5. Atari 400 (1979)

Atari's first low-end personal computer sported 8KB of RAM and a flat, sealed "membrane" keyboard--a design often touted as a rugged, spill-resistant alternative to the traditional full-stroke keyboard back in the early 1980s. The truth is that the one-piece membrane keyboard was vastly less expensive to manufacture. Aside from slightly raised borders around each key, the Atari 400's keys lay completely flat, devoid of tactile response; users could not physically tell if they successfully pushed one. Atari compensated for this by making the computer generate a click from an internal speaker every time users depressed a key. The Atari 400's keyboard benefits from a relatively standard key layout, but the dangerous Break key (one of the keys you'd presumably need the least) sat directly to the right of the oft-used Backspace key. Woe to the student who typed a term paper on this beast.