A long time ago, when I was a nipper, the Sega Neptune was whispered around in playgrounds like a strange urban legend. When the name was first bandied around we though it was a next gen console, but it turns out that the Neptune was actually an attempt to fuse the dreadfully mismanaged Sega 32X and the Sega Mega Drive into one superfluous console. Considering the massive consumer confusion that arose when Sega started releasing all these bizarre add-ons, a product like this made perfect sense.
But it wasn't to be. Sega was simply too close to the release of the Sega Saturn, so the Neptune project was canceled. Apparently several prototypes were designed and they actually worked, but the Sega Neptune became a ghost, an old wive's tale, resurfacing as a ubiquitous April Fool's jokes but nothing more.
But what if I told you you could build your own Sega Neptune? What if you could take a Sega Mega Drive 2 and a Sega 32X and fuse them together into a bizarre chimera that resembles what Sega Neptune would be? You would say, 'shut-up Mark, east your porridge and wake the hell up from this glorious lucid dream'. But it's true. It can be done and this set of instructions will tell you how.
Don't go into this endeavour under any illusions -- this shit is hard. This isn't a simple job, it's extremely difficult. In no way would I be able to do it. But it's worth looking at this set of instructions to see the process and the final product.
How to make a Sega Neptune [Longhorn Engineer]
Thanks to Marco Boncordo for sending this in!