You probably haven’t heard of the Space School games. There is almost no record of the games, created by Konami, online. A YouTube search will come up with little, nor will you find the game mentioned much in gaming blogs or on Google searches — that is, until this week.

Space School is an educational game for the Famicom (Japan’s version of the Nintendo Entertainment System) created with Japanese national broadcaster NHK. The series of seven games — six were created for schools, and the seventh was made for a Japanese gas company — is so rare because you can’t just stick it into the Famicom and play; you need a special adapter, called QTa, made specifically for these cartridges.

Nikolai Gubanov, also known as Russian Geek, a YouTube creator and game collector, found that the Space School games were never commercially available. Instead, they were only made available to educators for use in schools. Because of how niche the games are, they just slipped into the background and were largely forgotten — until Russian Geek bid on a cartridge and the adapter at a Japanese online auction. And they both worked.

“And not only were they rare, they also ran on unique hardware that had not previously been documented,” Video Game History Foundation founder Frank Cifaldi told Polygon about the games’ context in the industry. “Not only did the games have to be obtained somehow, which felt impossible enough, they also had to be dissected and reverse-engineered by one of only a handful of people around the world who do that sort of work. The likelihood of both happening felt really low.”

And yet, it happened. Russian Geek was approached by an infamous Russian ROM hacker, CaH4e3, who offered to help in “dumping” the files — which means copying the data off the cartridge and making it available online for others to download. It turns out, CaH4e3 — who remains anonymous due to the nature of his work, which can often be considered illegal bootlegging — was already in possession of some Space School series files, but he couldn’t run them without understanding how the physical QTa adapter worked. But now with the adapter and physical cart, he could manually reverse engineer the files. (The whole fascinating process is detailed on Russian Geek’s YouTube video on the game. It’s in Russian, but English subtitles are available.)

CaH4e3 kept those files for nearly 10 years, he told Polygon, before he learned that Russian Geek had an adapter. After some work, CaH4e3 and Russian Geek were able to get the files dumped — and now the cartridge and three more of the seven Space School game files that CaH4e3 already had are playable online with an emulator.

Today was a HUGE day for NES game preservation. Konami's ultra rare Space School series was completely undumped yesterday. Today, we have four of the seven ROMs playable on emulators. Listen to that unmistakable, PREVIOUSLY UNHEARD Konami-created music! https://t.co/S09pNCohMH — Frank Cifaldi the Last (@frankcifaldi) August 27, 2019

“We have here [a] very obscure, very specific piece of hardware/software that no one (except very few people) have ever seen until now, and most importantly, never interested in — because you can’t play it after all, this is just a teaching software,” CaH4e3 said.

But that doesn’t mean it’s not important. Cifaldi said that for some people, “experiencing a lost Konami game on the NES is the generational equivalent of unearthing a lost Beatles song.” Konami, which was founded in 1969 in Japan, has created formative games across decades in the industry.

“I don’t know if these games are any ‘good’ — I haven’t played them yet, and I doubt I’d get very far without any Japanese fluency — but that’s irrelevant,” Cifaldi said. “Good or bad, this is a piece of the larger puzzle that we didn’t have access to before now.”

There are still pieces to the Space School puzzle missing, however. Four of the seven games have been dumped and are available online, but there are three more lost out there. Cifaldi said the task of dumping these last three games should be less daunting — the documentation is already done, and now only the extracted data is required. And finding those are important in preserving the whole series.

“It’s part of a game story that may have been lost for future generations,” Russian Geek said.