Casemods follow a pretty simple equation: take a non-standard, preferably unusual container, add PC components, and voilà. Of course, then the interest comes from fitting a PC where previously it simply wouldn't fit. Enter modder Unravelled, and his Sinclair ZX81 casemod: a VIA EPIA Pico-ITX based computer stuffed inside this compact chunk of 80s memorabilia.
The ZX81 casing measures around 6.6 x 6.9 x 1.6 inches, which makes for a tight squeeze inside. Nonetheless, you're looking at a full motherboard, with separate hard-drive (no CF cop-out here) and multiple ports, capable of running either Windows or Linux.
It's not clear whether the wretched keyboard has been wired up to actually work with the new components. I'm thinking no, as it's pictured with a separate keyboard.