Between 1952 and 1954 Fritz Karl Preikschat filed five patent applications for his so-called "PKT printer", a dot matrix teletypewriter built between 1954 and 1956 in Germany. Like the earlier Hellschreiber, it still used electromechanical means of coding and decoding, but it used a start-stop method (asynchronous transmission) rather than synchronous transmission for communication. In 1956, while he was employed at Telefonbau und Normalzeit GmbH (TuN, later called Tenovis), the device was offered to the Deutsche Bundespost (German Post Office), which did not show interest. When Preikschat emigrated to the US in 1957 he sold the rights to utilize the applications in any country (except the USA) to TuN. The prototype was also shown to General Mills in 1957. An improved transistorized design became the basis for a portable dot matrix facsimile machine, which was prototyped and evaluated for military use by Boeing around 1966–1967. left|thumb|An Epson MX-80, a classic model that remained in use for many years. IBM sold it as their IBM 5152. IBM marketed its first dot matrix printer in 1957, the same year that the dye-sublimation printer entered the market.
Between 1952 and 1954 Fritz Karl Preikschat filed five patent applications for his so-called "PKT printer", a dot matrix teletypewriter built between 1954 and 1956 in Germany. Like the earlier Hellschreiber, it still used e,lectromechanical means of coding and decoding, but it used a start-stop method (asynchronous transmission) rather than synchronous transmission for communication. In 1956, while he was employe,d at Telefonbau und Normalzeit GmbH (TuN later called Tenovis), the device was offered to the Deutsche Bundespost. (German Post Office) which did not show interest. When Preikschat emigrated to the US in 1957 he sold the rights to utilize the applications in any country (except the USA) to TuN. The prototype was also shown to General Mills in 1957. An improved transistorized design became the basis for a portable dot matrix facsimile machine, which was prototyped and evaluated for military use by Boeing around 1966–1967. left|thumb|An Epson MX-80, a classic model that remained in use for many years. IBM sold it as their IBM 5152. IBM marketed its first dot matrix printer in 1957, the same year that the dye-sublimation printer entered the market