Editing Dot matrix printing (section)

==Manufacturers and models==
{{Summarize section|date=May 2023}}

===DEC===
{{Main|DECwriter}}
Unlike the [[#LA30|LA30]]'s 80-column, uppercase-only 5 x 7 dot matrix, DEC's product line grew. New models included:
* LA36 (1974): supported upper and lower case, with up to 132 columns of text (also 30 CPS)
* LA34: a lower-cost alternative to the LA36
* LA38: an LA34 with more features
* LA180: 180 CPS
* LS120: 120 CPS
* LA120: 180 CPS (and some advanced features)
* LA12: a portable terminal – the [[DECwriter#DECwriter Correspondent|DECwriter Correspondent]]<ref>{{cite magazine |title=DEC Introduces New 'Correspondent' |date=April 1982 |magazine=Hardcopy |page=13}}</ref>

====LA30====
The DECwriter LA30 was a 30 character per second dot matrix [[printing terminal]] introduced in 1970 by [[Digital Equipment Corporation]] (DEC) of [[Maynard, Massachusetts]]<ref>{{cite book |title=PDP-11 Processor Handbook |date=1973 |publisher=[[Digital Press]], [[Digital Equipment Corporation]] (DEC) |pages=1–4 |quote=Digital Equipment Corporation (DEC) designs and manufacturers many of the peripheral devices offered with PDP-11's. As a designer and manufacturer of peripherals, DEC can offer extremely reliable equipment... The LA30 DECwriter, a totally DEC-designed and built teleprinter, can serve as an alternative to the Teletype.}}</ref>

It printed 80 columns of uppercase-only 7 × 5 [[dot matrix]] characters across a unique-sized paper. The printhead was driven by a [[stepper motor]] and the paper was advanced by a noisy [[solenoid]] [[ratchet (device)|ratchet]] drive. The LA30 was available with both a [[parallel interface]] (LA30-P) and a [[serial interface]] (LA30-S); however, the serial LA30 required the use of [[fill character]]s during the carriage-return. In 1972, a receive-only variation named LA30A became available.

====LA36====
The LA30 was followed in 1974 by the LA36,<ref>{{cite web |title=The DEC LA36 Dot Matrix Printer Made Business Printing Faster |url=https://biztechmagazine.com/article/2017/03/dec-la36-dot-matrix-printer-made-business-printing-faster-and-more-efficient |access-date=2018-10-18 |url-status=live |archive-url=https://web.archive.org/web/20181018122252/https://biztechmagazine.com/article/2017/03/dec-la36-dot-matrix-printer-made-business-printing-faster-and-more-efficient |archive-date=2018-10-18 |quote=DEC brought the LA36 to market in 1974}}</ref> which achieved far greater commercial success,<ref name="UK2">{{cite web |title=Digital DECWriter II |website=ComputingHistory.org.uk |url=https://www.computinghistory.org.uk/det/3367/Digital-DECWriter-II |access-date=2018-10-18 |url-status=live |archive-url=https://web.archive.org/web/20181018122258/http://www.computinghistory.org.uk/det/3367/Digital-DECWriter-II |archive-date=2018-10-18 |quote=The LA36 DECwriter II was the companys first commercially successful ... The printer mechanism uses a dot-matrix technique to print 132 columns of text across standard 14 inch computer forms}}</ref> becoming for a time the standard dot matrix computer terminal. The LA36 used the same print head as the LA30 but could print on forms of any width up to 132 columns of mixed-case output on standard [[line printer#green bar paper|green bar fanfold paper]].<ref name="UK2"/> The carriage was moved by a much-more-capable [[servo drive]] using a [[DC electric motor]] and an optical encoder / [[tachometer]]. The paper was moved by a stepper motor. The LA36 was only available with a serial interface but unlike the earlier LA30, no fill characters were required. This was possible because, while the printer never communicated at faster than 30 characters per second, the mechanism was actually capable of printing at 60 characters per second. During the carriage return period, characters were ''buffered'' for subsequent printing at full speed during a catch-up period. The two-tone buzz produced by 60-character-per-second catch-up printing followed by 30-character-per-second ordinary printing was a distinctive feature of the LA36, quickly copied by many other manufacturers well into the 1990s. Most efficient dot matrix printers used this buffering technique.

Digital technology later broadened the basic LA36 line into a wide variety of dot matrix printers.

====LA50====
The DEC LA50 was designed to be a "compact, dot matrix"<ref name="MAN50"/> printer. When in graphic mode (as opposed to text mode), the printhead can generate graphic images. When in ([[bitmap]]) graphics mode, the LA50 can receive and print [[Sixel]]{{efn|short for "six pixels:" a pattern six [[pixel]]s high and one wide, resulting in 64 possible patterns.}} graphics format.
[[File:Sixel Wikipedia logo.png|thumb|The Wikipedia logo, converted to [[Sixel]] format]]

===Centronics 101===
{{Main|Centronics#Centronics 101}}
The [[Centronics#Centronics 101|Centronics 101]]<ref>Centronics and Digital Equipment corporation launch the dotmatrix printers, Centronics 101 and LA30 respectively. Centronics claimed to be the first..." {{cite book |author=Raveesh Mayya.K |title=BLITZ-THE IT QUIZ BOOK |date=2012 |publisher=Sapna Book House (P) |isbn=978-8128005800 |url=https://books.google.com/books?isbn=8128005804}}</ref> (introduced 1970) was highly innovative and affordable at its inception. Some selected specifications:
* Print speed: 165 characters per second
* Weight: 155 pounds (70.3&nbsp;kg)
* Size: 27 ½" W x 11 ¼" H x 19 ¼ D (approx. 70&nbsp;cm x 29&nbsp;cm x 49&nbsp;cm)
* Shipping: 200 pounds (approx. 91&nbsp;kg), wooden crate, unpacked by removal of 36 screws
* Characters: 62: 10 numeric, 26 upper case, and 26 special characters (no lower case)
* Character size: 10 characters per inch (10 "''pitch''")
* Line spacing: 6 lines per inch (6 LPI)
* Vertical control: punched tape reader for top of form and vertical tab
* Forms thickness: original plus four copies
* Interfaces: Centronics parallel, optional RS-232 serial

===IBM 5103===
[[File:IBM 5103 printer in Tekniska museet (1).jpg|thumb|IBM 5103 printer in [[Swedish National Museum of Science and Technology|Tekniska museet]]]]
The IBM 5103<ref>{{cite book |title=IBM 5103 printer |date=April 1979 |url=https://www.computerhistory.org/collections/catalog/102621955 |access-date=2021-07-15 |url-status=live |archive-url=https://web.archive.org/web/20210715210729/https://www.computerhistory.org/collections/catalog/102621955 |archive-date=2021-07-15}}</ref> was the only IBM printer that could be attached to the [[IBM 5100]], an early day portable computer. Printing was 8 DPI, 10 pitch, 6 LPI, and capable of printing bidirectionally from a 128-character set. Two models were offered:<ref>{{cite web |title=IBM Archives: IBM 5120 Computing System |date=23 January 2003 |website=[[IBM]] |url=https://www.ibm.com/ibm/history/exhibits/pc/pc_6.html |access-date=15 July 2021 |url-status=live |archive-url=https://web.archive.org/web/20210516205203/https://www.ibm.com/ibm/history/exhibits/pc/pc_6.html |archive-date=16 May 2021 |quote=two previously announced products: the IBM 5103 models 11 and 12 bidirectional, matrix printers}}</ref> 80 and 120 characters per second.<ref>{{cite web |title=IBM 5103 Dot matrix printer |website=computermuseum.informatik.uni-stuttgart.de |url=https://computermuseum.informatik.uni-stuttgart.de/dev/ibm_5110/technik/en/5103.html |access-date=2021-07-15 |url-status=live |archive-url=https://web.archive.org/web/20210715210729/http://computermuseum.informatik.uni-stuttgart.de/dev/ibm_5110/technik/en/5103.html |archive-date=2021-07-15}}</ref>

====Near Letter Quality (NLQ)====
{{Main|Near letter-quality printing}}
''Near Letter Quality'' mode—informally specified as almost good enough to be used in a business letter<ref name="MX6-3">{{cite book |title=Dot Matrix, InfoWorld Jul 28, 1986 |date=28 July 1986 |url=https://books.google.com/books?id=Vy8EAAAAMBAJ&q=dot%20matrix%20letter%20quality&pg=PA40}}</ref>—endowed dot-matrix printers with a simulated typewriter-like quality. By using multiple passes of the carriage, and higher dot density, the printer could increase the effective resolution. In 1985, ''The New York Times'' described the use of "''near letter-quality,'' or NLQ" as "just a neat little bit of hype"<ref name="NYT.dot2"/> but acknowledged that they "really show their stuff in the area of fonts, print enhancements and graphics."

NLQ printers could generally be set to print in "draft mode", in which case a single pass of the print head per line would be used. This produced lower quality print at much higher output speed.