Epson MX-80 (1980)

What the Epson MX-80 was

The Epson MX-80 was a 9-pin impact dot matrix printer introduced by Seiko Epson in October 1980. It printed on continuous, pin-feed (tractor) paper at up to 80 characters per second and offered user-selectable line lengths of 40, 66, 80, or 132 columns. In the United States it was distributed by Epson America, Inc.; the Computer History Museum's copy of the technical manual is attributed to Epson America and dated circa 1980. According to Seiko Epson's product history, the machine measured roughly 374 x 305 x 107 mm and weighed 5.5 kg. Related variants and revisions followed in the same product line, including F/T and III models; the Smithsonian's National Museum of American History holds an 'MX-80 Dot-Matrix Printer III F/T'.

How it printed: 9-pin impact dot matrix

Like other impact dot matrix printers, the MX-80 formed characters by driving thin pins through an inked ribbon against the paper, building each glyph from a grid of dots. Seiko Epson describes a nine-pin 'microdot' print head producing a 9 x 9 character composition, with bidirectional printing and logic seeking so the head prints in whichever direction reaches the next line sooner. Wikipedia describes the MX-80's 9-pin head as the first disposable, user-serviceable print head on the market. The underlying mechanism is covered in the dot matrix printing overview.

Connectivity and configuration

According to Wikipedia, the MX-80 shipped with a Centronics parallel interface as standard, with an optional RS-232 serial board (Epson's 8143) and an optional IEEE-488 (GPIB) board available for other host systems. Its adjustable pin-feed platen accepted continuous paper roughly 4 to 10 inches wide. Epson's spec sheet lists a 'JIS 128 or ASCII 96' character set, while Wikipedia records 95 printable ASCII characters together with 64 block-graphics characters (the TRS-80 set).

A commercial landmark

The MX-80 was a major commercial success. Seiko Epson's own history reports that by 1982 it held about half of the global market for 80-column printers, and Wikipedia additionally records a regional breakdown of roughly 35 percent in the United States, 60 percent in Europe, and 70 percent in Japan, along with sales of well over one million units across its market life. Contemporary accounts credit it with helping establish Epson as a leading printer brand during the early years of the personal computer. These market and sales figures are reported by Epson and Wikipedia; this page reproduces them with attribution rather than as independent measurements.

Origin of ESC/P

Wikipedia describes the MX-80 as the progenitor of ESC/P, the escape-code control language Epson formalized in the early 1980s and carried across later dot matrix and inkjet printers. ESC/P let software control features such as line spacing, character pitch, and emphasized or condensed type through in-stream escape sequences embedded in the print data. Epson's ESC/P language is documented separately.

Documented specifications

Authoritative records agree on the core specifications: a 9-pin impact dot matrix mechanism printing at 80 characters per second with selectable 40, 66, 80, or 132-column line lengths, bidirectional and logic-seeking. Figures that cannot be traced to a manufacturer, museum, or archive record - such as any dots-per-inch resolution rating, internal memory size, or duty cycle - are omitted here rather than estimated.

Reference scope

This page records only facts traceable to authoritative sources: Seiko Epson's product history and spec sheet, Wikipedia, the Computer History Museum, and the Smithsonian's National Museum of American History. It is not a buying guide and quotes no current pricing or availability; the single price figure shown - a US$650 introductory list price reported by Wikipedia - is historical. Any specification that cannot be sourced is omitted rather than guessed.