It's the original UMPC: Epson's HX-20, announced in 1981 - 25 years before Intel and Microsoft formally launched the ultra-mobile PC category, in April 2006. Epson's machine wasn't the first portable computer - that honour goes to the Osborne 1. But while the Osborne was a beast of a machine, designed more as a desktop you could take from place to place, the HX-20 was a truly a system for computing on the move. So while the HX-20 combined not only a full QWERTY keyboard, a display, storage and even a printer into its 28.4 x 21.3 x 4.4cm casing,...