Things fall apart, and then they are forgotten. In video games, there was the famous Atari dump, in which the company buried thousands of cartridges of E.T. and other games in a New Mexico landfill. There are more prosaic cases where the source codes for games are lost for dull reasons. For example, Prince of Persia for the Apple II was presumed gone until the developer’s dad found the code in a closet (stored on three fragile floppy discs), after which point the dev posted it to GitHub. Physical media, which makes up most of video game history, has a tendency to degrade, too. That means, even when properly stored, the past is in danger of being lost. As journalist Heather Alexandra wrote in Kotaku in 2016: “Gaming’s early years often painted video games as children’s toys. Only diehard collectors and enthusiasts had the foresight to hold onto their games. Even now, games are treated largely as consumable goods.”

The culture around games — magazines, merchandise, and the like — disappears, too, which leaves them less analyzable in their original context. The main problem with preservation is that it’s not immediately apparent what’s worth preserving. With video games, though, it becomes a little more complicated: playing them the way they were originally meant to be played is about as important as preserving their code. And that’s also what people think about when they think of emulation, which is a wonderful way to preserve code that might otherwise disappear. But they never think about the hardware.

That’s where Analogue, the company founded by Christopher Taber in 2011 while he was in college studying philosophy in Montana, comes in. Taber and his team have begun cloning classic consoles that offer full cartridge support and present-day necessities like HD video output. (The first piece of hardware they re-created was a Neo Geo system with an arcade stick.) Its latest console remake, the Sega Genesis-inspired Mega Sg, is simultaneously a faithful re-creation of its predecessor and a link to gaming’s past. It’s an undertaking that’s ridiculously difficult. As it happens, it’s very hard to reverse-engineer defunct, proprietary hardware and software.

To clone a console, it helps to start with the CPU, especially if you’re trying to clone a console you’ve never worked with before. “I didn’t know Genesis very well, and knew literally nothing about the 68000 CPU at all!” wrote Kevin Horton, lead engineer, in an email. “This was my first foray into both things and probably slowed the process down since I had to learn it all as I went.” The processor in question, the Motorola 68000, is the most complex part of the Sega Genesis because the entire system is based on it. That CPU was designed by Motorola in 1979, and it had been used in many arcade machines by the time it found its way into the Genesis. Horton figured out a way to exactly mimic the 68000’s performance, down to the cycle and sub cycle of its processor. He consulted the actual semiconducting circuits on the CPU to design his emulated hardware board — that is, a physical circuit board that mimics exactly the one in the original Sega Genesis.

All of Analogue’s products run using field-programmable gate array (FPGA) emulation, which entails designing an actual chip that does what the original hardware was wired to do. “Custom hardware was created to directly connect a 68000 CPU to the FPGA to allow a direct real time compare to ensure the highest level of accuracy,” Horton continued. In other words, Horton connected an original 68k CPU to his emulated chip to test its relative accuracy and then left that test running for a week straight. (Any deviation would cause the test to fail.) The chip works the same way as the original circuits, which means you get the same functions and performance as the hardware the FPGA is emulating. “When we’re recreating those chips on an FPGA, it’s like you’re taking the original transistor level schematics and you’re implementing them directly,” says Taber. “It translates to 100% accuracy.”

To put it another way: if you decided to disassemble any mass-produced electronic product — like, say, a Sega Genesis — any chip you saw on the green printed circuit board is what’s known as an application-specific integrated circuit (ASIC), which is just a circuit designed specifically for the hardware it’s in. “It’s a cost effective way to produce millions of chips, essentially, that are going to be used for mass manufactured products,” says Taber.

Horton said he spent nine months developing the Mega Sg’s hardware and software — two and a half of which were spent on the CPU alone. (It took three months to get Sonic to run.) Another month went by getting the audio to work, and it took a separate month to get Sega’s Master System functionality right. The rest of his time was spent debugging and implementing features. (Analogue went through a similarly exhaustive process to get its Super Nintendo console, the Super Nt, right.) The most satisfying part of re-creating the Sega Genesis, Horton said, was making it work. Especially Overdrive 2, which is a demo released in 2017 that pushes the original Genesis hardware to its limit. As Horton says, it’s “notoriously difficult to get correct for emulators (and only 1 emulator currently seems to be able to do it).”

The main technical advantage of using hardware emulation is that accuracy. It means very low latency, which, in turn, means it’s easier to play games that require fast reaction times — like many of the run ’n gunners, fighting games, and platformers made for the Genesis, which came out in the late ’80s. Because Analogue has re-created consoles on a hardware level, the Mega Sg and the rest of Analogue’s products are more accurate than just about any software emulators. Sega has its own line of remake Genesis consoles, which come with many games preloaded. But they’re re-creating the Genesis experience on the level of software, which means that they’re not quite as good as what Analogue has to offer. They’re the only company that’s actually rebuilding hardware in order to give players the same experience they’d have on a Sega Genesis manufactured in the 1980s. The point is to let modern players play old games the way they were meant to be played.

Although, that accuracy comes at a cost: the Mega Sg retails for $189.99, but you can find Sega’s Genesis Flashback for $59.98 on Amazon. “Our customers are definitely enthusiasts,” Taber says. “But this market, and the kind of people who are interested is, is much, much larger than I think most people expect.” That may be true, but it’s also worth pointing out that the people at Analogue are themselves enthusiasts. The logic of spending nearly $200 on a practically defunct piece of hardware only makes sense to those who have the time and money to appreciate it.

In emulation, what lies beyond the question of legality and piracy is preservation. Software has a half-life that can be measured by people’s foibles: code gets lost, corporate takeovers nuke smaller outfits, squishy brains and bodies fail. But what’s to be done?

In 2015, Jason Scott, a preservationist at the Internet Archive, gave a talk at that year’s Game Developers Conference exhorting employees to steal. “Workplace theft is the future of game history,” he said, meaning that if people don’t take active steps to preserve what they’re working on, corporate policies be damned, then that work is in danger of being lost forever. What’s most interesting about Scott’s statement is its call to individual action. It’s not the game and hardware manufacturers themselves that are taking action; it’s only a cadre of Taber’s enthusiasts. There are a few organizations dedicated to preserving the history of video games, like Frank Cifaldi’s nonprofit, the Video Game History Foundation, which was founded two years ago.

“The majority of games that have been created throughout history are no longer easily accessible to study and play,” their website reads. “And even when we can play games, that playable code is only a part of the story.” The foundation’s main work is its digital reference library, which it describes as “an online repository of artifacts related to the history of video games and video game culture.” The point is to have a searchable database of material accessible to researchers and historians that’s not just code.

While source code isn’t as perishable as, say, a book, saving it does present its own particular challenges. Emulation is one way to save defunct hardware and software from the boneyard. “A lot of the times when you’re seeing people talking about preservation, they’re talking about games: finding or unearthing games that are lost, or making available permanent ways to be able to access pieces of this history,” says Taber. It’s just as important to emulate consoles as it is to emulate the games themselves because the console experience is just as worth preserving as the games are.

For each of its consoles, Analogue has managed to convince developers to release previously unknown games exclusively for its products. “You know, games that were developed in the ’90s, nearly completed or cancelled.” These games include the run ’n gun Super Turrican had to be cut by a third because of memory constraints, which Analogue has obtained the full version of, or Ultracore, a canceled (and renamed, for copyright reasons) shooter from DICE that ships with the Mega Sg.

While saving two games doesn’t compose a movement, it does suggest a way forward: preserving games should be a priority for everyone who’s interested in games as a cultural form. “Our goal is essentially to elevate the medium to put the history of video games on a pedestal and say, ‘This is worth preserving, this is worth taking a close look at, it’s worth talking about,’” Taber says. Putting in nearly a year’s worth of work to create a perfect replica of a defunct console isn’t something everyone does.

“There’s no one else who’s doing what it is we’re doing,” Taber says. Horton, for his part, agrees: “It’s important to preserve game history so that these games can be played by future generations as they were intended to be played.”