Museum obtains rare demo of id Software's Super Mario Bros. 3 PC

1990 demo was rejected by Nintendo but led to id's own Commander Keen.

id software News, Rumors and Information - Bleeding Cool News Page 1

Museum studies alumna discovers rare 'Super Mario Bros. 3' video game demo

Retro - Museum obtains rare demo of id Software's Super Mario Bros. 3 PC port, 1990 demo was rejected by Nintendo but led to id's own Commander Keen

The phantom PC version of 'Super Mario Bros. 3' by the developer of DOOM is stored in the History Museum - GIGAZINE

Id Software's demo for Mario 3 on PC is now in a museum

Museum obtains rare demo of id Software's Super Mario Bros. 3 PC port

Best Id Software Posts - Reddit

Doom dev shares rare Super Mario Bros. 3 PC demo (update) - Polygon

Super Mario Bros. 3 PC port by Doom creator id Software recovered by museum

Random: John Romero's PC Port Of Super Mario Bros. 3 Turns Up On A Floppy In A Museum

Rare Look at the Unreleased Super Mario Bros. 3 PC Prototype by id Software from 1990 - TechEBlog

Super Mario Bros. 3 PC demo found by New York museum

Game Sound Museum: Super Mario Bros. 3 - Super Mario Wiki, the Mario encyclopedia

Best Id Software Posts - Reddit

id Software 'Super Mario Bros. 3' PC Port Rediscovered