It's hard to believe that there was a time, not that long ago, when pubs and clubs didn't have televisions. It wasn't a problem until patrons across the country started ducking off home around 8.25pm on weeknights to watch a certain television show.

And not just any show, either. Number 96, the racy soap set in an inner-Sydney apartment building, had exploded onto Australian prime-time screens at the beginning of the 1970s, screening five nights a week and scratching just about every itch known to the impatient, shifting, multi-cultural, ready-for-anything population.

The show, and its resulting spin-off 1974 movie, is going to be the subject of a saucy and nostalgic afternoon at the National Film and Sound Archive next week, with screenings and a panel discussion of what made this extraordinary show work – and why it will probably never happen again in our lifetime.

But back to the emptying pubs and the saga of the Knicker Snipper that had publicans getting antsy. Yes, that's right, the Knicker Snipper – an unknown panty snatcher who was cutting up women's underwear. Not a real one, mind, just another plot twist about two years into a show filled with such sagas, along with everyday domestic dramas and romantic intrigue. Like a soap, really, but Number 96 was no ordinary soap.

When patrons starting leaving drinking holes in droves to get home in time to watch the next instalment, pub-owners simply starting bringing in their own big screens, so people could drink on and still get their Number 96 fix. And thus began the era of flickering screens and televised sport in pubs, RSLs and clubs across the country. Not televised sport or politics – just satisfying and titillating human drama.

It was just one of many ways in which Number 96 was aeons ahead of its time. Premiering with great fanfare in March 1972 – a cryptic advertising campaign for weeks beforehand had counted down the number of days until Australian television would "lose its virginity" – the show had been conceived as a Coronation Street-style serial, only racier and on every night. Consequently, the show featured an openly gay regular character, an interracial kiss, sex scenes and nudity, indigenous and migrant characters, marital rape, drugs and, underpinning it all, a constant thrum of comedy to keep everyone comfortable.

The show's creator and script editor David Sale says the show's undercurrent of comedy, although it came to the fore later in the show's run, was crucial to its success. Already something of an enfant terrible in the Australian television scene, the Manchester native had been executive producer of The Mavis Bramston Show, a satirical Saturday Night Live-style weekly show that aired in the 1960s.

But when production executives Don Cash and Bill Harmon came calling, wanting to discuss a bold new evening serial, Sale just wasn't interested.

"I didn't give a damn, because I'd just written my first novel, it had been accepted for publication in London," he says.

"There was already talk of movie rights being bought. So I was all set to go to England. Then my agent said Bill Harman and Don Cash want to take us to lunch, they want to discuss you doing a treatment for a new television series, and I said, 'I can't be bothered!'."

But, once he was assured the meeting would at least take place in a fancy Italian restaurant, he agreed to go, thinking he had nothing to lose.

The rest, as they say, is history; the lunch ended with a visit to a particular block of flats in Paddington – the building that would become the title picture, Seinfeld-style, of the show, and Sale immediately began thinking of the kinds of interesting characters he'd have to create to keep the storylines ticking along.

"I was thinking in terms of people that were around me, you know? I didn't want to invent anything," says Sale.

"I said, a migrant couple, and then I said oh, and how about I put two homosexuals in one of the flats? And Bill Harman said [adopts husky tone], 'Ok, give me homosexuality without any deviation'. I don't know what that meant but I took it as a yes and went right ahead."

It's possible it was at this moment that the show's success was assured. Real people in all their glory – presented without comment on the nation's screens? But there was still more to come.

Sale, the brat, still wasn't interested in the project.

"I'd already rented out my own unit and I was staying with a friend – I was ready to go to England," he says.

"So I thought, I've got to get this over quickly, so that night, after dinner, I just sat in a corner, and just scribbled the treatment and the characters and about two pages of plotline, typed it up the next day, sent it off the Bill and Don and then I was off to London."

He says the words came easily mostly because he didn't care too much – a sure recipe for success, especially when his career by no means depended on it.

Of course, by the time he was in London, the phone was already ringing.

"Bill Harman rang me and said, 'Jesus, David, everybody loves it! Why aren't you on your way home?' So this local Australian show was sort of written in Athens, Bangkok and typed up on the hotel typewriter in Hong Kong, by a pommie."

Australian television and film historian Andrew Mercado reckons he loves Number 96 more than any show on earth, not least because he was never allowed to watch it growing up.

"Every day, you had to find someone in the schoolyard who had watched the show to find out what happened last night," he says.

But that didn't stop him from building up an encyclopaedic knowledge of the show and everything it stood for, everything it became and the standards it set for television throughout the western world.

He says the show's creation was underpinned by the simple fact Channel 10 was taking a massive, do-or-die gamble, in the face of dismal ratings and no money in the coffers.

"At that stage, in '71 and '72, sexual attitudes were really changing, and we'd been lagging behind a bit, I think, in the '60s, the sexual revolution had finally hit Australia – there was certainly an opening for something quite adult on TV," he says.

"They decided that this would be a serial aimed at adults, with some real adult content, and so this is when they came up with the idea that they would use sex and nudity to kind of give the show a burst of publicity when it started, so that people would take notice of it, because it was such a huge risk."

Another massive risk was the decision to screen the show five nights a week – unheard of in mainstream television.

"They literally had to get one of Australia's first ever computers and use it to figure out how the hell they were going to make this show. Nobody knew how to make five half hours of TV for prime time TV anywhere in the world," he says.

And the model that they came up with, to basically film all the scenes in flat one, and then re-dress it to make it look like flat three and do all of those, and then cut up all those scenes and splice it together, I mean that's more or less what soapie makers now do all around the world, based on that production model they started back then."

So, a nightly panoply of smashed taboos, that just got bolder and funnier as the years went on, with a multi-cultural cast – Jewish, black, white, Indian, South African, Lancastrian, indigenous – before the term was even invented.

But most shows end up jumping the shark at some point. For Mercado, that point came when, in 1975, a bomb exploded in the downstairs delicatessen, killing off four popular characters. In retrospect, a dramatic disaster is nothing more than a classic plot device to haul viewers back in and that's what the show needed with the advent of colour television. The cheap sets suddenly looked, well, cheap, and viewers were drifting off to more visually enticing fare.

The bomb blast was born of the desperation of television executives trying to claw back ratings and the whole thing went off like clockwork. The bomb exploded on Friday night, the show leaked the names of the characters who'd died to the press, and the papers on Monday screamed the news on all their front pages.

"They had to do three reprints of that paper because the news was still so huge," says Mercado with great satisfaction – these weren't even real people.

Still, he says, they killed off the wrong people.

"The fact that they'd killed regular characters was so shocking – it gave the show a little bit of a boost in the ratings for a little bit longer," he says.

"Again, they were trying to go for the shock value, but people were so upset in particular that one of these delightful characters had been killed, the new characters they'd brought in never really clicked and the show sort of limped along to a finish two years later."

Nigel Giles, who has a book about Number 96 coming out this year, agrees with Mercado about the bomb-blast mistake – as do many of the dozens of people he interviewed in the seven years it took him to finish the book.

Killing much-loved characters ended up mattering more than the producers could ever have predicted.

"It was early days of that sort of television – a lot of people believed that the characters were real. People believed that the flats were somewhere that they could go and meet these characters," Giles says.

And viewers – himself included – had no inkling at the time they were watching history in the making as they settled down to watch the next instalment after dinner each evening.

"You weren't watching it thinking, 'Wow, this is ground breaking television', you were just watching it and enjoying the characters and the storyline," he says.

"It's only when you look back, and as you get older, that you realise they really were doing amazing ground-breaking stuff on our screens back then."

He says it's hard to imagine how many people, from all walks of life, were watching the show on any given night.

"One of the producers said the writers thought that they were writing for Mr and Mrs Average, but it turned out they were writing across the board," he says.

David Sale is wistful at the thought of how far Australian television hasn't come since Number 96 last screened in 1977. Rather than shining a beacon into the future, the show has left something of a void.

"We thought it had paved the way, but now it seems to have all closed in again," he says.

"They were braver times. It's difficult to think that the gates were open, because we seem to have gone very white-bread again."

Number 96: TV's virginity lost, an afternoon of probing discussion, saucy nostalgia and a curated selection of TV highlights with David Sale, Andrew Mercado and Nigel Giles, followed by a rare screening of Number 96: The Movie (1974) on glorious 35mm. At the National Film and Sound Archive, June 11, from 4pm. Tickets $25/$20. For bookings and more information, visit nfsa.gov.au.