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IBM 1403 line printer, the classic line printer of the mainframe era.

A line printer prints one entire line of text before advancing to another line.[1] Most early line printers were impact printers.

Line printers are mostly associated with unit record equipment and the early days of digital computing, but the technology is still in use. Print speeds of 600 lines per minute[2] (approximately 10 pages per minute) were achieved in the 1950s, later increasing to as much as 1200 lpm. Line printers print a complete line at a time and have speeds in the range of 150 to 2500 lines per minute.

Some types of impact line printers are drum printers, band-printers, and chain printers. Non-impact technologies have also been used, e.g., thermal line printers were popular in the 1970s and 1980s,[3] some inkjet and laser printers produce output a line or a page at a time.

Designs

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Many impact printers, such as the daisywheel printer and dot matrix printer, used a print head that printed a character then moved on until an entire line was printed. Line printers were much faster,[4] as each impact printed an entire line.

There have been five principal designs:

  • Drum printers
  • Chain (train) printers
  • Bar printers
  • Comb printers
  • Wheel printers

Because all of these printing methods were noisy, line printers of all designs were enclosed in sound-absorbing cases of varying sophistication.

Timing-sensitive designs

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Several designs of printers have similar characteristics.

Drum printer

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Drum Printer
Typical print of a drum printer, showing the characteristic vertical misalignment of characters due to slight hammer timing errors (mainframe; about 1965)
Fragment of line printer drum
showing "%" characters.

In a typical drum printer design, a fixed font character set is engraved onto the periphery of a number of print wheels, the number matching the number of columns (letters in a line) the printer can print. The wheels, joined to form a large drum (cylinder), spin at high speed. Paper and an inked ribbon are stepped (moved) past the print position. As the desired character for each column passes the print position, a hammer strikes the paper from the rear and presses the paper against the ribbon and the drum, causing the desired character to be recorded on the continuous paper. Because the drum carrying the letterforms (characters) remains in constant motion, the strike-and-retreat action of the hammers has to be very fast. Typically, they are driven by voice coils mounted on the moving part of the hammer.

Large mechanical and electric stresses occur when the line to be printed requires firing all of the hammers simultaneously. With simple type layouts, this happens when the line consists of a single character repeated in all columns, such as a line of dashes ("----...---") To avoid this problem, some printers use a staggered arrangement, with the characters in each column rotated around the drum by a different amount. Then simultaneous firing occurs only if the printed line matches the character layout on the drum, which should not happen in normal text.

Lower-cost printers do not use a hammer for each column. Instead, a hammer is provided for every other column, and the entire hammer bank is arranged to shift left and right, driven by an additional voice coil. For this style of printer, two complete revolutions of the character drum are required to print each line, with one revolution being used to print all the "odd" columns and another revolution being used to print all of the "even" columns. This requires only half (plus one) the number of hammers, magnets, and the associated channels of drive electronics.

At least one low-cost printer, made by CDC, achieves the same end by moving the paper laterally while keeping the hammer bank at rest.

Dataproducts was a typical vendor of drum printers, often selling similar models with both a full set of hammers (delivering, for example, 600 lines-per-minute of output) and a half set of hammers (delivering 300 LPM).[5]

Printers with horizontally moving print elements

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Chain printer
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Chain Printers place the type on a horizontally-moving circular chain. As with the drum printer, as the correct character passes by each column, a hammer is fired from behind the paper. Compared to drum printers, chain printers have the advantage that the type chain can usually be changed by the operator. A further advantage is that vertical registration of characters in a line is much improved over drum printers, which need extremely precise hammer timing to achieve a reasonably straight line of print. By selecting chains that have a smaller character set (for example, just numbers and a few punctuation marks), the printer can print much faster than if the chain contains the entire upper- and lower-case alphabet, numbers, and all special symbols. This is because, with many more instances of the numbers appearing in the chain, the time spent waiting for the correct character to "pass by" is greatly reduced. Common letters and symbols appear more often on the chain, according to the frequency analysis of the likely input. IBM was probably the best-known chain printer manufacturer, and the IBM 1403 is probably the most famous example of a chain printer.

Train printer
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Train printers place the type on a horizontally-moving circular train of print slugs. with multiple characters per slug, on a track, The technology is almost identical to print chains.

Band printer
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Fragment of printer band, sitting on test printout for the characters (top) and hammer flight times (bottom)

Band printers are a variation of chain printers in which a thin steel band is used instead of a chain, with the characters embossed or etched onto the band. Again, a selection of different bands are generally available with a different mix of characters so a character set best matched to the characters commonly printed can be chosen. Dataproducts was a well known manufacturer of band printers, with their B300, B600, and B1000 range, the model number representing the lines per minute rate of the printer.[6] (The B300 is effectively a B600 with only half the number of hammers—one per two character positions. The hammer bank moves back and forth one character position, increasing the average number of band movements required for each line.)

Bar printer
[edit]

Bar printers were similar to chain printers but were slower and less expensive. Rather than a chain moving continuously in one direction, the characters were on fingers mounted on a bar that moved left-to-right and then right-to-left in front of the paper. An example was the IBM 1443.

Common characteristics
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In all four designs, timing of the hammers (the so-called "flight time") was critical, and was adjustable as part of the servicing of the printer. For drum printers, incorrect timing of the hammer resulted in printed lines that wandered vertically, albeit with characters correctly aligned horizontally in their columns. For train and bar printers, incorrect timing of the hammers resulted in characters shifting horizontally, printed closer or farther from the next character, or blurred on one side, albeit on vertically-level printed lines. The vertical misalignment of drum printers is more noticeable and annoying to human vision (see the sample pictured in this article).

Most drum, chain, and bar printers were capable of printing up to 132 columns, but a few designs could only print 80 columns and some other designs as many as 160 columns.

Comb printer

[edit]

Comb printers, also called line matrix printers, printed a matrix of dots instead of individual characters in the same way as single-character dot matrix printers, but using a comb of hammers to print a portion of an entire row of pixels at one time (for example, every eighth pixel). By oscillating the comb or "print shuttle" left and right a short distance, the entire pixel row could be printed (continuing the example, in eight cycles). The paper then advanced and the next pixel row was printed. Because far less print head motion was involved than in a conventional dot matrix printer, these printers were much faster, and competitive in speed with formed-character line printers without being restricted to a set of available characters, thus being able to print dot-matrix graphics and variable-sized characters.

Printronix and TallyGenicom are well-known vendors of comb printers. In 2009, TallyGenicom was acquired by Printronix.

Wheel printers

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In 1949 IBM introduced the IBM 407 Accounting Machine with a wheel print mechanism that could print 150 alphanumeric lines a minute. Each of the 120 print positions had its own type wheel which rotated under electromechanical control. Once all were in position, print hammers struck the wheels against a ribbon and the paper. The 407 or its wheel line printer mechanism was attached to a variety of early IBM computers, including the IBM 650, most members of the IBM 700/7000 series and the IBM 1130, the last introduced in 1965.

Paper (forms) handling

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An IBM 1403 printer opened up as it would be to change paper. Note the form tractors on each side of the paper, and the carriage control tape in upper right. The print chain is covered by a full-width ink ribbon, see lower right: The hinged chain-and-ribbon assembly is here swung open towards the camera like a gate.
Green-zebra-paper

All line printers used continuous form paper provided in boxes of continuous fan-fold forms rather than cut-sheets. The paper was usually perforated to tear into cut sheets if desired and was commonly printed with alternating white and light-green areas, allowing the reader to easily follow a line of text across the page. This was the iconic "green bar", "blue bar" or "music-ruled" form paper that dominated the early computer age in several variants. Standard "green bar" page sizes included portrait-format pages of 8½ × 11 inches (letter size), usually printed at 80 columns by 66 lines of characters (at 6 lines per inch) or 88 lines (at 8 LPI), and landscape-format pages of 14 × 11 inches, usually printed at 132 columns by 66 or 88 lines. Also common were landscape-format pages of 14 × 8½ inches (legal size), allowing for 132 columns by 66 lines (at 8 LPI) on a more compact page.

Pre-printed forms were also commonly used (for printing cheques, invoices, etc.). A common task for the system operator was to change from one paper form to another as one print job completed and another was to begin. Some line printers had covers that opened automatically when the printer required attention. These continuous forms were advanced through the printer by means of tractors (sprockets or sprocket belts). Depending on the sophistication of the printer, there might simply be two tractors at the top of the printer (pulling the paper) or tractors at the top and bottom (thereby maintaining paper tension within the printer). The horizontal position of the tractors was usually adjustable to accommodate different forms. The earliest printers by IBM used a hydraulic motor to move the forms. In later line printers, high-speed servomechanisms usually drove the tractors, allowing very rapid positioning of the paper, both for advancing line-by-line and slewing to the top of the next form. The faster line printers, of necessity, also used "stackers" to re-fold and stack the fan-fold forms as they emerged from the printer.

The high-speed motion of the paper often developed large electrostatic charges. Line printers frequently used a variety of discharge brushes and active (corona discharge-based) static eliminators to discharge these accumulated charges.

Many printers supported ASA carriage control characters[citation needed] which provided a limited degree of control over the paper, by specifying how far to advance the paper between printed lines. Various means of providing vertical tabulation were provided, ranging from a paper carriage control tape loop to fully electronic (software-controllable) tab simulation.

Origins

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A type bar line printer was incorporated in the IBM 402 and 403 accounting machines.
An IBM 716 line printer, based on the IBM 407 wheel mechanism, attached to an IBM 7090 mainframe at NASA's Goddard Spaceflight Center during Project Mercury.

Tabulators built by the U.S. Census Bureau for the 1910 census could print their results.[7] Prior to that, tabulator operators had to write down totals from counter wheels onto tally sheets.[8] IBM developed a series of printing accounting machines, beginning in 1920. The 285 Numeric Printing Tabulator could read 150 cards per minute. The 405, introduced in 1934, could print at 80 lines per minute. It had 88 type bars, one for each print position, with 43 alphanumeric bars on the left, followed by 45 numeric-only bars.[9][10] The IBM 402 series, introduced after World War II, had a similar print arrangement and was used by IBM in early computing devices, including the IBM Card-Programmed Electronic Calculator.[11]

IBM's first commercial computer, the IBM 701, introduced in 1952, used a line printer, the IBM 716, that was based on the type wheel IBM 407 accounting machine. The 716 was incorporated in subsequent mainstream computers in the IBM 700/7000 series.

An early drum printer was the "Potter Flying Typewriter", in 1952. "Instead of working laboriously, one character at a time, it prints whole lines at once, 300 lines per minute, on a paper band. ... Heart of the machine is a continuously spinning disk with the necessary letters and numbers on its rim. ... As the disk revolves, 80 electrically operated hammers tap the back of the paper against an inked ribbon in contact with the disk, thus printing the proper characters in the proper places on the line."[12]

Influence on hardware and software

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The names of the lp and lpr commands in Unix were derived from the term "line printer". Analogously, many other systems call their printing devices "LP", "LPT", or some similar variant, whether these devices are in fact line printers or other types of printers. These references served to distinguish formatted final output from normal interactive output from the system, which in many cases in line printer days was also printed on paper (as by a teletype) but not by a line printer. Line printers printed characters, letters and numbers line by line. The parallel ports of computers so equipped were usually designated LPTx, for line printer.

See also

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References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Line printer

View on Grokipedia
from Grokipedia
A line printer is a high-speed impact printer designed for computer output that prints an entire line of text simultaneously as a single unit, rather than character by character. First appearing in the early , these devices were essential for mainframe computing environments, enabling rapid production of large volumes of printed data such as reports and listings at speeds ranging from 300 to over 3,000 lines per minute. Line printers originated in the early 1950s as specialized output devices for early electronic computers, with the first high-speed model being Remington-Rand's 1953 printer for the computer, which achieved 600 lines per minute. Notable early examples also include Fujitsu's 1954 type-bar model for the FACOM 100 system, which printed 60 characters per line at 100 lines per minute. IBM's iconic 1403 printer, introduced in 1959 alongside the 1401 system, became a flagship model, using a mechanism to achieve speeds up to 1,100 lines per minute while supporting 120 or 132 print positions. Common technologies included drum printers, where characters were etched on a rotating cylinder; printers, featuring a looped metal with embossed typefaces struck by hammers against an inked ; and band printers, which used a flexible band for similar high-speed operation. These impact-based designs produced characteristic noise and were often housed in cabinets, but they excelled in reliability for continuous, high-volume printing on continuous-form paper. By the 1970s and 1980s, line printers evolved with faster variants reaching 2,000 lines per minute, though they were gradually supplemented by non-impact technologies like dot-matrix and printers for broader applications. Today, surviving forms such as band and line matrix printers persist in datacenters, industrial settings, and environments requiring multi-part forms, where a 1,000 lines-per-minute line printer can equate to the throughput of a 50 pages-per-minute printer on forms.

History

Origins

A line printer is a high-speed impact printer designed to output an entire line of text or simultaneously, in contrast to character printers, which produce output one character at a time. This parallel printing mechanism enabled significantly faster throughput, making line printers essential for handling large volumes of in early environments. The origins of line printers trace back to the early , amid the rise of commercial computers for business applications. In 1952, introduced the High Speed Off-Line Printer System, a drum-based model capable of 600 lines per minute, marking one of the first commercial implementations tailored for the computer. This innovation addressed the need for rapid printing of tabular data and reports in off-line configurations, separate from the main processing unit. Another early example was Fujitsu's 1954 type-bar model for the FACOM 100 system, which printed 60 characters per line at 100 lines per minute. IBM advanced line printing technology with the introduction of the IBM 1403 in 1959, designed specifically for the IBM 1401 data processing system. Operating at speeds up to 600 lines per minute, the 1403 chain printer supported 132-column output and became a staple for printing detailed listings, accounting reports, and batch-processed data in mainframe setups. Its debut coincided with the growing demand for efficient data output in medium-sized business environments, where batch processing dominated workflows. IBM and Remington Rand played pivotal roles in pioneering line printing for business data processing, transitioning from earlier tabulating machines to integrated high-volume peripherals that standardized output for early computers. Their efforts in the 1950s laid the groundwork for subsequent refinements in speed and reliability.

Development and key models

The development of line printers accelerated in the 1960s as computing demands grew, evolving from the foundational 1950s models tied to early batch processing systems into faster, more reliable devices essential for enterprise data output. IBM's 1403, introduced in October 1959 alongside the 1401 data-processing system, set a benchmark with its chain-based impact mechanism, printing at 600 lines per minute (lpm) across 132 columns using a continuously moving chain of embossed type slugs struck by electromagnetic hammers. Over its lifespan, eight variants emerged, with the Model 3 (announced 1963 for the 1460 system) achieving 1,100 lpm—rising to 1,400 lpm for numeric-only subsets—through refined hammer timing and chain speeds of 5.2 meters per second, enabling over 23,000 units shipped in the U.S. by the early 1980s. This model's durability and print quality, via precise 11-microsecond hammer actuation, established impact printing as the dominant approach, prioritizing reliability over early non-impact experiments that proved less robust for high-volume use. To support integration with the System/360 mainframes launched in 1964, introduced the 2821 , which buffered data and managed operations for the 1403 (Models 2, 3, 7, and N1) and 1404 printers, sustaining speeds of 600 to 1,100 lpm while enabling concurrent I/O tasks via selector or multiplexer channels. Concurrently, advanced drum-based designs with the Model 501 printer for its 3200 computer system in 1964, delivering 1,000 lpm for 48-character sets or 800 lpm for 64 characters, emphasizing compatibility with scientific and real-time applications. In the , speeds escalated further; 's 3203 series, announced in , employed interchangeable train cartridges (IBM 1416) for flexible character sets, with the Model 5 (documented 1979) printing nominally at 1,200 lpm for 48 characters but up to 1,580 lpm for a 32-character set, supporting Universal Character Sets and multi-part forms up to four sheets. Digital Equipment Corporation's LP11, released around 1975 for PDP-11 minicomputers, adapted Data Products impact printers (Models 2230 to 2470), offering 300 to 1,000 lpm to meet the needs of smaller-scale systems. Regional innovations complemented these U.S.-led advancements, as seen in Japan's H-8245 and H-8246 models for the HITAC 8000 series in 1965, which built on licensed and technologies to achieve reliable high-volume output for domestic mainframes, later succeeded by the in-house H-8276 and H-8277 in the late 1970s. Honeywell contributed with models like the Series 200 printers in the , focusing on mechanisms for midrange systems, though specific speeds varied by configuration to around 600-1,200 lpm. By the mid-1970s, line printers reached peak enterprise adoption, exemplified by Printronix's P3000 series line-matrix models, which innovated shuttle-based printing to attain 3,000 lpm while reducing noise and maintenance, marking a milestone in non-mechanical alternatives for sustained high-speed operation.

Designs and types

Drum printers

Drum printers, also known as barrel printers, represent one of the earliest high-speed impact line printing technologies, featuring a horizontal that rotates continuously to facilitate parallel printing across multiple columns. The core design consists of a solid metal , typically 12 to 18 inches in , with raised type characters arranged in axial bands around its surface—one band per print column, such as 120 or 132 columns for standard line widths. Each band contains a complete set of printable characters embossed at equal intervals along the circumference, allowing hammers positioned behind the paper and inked to strike selectively as the spins, transferring to the paper "" without stopping the rotation. This mechanism evolved from earlier tabulator print wheels, enabling significantly faster output compared to character-by-character printers of the era. The timing mechanism relies on precise between the drum's constant and the of solenoid-driven for each print position. The drum typically rotates at speeds of 600 to 2000 (10 to 33 per second), completing one full to print an entire line as each character's slot aligns sequentially under its corresponding hammer. Electronic sensing, often using photocells or magnetic pickups on a code wheel affixed to the drum shaft, detects the angular position of characters and triggers the appropriate hammers via timing circuits, ensuring alignment within microseconds to avoid smearing. For instance, in the UNIVAC High-Speed Printer, the drum and code wheel operate at 922 rpm, with binary codes for 63 characters enabling hammer firing approximately every 1 as character slots align during the 65- . Character sets are fixed at 48 to 120 symbols per band, commonly supporting uppercase letters, numerals, and basic punctuation in encodings like for IBM-compatible systems or custom codes for others, with slots aligned to match the drum's geometry. These printers offered notable advantages in speed for applications, achieving up to 1,500 lines per minute, which supported the demands of early mainframe in the . However, limitations included the inability to change fonts without fabricating a new custom , potential for print quality issues like character blur from variability or wavy lines due to rigidity, and high levels from the rapid hammering action. Seminal examples include the Potter Flying (1952), an early model printing at approximately 600 lines per minute using a single large for all columns, and the High-Speed Off-Line Printer (1952), which also reached 600 lpm and influenced subsequent designs in military and commercial systems. printers were introduced in the as output needs grew beyond manual tabulators.

Chain and comb printers

Chain and comb printers represent an early class of high-speed impact line printers that employed a linear moving type element to produce fully formed characters across an entire print line in a single pass. These printers utilized an endless loop of steel chain or a rigid comb-like bar embedded with raised type slugs arranged in repeating sequences. The type element traveled horizontally behind the paper and inked ribbon, while a bank of solenoid-actuated hammers—one per print column—struck the assembly to transfer ink when the correct character aligned with each position. This design allowed for simultaneous printing of up to 132 characters per line at 10 characters per inch, enabling output rates far exceeding character printers of the era. Operation relied on precise between the type element's motion and activation. The or bar rotated at speeds of approximately 10 to 20 feet per second, completing multiple cycles per line to ensure all characters could be printed within the available window. Electronic sensing mechanisms, such as magnetic or optical detectors, monitored the type slugs' positions to trigger hammers with accuracy, typically dividing the print cycle into sub-intervals for alignment. For instance, the 1403 chain printer divided each line into three subscans, optimizing for line lengths divisible by three to minimize timing errors. In comb variants, the bar's fixed structure reduced vibration compared to flexible chains but required similar timing for hammer strikes. A defining feature was the modularity of character sets, with interchangeable chains or bars supporting 48 to 96 characters, including numerals, uppercase letters, and special symbols, allowing customization for different applications without hardware redesign. The 1403, introduced in 1959, exemplified chain printers with models ranging from 550 lines per minute (LPM) in basic configurations to 1,100 LPM in high-performance variants like the Model N1, using a repeating of 48 characters (with three subscans per line) supporting up to 132 positions for business . Comb printers employed a similar bar-based approach with engraved slugs on a comb-structured element for comparable speeds and reliability in industrial environments, such as certain IBM train printer variants. Maintenance focused on preserving the type element's and motion consistency. Chains required periodic via an oil-soaked wiper that applied a thin film to reduce and during high-speed operation, while tension adjustments prevented slippage or misalignment, a frequent issue leading to print skew or character offsets. Common failure points included chain stretching over time, necessitating replacement every 6,000 to 10,000 hours of use, and hammer fatigue from repeated impacts. Proper tensioning involved calibrating the drive sprockets to maintain even tracking, often checked during preventive servicing to sustain print quality.

Wheel and band printers

Band printers represent an evolution from earlier designs, employing a thin vertical band or loop that continuously circulates in front of the print line, with embossed characters positioned to pass sequentially before hammers aligned to each column. The band, approximately 0.010 inches thick and etched with characters on one or both sides, moves at speeds up to 25 feet per second, while or piezoelectric hammers activate precisely when the desired character aligns with the column, striking through an inked onto the paper. This vertical orbiting motion ensures uniform character timing across the 132-character line, achieving print speeds of up to 3,000 lines per minute depending on the character set density. Notable examples include the IBM 6262, which utilized a modular band system with up to three interchangeable bands supporting character sets of 48 to 192 glyphs, allowing customization for different languages or symbols without hardware changes. Similarly, impact band variants like the Memorex printers employed steel bands approximately 0.015 inches thick at embossed points for durable, high-volume output. Band printers offered advantages such as quieter operation than chain mechanisms due to smoother motion and reduced vibration, along with potential for basic graphics through selective hammer patterns forming dot approximations, though full graphics required specialized bands. However, the need for periodic band replacements increased maintenance costs compared to fixed-element designs. Wheel printers, while related to daisy wheel technology, were less common as true line printers and typically operated serially rather than in parallel across the line.

Operation

Printing mechanism

Line printers operate on of impact printing, where characters are formed by mechanically striking an inked against the using or similar mechanisms. In this process, the , typically a continuous fabric or film impregnated with , is positioned between the print element—such as a rotating , , or band—and the . When a activates behind the at the precise moment the desired character on the print element aligns with a print position, it transfers to the through physical force, creating a dot or full character impression. This alignment and timing ensure accurate character formation across the print line, often supporting multipart forms for carbon copies. Control systems in line printers rely on electromechanical or electronic circuits to synchronize the . Timing circuits, often incorporating flip-flops for state and signal latching, manage the activation of based on the or movement of the print element. A buffer memory, typically holding one full line of data (up to 132 characters), stores incoming print data before initiating the print cycle, allowing the host computer to continue without waiting for mechanical completion. These systems ensure precise hammer firing to match character positions, preventing smearing or misalignment. Printing speed is measured in lines per minute (LPM), determined by the number of character positions (commonly 120 to 132 columns) and the cycle time required for one complete rotation or pass of the print element. For instance, a cycle time of approximately 50 milliseconds enables speeds around 1200 LPM for a 132-column line, though actual rates vary with character set size due to additional pauses. These printers generate significant , typically 70 to 90 dB, from the rapid impacts and mechanical movements, often requiring enclosures for operator comfort. Data encoding for line printers commonly uses 8-bit codes such as to select characters, with each byte representing a position in the print line buffer. Parity bits are included in the print data for error detection, flagging transmission issues that could lead to print faults, such as incorrect character rendering. This encoding facilitates compatibility with mainframe systems and ensures reliable character selection during the high-speed printing cycle.

Paper handling and forms

Line printers primarily employed tractor-feed mechanisms for handling continuous forms, where perforated pin holes along the edges of the paper engaged with sprockets on adjustable tractors to ensure precise, non-slip advancement. These tractors, typically positioned in pairs (one input and one output), maintained consistent tension and alignment across paper widths ranging from 3 to 18.75 inches, accommodating fanfold forms common in high-volume printing environments. Friction-feed options were available for cut-sheet paper in select models, using rollers or platens to grip the edges, though tractor systems dominated for reliability in continuous operation. Line spacing was controlled by step motors or sprocket-driven clutches, standardizing at 6 to 8 lines per inch to match form perforations and prevent misalignment during rapid feeds. Multi-part forms, essential for generating simultaneous copies such as invoices or reports, utilized carbon-interleaved sheets or pressure-sensitive carbonless paper, supporting up to 6 plies with individual sheet weights of 9 to 15 pounds. The printing impact transferred through all layers via spot carbon or chemical coatings, with form thickness adjusted via levers to optimize pressure without smudging. Form length was regulated by sensing holes or perforations detected by optical or mechanical sensors, enabling automatic page ejection and preventing overfeeds in sequences up to 24 inches per form. Output handling involved additional tractors to guide printed forms into stackers or bursters, which separated individual sheets along perforations while maintaining tension to avoid tears; powered stackers in high-speed models (e.g., 1200 lines per minute) supported neat accumulation of multi-part outputs. Input systems featured floor-standing or pedestal hoppers capable of holding over 1000 sheets of fanfold paper, with adjustable guides for loading. Jam detection relied on sensors monitoring paper motion, triggering alarms for obstructions, empty supplies, or slow feeds, often halting operations to protect the mechanism. Key challenges in paper handling included correcting skew through precise alignment (±0.25 inches) and horizontal adjustments, as misalignment could cause character offsets in subsequent lines. Dust accumulation from high-volume fanfold paper necessitated regular cleaning of paths and to prevent sensor failures or feed interruptions, particularly in dust-prone mainframe environments.

Impact and legacy

Influence on hardware and software

Line printers significantly influenced early by driving the standardization of high-throughput (I/O) interfaces, particularly in mainframe systems. The IBM byte-multiplexer channel, introduced with the System/360 in , was specifically designed to handle slow-speed peripherals like line printers by interleaving byte transfers from multiple devices, enabling concurrent operations and efficient data flow without dedicating full channels to individual units. This design optimized resource utilization in data centers, where line printers required sustained data streams for printing entire lines at speeds up to 1,400 lines per minute, as in models of the 1403. Such interfaces supported up to 255 subchannels per controller, allowing mainframes to process batch jobs effectively by balancing CPU computation with peripheral output demands. In software, line printers prompted adaptations in programming languages and operating systems to manage line-oriented output efficiently. Fortran's PRINT statement, developed in the 1950s and refined through subsequent standards, was optimized for sequential, fixed-format printing on line printers, incorporating carriage control characters in the first column to dictate line spacing, skipping, and positioning—features directly tied to hardware like the 1403's 132-print-position mechanism. Similarly, the (JCL) in 's OS/360, released in 1966, included directives to queue print jobs via output writers, decoupling program execution from printer availability and preventing bottlenecks in multi-user environments. These features extended to error handling routines in assembly and higher-level languages, where print failures triggered retries or logging to maintain during high-volume operations. Line printers also standardized data formats across ecosystems, promoting fixed-width, line-oriented files that aligned with printer hardware constraints. Early systems favored 80-column formats inherited from punched cards for input, but output routinely used 132 columns to match printers like the 1403, influencing COBOL's report generation and listings to structure data in columnar, non-proportional layouts for reliable rendering. This convention persisted in , where traditional line data streams included optional carriage control and table reference characters followed by up to 208 data bytes per line, ensuring compatibility with 132-column printers without additional formatting. Economically, line printers enabled cost-effective high-volume output in 1960s-1970s data centers, where they accounted for 20-30% of hardware budgets and supported applications like and billing by producing thousands of pages monthly at speeds from 300 to 2,000 lines per minute. Rental costs ranged from $900 to $1,960 monthly for models like the 1403-N1 and 3203-2, with annual maintenance and supplies adding $10,000-15,000 per unit, yet their efficiency reduced overall peripheral expenditures by consolidating output needs and minimizing manual intervention. This influenced data center planning, prioritizing printers in configurations where output volume often exceeded input by 5:1 ratios in management information systems.

Decline and modern equivalents

The decline of line printers began in the as the rise of personal computers diminished the demand for centralized batch printing associated with mainframe systems. With the proliferation of affordable desktop computing, organizations shifted away from large-scale that required high-volume, text-only output, reducing the need for dedicated line printing infrastructure. This transition accelerated with the advent of graphical user interfaces and non-impact printing technologies, particularly laser printers, which offered superior quality, quieter operation, and versatility for . The introduction of the LaserJet in 1984 marked a pivotal moment, providing desktop users with high-resolution printing at 8 pages per minute for around $3,500, thereby creating a new market for individual and office-based printing that overshadowed traditional line printers. By the late 1980s and into the 1990s, line printer shipments had significantly declined, peaking at 115,000 units in 1981 before dropping sharply as and inkjet alternatives dominated. Widespread phase-out occurred by the mid-1990s in most commercial settings, though legacy support persisted through software emulators for maintaining older systems. Niche industrial applications, such as high-volume forms and labels, continued into the early before further reduced even these uses. Contemporary equivalents to line printers include modern line matrix printers designed for demanding industrial environments, such as and production. For instance, the Printronix P8000 series achieves speeds up to 2,000 lines per minute while handling multi-part forms, wide formats, and recycled media with high reliability. As of 2025, line matrix printers like the Printronix P8000 series remain in production for high-volume industrial printing, such as in and compliance labeling. Additionally, virtual printing solutions in cloud-based services emulate line printer output for legacy software integration, allowing batch jobs to generate digital or high-speed print mimics without physical hardware. The legacy of line printers is preserved through emulation software, notably the open-source Hercules emulator, which supports simulation of the iconic IBM 1403 printer for running historical mainframe operating systems. This enables retro computing enthusiasts and archival projects to replicate authentic printing behaviors, fostering niche revivals in hobbyist communities dedicated to vintage hardware preservation.

References

  1. https://www.merriam-webster.com/dictionary/line%20printer
  2. https://www.nielit.gov.in/gorakhpur/sites/default/files/Gorakhpur/olevel_2_ict_08apr_AB.pdf
  3. https://spectrum.ieee.org/how-the-ibm-1403-printer-hammered-out-1100-lines-per-minute
  4. https://www.ldproducts.com/blog/famous-dates-in-printer-history/
  5. https://museum.ipsj.or.jp/en/computer/device/printer/history.html
  6. http://www.columbia.edu/cu/computinghistory/1403.html
  7. http://electronicstechnician.tpub.com/14091/css/Chain-And-Band-Printers-304.htm
  8. https://www.pcmag.com/encyclopedia/term/line-printer
  9. https://ed-thelen.org/comp-hist/Tomash.html
  10. https://bitsavers.org/pdf/ibm/2821/GA24-3312-9_2821_Unit_Description_Oct82.pdf
  11. https://collections.museumsvictoria.com.au/items/717074
  12. https://bitsavers.org/pdf/ibm/3203/GA33-1529-0_3203_Printer_Model_5_Component_Description_Jan79.pdf
  13. http://bitsavers.org/pdf/dec/unibus/LP11_UsersMan.pdf
  14. http://museum.ipsj.or.jp/en/computer/device/printer/0023.html
  15. https://museum.ipsj.or.jp/en/computer/device/printer/0024.html
  16. https://printronix.com/emea/support/oldestlmp/
  17. https://archive.computerhistory.org/resources/access/text/2018/09/102666863-05-01-acc.pdf
  18. https://museum.ipsj.or.jp/en/computer/device/printer/0003.html
  19. http://www.righto.com/2019/01/accounting-machines-ibm-1403-and-why.html
  20. https://ecscience.net/chain-printer/
  21. https://news.ycombinator.com/item?id=25972372
  22. https://ibm-1401.info/KenShirriff-1403Animation.html
  23. https://www.columbia.edu/cu/computinghistory/1403.html
  24. https://ibm-1401.info/0KenShirriff/IBM_Field_Engineering_Manual_of_Instruction_1403_Printers_225_6492_3.pdf
  25. https://mindmachine.co.uk/book/print_05_bandprinter.html
  26. https://chooseglmgroup.com/ibm-6262-line-printer/
  27. https://moca.ncl.ac.uk/iomedia/Memorex.htm
  28. http://bitsavers.org/pdf/ibm/3203/GA33-1529-0_3203_Printer_Model_5_Component_Description_Jan79.pdf
  29. http://bitsavers.informatik.uni-stuttgart.de/pdf/ict_icl/atlas/Atlas_Machine_Description_Sections_8-13_Nov64.pdf
  30. https://ibm-1401.info/1403-Noise.html
  31. https://public.dhe.ibm.com/printers/manuals/6400/s5445640.pdf
  32. https://bitsavers.computerhistory.org/pdf/univac/system_80_and_series_90/UP-8250r3_0776_Printer_Subsystem_-_Operator_Reference.pdf
  33. https://bitsavers.computerhistory.org/pdf/centronics/306/37400040I_Centronics_Model_306_Printer_Technical_Manual_May1977.pdf
  34. https://gunkies.org/wiki/IBM_I/O_channel
  35. https://ibm1401.computerhistory.org/KenShirriff-1403Animation.html
  36. http://jeff-barr.com/2009/03/15/of-pli-line-printers-punch-cards-and-carriage-control/
  37. http://www.bitsavers.org/pdf/ibm/360/os/R20.1_Mar71/GC28-6704-1_OS_JCL_Reference_Rel_20.1_Jun71.pdf
  38. https://www.ibm.com/docs/en/zos/2.5.0?topic=data-traditional-line
  39. https://bitsavers.trailing-edge.com/pdf/dec/_Books/_Digital_Press/Phister_Data_Processing_Technology_and_Economics_2ed_1979.pdf
  40. https://www.nytimes.com/1984/02/05/business/bailing-out-of-the-mainframe-industry.html
  41. https://www.historyofinformation.com/detail.php?id=5169
  42. https://americanhistory.si.edu/collections/nmah_334650
  43. https://printronix.com/line-matrix-printers/p8000-p8000-plus-cabinet/
  44. https://www.retroprinter.com/accessing-printer-data-from-legacy-systems/
  45. http://www.hercules-390.org/HerculesUserReference.pdf
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