IBM 024
| Industry | Computer hardware |
|---|---|
| Founded | June 16, 1911 |
| Headquarters | Armonk, New York , United States |
| Products | Keypunch machines, punched cards, card verifiers, typewriter card punches |
A keypunch refers to a machine designed to create holes in rigid paper cards at positions dictated by keys pressed by an operator. Comparable devices include the gang punch, pantograph punch, and stamp. The term also encompassed equipment that recorded information onto punched tape.
In early computing and Unit record equipment, punched cards served as carriers for data or programs processed by these devices. Initial Hollerith keypunch models were manually operated; subsequent versions became electromechanical, integrating a keyboard with feeders for blank cards and collectors for punched ones. Certain models featured printing of characters above the columns aligned with the punched holes. The discarded punched-out fragments collected in a container known as a chad box, chip box, or bit bucket.
To ensure accuracy, data entry often involved re-punching cards during a verification step (two pass verification). This process generated significant demand for keypunch operators, predominantly women, employed full-time within extensive keypunch departments dedicated to data input.
During the 1950s, Remington Rand launched the UNITYPER, which allowed direct entry of data onto magnetic tape for UNIVAC computers. In 1965, Mohawk Data Sciences introduced an enhanced magnetic tape encoder marketed as a substitute for traditional keypunches. The emergence of microprocessors and affordable terminals led to key-to-tape and key-to-disk solutions from companies such as Inforex and Pertec.
While keypunch machines and punched cards remained prevalent through the 1970s, they were swiftly supplanted by cost-effective CRT computer terminals. Removing the need to handle punched cards reduced expenses and enhanced data entry precision. The development of video display terminals, interactive timeshared systems, and eventually personal computers allowed data originators to input information directly, eliminating reliance on keypunch operators.
Stamping Jacquard cards, 1801 through 1890
Jacquard cards were originally produced by hand-stamping or cutting, occasionally using guiding templates. An improved technique involved placing the card between two perforated metal plates, inserting punches according to the desired pattern, and pressing to perforate the card. These manual approaches were later replaced by mechanized methods. Instruments known as 'piano machines,' named for their keyboard-like keys, became widespread; they operated similarly to unit record keypunches.
Hollerith and IBM keypunches, 1890 through 1930s
Herman Hollerith's initial punching device from the 1890s employed a simple ticket punch that created round holes near the edges of cards. He soon advanced to a more accurate Keyboard Punch featuring a pantograph mechanism that linked a punch to a pointer moving over a 12 by 20 grid, allowing manual punching across 20 columns.
In 1901, Hollerith secured a patent for a device where pressing one of twelve keys would punch a hole while automatically advancing the card. This first-generation Type 001 keypunch utilized 45-column cards with round holes. By 1923, The Tabulating Machine Company had introduced its first electric keypunch, the Type 011 Electric Keypunch, which used electrical contacts under each key to activate solenoids for punching holes. The 80-column punched card format was launched in 1928.
Subsequent Hollerith keypunch 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 recorded alphabetic data on tabulating cards so that complete words and names, alongside numerical information, could be printed by an alphabetical accounting machine. Introduced in 1933, the Type 31 Alphabetical Duplicating Punch automatically ejected one card and fed another within 0.65 seconds. These machines featured separate keyboards for alphabetic and numeric input; the alphabetical keyboard resembled a manual typewriter but omitted shift, tab, backspace, and character keys while including skip, release, stacker, and '1' keys." – IBM Archives
Post-World War II IBM Keypunch and Verification Machines for 80-Column Cards
A majority of IBM keypunches and verifiers utilized a shared electro-mechanical keyboard system to encode keystrokes. When a key was pressed, it activated a series of bails located at the keyboard's upper section, closing electrical contacts that encoded the selected character. Subsequently, a feedback loop energized magnets which mechanically reset the keystem and returned the encoding bails to their original position, delivering both tactile and audible feedback to the operator. Each device developed a distinct tactile sensation influenced by factors such as wear, accumulated dirt, and contact spacing, with only limited adjustments available beyond calibrating the contacts. Special function keys like shift and duplication relied solely on electrical contacts without any mechanical encoding linkage.
IBM keypunch models including the 024, 026, and 029 offered the capability to attach program cards that managed functions such as tabbing and field duplication. The later 129 model incorporated electronic circuit cards that allowed operators to create simple custom programs.
IBM 024 and 026 Card Punches
Debuting in 1949, the IBM 024 Card Punch and IBM 026 Printing Card Punch were almost identical except that the latter had printing functionality. Both machines employed twelve precision punches—one aligned with each card row—powered by strong actuators. Cards advanced one column at a time as holes were punched, producing a characteristic "chunk, chunk" noise. These machines could handle cards with 51, 60, 66, or 80 columns.
The IBM 026 model printed characters above each punched column. By 1964, ten variants existed featuring different character sets; scientific versions replaced four seldom-used commercial characters with parentheses, an equal sign, and a plus sign.
The logic circuitry incorporated diodes, 25L6 vacuum tubes, and relays. Vacuum tube circuits operated primarily at 150 VDC to power punch-clutch magnets, while most other circuits functioned at 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 corresponding to unprinted dots were machined off. When pressed against the wire array, this plate selectively engaged wires to imprint characters onto the ribbon and card. This printing mechanism was known for its maintenance difficulties—wires frequently broke inside narrow tubes between the code plate and ribbon, making repairs labor-intensive. Additionally, non-standard punch patterns on "binary" cards could misalign or damage the code plate positioning system. Disabling printing prevented pin activation but did not disengage the code plate assembly, meaning damage could still occur.
The external design of the IBM 024/026 Card Punches was created by industrial designer Raymond Loewy, celebrated for his streamlined designs including railway passenger cars from the 1930s–40s. These machines featured sturdy steel construction with rounded corners embodying an industrial Art Deco aesthetic.
IBM 056 Card Verifier
The IBM 056 served as the verification unit paired with the IBM 024 Card Punch and IBM 026 Printing Card Punch. Visually similar to the 026 keypunch but distinguished by a red error indicator lens on its cover, this verifier required operators to re-enter data originally punched by another operator. The machine then compared both entries for accuracy. Cards that passed verification received a small notch along their right edge.
Mechanically and electrically, the IBM 056 shared most components with the 024/026 models except for its punch unit and print head. Instead of punches, its punch unit contained sensing pins designed to detect existing holes; any mismatch halted card feeding and illuminated a red error light. The verifier replaced the print mechanism found in the 026 with a solenoid-driven notching system that marked cards as verified or erroneous.
Operators had up to three attempts to correct detected errors; after three unsuccessful tries, an error notch was punched above the problematic column on top of the card without applying an "OK" punch at its end. This process reduced repeated mistakes; however, some operators could guess errors correctly, prompting certain machines to limit input attempts to one before marking errors.
Cards identified with errors were typically re-punched by duplicating data up to the error column onto a blank card before making corrections. The duplication feature read holes from the original card without punching new ones, allowing selective modification of data fields. Corrected cards underwent re-verification before approval.
Typewriter Card Punch Devices
In 1925, Powers introduced the first integrated device that combined a typewriter with a card punch, enabling direct punching of typed characters. IBM later replaced the 024 keyboard with an electric typewriter in its 824 Typewriter Card Punch model, while the IBM 826 retained the IBM 026 Keypunch keyboard for input.
IBM 029 Card Punch
Launched alongside the System/360 in 1964, the IBM 029 incorporated new character codes to support symbols such as parentheses, equal signs, and plus signs found in the EBCDIC character set. While its mechanical design closely resembled the IBM 026, it featured an expanded code plate containing 2240 printing-pin positions to accommodate EBCDIC’s broader range of characters. The device printed punched characters along the top edge of the card.
Early versions of the 029 employed reed relays paired with diodes mounted on SMS cards for logic functions. Due to reliability challenges with reed relays, IBM reverted to wire contact relay mechanisms in subsequent models. Operating at 48 volts DC, this design eliminated the need for vacuum tubes that earlier models like the 024 and 026 required. An optional "Left-Zero" function, implemented via additional SMS cards and programmed using a program card, automated leading zero punches to right-align numeric fields, thereby streamlining data entry processes.
IBM 5924 Key Punch
As part of the 1971 announcement of IBM’s IBM Kanji System, the IBM 5924 Key Punch—based on the IBM 029 model T01—featured a unique keyboard layout. Operators used their left hand to select one of 15 shift keys and their right hand to choose from among 240 Kanji characters. This innovation facilitated computer processing of complex East Asian scripts—including Chinese, Japanese, and Korean—supporting extensive character sets exceeding 10,000 symbols.
IBM 059 Card Verifier
The IBM 059 Verifier was designed as a companion to the IBM 029 Card Punch but differed significantly from its predecessor, the IBM 056 verifier, by utilizing optical sensing technology instead of mechanical sensing pins. This advancement greatly reduced operational noise compared to the louder mechanical design of the 056. The optical system employed a single light source distributed throughout the machine via fiber-optic lightpipes. Despite this technological enhancement, its verification process remained consistent with earlier models.
Notably, some operators preferred the audible feedback provided by the noisier IBM 056 and compensated for the quieter operation of the IBM 059 by pressing keys more forcefully, which occasionally led to increased wear on keyboard components.
IBM 129 Card Data Recorder
Introduced alongside the System/370 in 1971, the IBM 129 combined functions including punching, verifying, and auxiliary on-line reading and punching of standard 80-column cards for select computer systems. A toggle switch on its keyboard allowed users to switch between punch and verify modes.
The transistorized design of the IBM 129 featured an electronic buffer capable of holding an entire image of an 80-column card. Unlike previous keypunch machines where correcting keystroke errors was cumbersome and manual, this model allowed users to erase mistakes using the Backspace key and re-enter data before punching. The full card was then punched automatically upon pressing the Release key.
Its control logic was implemented using SLT modules mounted on a swing-out backplane. The keying speed was not constrained by column-by-column punching limitations.
The machine could store up to six programs selectable via a rotary switch. In contrast to earlier models that used program drums, program instructions were loaded into memory through the standard card-feed mechanism.
Thanks to its electronic memory capabilities, duplicating cards relied on stored images rather than requiring a separate read station. Additionally, cards could be "read-in" via an optical reading unit integrated directly into the punch station.
Program card
IBM keypunch models 024, 026, and 029, along with their verifiers 056 and 059, could be configured using a Program Card or drum card. This innovation allowed for features such as automatic field alignment, default character types, field replication, and additional functions—representing a significant improvement over the earlier Skip Bars.
The program card contained control codes punched into it and was mounted on a rotating drum. Starwheels detected the punched patterns by triggering electrical contacts. Programming information was encoded within the upper six rows [12,11,0,1,2,3], while an optional "Second Program" utilized the lower six rows [4-9], selectable via a switch. The drum was accessible by tilting open the center cover.
Key control operations included:
| Function | #1 | Character | #2 | Character | Description |
|---|---|---|---|---|---|
| Field Definition | 12 | & | 4 | 4 | Punches all columns except the first in a field |
| Start Automatic Skip | 11 | - | 5 | 5 | Skips the initial column of fields automatically |
| Start Automatic Duplication | 0 | 0 | 6 | 6 | Duplicates fields from the previous card |
| Alphabetic Shift | 1 | 1 | 7 | 7 | Switches keyboard to alphabetic input mode |
| Left Zero Print | 2 | 2 | 8 | 8 | Forces printing of leading zeros or signs |
| Print Suppression | 3 | 3 | 9 | 9 | Prevents printing in specified columns |
Programming languages such as FORTRAN, RPG, and IBM Assembly language designated particular columns for commands (for example, columns 1, 10, 16, 36, and 72). The program card configured these fields to automate cursor movement and numeric shifting.
An example layout might look like this:
1.......10........20........30........40........50........60........70........80 1AAAAAAAA1AAAAA1AAAAAAAAAAAAAAAAAAA1AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA &&&&&&&&
In this instance, activating skip would move the cursor to column 10; columns 72 through 80 could define a numeric shift zone for special characters or sequence numbering.
Note that both "Field Definition" (12) and "Alphabetic Shift" (1) control codes print as A.
Utilizing program code 2 carried the risk of producing invalid characters that might harm printing devices.
The program card system streamlined operations like "gang punching," which involved inserting fixed data across multiple cards in a deck. It also found unconventional uses such as creating music by punching rhythmic patterns of noisy characters.
IBM 5496 Data Recorder for 96 column cards
In 1969, IBM introduced its System/3 series of entry-level business computers featuring a novel compact 96-column punched card. The IBM 5496 Data Recorder—a keypunch combining printing and verification capabilities—and the IBM 5486 Card Sorter were specifically engineered to handle these cards.
Powers, Remington Rand (UNIVAC) keypunches
Circa 1906, James Powers at the United States Census Bureau developed the Powers Keypunch, designed with 240 keys to meet census requirements. In 1911, Powers established the Powers Accounting Machine Company, which Remington Rand acquired in 1927. Remington Rand's UNIVAC division manufactured keypunch machines compatible with their own 90-column cards as well as IBM's standard 80-column cards. Their 90-column keypunches employed a mechanical approach that circumvented IBM's patents. UNIVAC keypunches buffered an entire card’s character data before punching all holes in a single pass, enabling correction of errors and minimizing wasted cards.
Among Remington Rand’s offerings were the UNIVAC Card Code Punch Type 306-5 (including 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 supported verification by running cards through twice; accurately punched holes were elongated while incorrect punches appeared as round holes. The Automatic Verifying Machine quickly detected errors through mechanical means.
The UNIVAC 1710 Verifying Interpreting Punch was introduced in 1969.
Keypunch as a verb
The word keypunched (from the verb keypunch) initially described the process of encoding information onto punched cards using a keypunch machine. Although these devices have become outdated, the term continues to be used in professional environments to signify data entry. This evolution mirrors the shift from mechanical card punching to electronic data input techniques.
Transition to direct data entry
During the 1950s, Remington Rand launched the UNITYPER, a device that allowed users to input data directly onto magnetic tape for UNIVAC computers. Subsequently, in 1965, Mohawk Data Sciences introduced an enhanced magnetic tape encoder designed as a substitute for traditional keypunch machines. By the mid-1970s, advancements in microprocessor technology and the availability of cost-effective computer terminals led to the development of key-to-tape and key-to-disk solutions from manufacturers such as Inforex and Pertec.
Punched cards continued to be widely used for data entry and programming up until the mid-1980s. Nevertheless, removing the intermediate step of transferring data from cards to tape or disk helped lower expenses and improved accuracy checks during input. The emergence of video display terminals, interactive timeshared systems, and eventually personal computers enabled data creators to input information directly, reducing reliance on traditional data entry clerk positions.