IBM 1403 (Line Printer, 1959)

What the IBM 1403 was

The IBM 1403 was an impact line printer that IBM introduced in 1959 alongside the IBM 1401 Data Processing System, where it served as the system's high-speed output device. Rather than forming one character at a time, it printed an entire line in a single operation, making it far faster than the typewriter-style printers common at the time. The 1403 was subsequently attached to a range of other IBM computers and remained in production and use for well over two decades.

A new class of high-speed printing

IBM positioned the 1403 as a high-speed printer, and it became one of the defining peripherals of the early commercial computer era. IBM's own history of the 1401 describes the 1403 as a high-speed printer capable of 600 lines of text per minute. IEEE Spectrum notes that IBM regarded the 1403 as setting "the standard of quality for high-speed impact printing," and reports that more than 23,000 units were delivered to U.S. customers, with sales continuing into the early 1980s.

How the print chain worked

The 1403 printed using a horizontally moving print chain that carried the type. According to IEEE Spectrum and Columbia University, the chain held 48 different characters repeated five times, and it spun continuously in front of an inked ribbon and the paper. Behind the paper sat a row of hammers — one for each print column — each paired with an electromagnet. As the required character passed a given column, that column's hammer fired at precisely the right instant to press the paper and ribbon against the moving type, printing the character in place without smearing. Because every hammer could fire independently as its character came around, the machine assembled a complete line during a single pass of the chain.

From print chain to print train

Later 1403 variants changed the type carrier. As IEEE Spectrum describes, the Model 3 replaced the character chain with type slugs that slid in a track driven by gears, rather than being linked together in a continuous chain; Columbia University's computing history refers to this later type carrier as a "print train." The mechanism supported higher printing speeds while retaining the same basic hammer-and-ribbon impact principle.

Models and print speeds

The original 1403 shipped with the 1401 in 1959 and printed about 600 lines per minute, a figure given by IBM's history of the 1401. Faster variants followed: IEEE Spectrum reports that the Model 3 could print up to 1,100 lines per minute, rising to about 1,400 lines per minute when only a reduced subset of characters was used. IEEE Spectrum also notes that some versions carried up to 132 print positions, each with its own hammer.

Place in printing history

The 1403 is remembered chiefly for its combination of speed and print quality. Columbia University's computing history records that its output remained unsurpassed for print quality until the advent of laser printing technology in the 1970s. The 1403 has since been restored to full working order by the Computer History Museum's IBM 1401 restoration team, a testament to the durability of the design.

Reference scope

This page records only specifications that can be traced to authoritative sources — IBM's own history, Columbia University's computing history, IEEE Spectrum, and the Computer History Museum. Figures that could not be corroborated (for example, conflicting reported chain speeds) are omitted rather than presented as settled fact. It is a historical reference, not a buying guide, and quotes no pricing or availability.