Radio Shack’s TRS-80 Model 100 computer—the first successful laptop, introduced in 1983–is both respected and loved . But it’s an even more important computer than it generally gets credit for.

Before the Model 100’s arrival, portable computing was defined by the Osborne 1, a 24-pound beast that sported a handle and could be hauled from place to place, then plugged into AC power. The Model 100 weighed less than a sixth as much, fit in a briefcase, and ran off AA batteries. Though not the first notebook computer, it was the first one that caught on and the one that introduced people to mind-bending ideas such as using a PC on an airplane.

The fact that the Model 100 was portable only captures part of what made it special. It was an uncommonly approachable, appliance-like device for its time, with instant-on capability and an integrated software suite provided by Microsoft. Featuring the last code that Bill Gates wrote himself, it let you process words, manage your schedule, and keep an address book right out of the box, as well as write and run BASIC programs. My mother—not a nerd—was devoted to her Model 100 and got a ton of work done from the comfort of her own sofa, which at the time was kind of amazing.

The Model 100 also came with a built-in 300-bps dial-up modem for transferring files and dialing into services such as CompuServe, a remarkably forward-looking move. This was a connected device, long before anyone started thinking of devices as being connected.

I’m not saying that RadioShack’s portable was the iPhone of its time. But you know what? Every modern smartphone owes a greater conceptual debt to it than to other PCs of the time. (Apple’s proto-Mac, the Lisa, had a much more recognizably modern user interface—but it sure wasn’t portable and cost $10,000 to the Model 100’s $799.)

All of this is just to prepare you for Selling the TRS-80 Model 100, the video below. Presumably dating to the Model 100’s launch or thereabouts, it’s a RadioShack internal training film introducing the machine to store staffers so they could explain it to prospective purchasers.

Most of this is a straightforward walk-through of the Model 100’s capabilities by a guy with a stentorian voice. Then, at the end, there are bits with scenes of a typical Model 100 owner (who also has a TRS-80 Model III) getting stuff done. He’s a he, of course, with a three-piece suit and a secretary. But he’s shown dialing up financial data from his hotel room, which would have sold the Model 100 to some people all by itself.