A submission to the Strong National Museum of Play from an unnamed game developer contained among its contents a very notable find. The PC port demo for Super Mario Bros 3, made by id Software back when it was known as Ideas from the Deep, will now be preserved by the museum, and is open for researchers "and other parties."
Many people may be surprised to hear that Mario appeared on other platforms back in the day. As Ars Technica explains, back in 1990, id Software, which was known as Ideas from the Deep (IDF,) coded the demo in under a week and sent it to Nintendo, hoping to get an official contract for porting the game to MS-DOS PCs. What was particularly notable about the demo was a screen-scrolling algorithm, coded by John Carmack, that was much more advanced than the stuttering background movements and full-screen wipes in other PC games of the era. Nintendo ultimately rejected the idea of a port, but the screen-scrolling technology was later used in the Commander Keen series. The closest most people have got to seeing the demo was when John Romero showed off the demo's levels in a video released in 2015, in order to commemorate the 25th anniversary of Commander Keen.
Andrew Borman, the games curator at the Strong National Museum of Play, said that the demo disc was part of a larger submission of content by an unnamed game dev. They didn't work on the demo, but received it "during their work." Nevertheless, Borman found this find "extremely exciting," and managed to test out the demo. The demo itself was obviously an early build, lacking many of the features the original Super Mario Bros 3 had. However, the demo also has some other differences, such as a "fairly flat" Level 1-4 (compared to the original game's auto-scroller level) and a IFD logo hidden above the start of Level 1-1.
There are no current plans to exhibit the Super Mario Bros 3 PC port demo. However, it's available "upon request" to researchers and other interested parties.