A punched card (also punch card [1] or punched-card [2] ) is a piece of card stock that stores digital data using punched holes. Punched cards were once common in data processing and the control of automated machines.
Punched cards were widely used in the 20th century, where unit record machines, organized into data processing systems, used punched cards for data input, output, and storage. [3] [4] The IBM 12-row/80-column punched card format came to dominate the industry. Many early digital computers used punched cards as the primary medium for input of both computer programs and data.
Data can be entered onto a punched card using a keypunch.
While punched cards are now obsolete as a storage medium, as of 2012, some voting machines still used punched cards to record votes. [5] Punched cards also had a significant cultural impact in the 20th century.
The idea of control and data storage via punched holes was developed independently on several occasions in the modern period. In most cases there is no evidence that each of the inventors was aware of the earlier work.
Basile Bouchon developed the control of a loom by punched holes in paper tape in 1725. The design was improved by his assistant Jean-Baptiste Falcon and by Jacques Vaucanson. [6] Although these improvements controlled the patterns woven, they still required an assistant to operate the mechanism.
In 1804 Joseph Marie Jacquard demonstrated a mechanism to automate loom operation. A number of punched cards were linked into a chain of any length. Each card held the instructions for shedding (raising and lowering the warp) and selecting the shuttle for a single pass. [7]
Semyon Korsakov was reputedly the first to propose punched cards in informatics for information store and search. Korsakov announced his new method and machines in September 1832. [8]
Charles Babbage proposed the use of "Number Cards", "pierced with certain holes and stand[ing] opposite levers connected with a set of figure wheels ... advanced they push in those levers opposite to which there are no holes on the cards and thus transfer that number together with its sign" in his description of the Calculating Engine's Store. [9] There is no evidence that he built a practical example.
In 1881, Jules Carpentier developed a method of recording and playing back performances on a harmonium using punched cards. The system was called the Mélographe Répétiteur and "writes down ordinary music played on the keyboard dans le langage de Jacquard", [10] that is as holes punched in a series of cards. By 1887 Carpentier had separated the mechanism into the Melograph which recorded the player's key presses and the Melotrope which played the music. [11] [12]
At the end of the 1800s Herman Hollerith created a method for recording data on a medium that could then be read by a machine, [13] [14] [15] [16] developing punched card data processing technology for the 1890 U.S. census. [17] His tabulating machines read and summarized data stored on punched cards and they began use for government and commercial data processing.
Initially, these electromechanical machines only counted holes, but by the 1920s they had units for carrying out basic arithmetic operations. [18] : 124 Hollerith founded the Tabulating Machine Company (1896) which was one of four companies that were amalgamated via stock acquisition to form a fifth company, Computing-Tabulating-Recording Company (CTR) in 1911, later renamed International Business Machines Corporation (IBM) in 1924. Other companies entering the punched card business included The Tabulator Limited (Britain, 1902), Deutsche Hollerith-Maschinen Gesellschaft mbH (Dehomag) (Germany, 1911), Powers Accounting Machine Company (US, 1911), Remington Rand (US, 1927), and H.W. Egli Bull (France, 1931). [19] These companies, and others, manufactured and marketed a variety of punched cards and unit record machines for creating, sorting, and tabulating punched cards, even after the development of electronic computers in the 1950s.
Both IBM and Remington Rand tied punched card purchases to machine leases, a violation of the US 1914 Clayton Antitrust Act. In 1932, the US government took both to court on this issue. Remington Rand settled quickly. IBM viewed its business as providing a service and that the cards were part of the machine. IBM fought all the way to the Supreme Court and lost in 1936; the court ruled that IBM could only set card specifications. [20] [21] : 300–301
"By 1937... IBM had 32 presses at work in Endicott, N.Y., printing, cutting and stacking five to 10 million punched cards every day." [22] Punched cards were even used as legal documents, such as U.S. Government checks [23] and savings bonds. [24]
During World War II punched card equipment was used by the Allies in some of their efforts to decrypt Axis communications. See, for example, Central Bureau in Australia. At Bletchley Park in England, "some 2 million punched cards a week were being produced, indicating the sheer scale of this part of the operation". [25] In Nazi Germany, punched cards were used for the censuses of various regions and other purposes [26] [27] (see IBM and the Holocaust).
Punched card technology developed into a powerful tool for business data-processing. By 1950 punched cards had become ubiquitous in industry and government. "Do not fold, spindle or mutilate," a warning that appeared on some punched cards distributed as documents such as checks and utility bills to be returned for processing, became a motto for the post-World War II era. [28] [29]
In 1956 [30] IBM signed a consent decree requiring, amongst other things, that IBM would by 1962 have no more than one-half of the punched card manufacturing capacity in the United States. Tom Watson Jr.'s decision to sign this decree, where IBM saw the punched card provisions as the most significant point, completed the transfer of power to him from Thomas Watson, Sr. [21]
The Univac UNITYPER introduced magnetic tape for data entry in the 1950s. During the 1960s, the punched card was gradually replaced as the primary means for data storage by magnetic tape, as better, more capable computers became available. Mohawk Data Sciences introduced a magnetic tape encoder in 1965, a system marketed as a keypunch replacement which was somewhat successful. Punched cards were still commonly used for entering both data and computer programs until the mid-1980s when the combination of lower cost magnetic disk storage, and affordable interactive terminals on less expensive minicomputers made punched cards obsolete for these roles as well. [31] : 151 However, their influence lives on through many standard conventions and file formats. The terminals that replaced the punched cards, the IBM 3270 for example, displayed 80 columns of text in text mode, for compatibility with existing software. Some programs still operate on the convention of 80 text columns, although fewer and fewer do as newer systems employ graphical user interfaces with variable-width type fonts.
The terms punched card, punch card, and punchcard were all commonly used, as were IBM card and Hollerith card (after Herman Hollerith). [1] IBM used "IBM card" or, later, "punched card" at first mention in its documentation and thereafter simply "card" or "cards". [33] [34] Specific formats were often indicated by the number of character positions available, e.g. 80-column card. A sequence of cards that is input to or output from some step in an application's processing is called a card deck or simply deck. The rectangular, round, or oval bits of paper punched out were called chad (chads) or chips (in IBM usage). Sequential card columns allocated for a specific use, such as names, addresses, multi-digit numbers, etc., are known as a field. The first card of a group of cards, containing fixed or indicative information for that group, is known as a master card. Cards that are not master cards are detail cards.
The Hollerith punched cards used for the 1890 U.S. census were blank. [35] Following that, cards commonly had printing such that the row and column position of a hole could be easily seen. Printing could include having fields named and marked by vertical lines, logos, and more. [36] "General purpose" layouts (see, for example, the IBM 5081 below) were also available. For applications requiring master cards to be separated from following detail cards, the respective cards had different upper corner diagonal cuts and thus could be separated by a sorter. [37] Other cards typically had one upper corner diagonal cut so that cards not oriented correctly, or cards with different corner cuts, could be identified.
Herman Hollerith was awarded three patents [39] in 1889 for electromechanical tabulating machines. These patents described both paper tape and rectangular cards as possible recording media. The card shown in U.S. patent 395,781 of January 8 was printed with a template and had hole positions arranged close to the edges so they could be reached by a railroad conductor's ticket punch, with the center reserved for written descriptions. Hollerith was originally inspired by railroad tickets that let the conductor encode a rough description of the passenger:
I was traveling in the West and I had a ticket with what I think was called a punch photograph...the conductor...punched out a description of the individual, as light hair, dark eyes, large nose, etc. So you see, I only made a punch photograph of each person. [18] : 15
When use of the ticket punch proved tiring and error-prone, Hollerith developed the pantograph "keyboard punch". It featured an enlarged diagram of the card, indicating the positions of the holes to be punched. A printed reading board could be placed under a card that was to be read manually. [35] : 43
Hollerith envisioned a number of card sizes. In an article he wrote describing his proposed system for tabulating the 1890 U.S. census, Hollerith suggested a card 3 by 5+1⁄2 inches (7.6 by 14.0 cm) of Manila stock "would be sufficient to answer all ordinary purposes." [40] The cards used in the 1890 census had round holes, 12 rows and 24 columns. A reading board for these cards can be seen at the Columbia University Computing History site. [41] At some point, 3+1⁄4 by 7+3⁄8 inches (83 by 187 mm) became the standard card size. These are the dimensions of the then-current paper currency of 1862–1923. [42] This size was needed in order to use available banking-type storage for the 60,000,000 punched cards to come nationwide. [41]
Hollerith's original system used an ad hoc coding system for each application, with groups of holes assigned specific meanings, e.g. sex or marital status. His tabulating machine had up to 40 counters, each with a dial divided into 100 divisions, with two indicator hands; one which stepped one unit with each counting pulse, the other which advanced one unit every time the other dial made a complete revolution. This arrangement allowed a count up to 9,999. During a given tabulating run counters were assigned specific holes or, using relay logic, combination of holes. [40]
Later designs led to a card with ten rows, each row assigned a digit value, 0 through 9, and 45 columns. [43] This card provided for fields to record multi-digit numbers that tabulators could sum, instead of their simply counting cards. Hollerith's 45 column punched cards are illustrated in Comrie's The application of the Hollerith Tabulating Machine to Brown's Tables of the Moon. [44]
By the late 1920s, customers wanted to store more data on each punched card. Thomas J. Watson Sr., IBM's head, asked two of his top inventors, Clair D. Lake and J. Royden Pierce, to independently develop ways to increase data capacity without increasing the size of the punched card. Pierce wanted to keep round holes and 45 columns but to allow each column to store more data; Lake suggested rectangular holes, which could be spaced more tightly, allowing 80 columns per punched card, thereby nearly doubling the capacity of the older format. [45] Watson picked the latter solution, introduced as The IBM Card, in part because it was compatible with existing tabulator designs and in part because it could be protected by patents and give the company a distinctive advantage. [46]
This IBM card format, introduced in 1928, [47] has rectangular holes, 80 columns, and 10 rows. [48] Card size is 7+3⁄8 by 3+1⁄4 inches (187 by 83 mm). The cards are made of smooth stock, 0.007 inches (180 μm) thick. There are about 143 cards to the inch (56/cm). In 1964, IBM changed from square to round corners. [49] They come typically in boxes of 2,000 cards [50] or as continuous form cards. Continuous form cards could be both pre-numbered and pre-punched for document control (checks, for example). [51]
Initially designed to record responses to yes–no questions, support for numeric, alphabetic and special characters was added through the use of columns and zones. The top three positions of a column are called zone punching positions, 12 (top), 11, and 0 (0 may be either a zone punch or a digit punch). [52] For decimal data the lower ten positions are called digit punching positions, 0 (top) through 9. [52] An arithmetic sign can be specified for a decimal field by overpunching the field's rightmost column with a zone punch: 12 for plus, 11 for minus (CR). For Pound sterling pre-decimalization currency a penny column represents the values zero through eleven; 10 (top), 11, then 0 through 9 as above. An arithmetic sign can be punched in the adjacent shilling column. [53] : 9 Zone punches had other uses in processing, such as indicating a master card. [54]
Diagram: [55] Note: The 11 and 12 zones were also called the X and Y zones, respectively.
_______________________________________________ / &-0123456789ABCDEFGHIJKLMNOPQR/STUVWXYZ 12| x xxxxxxxxx 11| x xxxxxxxxx 0| x xxxxxxxxx 1| x x x x 2| x x x x 3| x x x x 4| x x x x 5| x x x x 6| x x x x 7| x x x x 8| x x x x 9| x x x x |________________________________________________
In 1931, IBM began introducing upper-case letters and special characters (Powers-Samas had developed the first commercial alphabetic punched card representation in 1921). [56] [57] [nb 1] The 26 letters have two punches (zone [12,11,0] + digit [1–9]). The languages of Germany, Sweden, Denmark, Norway, Spain, Portugal and Finland require up to three additional letters; their punching is not shown here. [58] : 88–90 Most special characters have two or three punches (zone [12,11,0, or none] + digit [2–7] + 8); a few special characters were exceptions: "&" is 12 only, "-" is 11 only, and "/" is 0 + 1). The Space character has no punches. [58] : 38 The information represented in a column by a combination of zones [12, 11, 0] and digits [0–9] is dependent on the use of that column. For example, the combination "12-1" is the letter "A" in an alphabetic column, a plus signed digit "1" in a signed numeric column, or an unsigned digit "1" in a column where the "12" has some other use. The introduction of EBCDIC in 1964 defined columns with as many as six punches (zones [12,11,0,8,9] + digit [1–7]). IBM and other manufacturers used many different 80-column card character encodings. [59] [60] A 1969 American National Standard defined the punches for 128 characters and was named the Hollerith Punched Card Code (often referred to simply as Hollerith Card Code), honoring Hollerith. [58] : 7
For some computer applications, binary formats were used, where each hole represented a single binary digit (or "bit"), every column (or row) is treated as a simple bit field, and every combination of holes is permitted.
For example, on the IBM 701 [61] and IBM 704, [62] card data was read, using an IBM 711, into memory in row binary format. For each of the twelve rows of the card, 72 of the 80 columns, skipping the other eight, would be read into two 36-bit words, requiring 864 bits to store the whole card; a control panel was used to select the 72 columns to be read. Software would translate this data into the desired form. One convention was to use columns 1 through 72 for data, and columns 73 through 80 to sequentially number the cards, as shown in the picture above of a punched card for FORTRAN. Such numbered cards could be sorted by machine so that if a deck was dropped the sorting machine could be used to arrange it back in order. This convention continued to be used in FORTRAN, even in later systems where the data in all 80 columns could be read.
The IBM card readers 3504, 3505 and the multifunction unit 3525 used a different encoding scheme for column binary data, also known as card image, where each column, split into two rows of 6 (12–3 and 4–9) was encoded into two 8-bit bytes, holes in each group represented by bits 2 to 7 (MSb numbering, bit 0 and 1 unused ) in successive bytes. This required 160 8-bit bytes, or 1280 bits, to store the whole card. [63]
As an aid to humans who had to deal with the punched cards, the IBM 026 and later 029 and 129 key punch machines could print human-readable text above each of the 80 columns.
As a prank, punched cards could be made where every possible punch position had a hole. Such "lace cards" lacked structural strength, and would frequently buckle and jam inside the machine. [64]
The IBM 80-column punched card format dominated the industry, becoming known as just IBM cards, even though other companies made cards and equipment to process them. [65]
One of the most common punched card formats is the IBM 5081 card format, a general purpose layout with no field divisions. This format has digits printed on it corresponding to the punch positions of the digits in each of the 80 columns. Other punched card vendors manufactured cards with this same layout and number.
Long cards were available with a scored stub on either end which, when torn off, left an 80 column card. The torn off card is called a stub card.
80-column cards were available scored, on either end, creating both a short card and a stub card when torn apart. Short cards can be processed by other IBM machines. [51] [66] A common length for stub cards was 51 columns. Stub cards were used in applications requiring tags, labels, or carbon copies. [51]
According to the IBM Archive: IBM's Supplies Division introduced the Port-A-Punch in 1958 as a fast, accurate means of manually punching holes in specially scored IBM punched cards. Designed to fit in the pocket, Port-A-Punch made it possible to create punched card documents anywhere. The product was intended for "on-the-spot" recording operations—such as physical inventories, job tickets and statistical surveys—because it eliminated the need for preliminary writing or typing of source documents. [67]
In 1969 IBM introduced a new, smaller, round-hole, 96-column card format along with the IBM System/3 low-end business computer. These cards have tiny, 1 mm diameter circular holes, smaller than those in paper tape. Data is stored in 6-bit BCD, with three rows of 32 characters each, or 8-bit EBCDIC. In this format, each column of the top tiers are combined with two punch rows from the bottom tier to form an 8-bit byte, and the middle tier is combined with two more punch rows, so that each card contains 64 bytes of 8-bit-per-byte binary coded data. [68] As in the 80 column card, readable text was printed in the top section of the card. There was also a 4th row of 32 characters that could be printed. This format was never widely used; it was IBM-only, but they did not support it on any equipment beyond the System/3, where it was quickly superseded by the 1973 IBM 3740 Data Entry System using 8-inch floppy disks.
The Powers/Remington Rand card format was initially the same as Hollerith's; 45 columns and round holes. In 1930, Remington Rand leap-frogged IBM's 80 column format from 1928 by coding two characters in each of the 45 columns – producing what is now commonly called the 90-column card. [31] : 142 There are two sets of six rows across each card. The rows in each set are labeled 0, 1/2, 3/4, 5/6, 7/8 and 9. The even numbers in a pair are formed by combining that punch with a 9 punch. Alphabetic and special characters use 3 or more punches. [69] [70]
The British Powers-Samas company used a variety of card formats for their unit record equipment. They began with 45 columns and round holes. Later 36, 40 and 65 column cards were provided. A 130 column card was also available – formed by dividing the card into two rows, each row with 65 columns and each character space with 5 punch positions. A 21 column card was comparable to the IBM Stub card. [53] : 47–51
Mark sense (electrographic) cards, developed by Reynold B. Johnson at IBM, [71] have printed ovals that could be marked with a special electrographic pencil. Cards would typically be punched with some initial information, such as the name and location of an inventory item. Information to be added, such as quantity of the item on hand, would be marked in the ovals. Card punches with an option to detect mark sense cards could then punch the corresponding information into the card.
Aperture cards have a cut-out hole on the right side of the punched card. A piece of 35 mm microfilm containing a microform image is mounted in the hole. Aperture cards are used for engineering drawings from all engineering disciplines. Information about the drawing, for example the drawing number, is typically punched and printed on the remainder of the card.
IBM's Fred M. Carroll [72] developed a series of rotary presses that were used to produce punched cards, including a 1921 model that operated at 460 cards per minute (cpm). In 1936 he introduced a completely different press that operated at 850 cpm. [22] [73] Carroll's high-speed press, containing a printing cylinder, revolutionized the company's manufacturing of punched cards. [74] It is estimated that between 1930 and 1950, the Carroll press accounted for as much as 25 percent of the company's profits. [21]
Discarded printing plates from these card presses, each printing plate the size of an IBM card and formed into a cylinder, often found use as desk pen/pencil holders, and even today are collectible IBM artifacts (every card layout [75] had its own printing plate).
In the mid-1930s a box of 1,000 cards cost $1.05 (equivalent to $23in 2023). [76]
While punched cards have not been widely used for generations, the impact was so great for most of the 20th century that they still appear from time to time in popular culture. For example:
metaphor... symbol of the "system"—first the registration system and then bureaucratic systems more generally ... a symbol of alienation ... Punched cards were the symbol of information machines, and so they became the symbolic point of attack. Punched cards, used for class registration, were first and foremost a symbol of uniformity. .... A student might feel "he is one of out of 27,500 IBM cards" ... The president of the Undergraduate Association criticized the University as "a machine ... IBM pattern of education."... Robert Blaumer explicated the symbolism: he referred to the "sense of impersonality... symbolized by the IBM technology."...
- — Steven Lubar [28]
A common example of the requests often printed on punched cards which were to be individually handled, especially those intended for the public to use and return is "Do Not Fold, Spindle or Mutilate" (in the UK "Do not bend, spike, fold or mutilate"). [28] : 43–55 Coined by Charles A. Phillips, [86] it became a motto [87] for the post–World War II era (even though many people had no idea what spindle meant), and was widely mocked and satirized. Some 1960s students at Berkeley wore buttons saying: "Do not fold, spindle or mutilate. I am a student". [88] The motto was also used for a 1970 book by Doris Miles Disney [89] with a plot based around an early computer dating service and a 1971 made-for-TV movie based on that book, and a similarly titled 1967 Canadian short film, Do Not Fold, Staple, Spindle or Mutilate .
Processing of punched cards was handled by a variety of machines, including:
Herman Hollerith was a German-American statistician, inventor, and businessman who developed an electromechanical tabulating machine for punched cards to assist in summarizing information and, later, in accounting. His invention of the punched card tabulating machine, patented in 1884, marks the beginning of the era of mechanized binary code and semiautomatic data processing systems, and his concept dominated that landscape for nearly a century.
Punched tape or perforated paper tape is a form of data storage device that consists of a long strip of paper through which small holes are punched. It was developed from and was subsequently used alongside punched cards, the difference being that the tape is continuous.
The IBM 1620 was a model of scientific minicomputer produced by IBM. It was announced on October 21, 1959, and was then marketed as an inexpensive scientific computer. After a total production of about two thousand machines, it was withdrawn on November 19, 1970. Modified versions of the 1620 were used as the CPU of the IBM 1710 and IBM 1720 Industrial Process Control Systems.
The IBM 1401 is a variable-wordlength decimal computer that was announced by IBM on October 5, 1959. The first member of the highly successful IBM 1400 series, it was aimed at replacing unit record equipment for processing data stored on punched cards and at providing peripheral services for larger computers. The 1401 is considered by IBM to be the Ford Model-T of the computer industry due to its mass appeal. Over 12,000 units were produced and many were leased or resold after they were replaced with newer technology. The 1401 was withdrawn on February 8, 1971.
A punched card sorter is a machine for sorting decks of punched cards.
Electronic data processing (EDP) or business information processing can refer to the use of automated methods to process commercial data. Typically, this uses relatively simple, repetitive activities to process large volumes of similar information. For example: stock updates applied to an inventory, banking transactions applied to account and customer master files, booking and ticketing transactions to an airline's reservation system, billing for utility services. The modifier "electronic" or "automatic" was used with "data processing" (DP), especially c. 1960, to distinguish human clerical data processing from that done by computer.
The IBM 1130 Computing System, introduced in 1965, was IBM's least expensive computer at that time. A binary 16-bit machine, it was marketed to price-sensitive, computing-intensive technical markets, like education and engineering, succeeding the decimal IBM 1620 in that market segment. Typical installations included a 1 megabyte disk drive that stored the operating system, compilers and object programs, with program source generated and maintained on punched cards. Fortran was the most common programming language used, but several others, including APL, were available.
Starting at the end of the nineteenth century, well before the advent of electronic computers, data processing was performed using electromechanical machines collectively referred to as unit record equipment, electric accounting machines (EAM) or tabulating machines. Unit record machines came to be as ubiquitous in industry and government in the first two-thirds of the twentieth century as computers became in the last third. They allowed large volume, sophisticated data-processing tasks to be accomplished before electronic computers were invented and while they were still in their infancy. This data processing was accomplished by processing punched cards through various unit record machines in a carefully choreographed progression. This progression, or flow, from machine to machine was often planned and documented with detailed flowcharts that used standardized symbols for documents and the various machine functions. All but the earliest machines had high-speed mechanical feeders to process cards at rates from around 100 to 2,000 per minute, sensing punched holes with mechanical, electrical, or, later, optical sensors. The operation of many machines was directed by the use of a removable plugboard, control panel, or connection box. Initially all machines were manual or electromechanical. The first use of an electronic component was in 1937 when a photocell was used in a Social Security bill-feed machine. Electronic components were used on other machines beginning in the late 1940s.
A keypunch is a device for precisely punching holes into stiff paper cards at specific locations as determined by keys struck by a human operator. Other devices included here for that same function include the gang punch, the pantograph punch, and the stamp. The term was also used for similar machines used by humans to transcribe data onto punched tape media.
The IBM 407 Accounting Machine, introduced in 1949, was one of a long line of IBM tabulating machines dating back to the days of Herman Hollerith. It had a card reader and printer; a summary punch could be attached. Processing was directed by a control panel.
The IBM System/3 was an IBM midrange computer introduced in 1969, and marketed until 1985. It was produced by IBM Rochester in Minnesota as a low-end business computer aimed at smaller organizations that still used IBM 1400 series computers or unit record equipment. The first member of what IBM refers to as their "midrange" line, it also introduced the RPG II programming language. It is the first ancestor in the product line whose current version is the IBM i series and includes the highly successful AS/400.
The tabulating machine was an electromechanical machine designed to assist in summarizing information stored on punched cards. Invented by Herman Hollerith, the machine was developed to help process data for the 1890 U.S. Census. Later models were widely used for business applications such as accounting and inventory control. It spawned a class of machines, known as unit record equipment, and the data processing industry.
Powers-Samas was a British company which sold unit record equipment.
A plugboard or control panel is an array of jacks or sockets into which patch cords can be inserted to complete an electrical circuit. Control panels are sometimes used to direct the operation of unit record equipment, cipher machines, and early computers. The array of holes is often contained in a flat removable panel that can be inserted into a machine and pressed against an array of contacts. This allows the machine to be quickly switched between different applications.
From the invention of computer programming languages up to the mid-1970s, most computer programmers created, edited and stored their programs line by line on punch cards.
Paper data storage refers to the use of paper as a data storage device. This includes writing, illustrating, and the use of data that can be interpreted by a machine or is the result of the functioning of a machine. A defining feature of paper data storage is the ability of humans to produce it with only simple tools and interpret it visually.
A computer punched card reader or just computer card reader is a computer input device used to read computer programs in either source or executable form and data from punched cards. A computer card punch is a computer output device that punches holes in cards. Sometimes computer punch card readers were combined with computer card punches and, later, other devices to form multifunction machines.
BCD, also called alphanumeric BCD, alphameric BCD, BCD Interchange Code, or BCDIC, is a family of representations of numerals, uppercase Latin letters, and some special and control characters as six-bit character codes.
The IBM 711 was a punched card reader used as a peripheral device for IBM mainframe vacuum tube computers and early transistorized computers. Announced on May 21, 1952, it was first shipped with the IBM 701. Later IBM computers that used it were the IBM 704, the IBM 709, and the transistorized IBM 7090 and 7094.
semiautomatic
At this early stage, the corresponding playback mechanism, the Mélotrope, was permanently installed inside the same harmonium used for the recording process, but by 1887 Carpentier had modified both devices, restricting the range to three octaves, allowing for the Mélotrope to be attached to any style of keyboard instrument, and designing and constructing an automatic perforating machine for mass production.
After some initial trials with paper tape, he settled on punched cards...
1962: 20th year […] producing savings bonds […] 1964: $75 savings bond […] produce
Security checks issued starting in 1936 […](13 pages); Lubar, Steven (May 1991). "Do not fold, spindle or mutilate: A cultural history of the punch card". Smithsonian Institution. Archived from the original on 2006-08-30. (NB. An earlier version of this paper was presented to the Bureau of the Census's Hollerith Machine Centennial Celebration on 1990-06-20.)
Once the cards were assembled in order in a deck, the programmer would usually draw a long diagonal line across the top edges of the cards, so that if ever one got out of order it would easily be noticed
An important function in IBM Accounting is the automatic preparation of IBM cards.
The IBM 1402 Card Read-Punch provides the system with simultaneous punched-card input and output. This unit has two card feeds.
Master Card: The first card of a group containing fixed or indicative information for that group
The variable-length card feed feature on the 24 or 26 allows the processing of 51-, 60-, 66-, and 80-column cards (Figure 20)
Edward Ziegler […] an editor at the Reader's Digest […] wrote a science fiction novel, The Man Whose Name Wouldn't Fit, under the pen name Theodore Tyler
At the bottom of the bill, it said […] and Jane, in her anger, […]