Retro : Post-Mod Times : CLARENCE WILLIAMS III CO-STARS IN FEATURE AND HBO FILM

Before he became famous as hippie cop Link Hayes on the 1968-73 ABC series “The Mod Squad,” Clarence Williams III was a well-respected stage actor.

“They brought me out (from New York) to do ‘Mod Squad,’ ” recalls Williams, who starred in the trend-setting show with Peggy Lipton, Michael Cole and Tige Andrews.

“I did so much enjoy doing it. I enjoyed working with Tige, Peg and Michael Cole,” he says.

After “Mod Squad” left the airwaves, Williams says, he was invited by a regional theater in Massachusetts to re-create a role he had originated on Broadway before the series. The play was “Slow Dance on the Killing Ground,” and Williams had been nominated for a Tony for his part.

“One of the reviewers in Boston said how wonderful my work had grown since ‘Mod Squad,’ ” Williams says with a chuckle. “Obviously, the writer didn’t realize I had created the part on Broadway before I did ‘Mod Squad.’ ”

Williams, who was an artist-in-residence at Brandeis University, didn’t realize the impact a TV series had on viewers until his first hiatus on “Mod Squad.”

“One of the staggering things is that if you work in TV, and particularly in a series, that first season you’re at the studio all day long, working 14 and 15 hours a day. But when you hit the hiatus period and you go off to wherever you decide to go for relaxation, all of a sudden everybody knows you.”

Though Williams has never done another series, he’s kept busy in TV, films and theater, most notably starring in 1980 with Maggie Smith on Broadway in Tom Stoppard’s “Night and Day” and playing Prince’s dad in 1984’s “Purple Rain.”

Currently, Williams co-stars with Wesley Snipes in the movie “Sugar Hill,” and is featured in the upcoming HBO film “Against the Wall,” which dramatizes the 1971 inmate rebellion at New York’s Attica Correctional Facility.

In “Sugar Hill,” Williams plays the drug-addicted father of Snipes and Michael Wright. The actor was drawn to the role because he thought it was a brilliant part.

“I wanted to have the opportunity to play it,” Williams explains. The film, he adds, “also was about a family’s struggle. There’s no glamour, no Armani suits and everybody walking around being beautiful. (Drugs are) a road to hell and destruction.”

The family’s destruction, Williams says, also is a metaphor for the destruction of Harlem, where the film is set. “I don’t know if you have been to New York or Harlem, but certain areas of it look like Dresden after the bombings. This destruction has happened to Sugar Hill, this place in Harlem where successful African Americans lived (during the ‘50s). There was a tremendous creative renaissance there.”

In “Against The Wall,” which is directed by John Frankenheimer, Williams gives a chilling performance as Chaka, a sociopathic ringleader of the riot.

Williams doesn’t know if Chaka was an actual person. The film, he says, is based on the real experiences of a young prison guard, Michael Smith (Kyle MacLachlan), who survived the uprising. Twenty-nine inmates and 10 guards were killed after government forces stormed the facility.

“I followed my work through the prism of his eyes,” Williams says. “I assume Chaka is an amalgam of people. There were 12,000 inmates at Attica at that time. Obviously, we didn’t travel through all of that.”

“Sugar Hill” is currently playing in movie theaters; “Against the Wall” premieres March 26 at 8 p.m. on HBO.