Just to add a little detail to the beginning of the article: Mechanical typewriter like the great little Smith-Corona shown above, and early electric typewriters, used pivoting arms with molded letterforms on the paper-striking end. This was followed by IBM's Selectric typewriter (and later the 2741 computer terminal), which used a semi-spherical typehead usually referred to as a golfball containing all of the characters. Somewhere around that same time, the Teletype Model ASR-33 was using a cylinder for a printhead. The actual daisy-wheel printers (made primarily by Xerox, Diablo, and Qume) used a metal or plastic disk of "petals" each with a molded character. I've used typewriters and printers with all 3 mechanisms. Thanks for the great article, and good comments too!