IBM 015

IBM Keypunch
Industry	Data processing equipment
Founded	1890s
Headquarters	Armonk, New York, United States
Products	Keypunch machines (e.g., IBM 024, IBM 026, IBM 029, IBM 056)

A keypunch is a tool designed to create holes in rigid paper cards at designated spots determined by the keys pressed by an operator. Comparable devices include the gang punch, pantograph punch, and stamp machines. The term also extended to equipment that transcribed information onto punched tape media.

In the context of Hollerith machines and other unit record systems, punched cards served as carriers of data for processing tasks. Within computers utilizing punched card input/output, these cards represented either data sets or instructions guiding operations.

The earliest Hollerith keypunches operated manually; subsequent versions were electromechanical and resembled compact desks equipped with keyboards, hoppers holding blank cards, and stackers for punched cards. Certain models could print the character corresponding to the punched holes above each column. Discarded paper fragments, known as chad, collected in a container called a chad box or, at IBM, a chip box or bit bucket.

In numerous data processing scenarios, punched cards underwent a two-pass verification process—data was entered twice to confirm accuracy. This practice created substantial employment opportunities for keypunch operators, predominantly women, who worked full-time within large keypunch departments responsible for data input.

During the 1950s, Remington Rand launched the UNITYPER, which allowed direct data entry onto magnetic tape for UNIVAC systems. Subsequently, Mohawk Data Sciences introduced an enhanced magnetic tape encoder in 1965 marketed as a replacement for traditional keypunches. The emergence of microprocessors and cost-effective terminals gave rise to key-to-tape and key-to-disk systems from manufacturers such as Inforex and Pertec.

Although keypunches and punched cards remained prevalent through the 1970s, they were swiftly supplanted by CRT computer terminals. Eliminating the intermediate card-to-tape or card-to-disk transfer lowered expenses and enhanced error detection during data entry. The introduction of video display terminals, interactive timeshared systems, and eventually personal computers enabled originators to enter data or programs directly without requiring keypunch operators.

Stamping Jacquard cards, 1801 through 1890

Jacquard cards were originally stamped or manually cut, occasionally with the assistance of a guide plate. A notable improvement involved positioning the card between two hinged perforated metal plates; punches were inserted following the pattern and then pressed to create holes. These hand-operated methods were ultimately replaced by mechanized devices. 'Piano machines,' named after their keyboard-like keys and resembling unit record keypunches, became the dominant technology.

Hollerith and IBM keypunches, 1890 through 1930s

Herman Hollerith's initial device from the early 1890s punched cards using a standard ticket punch that created round holes near the edges of cards. He soon advanced to a more accurate Keyboard Punch employing a pantograph mechanism to guide punches across a 12 by 20 grid of positions.

In 1901 Hollerith patented a design where pressing one of twelve keys would punch a hole automatically while advancing the card. This first-generation Type 001 keypunch utilized 45 columns with round holes. In 1923, The Tabulating Machine Company released its first electric keypunch—the Type 011 Electric Keypunch—where keys engaged solenoids to produce holes. The 80-column punched card format debuted in 1928. Subsequent models included the Type 016 Motor-Driven Electric Duplicating Keypunch (1929), Type 31 Alphabetical Duplicating Punch (1933), and Type 32 Alphabetical Printing Punch (1933).

"Alphabetical duplicating keypunches captured alphabetic data on tabulating cards so that entire words and names, alongside numeric information, could be printed by an alphabetical accounting machine. IBM introduced the Type 31 Alphabetical Duplicating Punch in 1933; it automatically ejected one card and fed another within 0.65 seconds. These devices featured separate keyboards for alphabetic and numeric input; the alphabetical keyboard resembled a manual typewriter but excluded shift, tab, backspace, and character keys, instead providing skip, release, stacker, and '1' keys." – IBM Archives

Post-World War II IBM Keypunches and Verifiers for 80-Column Cards

The majority of IBM keypunch and verifier machines utilized an electro-mechanical keyboard mechanism that encoded keystrokes through a network of bails and electrical contacts. Each key press activated magnets that reset the encoding bails and returned the keystem to its original position, providing tactile feedback to the operator. The tactile response varied depending on wear and the adjustment of contacts, although there was no provision for direct adjustment of the key feel. Special function keys were operated electrically and did not involve mechanical encoding linkages.

Models such as the IBM 024, 026, and 029 keypunches accepted program cards enabling automation for tasks including tabbing and duplicating fields. Later, the IBM 129 incorporated electronic circuit cards allowing operators to write simple programs.

IBM 024 and 026 Card Punches

Launched in 1949, the IBM 024 Card Punch and the IBM 026 Printing Card Punch were very similar machines, with the primary difference being that the 026 included a printing capability. Both machines employed twelve precision punches—one corresponding to each row of the card—punching holes column by column across various card formats including 51-, 60-, 66-, and 80-column cards. The characteristic "chunk" noise was produced during punching.

The IBM 026 printed characters above each punched column using a 5×7 dot matrix generated by a metal "code plate" that controlled 1960 pins. By 1964, variants supported up to ten different character sets; scientific models replaced some commercial symbols with parentheses, equals signs, and plus signs.

The internal logic combined diodes, 25L6 vacuum tubes, and relays. Vacuum tube circuits operated at approximately 150 VDC primarily to power punch-clutch magnets, while most other circuits functioned at 48 VDC.

The printing assembly was intricate and susceptible to malfunctions; broken wires within the narrow tube connecting the code plate to the ribbon were particularly challenging to repair. Attempts to replicate non-standard "binary" punch patterns could damage the code-plate positioning system because it would attempt to move beyond its mechanical limits even when printing was deactivated.

Renowned industrial designer Raymond Loewy applied his signature streamlined Art Deco aesthetic to the IBM 024/026 models, resulting in robust steel constructions with rounded edges consistent with his acclaimed design principles.

IBM 056 Card Verifier

The IBM 056 served as the verification counterpart to the IBM 024 Card Punch and IBM 026 Printing Card Punch. It closely resembled the 026 but featured a red error indicator lens on its cover. During verification, operators re-entered data previously punched; the machine compared this input against existing holes on the card. Cards that passed verification received a small notch on their right edge.

Most components of the IBM 056 were shared with the 024/026 series except for the punch unit and print head. In place of punches, its punch unit contained sensing pins designed to detect existing holes. If discrepancies were found between entered data and card holes, a contact bail was triggered which halted card movement and illuminated a red error light. The notching mechanism—powered by solenoids—occupied the space normally used by the printer on the 026 and produced either a top-edge notch or an end-of-card punch.

Operators were allowed up to three attempts to correct errors during verification. After three unsuccessful tries, an error notch was punched above the problematic column, and further "OK" punches were disabled. While data errors could still be corrected despite these warnings, multiple retries reduced repeated inaccuracies. Some operators attempted to bypass this restriction by guessing corrections; in response, machines were modified to permit only one retry before applying an error notch.

Cards marked with error notches were typically re-punched using an IBM 024 or 026 machine. This process often involved duplicating data up to the point of error without punching new holes; sensing pins read existing holes which were then transferred onto a blank card’s punch station. After corrections were made, these cards underwent re-verification before receiving an "OK" notch.

Typewriter Card Punch Devices

In 1925, Powers introduced the inaugural card punch integrated with a typewriter, allowing users to both type and punch designated text. The IBM 824 Typewriter Card Punch succeeded the IBM 024 keyboard by incorporating an IBM electric typewriter. Likewise, the IBM 826 merged the IBM 026 Keypunch with a typewriter interface, streamlining data input for commercial purposes.

IBM 029 Card Punch

Launched alongside the System/360 in 1964, the IBM 029 incorporated updated character codes for symbols such as parentheses, equal signs, and plus signs within the EBCDIC encoding scheme. Mechanically akin to the IBM 026, it featured a larger code plate with 2240 printing-pin positions atop the card to accommodate EBCDIC's broader character repertoire.

The device’s logic initially employed reed relays combined with diodes on SMS cards, but due to reliability challenges, IBM reverted to wire-contact relay mechanisms in subsequent versions. Powered by 48 volts DC, it eliminated the vacuum tubes found in predecessors like the 024 and 026. An optional "Left-Zero" feature—available at extra cost—automatically punched leading zeros in right-justified numeric fields, enhancing data entry productivity.

IBM 5924 Key Punch

The IBM 5924 Key Punch, a variant T01 of the 029 model, debuted in IBM's 1971 IBM Kanji System announcement. It was equipped with a specialized keyboard enabling operators to press one of fifteen shift keys with their left hand and select from 240 Kanji characters using their right hand. This advancement facilitated computer processing of intricate East Asian scripts—Chinese, Japanese, and Korean—with character sets surpassing 10,000 symbols.

IBM 059 Card Verifier

Designed to complement the IBM 029 Card Punch, the IBM 059 Verifier differed markedly from its predecessor, the IBM 056 verifier, by utilizing optical hole detection rather than mechanical sensing pins. This innovation rendered the 059 considerably quieter compared to the noisier 056 model. Its optical system used a single light source distributed throughout the machine via fiber-optic lightpipes. Despite this technological enhancement, its fundamental verification methodology remained consistent with that of the 056.

Interestingly, some operators favored the louder feedback of the earlier verifier for tactile assurance and occasionally compensated for the quieter operation by pressing keys more forcefully—sometimes resulting in accelerated keyboard wear.

IBM 129 Card Data Recorder

Introduced with System/370 in 1971, the IBM 129 combined card punching, verification, and an auxiliary online capability for reading and punching standard 80-column cards. A keyboard switch allowed toggling between punch and verify modes.

The transistorized IBM 129’s principal innovation was its electronic buffer capable of storing an entire card image in memory. Unlike earlier keypunches where mistakes required manual correction and card removal, this model permitted error erasure using the Backspace key and re-entry before automatic punching upon pressing the Release key.

Its circuitry utilized SLT modules mounted on a swing-out wire-wrapped backplane. The electronic memory decoupled typing speed from punching speed, significantly improving throughput.

The device could retain six distinct programs selectable via a rotary switch. Rather than relying on a mechanical program drum as previous models did, program cards were read into memory through the card-feed mechanism. Duplication processes depended on stored images instead of separate read stations. An integrated optical reader allowed "read-in" of cards directly through the punch station.

Program card

IBM keypunch models 024, 026, and 029, along with verifiers 056 and 059, could be programmed using a Program Card or drum card. This innovation automated navigation through fields, set default characters, enabled duplication, and more—offering significant improvements over earlier Skip Bar techniques.

The program card was created on any keypunch and wrapped around a rotating drum that turned as cards passed through the machine. Starwheels detected punched holes encoding instructions within the top six rows [12,11,0,1,2,3]; an optional Second Program utilized the bottom six rows [4–9]. Operators chose the desired program via a selector switch, and drums could be removed for reprogramming purposes.

Key encoded functions included:

Function	#1	Char.	#2	Char.	Purpose
Field Definition	12	&	4	4	Punch all columns except the first in a field
Initiate Automatic Skip	11	-	5	5	Skip the first column of fields automatically
Begin Automatic Duplication	0	0	6	6	Duplicate the first column of fields automatically
Alphabetic Shift Mode	1	1	7	7	Switch keyboard input to Alphabetic mode
Left Zero Print Enforcement	2	2	8	8	Force printing of leading zeros or signs
Print Suppression Mode	3	3	9	9	Suppress printing output in specified columns

Programming languages such as FORTRAN, RPG, and IBM Assembly language assigned particular card columns for executing operations. Program cards enabled tabbing through fields or defining shifts between numeric and alphabetic modes.

For instance:

1.......10........20........30........40........50........60........70........80  
1AAAAAAAA1AAAAA1AAAAAAAAAAAAAAAAAAA1AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA &&&&&&&&

In this example, the skip function tabs to column 10; columns 72 through 80 might contain continuation markers or sequence numbers.

Note: The "Field Definition" (code 12) and "Alphabetic Shift" (code 1) print as A. Program code 2 could generate invalid characters that might harm printers.

Tasks such as "gang punching," which involved inserting constant data fields across multiple cards in a deck, were automated by program cards. Additionally, they were creatively employed to produce rhythmic effects by alternating noisy and quiet character punches.

IBM 5496 Data Recorder for 96 column cards

In 1969, IBM introduced the System/3 series of entry-level business computers that utilized a new compact 96-column punched card. The IBM 5496 Data Recorder—a keypunch with integrated print and verify capabilities—and the IBM 5486 Card Sorter were specifically engineered to handle these 96-column cards.

Powers, Remington Rand (UNIVAC) keypunches

Around 1906, James Powers at the United States Census Bureau developed the Powers Keypunch, designed especially for census data entry with its unique 240-key layout. Powers established the Powers Accounting Machine Company in 1911; this company was later acquired by Remington Rand in 1927. Under Remington Rand's ownership, the UNIVAC division manufactured keypunches for their proprietary 90-column cards as well as compatible devices for IBM’s standard 80-column cards. Their 90-column keypunches employed a mechanical design that circumvented IBM patents prior to their acquisition of Eckert–Mauchly Computer Corporation. UNIVAC keypunches captured the entire character sequence of a card before punching all holes simultaneously, allowing corrections without wasting cards.

Remington Rand’s product range included models such as the UNIVAC Card Code Punch Type 306-5 (including Alphabetical Types 306-2 and 306-3), 90 Column Numerical punches (Types 204-2 and 204-3), Portable Electric Punch Type 202, Spot Punch Type 301, and Automatic Verifying Machine Type 313.

The Type 306-2 supported verification by running cards through twice; correctly punched data produced elongated holes while errors appeared as round holes. The Automatic Verifying Machine offered rapid mechanical error detection.

The UNIVAC 1710 Verifying Interpreting Punch was introduced in 1969.

Keypunch as a verb

The expression keypunched (derived from keypunch) initially described the process of encoding data onto punched cards through the use of a keypunch machine. Although the original mechanical keypunch devices have become obsolete, the term endures in business contexts as a synonym for performing data entry tasks. This evolution mirrors the shift from physical punched-card inputs to contemporary digital data entry techniques.

Transition to direct data entry

During the 1950s, Remington Rand launched the UNITYPER, an input apparatus that allowed direct recording of data onto magnetic tape for use with UNIVAC computers. By 1965, Mohawk Data Sciences developed an enhanced magnetic tape encoder designed to replace traditional keypunch machines. The emergence of microprocessors and cost-effective computer terminals in the mid-1970s encouraged smaller firms such as Inforex and Pertec to create systems capable of direct key-to-tape and key-to-disk data entry.

Although punched cards continued to be widely utilized for data input and programming through the mid-1980s, eliminating the intermediary step of transferring data from punched cards to tape or disk significantly lowered expenses and improved error detection during entry. The introduction of video display terminals, interactive timeshared systems, and subsequently personal computers facilitated direct data input by the original source, optimizing workflows and reducing dependence on specialized data entry clerk personnel.

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