An extraordinarily rare prototype of the SNES-CD console, which was created as part of a failed partnership between Nintendo and Sony some 25 years ago, has been discovered.

Never-before-seen images offer the first ever close-ups of the machine, now yellowed with age, which combines the form factor of the SNES along with the branding of PlayStation.

The console is so rare that its specific design features, such as a horizontal volume slider at the front and an assortment of outputs at the back, were not public knowledge. There are several other known prototypes of the SNES-CD, each with different variations on its design, which likely means that the version pictured below is the only in existence.

Click on the thumbnails below to view the images in full-screen

The console is historically significant because it represents the brief partnership between Nintendo and Sony prior to its intense rivalry that still exists today.

At the Consumer Electronics Show in 1991, Sony showcased its Nintendo-endorsed vision for a SNES-CD, which it branded with a “PlayStation” logo. Nintendo shocked Sony, however, by suddenly announcing–at the same show–that it would be partnering with electronics firm Phillips instead.

Incensed and embarrassed, the Sony executive Ken Kutaragi began to internally lobby the company to fund plans to build a console without Nintendo’s support. The outcome of that plan, also called the PlayStation, brought about a tectonic power-shift in the games business.

This prototype model was found by the son of a businessman who had ties with a former Sony executive, believed to be Olafur Olafsson, who was the chief executive of Sony Interactive Entertainment in 1991.

The son, who is only known by his online handle ‘Dnldbld’, first published the images on Reddit, and then on Assembler Games. He says that he will try to find the power supply for the prototype and boot the system up for the first time.