# Epson MX-80

The MX-80 is a serial dot matrix printer introduced by Seiko Epson in 1980. The MX-80 is capable of printing a maximum of 132 columns per line, while its 9-pin printhead was the first disposable, user-serviceable printhead on the market. The MX-80 was a massive commercial success for Epson and soon became the best-selling dot matrix printer in the world, selling well over one million units over the course of its market lifespan. It enjoyed a high level of popularity in the personal computer marketplace for much of the 1980s and was the progenitor of the ESC/P printer control language. The form factor and basic functionality of the MX-80 soon became a de facto standard for manufacturers of inexpensive dot matrix printers. Epson released a number of succeeding revisions of the MX-80 before replacing the entire line with the FX-80 in 1983.

## Background and development

Seiko Epson (known as Shinshu Seiki until 1975) entered the market for computer printers with the EP-101, a miniature drum printer, in 1968. In early 1978, the company introduced their first serial dot matrix printer, the TX-80. The product of only three months of development, the TX-80 was the first sub-US$2,000 dot matrix printer on the market. It was also Epson's first printer marketed in the United States.$^{:8}$ Despite its relatively low cost, as well as a lucrative contract with Commodore to market the printer for users of their PET microcomputer, the TX-80 sold slower than Epson had anticipated and ultimately failed to achieve a large market share, being pulled from the American market not too long after its introduction.$^{:8}$
Epson then spent three years devising their next dot matrix printer. During development, the company pioneered a number of features, such as logical bidirectional printing to maximize throughput; and disposable printheads.$^{:4}$ The resulting MX-80 was released October 1980, amid a period of explosive growth in the microcomputer industry.$^{:5}$$^{:191}$ Epson supported the rollout of the MX-80 with an extensive print marketing campaign, produced by Ripley-Woodbury Advertising.$^{:4–5}$ The company meanwhile hired David A. Lien, a prolific computer writer at the time, to write the printer's manual in a user-friendly manner, eschewing the jargon and otherwise terse technical language ubiquitous in contemporary printer manuals.$^{:6–7}$ Epson also partnered with the retailer ComputerLand for the latter to sell and service MX-80, supplementing Epson's own national service centers.$^{:7}$

## Specifications

The case of the MX-80 measures roughly 12 by 15 by 4 inches (300 by 380 by 100 mm). Its pin-feed platen is adjustable, supporting tractor-feed paper between 4 and 10 inches (100 and 250 mm) wide.$^{:13}$ The original version of the MX-80 printer requires the use of tractor-feed paper and lacks a friction-feed platen;$^{:91}$ later variants of the MX-80 come with both a tractor-feed platen and a pin-feed platen, with the latter as a removable piece.$^{:18}$ The printer's electronics contain a sufficient data buffer to allow the printhead to print bidirectionally—printing in the opposite direction immediately after reaching the end of one line—in order to minimize the printhead's seek time and maximize throughput. In addition, the MX-80's firmware ROM takes count of the length of each line printed as well as the position of the printhead on the paper in order to calculate exactly how much and in what direction the printhead needs to move to reach the start (or end) of the next line. This logical bidirectional printing increases throughput further.$^{:10}$ The MX-80 also detects special escape characters as part of its printer control language, allowing the printhead to be tabbed over to specific areas on the page, useful for automated form filling.$^{:11}$
The MX-80's printhead is a 9-pin design, allowing for a maximum vertical resolution of nine dots per line.$^{:52}$ Across an eight-inch space, the MX-80 can print lines in densities of 40, 66, 80, or 132 columns. While textual characters are normally laid out in a 6 by 9 dot grid, the printer's ROM can have the printhead impact the paper in half-steps horizontally, allowing for slightly smoother letterforms.$^{:52–53}$ The MX-80 was the first printer on the market with disposable, user-serviceable printheads, with replacement heads costing roughly US$30 in 1980. The printhead is good for roughly 50 million character impressions; after its end-of-life, it can be disposed of and replaced by the user without needing tools.
The MX-80 is capable of printing all 95 printable ASCII characters.$^{:11}$ The printer also supports printing block graphics characters from a set of 64 characters (corresponding to the TRS-80 character set). This allows for the creation of low-resolution graphical prints. A set of DIP switches on the back of the MX-80 can be flipped to switch out the stock ASCII character set with ones for other languages, including a Japanese katakana character set. By sending certain escape characters to the printer, text can be formatted in a multitude of ways, including varying the width and weight of each character.$^{:13}$ Weight can be increased by doublestriking each letter in one of two modes: "emphasized mode", in which the character is doublestruck after advancing the printhead the length of a half-dot; and "double-strike mode", in which the paper is advanced 1/216th of an inch and doublestruck.$^{:80–82}$

## Graftrax

Graftrax was a set of three$^{:60}$ EPROMs offered by Epson for the MX-80, enhancing the printer's functionality and behavior. The original Graftrax 80, released in 1981, added a high-resolution graphical printing mode with the ability to control each pin of the printhead arbitrarily to produce complex bitmap graphics. In addition, the Graftrax 80 added italics character sets for each font weight and width; software-redefinable escape characters, allowing end users to use the MX-80 with software meant for other printers; the ability to control the line height by increments of 1/216th of an inch; the ability to change the formatting of text in the middle of a line, instead of having the entire line affected.$^{:23–25}$ In 1982, Epson introduced Graftrax Plus, which dropped support for the TRS-80 block characters in favor of the ability to backspace, or to move the printhead backwards the length of one character in order to (for example) doublestrike arbitrarily; added superscript, subscript, and true underline formatting (as opposed to typewriter-convention underlining, wherein the users doublestrikes letters with the underscore characters, often clashing with descenders); added special international symbols such as the tilde (~), the unofficial franc symbol (₣), and the umlaut (¨).$^{:60–61}$$^{:25}$

## Other models

Epson released a number of variants of the MX-80 during the 1980s. Collectively, these printers comprise the Epson MX series:$^{:15–20}$
* MX-70 (early 1981) – a cost-reduced version of the MX-80 with unidirectional printing, a 7-pin printhead (with alphanumeric characters lacking descenders and half-step dot features), and the Graftrax II ROM set, the latter allowing for the printing out of high-resolution, arbitrary bitmap graphics;
* MX-80 F/T (early 1981) – a version of the MX-80 with a removable friction-feed platen, allowing the user to feed in plain loose-leaf paper, without the need for perforations; and
* MX-100 (June 1981) – a wide-format version of the MX-100 with a 15-inch pin-feed and friction-feed platen (capable of printing up to 233 columns of text), a high-resolution graphical printing mode, additional international character sets, adjustable right margins, and the ability to print on perforations.
IBM sold a badge-engineered version of Epson's MX-80 as the IBM 5152 Graphics Printer, featuring a modified firmware ROM with a different character set and a slightly altered PCL, as an accessory to their original IBM PC.$^{:6}$
The MX series of printers was retired in the mid-1980s, after Epson released its successor the FX-80 in 1983, featuring a wider platen, a faster printhead, a larger data buffer, user-definable character sets for custom symbols and typefaces, and more.$^{:28–30}$

## Sales and reception

The MX-80 was an immediate critical and commercial success for Epson, the company selling tens of thousands of units within two months of its introduction. Over 200 thousand MX-80s were sold throughout the entirety of 1981, with monthly production ramping up from 10,000 units a month in January 1981 to 40,000 units a month in October that year.$^{:191}$ By 1982 the MX-80 had captured half of the global market share for 80-column printers, with a 35-percent share in the United States, a 60-percent share in Europe, and a 70-percent share in Japan.$^{:191}$ It was the best-selling dot matrix printer for much of the 1980s, its global market share eventually peaking at 60 percent. By the end of the MX-80's lifespan in the mid-1980s, Epson had sold well over one million units of the printer. According to the Byte writers David and Richard Kater, the widespread adoption of the MX-80 was down to a mixture of the printer's low price, ease of use, and smart design, as well as Epson's marketing push and the concurrent meteoric growth of the personal computer market.$^{:5}$
The MX-80 was widely cloned by other manufacturers,$^{:5}$ with its form factor and functionality quickly becoming a de facto standard for nearly all dot matrix printers that followed it. A market for printer accelerator boards and other accessories designed specifically for the MX-80 also sprang up after its release,$^{:7}$ while its printer control language was heavily borrowed by other printer manufactuers and software developers in the industry. This PCL was eventually codified in the early 1980s by Epson as ESC/P and received a number of updates over the years, increasing its feature set.
The MX-80 was named by PC World's Christopher Null as the 42nd greatest technology product of all time in 2007.