A long-rumored prototype of the Super NED CD-ROM was finally found back in 2015. While it could play SNES cartridges, the CD-ROM would not work. After about a year and a half of work, electronics wizard Ben Heck has completed repairs on the prototype.
http://www.notebookcheck.net/Ben-Heck-completes-repair-of-Nintendo-Playstation-prototype.217954.0.html