HackAday have posted a nice tutorial on how to run dumb terminal built from Atmega128.
With simple hardware you can have handy tool that can help to rescue a headless server or simply use as minicomputer with keyboard and LCD screen. Device can work with windows and Linux. But with Linux you can see the real power of usage. Curious? – Just connect device and start Linux booting on PC – you will seethe whole booting process where you will have to interact by “Pressing any key and event entering Login information.