"Honestly, I wasn't a huge fan of Prodigy," says Carpenter, a 38 year-old freelance programmer based in Massachusetts, recalling his time on the service around the turn of the 1990s. "I had already been using the Internet for a couple of years and Prodigy seemed so closed in. But I still used Prodigy every single day. It was the graphics."

It was Carpenter's drive to see those graphics once again that got him fiddling with Prodigy clients in late 2012. "Finding decent color screen shots of Prodigy is nearly impossible," says Carpenter.

He knew the sign-on screen was stored on the hard drive, so he began to wonder what else he might find in the client software. Using a hex editor, Carpenter fiddled with the client software until he found even more graphical data. "As far as I knew, the only thing I might be able to get is a screenshot of the set-up options dialog."

And he did. But what he found next blew his mind.

* * *

When any sizable online service disappears, a piece of our civilization's cultural fabric goes with it. In this case, the missing cultural repository is Prodigy, a consumer-oriented online service that launched in 1988 as a partnership between Sears and IBM. Users accessed it by dialing into regional servers with a personal computer and a modem over traditional telephone lines. Once connected, they could trade emails, participate in online message board discussions, read the daily news, shop for mail-order items, check the weather, stocks, sports scores, play games, and more.

Prodigy even devoted a portion of the user's screen to graphical banner ads. It was very much like a microcosm of the modern Internet—if the entire World Wide Web was published by a single company. Over its 11-year lifespan, a generation of Americans grew up with Prodigy as part of their shared cultural heritage. In an earlier era, we may have spoken about another common cultural experience—say, Buster Keaton films—as a cultural frame of reference for an entire generation. Everybody saw them, everybody referenced them. And while Prodigy was nowhere near as popular as Buster Keaton among the general public, hundreds of thousands of people with a computer and a modem in the early 1990s tried Prodigy at least once. What those early online explorers saw when they logged in was, to them, glorious: colors, fonts, illustrations, and a point-and-click interface—features which, at Prodigy's launch in 1988, were entirely new. Prior to Prodigy, competitors like CompuServe and GEnie forced users to type obtuse commands to get any meaningful result (and that result also happened to be a screen full of lifeless text).

Prodigy gained its distinctive flair from a now-forgotten graphical protocol called North American Presentation Level Protocol Syntax, or NAPLPS for short. NAPLPS was a product of the brief Teletext era of the late 1970s, when TV networks sought to piggyback extra digital information such as weather forecasts or sports scores using something called the "vertical blanking interval" of a TV broadcast signal. The vertical blanking interval could only hold a small amount of data, so engineers devised a way to present digital color graphics and text in the most economical way possible. NAPLPS did this by reducing an image into a set of mathematical instructions (i.e. "draw an oval at this location and fill it with blue") instead of storing data on every pixel in a bitmap image like JPEG or GIF files do today.

The NAPLPS method required a custom piece of hardware or software, commonly called a "terminal" or "client," on the receiving end to receive the drawing instructions and to translate them into an image or page layout on the user's screen. Teletext never caught on in the US (although it did flourish in Europe), nor did Videotex, the two-way interactive version of the concept that required remote computers accessed by modem and corresponding terminals hooked to TV sets.