David Simon and Tom Fontana have multiple cult hits between them, but they say it all started with Homicide: Life on the Street. The two sat down to discuss their history, their shows and how life at HBO has changed in the post-Sopranos age at the ATX TV Fest in Austin Saturday.

Fontana says it was Barry Levinson who first brought Simon’s book, Homicide: A Year on the Killing Streets to his attention, with the intent to create a show based on the book. This naturally led to Simon having a consulting role with the show.

Simon didn’t join the show full time until season 4. He credits the decision, and his subsequent work in creating The Wire, with his working relationship with Fontana. “By the end [of Homicide], I knew how to make television. The promise was, ‘I’ll show you how to do this.’ This is my tutorial,” he said.

Simon’s The Wire and Fontana’s Oz would have even farther reaching impacts. “The DNA of what HBO became is right in Oz,” Simon explained. Oz was HBO’s first one-hour dramatic television series, and Simon says it inspired him to later take The Wire to HBO, instead of NBC, with whom he had some past differences of opinion. In one particularly telling anecdote, Fontana blurted out that “[co-executive producer Jim Yoshimura and Simon] would sit in Jim’s office and the network would call from LA with the notes and they would get naked and dance.”

Simon says it wasn’t quite like that, however. He explained, “Jim would put the phone, he would drag it from his desk and put it on the floor, and the network would give us the notes, and we would have to not laugh and our voices would have to convey, ‘That’s real interesting, I think we’ll try and incorporate that.’ And to hear us in LA it would sound like we were cooperating, but we were dancing around the phone, and it is true that by the end of the call we would have our flies open and we would sort of stick our thumbs as if we were pissing on the phone. We never actually pissed on the phone or got naked, though.”

Simon says that he took his idea for The Wire to HBO, where he had previously worked on his miniseries The Corner. By that time, HBO was buzzing from its success with The Sopranos and Sex and the City.

When moderator Beau Willimon (House of Cards) asked what it was like to work with HBO when it reached massive success, Simon and Fontana agreed it was a good experience, albeit with some small downsides.

“It was great. A lot of the shows were being done in New York – The Sopranos was, Sex and the City was – so we would constantly be seeing each other. So it became a little bit like an HBO community,” Fontana said. However, he notes, the success of shows like those ultimately changed the culture. “There’s a very bizarre phenomenon that happens on television, which probably happens everywhere, but success breeds fear as much as failure,” Fontana said.

He said he felt that at the time, HBO became afraid that they weren’t going to find the next Sopranos. Simon chimed in, saying, “I don’t want to suggest there isn’t good work being done at HBO. Game of Thrones is subsidizing all of us.”