The Apple Lisa was by no means a hit product by any definition. Released in 1983, the ambitious but flawed machine was immediately overshadowed by Apple’s successor, the 1984 Macintosh – which helped cement the computer as a fixture in homes and offices around the world.

But the design language of the Lisa is the design language of modern computers. It was one of the first machines to use the metaphor of a desktop, including things like folders, icons, and application windows that mimicked sheets of paper. Apple took inspiration from outside sources, most notably the Alto, a groundbreaking machine developed at the Xerox Palo Alto Research Center. But it repeated the formula with obsessive user testing that adapted to the intuition of new users. The result is something that feels strange and familiar at the same time 40 years later.

There are a dwindling number of Lisas in the world, but I was lucky enough to get my hands on one, thanks to a generous (and prolific) Apple hardware collector. It was a chance to explore what made the Lisa so special…while, admittedly, giving us a sense of why so many people opted for a Mac instead. It’s one of the most fun things I’ve had on a computer in years, and you can watch the video above to get a tour of it.