Saturday eveninga noisy account of the chaotic ninety minutes leading up to the first episode of Saturday evening liveopens in theaters nationwide on October 11, in a nod to the October 11, 1975 air date of the comedy series’ first episode, broadcast from NBC’s studio 8H. The film release coincides with the show’s 50th season, which kicked off on September 28.

Just as the social movements of the 1960s transformed every aspect of American life, the live comedy show was part of a television revolution in the 1970s. But Saturday evening is more about imitating a feeling than about imitating actual events. “The goal is to make you feel what it feels like when your 8H is on the ground right before, how it feels like the show can’t possibly get on the air because everything is so last minute,” says Saturday evening director Jason Reitman. “They are still painting the sets, hemming the clothes and the wigs – all that happens until the last second.”

The filmmakers (Reitman also co-wrote the screenplay with Gil Kenan) interviewed everyone they could find who was on set for the premiere, including SNL creator and showrunner Lorne Michaels, actors, writers, people in the art department and even former NBC pages. And while the film may be more about capturing the spirit of the night than the exact events, many viewers may walk away with some questions about a llama, a fire, and an aggressive censor. To see which parts of the film were based on truth or fiction, TIME spoke with Reitman and James Andrew Miller, an author of Live from New York: The Complete Uncensored History of Saturday evening live as told by the stars, writers and guests.

Read more: A who’s who of the famous faces in Saturday evening

How did Saturday evening live come?

NBC was looking for something that could replace reruns of Johnny Carson’s late-night TV show, and Carson (played in the movie by Jeff Witzke) was all for the SNL experiment.

Lorne Michaels (Gabriel LaBelle), a Canadian TV writer, wanted to create a show for the generation that grew up on television, representing their fashion sense, their taste in music and their sense of humor. Reitman describes SNL as an “orphanage for a variety of artists and writers of all styles.” For example, the original cast was known as “The Not Ready for Prime Time Players,” and included: Dan Aykroyd (played by Dylan O’Brien), John Belushi (Matt Wood), Chevy Chase (Cory Michael Smith), Jane Curtin (Kim Matula), Gilda Radner (Ella Hunt), Garrett Morris (Lamorne Morris) and Laraine Newman (Emily Fairn).

Al Franken (Taylor Gray), one of the first SNL writers, recalls Live from New York: “We wrote a perfect entry for it Saturday evening live, a package of things we’d like to see on TV: a news parody, commercial parody and a few skits. We were hired on that basis.”

Saturday evening became Saturday evening live in 1977.

Did Lorne Michaels really find one? SNL writer in a bar?

Yes, as seen in Saturday eveningAlan Zweibel (Josh Brener) was discovered in a bar, although unlike in the film, this did not happen on the same night as the first show. Michaels visited every kind of nightclub he was looking for writers for SNL. According to Live from New York, Michaels went up to Zweibel in a bar and said, “You know, you’re the worst comedian I’ve ever seen in my life.” Zweibel said he wanted to have a wife and children one day, but if he didn’t get a job soon, they would starve. Michaels asked Zweibel if he could look at his notes, and they agreed to meet again to talk further. Zweibel went back to his Long Island home that evening and says he stayed up two days straight typing up every good joke he ever came up with to present during his interview at the Plaza hotel.

Michaels asked him how much money he needed to live on, and Zweibel told him it would be great if he could match the $2.75 an hour he made working at a deli. “But,” Zweibel recalls saying, “If there’s one damn mime on the show, I’m out of there.”

The first joke in the compendium Zweibel presented was the only joke Michaels read, about how a new stamp commemorating prostitution in the US costs a dime, but if the mailman wants to lick it, it costs a quarter. Chevy Chase performed the prank during the first Weekend Update.

Why wouldn’t John Belushi sign his contract?

In the film, Belushi avoids signing his contract for as long as possible. In the minutes before the show, Michaels finds him skating on the Rockefeller Center ice rink. It’s true that Belushi didn’t sign his contract until the day of the show. (Although it’s unlikely he went ice skating.)

“Belushi went completely missing on that opening Saturday night,” Reitman says.

The actor had “nothing but contempt for television,” Miller says. “He thought it was an inferior art. He thought there was a lot of nonsense on TV.”

As Reitman explained his portrayal of Belushi, “I was deeply interested in Belushi’s vulnerability and fear of being on live television – how that would change his life and how that would define him from then on.”

Did the set really catch fire before the? SNL premiere?

There was no fire. The set catching fire is a dramatization of several accidents during the run-up to the premiere. But there is a story in it SNL about John Belushi accidentally setting Lorne Michaels’ mattress on fire. When Belushi’s fiancé Judith kicked him out of the house after an argument, he went to stay with Michaels and eventually fell asleep with a lit cigarette.

However, it is true that on the SNL During the set, Michaels kept asking for more lighting, which fuels the fire in the film. As Reitman explains, “He wanted (the show) to look as good as any movie, and as a result he just kept adding sets and camera directions and lighting and things that had never been done before.”

Were any sketches planned until the last minute?

Yes, the show was over three hours long when the dress rehearsal started. In the film, Michaels gets the third degree from NBC executives who want to know what he’s cutting — as well as what the show is even about. But Michaels never really gives them an answer. There’s a reason for that, Miller says: “There was a lot of craziness going on, but Lorne probably didn’t want to be boxed in either. He didn’t want to give them too much information. He wanted to have as much creative freedom as possible.”

How stoned was the host, George Carlin?

Carlin (Matthew Rhys) was loaded. All kinds of substances have stirred things up SNL team over the years. Apparently it was a miracle that he even took the stage in clothes. He smelled bad the night of the show because he wanted to wear a T-shirt on air, but NBC wanted him to wear a suit. Since the affiliates were not 100% committed to airing the show, the compromise was that Carlin would wear a suit and T-shirt instead of a tie. “That was a much bigger distraction than we can understand now,” Michaels says Live from New York.

Was Lorne Michaels supposed to host the Weekend Update?

That was the plan. At one point during the dress rehearsal in the film, he is seen as stumbling through his lines without having mastered the material. In reality, he had to decide whether he wanted to be one of the actors or one of the producers. He was about the same age as the cast. Reitman describes the decision as: “Are you going to be one of the kids? Or will you be the father?’

But the role went to Chase. Reitman remembers Dave Tebet (Willem Dafoe), who managed talent for the network and immediately identified Chase as a star. “Through Tebet’s eyes, Chevy represented the possibility of Saturday evening live,‘, as Reitman puts it. That’s why Chase’s character in the movie is so stubborn. Herb Sargent (Tracy Letts), one of the early writers, recalls a more modest encounter in the minutes leading up to the first broadcast, when Chase said to him, “What’s going to happen to me? Where do I go from here? Sargent said, “You’ll probably end up hosting a talk show.”

Why is there a llama backstage SNL?

The llama in the film would represent the showrunners’ decision early on that, as a running gag, every time the cameras went backstage, the audience would see a live llama, a showgirl, and a man dressed as Abraham Lincoln. The joke has been a tradition for fifty years.

Who is the woman representing the NBC standards division?

Reitman says the character, played by Catherine Curtin, is a composite based on several women who made sure nothing X-rated was broadcast to NBC’s family-friendly audience. According to the movie, there really was a woman in the standard department at NBC who asked what a golden shower is. “Several people told me they tried to hide things in the script to see what they would notice,” says Reitman.

Were there really masons on the set of the premiere?

Yes, they laid the bricks in the shape of a home base (like in baseball), and it was supposed to represent a street corner in NYC. “If you looked anywhere in America, you would see home base and feel like you were teleported to a rough New York street.”

The image of people literally laying bricks is a metaphor for how groundbreaking the show was. Reitman says, “Lorne approached every part of making a television show as if it never had to be done that way, like bricklaying, which no one would ever do on a TV show.”