Zainsoft's Dios: Rare PC-8801MC CD-ROM Game Preserved and Archived Online

Zainsoft's Dios: A Milestone in Game Preservation for PC-8801MC In a significant achievement for video game preservation, the elusive sidescroller Dios from Japanese developer Zainsoft has been rediscovered and made available online.

Originally released in 1989, Dios was distributed on floppy disk for several Japanese computers, including the Sharp X68000, MSX2, PC-8801, and PC-9801.

However, one of the rarest versions was created for the PC-8801MC CD-ROM — a unique iteration of NEC’s esteemed PC-88 home computer line. Background: Zainsoft and the PC-8801MC CD-ROM The PC-8801MC, an iteration of the PC-88 platform introduced by NEC, featured compatibility with the PC Engine CD-ROM² drive, opening the door to a new format for game releases.

In 1990, Zainsoft announced the release of Dios on CD-ROM for this hardware, making it one of only two known commercial games issued in this format for the PC-8801MC.

The other title, a Japanese adventure game named Mirrors, completes this exclusive pair, making both titles significant in the annals of retro computing. Resurfacing Through Community and Preservation Efforts For years, collectors and enthusiasts debated whether Zainsoft's Dios on PC-8801MC CD-ROM ever reached the marketplace, as there was scant evidence of its existence.

This uncertainty changed when PC-88 aficionados discovered a Twitter post by a Japanese user showing a personal copy.

Recently, the game preservation community achieved a breakthrough after Krugman, a Japanese computer enthusiast and preservationist, confirmed obtaining the rare CD version. Journalistic sources such as the Basement Brothers YouTube channel outlined that the game had not only been found but successfully archived online.

The channel provided detailed insights into the differences between the original floppy disk edition and this near-mythical CD-ROM release, further enriching the documentation of the title’s legacy in Japanese gaming. Preserving Nostalgia: An Ongoing Mission By digitally archiving Dios for the PC-8801MC CD-ROM, Krugman and his peers have ensured the survival of a unique piece of video game history.

Their efforts highlight the broader importance of digital preservation, especially for platforms like the PC-88 and its offshoots, which share a distinct legacy within computer and console history. This milestone also serves as encouragement for continued documentation and preservation of retro games, many of which remain obscure due to hardware limitations or regional exclusivity.

As more classic Japanese games resurface through collaborative online efforts, enthusiasts and historians gain an increasingly comprehensive look at the formative years of gaming across platforms like NEC’s PC-8801, the Sharp X68000, MSX2, and beyond. For a full breakdown of Dios and an in-depth look at the preservation process, viewers are encouraged to watch Basement Brothers' dedicated video, which charts the recovery journey and outlines the key distinctions between the game’s various editions.

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