramount Chairman Frank Mancuso, interviewed briefly, comes off like a pillar of wisdom in comparison with the unseen and unnamed executives Coppola talks about.

The films represent a multigenerational saga in more ways than one. Sofia Coppola, the director's daughter, was the baby in the first film's now-classic baptism scene. Now a young woman, she plays a role in the third film.

It's dismaying, considering the richness and brilliance of the first two films, how shallow Coppola sounds at times when discussing them or when directing Pacino in scenes for the new one; the old boy rattles off one hoary banality after another. Maybe this has something to do with his inscrutable technique.

He long rejected the idea of making a third film, Coppola says, unless it were to be something along the lines of "Abbott and Costello Meet the Godfather." Advance reports about the new film are mixed, but even if it's only half as good as the first two, it could still be great.

Among others interviewed for this report are Coppola's sister, Talia Shire ("We're the most dangerous act in town," she says of the Coppolas); Coppola's wife, Eleanor (who compares herself to the WASPy Kay played by Diane Keaton); Andy Garcia, who stars in "Part III" with Pacino and Keaton; the great cinematographer Gordon Willis; and Caan and De Niro, who both tell engaging tales of life behind the scenes.

Director and editor Jeff Werner seriously overdid reprises of violent scenes from the first two films in his documentary; he seems determined to include every bloody murder. But for the most part, "Godfather Family" plays like a very glorified home movie, one in which many members of the clan have achieved the status of royalty.