Department 84 of the Los Angeles County civil courthouse:

On the left side of the courtroom sits Harry Perzigian, a heavyset man in an ill-fitting suit. He is suing the person on the right side of the room, another heavyset man in an ill-fitting suit, but with a familiar fleshy face: Carroll O'Connor, better known as Archie Bunker.

Perzigian, 41, was convicted last year of possessing cocaine and furnishing it to O'Connor's 32-year-old son, Hugh. Hugh O'Connor, an actor and an addict, shot himself to death on March 28, 1995. It was his wedding anniversary. Afterward, his father called Perzigian "a partner in murder" on national television. Perzigian is now suing O'Connor for $10 million, accusing him of slander and causing emotional distress.

But O'Connor, 72, seems determined to use the trial for his own purposes. Today the white-haired actor admitted on the witness stand that he was glad Perzigian sued him.

"I invited him to sue me, not ever thinking he would, but I was happy when he did. He gave me the further opportunity. He exposed himself," he said.

In emotional testimony, O'Connor described how he called Harry Perzigian, his son's friend, a week before the suicide and warned him to stop giving him cocaine.

"Don't send my son Hugh any more drugs or I'm coming after you," O'Connor said he told the drug supplier, his voice rasping and slow. O'Connor said he warned Perzigian he would "use every legal means at my disposal to come after him."

Wiping an eye, O'Connor said he hired a private detective and went to police with information about Perzigian, whom he believed to be providing his son with drugs.

In testimony today, O'Connor described how he desperately tried to curb his son's drug use -- even denouncing Hugh to the police -- heading family interventions to get him into drug rehab programs. And he said he had no regrets over vilifying Perzigian.

"All his best friends except one came to see me and tell me he was sorry," said O'Connor, glaring at Perzigian. "I never saw that best friend till I saw him in court. So I forgave the others. They didn't know what they were doing. A pusher knows what he's doing."

O'Connor has become an anti-drug crusader with a vengeance in the wake of his son's death. He has recorded public service announcements, joined the Partnership for a Drug-Free America and gone to Washington to push for legislation that would allow police to investigate the tax records of suspected drug dealers. The actor was instrumental in getting laws named for his son passed in Florida and California that give individuals the right to sue drug dealers for civil damages.

Perzigian, though getting his day in court, could hardly have looked worse. Few in the media showed up for his testimony last week, in which the plaintiff -- previously a struggling songwriter and now selling vacation packages for a travel company -- said he feared that some crazed Archie Bunker fan might come after him. He also said he never sold drugs to Hugh O'Connor, that they would get high together and share the cost of the drugs they used. He testified that 24 checks written to him by Hugh O'Connor were for stereo equipment. But defense lawyers succeeded in introducing an unflattering photograph of Perzigian taken at the jail where he was booked on drug-dealing charges, with a ponytail, scruffy beard and disheveled shirt open to the waist. More bad news: Last Wednesday Perzigian was arrested at the end of the court day for driving under the influence, which would be a violation of his earlier sentence.

Then last Friday all the O'Connors -- father Carroll, mother Nancy, wife Angela and uncle Garrett, a psychiatrist -- testified about the depths of addiction into which Hugh had fallen. Sobbing, Angela O'Connor testified that her husband was in a drug-induced fog just before his death, hallucinating and severely paranoid. She said he would go to Perzigian's apartment and return high, and that the checks her husband wrote to Perzigian during his drug binges could not have been for stereo equipment, since he owned $25,000 worth of top-of-the-line equipment already.

There are two ways of looking at this case. One involves the underdog facing down a rich and powerful celebrity.

"What it's really about is not about publicity, not about money," says Perzigian's lawyer Allan Sigel, with some earnestness. "It's about Carroll O'Connor telling the world that Harry Perzigian is responsible for murder. . . . If they give {Perzigian} $1 or $10 million, he basically got to tell his side."

The problem is, of course, that in this case the underdog has a criminal record.

"He's angry and greedy," says O'Connor lawyer Ron Silverman. "This goes in the category of outrageous lawsuits as far as we're concerned. To perpetuate the agony for the O'Connor family, to have them relive a nightmare of huge proportions. . . . It is unmitigated gall to suggest that the O'Connors have damaged him and may owe him money."

Today defense lawyers showed a tape from "Geraldo Live," part of the basis for Perzigian's accusation of slander. First came an argument over the tape, since the talk show identified Perzigian as a "convicted drug dealer," which the plaintiff's lawyer deemed "arguable." Instead, Perzigian was to be considered a "drug furnisher." When the segment -- edited -- finally aired, the offending comment by O'Connor went as follows: "This guy is a lawbreaker who caused the death of a helpless addict." Geraldo Rivera, making sympathetic noises, called the actor "a courageous and wonderful fellow."

O'Connor has not been idle since the end of "All in the Family" and the show that succeeded it in 1979, "Archie Bunker's Place." He was first the star, then a writer and producer of the TV series "In the Heat of the Night" for eight years; his son was a cast member. He has written a play, "A Certain Labor Day," that will premiere in Dallas in September with himself and George C. Scott. He's also working on an autobiography.

If a potential nuisance, the lawsuit, which is expected to go to the jury on Wednesday, has been a new platform for O'Connor to bring his issues to the public's attention.

He said later: "I wanted and still want the public, if they know the name and identity of a pusher, to go to the police and reveal what they know. I wanted to encourage people to do that. I wanted to use every opportunity, and Harry had given me the opportunity, to call to the attention of the public to his cocaine problem. The danger it was. The way it can end in the loss of someone very dear." CAPTION: Carroll O'Connor: Playing out a family drama in public.