The 1982 Us Festival, funded by Apple genius Steve Wozniak after the computer company’s value went “through the roof,” is the subject of the forthcoming concert film The Us Generation. You can watch a preview trailer below.

Some 400,000 people attended the event, as Fleetwood Mac, Tom Petty and the Heartbreakers, the Police, the Cars and others performed in San Bernardino, Calif. Many of those performances are included in the movie.

“The film tells the story of … an epic three-day event featuring an eclectic and unprecedented lineup boasting some of the biggest names in music, performing live in front of over one million people,” producers said in a statement. “Wozniak … wanted to create something that was a true celebration of Americana, cultivating positive vibes and building a deep sense of community through the power of technology and music.”

Wozniak – the engineer and programmer who designed the Apple I, Apple II and a significant portion of the Apple Macintosh machines – says in the clip: “I was so thankful that I had all this money from Apple, because I could do it, and nobody else would.” Festival president Peter Ellis adds: “Money wasn’t an issue. It was something he wanted to do, and do right.” Their colleague Carlos Harvey also praised Wozniak: “Steve wanted people to have a great time. He wanted them to be comfortable; he wanted them to be safe.”

The Us Generation: The Making Of the 1982 Us Festival will be released on DVD and Blu-Ray on Aug. 10.