Recently, Aaron Sorkin got a note from HBO entertainment president Sue Naegle about a passage he’d written in a script for his new series, The Newsroom, a workplace dramedy set at a fictional cable-news show and premiering on the network in June. The comment, which was not approving, got his attention. It concerned a moment at the end of Episode Four. As Sorkin explained the scene to me, “Everybody is having a petty argument about something, and it’s a Saturday, and—”

And then a certain actual national tragedy (the show is set in the very recent past against real news events) takes place. Suddenly, “they have to scramble to get on the air,” Sorkin said. “And I called for source music.”

He meant an already recorded song, rather than part of the score—something to play over a scene to heighten its emotion. Naegle had objected. “Sue’s note was ‘They do this a lot at the end of Grey’s Anatomy,’ ” Sorkin told me. “I wrote back saying, ‘You know what? I’ve never seen Grey’s Anatomy, but I’m sure they didn’t invent this thing.’ Sue said, ‘It’s just an observation. Just letting you know that HBO has to vigorously distinguish itself from network television.’ ”

Aaron Sorkin has done network television—quite a bit of it. There was his beloved, multiple-award-winning The West Wing, which ran on NBC from 1999 to 2006; he also created Sports Night, a critically acclaimed but ratings-challenged satire of an ESPN-like all-sports network that ran on ABC from 1998 to 2000; and Studio 60 on the Sunset Strip, which explored the backstage dynamics at an L.A.-based Saturday Night Live-type show and sputtered to a close on NBC in 2007, after one season.

But that was network, and, as Sorkin can now testify personally, cable is a different animal. Especially HBO, which pioneered original cable drama in 1997 with Oz, then marched on to greatness with The Sopranos and The Wire, opening the floodgates for Mad Men, Breaking Bad, Homeland, and a spate of other good to great shows on Showtime, AMC, TBS, and IFC, among other outlets.

Naturally, HBO has had its share of misfires and mediocrities over the past 15 years—make your own list—but in the moneyball world of premium-cable programming (HBO topped $4 billion in global revenue in 2011), it’s still the gold standard. “It’s why you see so many people now—Michael Mann, Dustin Hoffman, Martin Scorsese—who cut their teeth in the feature world thrilled to come work at HBO,” Sorkin told me.

We were sitting in his office at Sunset Gower Studios, just across the way from the soundstage where The Newsroom was being shot. It’s a quietly elegant man cave: Leather furniture, dark-wood cabinetry, major Apple gear on the mogul-size desk. An expensive-looking cowhide valise plopped significantly on the carpet. Six Emmys on a shelf.

Sorkin, who has a million-mile-an-hour edge behind a camp-counselor-friendly, highly focused exterior, asked if it was O.K. if he smoked, fretted about smoking, lit a cigarette. “They were concerned about you seeing my office,” he finally said, exhaling.

I asked why.

“They felt it was too nice,” he said. “They wanted me to make sure that you understood it’s because I essentially live here. I sleep here.”

Noted. And believed. For while Sorkin’s bad habits have attracted their share of notoriety—in 1995 he spent time in rehab for addiction to crack cocaine; a backslide after recovery led to a widely publicized 2001 bust for drug possession at Burbank airport—no one has ever called him a slacker. Quite the opposite. From all evidence, his capacity for work is herculean: beginning with 1992’s A Few Good Men, the highly successful movie he adapted from his 1989 Broadway drama, there’s scarcely been a moment in his career when he hasn’t had projects afoot simultaneously in theater, film, and television.