IBM 031

IBM Keypunches

Industry	Data processing equipment
Predecessor	Hollerith keypunch machines
Founded	1890s
Founder	Herman Hollerith
Fate	Supplanted by CRT computer terminals and personal computers in the 1970s
Successor	Computer terminals, personal computers
Area served	Worldwide
Key people	Herman Hollerith, Raymond Loewy (designer)
Products	Keypunch machines (e.g. IBM 024, IBM 026, IBM 029, IBM 129)
Owner	International Business Machines (IBM)
Parent	IBM

A keypunch refers to a mechanism designed to create holes in rigid paper cards at designated points, controlled by keys pressed by an operator. Comparable devices encompass the gang punch, pantograph punch, and stamp. The designation also extended to apparatuses that encoded information onto punched tape.

In the context of Jacquard looms, punched cards were connected sequentially to form a "chain" that encoded the instructions governing loom functionality.

Regarding Hollerith machines and similar unit record devices, punched cards served as carriers of information processed by these machines. Within computer systems utilizing punched card input/output devices, such cards represented either data or software programs directing operations.

The earliest Hollerith keypunches operated manually; subsequent versions became electromechanical units resembling compact desks equipped with keyboards akin to typewriters. These models incorporated hoppers for unpunched cards and stackers for completed punched cards. Certain versions also printed the character symbolizing the punched holes atop each column. The discarded punched fragments collected in a chad box, or at IBM, were known as a chip box or bit bucket.

In numerous data processing environments, accuracy was ensured through re-entry and comparison of data (referred to as two pass verification). There was considerable demand for keypunch operators, frequently women, who typically worked full-time within extensive keypunch departments performing data input tasks.

During the 1950s, Remington Rand launched the UNITYPER, which allowed direct input onto magnetic tape for UNIVAC computers. In 1965, Mohawk Data Sciences introduced an enhanced magnetic tape encoder marketed as an alternative to traditional keypunches. The emergence of microprocessors and affordable computer terminals prompted smaller firms such as Inforex and Pertec to produce key-to-tape and key-to-disk solutions.

Throughout the 1970s, keypunches and punched cards remained prevalent but were swiftly supplanted by cost-effective CRT computer terminals. Removing the intermediate step of transferring data to tape or disk lowered expenses and enhanced error detection during entry. The introduction of video display terminals, interactive timeshared systems, and eventually personal computers facilitated direct input of data and programs by originators themselves rather than relying on keypunch operators.

Stamping Jacquard cards, 1801 through 1890

Initially, Jacquard cards were manually stamped or cut, occasionally utilizing a guiding template. A later improvement involved positioning the card between two perforated metal plates, inserting punches in accordance with the desired pattern, and passing the assembly through a press. These manual techniques were ultimately replaced by 'Piano machines,' which operated via keyboards and bore resemblance to unit record keypunch devices.

Hollerith and IBM Keypunch Devices, 1890s to 1930s

In the 1890s, Herman Hollerith introduced a punching tool that utilized a standard ticket punch, creating circular holes near the card edges to enable functionality. He subsequently advanced this concept by inventing a Keyboard Punch featuring a pantograph mechanism that linked a punching unit to a guiding pointer over a 12 by 20 grid, allowing for accurate hole positioning.

By 1901, Hollerith secured a patent for a keypunch device where pressing any of the twelve keys produced a hole and simultaneously advanced the card. This device, known as the Type 001 keypunch, operated on 45-column cards with round holes. In 1923, The Tabulating Machine Company launched the first electrically powered keypunch—the Type 011 Electric Keypunch—where key presses closed electrical circuits that activated solenoids to punch holes. The 80-column punched card format was introduced in 1928. Subsequent iterations 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 full words and names could later be printed by alphabetical accounting machines. The Type 31 Alphabetical Duplicating Punch (1933) had an automatic card ejection and feeding cycle completed in 0.65 seconds. These devices featured separate keyboards for alphabetical and numerical input; the alphabetical keyboard resembled a manual typewriter but omitted shift, tab, backspace, and character keys, instead incorporating skip, release, stacker, and '1' keys."  – IBM Archives

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

Most IBM keypunches and verifiers utilized an electro-mechanical keyboard design to encode keystrokes. Pressing a key triggered a set of bails that closed electrical contacts to register characters electronically. A feedback loop energized magnets that restored the keystem position, reset the encoding bails, and provided both tactile and audible confirmation of each keystroke. Although each machine developed its unique tactile response influenced by wear and contact adjustments, no direct mechanism existed to modify this "feel." Special function keys operated purely electrically without any mechanical linkage.

Models such as the IBM 024, 026, and 029 keypunches supported program cards that controlled functions like tabbing and automatic duplication. The later IBM 129 incorporated electronic circuit cards enabling operators to write simple customized programs.

IBM 024 and 026 Card Punch Machines

Introduced in 1949, the IBM 024 Card Punch and IBM 026 Printing Card Punch were essentially identical except for the inclusion of a printing mechanism in the latter. Each was equipped with twelve precision punches—one corresponding to each row on the card—and powered by robust actuators that punched cards column by column, producing a distinctive "chunk" sound during operation. These machines were compatible with cards containing 51, 60, 66, or 80 columns.

The IBM 026 model printed characters above each punched column; by 1964, ten different versions existed offering various character sets. Scientific models replaced four seldom-used commercial characters with parentheses, equal sign, and plus sign symbols.

Logic circuits employed diodes, 25L6 vacuum tubes, and relays. Vacuum tube circuits operated at approximately 150 VDC primarily to power the punch-clutch magnet; most other circuits functioned at around 48 VDC.

Characters were printed using a 5 × 7 dot matrix wire array controlled by a metal "code plate" containing up to 1960 pins (35 pins × 56 characters). Pins were selectively removed where dots were unnecessary. This plate pressed chosen wires against an ink ribbon and card surface to form printed characters. The printing mechanism was complex to maintain; broken wires within narrow tubes were common problems. Printing errors could occur if users duplicated "binary" cards containing non-standard punch patterns causing misalignment of the code plate despite printing being disabled.

The external design of the IBM 024/026 Card Punches was crafted by industrial designer Raymond Loewy, renowned for his streamlined aesthetics and work on railway passenger cars. Their robust steel construction featuring rounded corners exemplifies the industrial Art Deco style.

IBM 056 Card Verifier

The IBM 056 served as a verification device designed to work alongside the 024 Card Punch and the 026 Printing Card Punch. Like the 026 keypunch, it included a red error indicator lens mounted on the machine’s cover. During operation, the verifier user re-entered data, and the machine compared it against the punched card’s contents. Cards that passed verification were marked with a small notch along the right edge.

Most mechanical and electrical parts of the IBM 056 were identical to those found in the 024 and 026 keypunches, except for differences in the punch assembly and print head. Rather than punches, this unit had sensing pins that detected existing holes; if discrepancies arose, a contact bail was triggered, stopping card advancement and illuminating a red error light. The area typically housing the 026’s print mechanism was replaced by a notching system powered by solenoids, which could make either a top-edge notch or an end-of-card punch.

Operators were allowed up to three attempts to correct errors during verification. If errors persisted after three tries, an error notch was punched above the faulty column, and the "OK" punch at the card’s end was disabled. Although mistakes could originate from either operator, this method helped minimize repeated errors. Some users attempted to bypass verification by guessing previous errors; as a result, certain machines were modified to permit only one attempt before error notching occurred.

Cards flagged with error notches were generally re-punched on an 024 or 026 by duplicating all columns up to the point of error and then correcting the data. Duplication involved detecting holes with sensing pins and transferring that information onto blank cards. Once corrected, these cards underwent re-verification to ensure accuracy and received an "OK" notch.

Typewriter Card Punches

The earliest device combining a card punch with a typewriter function—allowing typed characters to be punched—was created by Powers in 1925. IBM later introduced the 824 Typewriter Card Punch, which replaced the traditional 024 keyboard with an IBM electric typewriter mechanism. The IBM 826 model incorporated an IBM 026 Keypunch keyboard instead. These developments merged the ease of typing with punched card data entry for business environments.

IBM 029 Card Punch

Released alongside System/360 in 1964, IBM’s 029 model introduced new character codes for symbols such as parentheses, equal signs, plus signs, and others within the EBCDIC character set. Mechanically resembling the IBM 026, it printed punched characters directly above card holes using an expanded code plate featuring 2,240 printing-pin positions to accommodate EBCDIC’s broader range of characters.

The logic circuitry in later versions of the 029 utilized wire contact relays, while earlier models relied on reed relays combined with diodes mounted on SMS cards. Due to reliability concerns with reed relays, IBM reverted to wire-contact relay technology. Operating at 48 volts DC, this design eliminated the need for vacuum tubes present in earlier models such as the 024 and 026. An optional "Left-Zero" feature could be programmed via SMS cards to automatically punch leading zeros, simplifying data entry by right-aligning numeric fields—for example, entering "73" would punch "000073" in a six-digit field.

IBM 5924 Key Punch

Introduced in 1971 as part of IBM's IBM Kanji System, the IBM 5924 Key Punch was based on the 029 model T01 but featured a specialized keyboard layout. It enabled operators to input complex East Asian scripts—including Chinese, Japanese, and Korean—by using one of fifteen shift keys with their left hand combined with one of 240 Kanji character keys pressed with their right hand. This advancement facilitated handling extensive character sets exceeding 10,000 symbols.

IBM 059 Card Verifier

The IBM 059 Verifier served as a counterpart to the IBM 029 Card Punch, differing notably from its forerunner, the IBM 056. Rather than utilizing mechanical sensing pins, it featured optical sensors illuminated by a single light source channeled through fiber-optic lightpipes, which contributed to much quieter functioning. Despite this advancement in technology, its mode of operation closely resembled that of the 056.

Interestingly, some operators favored the louder feedback of the older 056 model and occasionally pressed keys more forcefully on the 059 to simulate that sound, which sometimes led to faster deterioration of keyboard parts.

IBM 129 Card Data Recorder

Launched alongside the System/370 in 1971, the IBM 129 was a transistor-based keypunch machine capable of punching, verifying, and serving as an auxiliary online 80-column card reader/punch. Users could switch between punch and verify modes via a keyboard toggle.

Its main improvement over previous IBM keypunch models was an electronic buffer capable of storing an entire 80-column card image. This feature allowed users to correct errors by pressing Backspace and re-entering data before punching, eliminating the need for manual card removal and correction required by earlier devices. The card was punched in full once the Release key was activated.

The logic circuitry employed SLT modules mounted on a swing-out wire-wrapped backplane.

Since punching each column no longer occurred simultaneously with keystrokes, the keying speed increased. The 129 could hold up to six programs in memory, selectable using a rotary switch. Unlike earlier models where program cards were read via a drum, these were loaded through the standard card-feed path.

Because of electronic memory storage, duplication operations used the stored card image instead of requiring a separate reading station. Additionally, cards could be "read-in" through an optical device built into the punch station itself.

Program card

IBM's 024, 026, and 029 keypunches along with verifiers (056 and 059) could be programmed using a Program Card or drum card. This allowed for automatic field advancement, default character settings, and duplication of fields from preceding cards—offering enhancements beyond earlier Skip Bars.

The program card was punched on any keypunch and mounted around a rotating drum synchronized with card feeding. Mechanical sensing of holes in the program card triggered electrical contacts encoding commands via holes in the top six rows [12,11,0,1,2,3]. An optional "Second Program" utilized holes in the bottom six rows [4,5,6,7,8,9]. Operators chose programs through a selector switch; the drum could be removed for replacement or change.

Functions provided by program cards included field definition, automatic skip or duplication commands, alphabetic shift activation, left zero printing enforcement, and print suppression:

Function	Program				Description
	#1	Char.	#2	Char.
Field Definition	12	&	4	4	Punches every column except first within a field
Start Automatic Skip	11	-	5	5	Punches first column of fields designated to skip
Start Automatic Duplication	0	0	6	6	Punches first column of fields set for duplication
Alphabetic Shift	1	1	7	7	Switches keyboard into Alphabetic mode
Left Zero Print	2	2	8	8	Forces printing of leading zeros or signs
Print Suppression	3	3	9	9	Suppresses printing output in specified columns

Programming languages such as FORTRAN, RPG, and IBM Assembly language designated specific columns (e.g., 1, 10, 16) for operational commands. Program cards automated tabbing and field definitions to streamline data input.

For instance:

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

In this example, pressing skip after entering initial characters would move the cursor directly to column 10; columns from 72 to 80 might be programmed for numeric shift fields containing special symbols or sequence numbers.

Note that "Field Definition" (code 12) and "Alphabetic Shift" (code 1) print as A. Improper use of program code 2 could produce invalid or harmful printer characters.

Program cards also facilitated tasks such as "gang punching," where constant data fields were inserted across multiple decks automatically. Additionally, they enabled creative uses like generating rhythmic patterns by punching characters that produced distinctive sounds during processing.

IBM 5496 Data Recorder for 96-Column Cards

In 1969, IBM introduced the System/3 series of entry-level business computers, which utilized a novel, more compact 96-column punched card format. To support this new card type, IBM developed the IBM 5496 Data Recorder—a keypunch machine equipped with printing and verification capabilities—as well as the IBM 5486 Card Sorter, both tailored specifically for handling 96-column cards.

Powers and Remington Rand (UNIVAC) Keypunch Machines

Circa 1906, James Powers at the United States Census Bureau created the Powers Keypunch, featuring 240 keys designed for census data processing. Powers went on to establish the Powers Accounting Machine Company in 1911, which was later acquired by Remington Rand in 1927. Under Remington Rand’s UNIVAC division, keypunches were manufactured for their proprietary 90-column punched cards as well as compatible devices for IBM’s 80-column format. The 90-column keypunches employed a mechanical design to circumvent IBM’s patents. Notably, UNIVAC keypunches buffered an entire card’s data before punching all holes in a single operation, allowing corrections to be made without wasting cards.

Remington Rand’s product lineup included models such as the UNIVAC Card Code Punch Type 306-5 (90 Column Alphabetical), Types 306-2 and 306-3, Numerical 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 model offered verification by running cards through the keypunch twice; accurate entries resulted in elongated holes while errors produced round perforations. The Automatic Verifying Machine provided rapid mechanical error detection.

In 1969, Remington Rand introduced the UNIVAC 1710 Verifying Interpreting Punch.

To Keypunch: The Verb Form

The expression keypunched—derived from using a key punch device—originally described the process of encoding data onto punched cards. Although physical keypunch machines have become obsolete, the verb remains in use as a general term for entering data. This evolution reflects how mechanical keypunching once served as the primary human-computer interface before being supplanted by digital input technologies.

Shift Toward Direct Data Entry

During the 1950s, Remington Rand launched the UNITYPER, an input device that allowed users to enter data directly onto magnetic tape for UNIVAC computer systems. Subsequently, in 1965, Mohawk Data Sciences introduced an enhanced magnetic tape encoder marketed as a replacement for traditional keypunch machines. By the mid-1970s, advances in microprocessor technology and affordable computer terminals enabled smaller firms such as Inforex and Pertec to develop key-to-tape and key-to-disk systems.

While punched cards continued to be widely used for data entry and programming through the mid-1980s, eliminating the intermediate step of transferring card data to tape or disk significantly lowered costs and improved error detection during input. The emergence of video display terminals, interactive timeshared systems, and later personal computers empowered data originators to input information directly. This advancement streamlined workflows and reduced dependence on specialized data entry clerks.

See also

• Punched card
• Punched card input/output
• Hollerith code
• Unit record equipment
• Computer programming in the punched card era
• List of IBM products
• Chad (paper)

Further reading

• Columbia University Computing History: IBM Key Punch Devices

External links

• Columbia University Computing History: IBM Keypunch Machines
• IBM Archives: The IBM 029 Card Punch
• IBM Archives: Railroad Applications of the 001 Keypunch
• IBM Punched Card Accounting Equipment (1955)