Punched card
Encyclopedia
A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper
that contains digital
information represented by the presence or absence of holes in predefined positions. Now an obsolete recording medium, punched cards were widely used throughout the 19th century for controlling textile looms
and in the late 19th and early 20th century for operating fairground organ
s and related instruments. They were used through the 20th century in unit record machines
for input, processing, and data storage
. Early digital computers used punched cards, often prepared using keypunch machines, as the primary medium for input of both computer program
s and data
. Some voting machine
s use punched cards.
Punched cards were first used around 1725 by Basile Bouchon
and Jean-Baptiste Falcon as a more robust form of the perforated paper rolls then in use for controlling textile looms
in France. This technique was greatly improved by Joseph Marie Jacquard
in his Jacquard loom
in 1801.
Semen Korsakov
was reputedly the first to use the punched cards in informatics for information store and search. Korsakov announced his new method and machines in September 1832, and rather than seeking patents offered the machines for public use.
Charles Babbage
proposed the use of "Number Cards", "pierced with certain holes and stand opposite levers connected with a set of figure wheels ... advanced they push in those levers opposite to which there are no holes on the card and thus transfer that number" in his description of the Calculating Engine's Store.
Herman Hollerith
invented the recording of data on a medium that could then be read by a machine. Prior uses of machine readable media, such as those above (other than Korsakov), had been for control, not data. "After some initial trials with paper tape, he settled on punched cards...", developing punched card data processing technology for the 1890 US census
. He founded the Tabulating Machine Company (1896) which was one of four companies that merged to form Computing Tabulating Recording Corporation (CTR)
, later renamed IBM. IBM manufactured and marketed a variety of unit record machines for creating, sorting, and tabulating punched cards, even after expanding into electronic computers in the late 1950s. IBM developed punched card technology into a powerful tool for business data-processing and produced an extensive line of general purpose unit record machines
. By 1950, the IBM card and IBM unit record machines had become ubiquitous in industry and government. "Do not fold, spindle or mutilate," a generalized version of the warning that appeared on some punched cards (generally on those distributed as paper documents to be later returned for further machine processing, checks for example), became a motto for the post-World War II
era (even though many people had no idea what spindle
meant).
From the 1900s, into the 1950s, punched cards were the primary medium for data entry, data storage
, and processing in institutional computing. According to the IBM Archives: "By 1937... IBM had 32 presses at work in Endicott, N.Y., printing, cutting and stacking five to 10 million punched cards every day." Punched cards were even used as legal documents, such as U.S. Government checks and savings bonds. 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. Punched cards were still commonly used for data entry and programming until the mid-1970s when the combination of lower cost magnetic disk storage, and affordable interactive terminals on less expensive minicomputer
s made punched cards obsolete for this role as well. 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 interface
s with variable-width type fonts.
Today punched cards are mostly obsolete and replaced with other storage methods, except for a few legacy system
s and specialized applications.
). IBM used "IBM card" or, later, "punched card" at first mention in its documentation and thereafter simply "card" or "cards". The term punched card was generally avoided for blank cards, with other terms such as tabulating card used. Specific formats were often indicated by the number of character positions available, e.g. 80-column card.
Herman Hollerith
was awarded a series of patents in 1889 for mechanical tabulating machines. These patents described both paper tape and rectangular cards as possible recording media. The card shown in of June 8 was preprinted with a template and had holes 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:
Use of the ticket punch proved tiring and error prone, so Hollerith invented a pantograph "keyboard punch" that allowed the entire card area to be used. It also eliminated the need for a printed template on each card, instead a master template was used at the punch; a printed reading card could be placed under a card that was to be read manually. 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 inches by 5½ inches of Manila
stock "would be sufficient to answer all ordinary purposes."
The cards used in the 1890 census had round holes, 12 rows and 24 columns. A census card and reading board for these cards can be seen at the Columbia University Computing History site. At some point, 3+1/4 by became the standard card size, a bit larger than the United States one-dollar bill
of the time (the dollar was changed to its current size in 1929). The Columbia site says Hollerith took advantage of available boxes designed to transport paper currency.
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 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 10,000. During a given tabulating run, each counter was typically assigned a specific hole. Hollerith also used relay logic
to allow counts of combination of holes, e.g. to count married females.
Later designs standardized the coding
, with twelve rows, where the lower ten rows coded digits 0 through 9. This allowed groups of holes to represent numbers that could be added, instead of simply counting units. 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.
This IBM
card format, designed in 1928,
had rectangular holes, 80 columns with 12 punch locations each, one character to each column. Card size was exactly by inches (187.325 mm × 82.55 mm). The cards were made of smooth stock, 0.007 inch thick. There are about 143 cards to the inch (/cm). In 1964, IBM changed from square to round corners. They came typically in boxes of 2000 cards or as continuous form
cards. Continuous form cards could be both pre-numbered and pre-punched for document control (checks, for example).
The lower ten positions represented (from top to bottom) the digits 0 through 9. The top two positions of a column were called zone punches, 12 (top) and 11. Originally only numeric information was punched, with 1 punch per column indicating the digit. Signs could be added to a field by overpunching the least significant digit
with a zone punch: 12 for plus and 11 for minus. Zone punches had other uses in processing as well, such as indicating a master record.
Later, multiple punches were introduced for upper-case letters and special characters. A letter had two punches (zone [12,11,0] + digit [1-9]); most special characters had two or three punches (zone [12,11,0,or none] + digit [2-7] + 8); a few special characters were exceptions (in EBCDIC
"&" was 12 only, "-" was 11 only, and "/" was 0 + 1). With these changes, the information represented in a column by a combination of zones [12, 11] and digits [1-9] was dependent on the use of that column. For example the combination "12-1" was 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" had some other use. The introduction of EBCDIC
in 1964 allowed 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. 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.
For some computer applications, binary
formats were used, where each hole represented a single binary digit (or "bit
"), every column (or row) was treated as a simple bitfield, and every combination of holes was permitted. For example, the IBM 711 card reader used with the 704/709/7090/7094 series scientific computers treated every row as two 36-bit words, ignoring 8 columns. (The specific 72 columns used were selectable using a plugboard
control panel, which was almost always wired to select columns 1-72.) Sometimes the ignored columns (usually 73–80) were used to contain a sequence number for each card, so the card deck could be sorted to the correct order in case it was dropped. Other computers, such as the IBM 1130
or System/360
, used every column. The IBM 1402
could be used in "column binary" mode, which stored two characters in every column, or one 36-bit word in three columns. However, most of the older card punches were not intended to punch more than 3 holes in a column, so they couldn't be used to produce binary cards.
As a prank, in binary mode, cards could be punched where every possible punch position had a hole. Such "lace card
s" lacked structural strength, and would frequently buckle and jam inside the machine.
The 80-column card format dominated the industry, becoming known as just IBM cards, even though other companies made cards and equipment to process them.
One of the most common printed punched cards was the IBM
5081, a general purpose layout with no field divisions. Indeed, it was so common that other card vendors used the same number (see image at right) and even users knew its number.
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..
Unfortunately, the resulting holes were "furry" (i.e. not cleanly cut, owing to the perforations) and sometimes caused problems with the equipment used to read the cards.
In the early 1970s IBM introduced a new, smaller, round-hole, 96-column card format along with the IBM System/3
computer. The IBM 5496 Data Recorder, a keypunch machine with print and verify functions, and the IBM 5486 Card Sorter were made for these 96-column cards.
These cards had tiny (1 mm), circular holes, smaller than those in paper tape. Data was stored in six-bit binary-coded decimal
code, 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 data.
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 1928 introduced 80 column format by coding two characters in each of the 45 columns - producing what is now commonly called the 90-column card. For its character codings, see Centrum Wiskunde & Informatica.
IBM's Fred M. Carroll developed a series of rotary type presses that were used to produce the well-known standard tabulating cards, including a 1921 model that operated at 400 cards per minute (cpm). Later, he developed a completely different press capable of operating at speeds in excess of 800 cpm, and it was introduced in 1936. Carroll's high-speed press, containing a printing cylinder, revolutionized the manufacture of punched tabulating cards. It is estimated that between 1930 and 1950, the Carroll press accounted for as much as 25 percent of the company's profits
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 had its own printing plate).
IBM initially required that its customers use only IBM manufactured cards with IBM machines, which were leased, not sold. IBM viewed its business as providing a service and that the cards were part of the machine. In 1932 the government took IBM to court on this issue. IBM fought all the way to the Supreme Court and lost; the court ruling that IBM could only set card specifications. In another case, heard in 1955, 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
.
Paperboard
Paperboard is a thick paper based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker than paper. According to ISO standards, paperboard is a paper with a basis weight above 224 g/m2, but there are exceptions. Paperboard can be single...
that contains digital
Digital
A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...
information represented by the presence or absence of holes in predefined positions. Now an obsolete recording medium, punched cards were widely used throughout the 19th century for controlling textile looms
Loom
A loom is a device used to weave cloth. The basic purpose of any loom is to hold the warp threads under tension to facilitate the interweaving of the weft threads...
and in the late 19th and early 20th century for operating fairground organ
Fairground organ
A fairground organ is a pipe organ designed for use in a commercial public fairground setting to provide loud music to accompany fairground rides and attractions...
s and related instruments. They were used through the 20th century in unit record machines
Unit record equipment
Before the advent of electronic computers, data processing was performed using electromechanical devices called unit record equipment, electric accounting machines or tabulating machines. Unit record machines were as ubiquitous in industry and government in the first half of the twentieth century...
for input, processing, and data storage
Computer storage
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is one of the core functions and fundamental components of computers....
. Early digital computers used punched cards, often prepared using keypunch machines, as the primary medium for input of both computer program
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...
s and data
Data (computing)
In computer science, data is information in a form suitable for use with a computer. Data is often distinguished from programs. A program is a sequence of instructions that detail a task for the computer to perform...
. Some voting machine
Voting machine
Voting machines are the total combination of mechanical, electromechanical, or electronic equipment , that is used to define ballots; to cast and count votes; to report or display election results; and to maintain and produce any audit trail information...
s use punched cards.
History
Basile Bouchon
Basile Bouchon was a textile worker in the silk center in Lyon who invented a way to control a loom with a perforated paper tape in 1725. The son of an organ maker, Bouchon partially automated the tedious setting up process of the drawloom in which an operator lifted the warp threads using...
and Jean-Baptiste Falcon as a more robust form of the perforated paper rolls then in use for controlling textile looms
Loom
A loom is a device used to weave cloth. The basic purpose of any loom is to hold the warp threads under tension to facilitate the interweaving of the weft threads...
in France. This technique was greatly improved by Joseph Marie Jacquard
Joseph Marie Jacquard
Joseph Marie Charles dit Jacquard played an important role in the development of the earliest programmable loom , which in turn played an important role in the development of other programmable machines, such as computers.- Early life :Jean Jacquard’s name was not really...
in his Jacquard loom
Jacquard loom
The Jacquard loom is a mechanical loom, invented by Joseph Marie Jacquard in 1801, that simplifies the process of manufacturing textiles with complex patterns such as brocade, damask and matelasse. The loom is controlled by punched cards with punched holes, each row of which corresponds to one row...
in 1801.
Semen Korsakov
Semen Korsakov
Semen Nikolaevich Korsakov was a Russian government official, noted both as a homeopath and an inventor who was involved with an early version of information technology.-Biography:...
was reputedly the first to use the punched cards in informatics for information store and search. Korsakov announced his new method and machines in September 1832, and rather than seeking patents offered the machines for public use.
Charles Babbage
Charles Babbage, FRS was an English mathematician, philosopher, inventor and mechanical engineer who originated the concept of a programmable computer...
proposed the use of "Number Cards", "pierced with certain holes and stand opposite levers connected with a set of figure wheels ... advanced they push in those levers opposite to which there are no holes on the card and thus transfer that number" in his description of the Calculating Engine's Store.
Herman Hollerith
Herman Hollerith
Herman Hollerith was an American statistician who developed a mechanical tabulator based on punched cards to rapidly tabulate statistics from millions of pieces of data. He was the founder of one of the companies that later merged and became IBM.-Personal life:Hollerith was born in Buffalo, New...
invented the recording of data on a medium that could then be read by a machine. Prior uses of machine readable media, such as those above (other than Korsakov), had been for control, not data. "After some initial trials with paper tape, he settled on punched cards...", developing punched card data processing technology for the 1890 US census
United States Census, 1890
The Eleventh United States Census was taken June 2, 1890. The data was tabulated by machine for the first time. The data reported that the distribution of the population had resulted in the disappearance of the American frontier...
. He founded the Tabulating Machine Company (1896) which was one of four companies that merged to form Computing Tabulating Recording Corporation (CTR)
Computing Tabulating Recording Corporation (CTR)
The Computing Tabulating Recording Corporation was incorporated on June 16, 1911 in Endicott, New York a few miles west of Binghamton. CTR was formed through a merger of four separate corporations: Tabulating Machine Company , the Computing Scale Corporation , the International Time Recording...
, later renamed IBM. IBM manufactured and marketed a variety of unit record machines for creating, sorting, and tabulating punched cards, even after expanding into electronic computers in the late 1950s. IBM developed punched card technology into a powerful tool for business data-processing and produced an extensive line of general purpose unit record machines
Unit record equipment
Before the advent of electronic computers, data processing was performed using electromechanical devices called unit record equipment, electric accounting machines or tabulating machines. Unit record machines were as ubiquitous in industry and government in the first half of the twentieth century...
. By 1950, the IBM card and IBM unit record machines had become ubiquitous in industry and government. "Do not fold, spindle or mutilate," a generalized version of the warning that appeared on some punched cards (generally on those distributed as paper documents to be later returned for further machine processing, checks for example), became a motto for the post-World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
era (even though many people had no idea what spindle
Spindle (stationery)
A spindle is an upright spike used to hold papers waiting for processing. "Spindling" or "spiking" was the act of spearing a paper document onto the spike....
meant).
From the 1900s, into the 1950s, punched cards were the primary medium for data entry, data storage
Computer storage
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is one of the core functions and fundamental components of computers....
, and processing in institutional computing. According to the IBM Archives: "By 1937... IBM had 32 presses at work in Endicott, N.Y., printing, cutting and stacking five to 10 million punched cards every day." Punched cards were even used as legal documents, such as U.S. Government checks and savings bonds. During the 1960s, the punched card was gradually replaced as the primary means for data storage
Computer storage
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is one of the core functions and fundamental components of computers....
by magnetic tape
Magnetic tape data storage
Magnetic tape data storage uses digital recording on to magnetic tape to store digital information. Modern magnetic tape is most commonly packaged in cartridges and cassettes. The device that performs actual writing or reading of data is a tape drive...
, as better, more capable computers became available. Punched cards were still commonly used for data entry and programming until the mid-1970s when the combination of lower cost magnetic disk storage, and affordable interactive terminals on less expensive minicomputer
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...
s made punched cards obsolete for this role as well. However, their influence lives on through many standard conventions and file formats. The terminals that replaced the punched cards, the IBM 3270
IBM 3270
The IBM 3270 is a class of block oriented terminals made by IBM since 1972 normally used to communicate with IBM mainframes. As such, it was the successor to the IBM 2260 display terminal. Due to the text colour on the original models, these terminals are informally known as green screen terminals...
for example, displayed 80 columns of text
Characters per line
In typography and computing characters per line or terminal width refers to the maximal number of monospaced characters that may appear on a single line...
in text mode
Text mode
Text mode is a kind of computer display mode in which the content of the screen is internally represented in terms of characters rather than individual pixels. Typically, the screen consists of a uniform rectangular grid of character cells, each of which contains one of the characters of a...
, 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 interface
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
s with variable-width type fonts.
Today punched cards are mostly obsolete and replaced with other storage methods, except for a few legacy system
Legacy system
A legacy system is an old method, technology, computer system, or application program that continues to be used, typically because it still functions for the users' needs, even though newer technology or more efficient methods of performing a task are now available...
s and specialized applications.
Nomenclature
The terms punched card, punch card, and punchcard were all commonly used, as were IBM card and Hollerith card (after Herman HollerithHerman Hollerith
Herman Hollerith was an American statistician who developed a mechanical tabulator based on punched cards to rapidly tabulate statistics from millions of pieces of data. He was the founder of one of the companies that later merged and became IBM.-Personal life:Hollerith was born in Buffalo, New...
). IBM used "IBM card" or, later, "punched card" at first mention in its documentation and thereafter simply "card" or "cards". The term punched card was generally avoided for blank cards, with other terms such as tabulating card used. Specific formats were often indicated by the number of character positions available, e.g. 80-column card.
Card formats
The early applications of punched cards all used specifically designed card layouts. It wasn't until around 1928 that punched cards and machines were made "general purpose". The rectangular, round, or oval bits of paper punched out are called chad (recently, chads) or chips (in IBM usage). Multi-character data, such as words or large numbers, were stored in adjacent card columns known as fields. A group of cards is called a deck. One upper corner of each card was usually cut so that cards not oriented correctly, or cards with different corner cuts, could be easily identified. Cards were commonly printed so that the row and column position of a punch could be identified. For some applications printing might have included fields, named and marked by vertical lines, logos, and more.Hollerith's punched card formats
Herman Hollerith
Herman Hollerith was an American statistician who developed a mechanical tabulator based on punched cards to rapidly tabulate statistics from millions of pieces of data. He was the founder of one of the companies that later merged and became IBM.-Personal life:Hollerith was born in Buffalo, New...
was awarded a series of patents in 1889 for mechanical tabulating machines. These patents described both paper tape and rectangular cards as possible recording media. The card shown in of June 8 was preprinted with a template and had holes arranged close to the edges so they could be reached by a railroad conductor's ticket punch
Ticket punch
A ticket punch is a hand tool for permanently marking admission tickets and similar items of paper or card stock. It makes a perforation and a corresponding chad. A ticket punch resembles a hole punch, differing in that the ticket punch has a longer jaw and the option of having a distinctive...
, 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."
Use of the ticket punch proved tiring and error prone, so Hollerith invented a pantograph "keyboard punch" that allowed the entire card area to be used. It also eliminated the need for a printed template on each card, instead a master template was used at the punch; a printed reading card could be placed under a card that was to be read manually. Hollerith envisioned a number of card sizes. In an article he wrote describing his proposed system for tabulating the 1890 U.S. Census
United States Census Bureau
The United States Census Bureau is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data...
, Hollerith suggested a card 3 inches by 5½ inches of Manila
Manila hemp
Manila hemp, also known as manilla, is a type of fiber obtained from the leaves of the abacá , a relative of the banana. It is mostly used for pulping for a range of uses, including speciality papers. It was once used mainly to make manila rope, but this is now of minor importance...
stock "would be sufficient to answer all ordinary purposes."
The cards used in the 1890 census had round holes, 12 rows and 24 columns. A census card and reading board for these cards can be seen at the Columbia University Computing History site. At some point, 3+1/4 by became the standard card size, a bit larger than the United States one-dollar bill
United States one-dollar bill
The United States one-dollar bill is the most common denomination of US currency. The first president, George Washington, painted by Gilbert Stuart, is currently featured on the obverse, while the Great Seal of the United States is featured on the reverse. The one-dollar bill has the oldest...
of the time (the dollar was changed to its current size in 1929). The Columbia site says Hollerith took advantage of available boxes designed to transport paper currency.
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 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 10,000. During a given tabulating run, each counter was typically assigned a specific hole. Hollerith also used relay logic
Relay logic
Relay logic is a method of controlling industrial electronic circuits by using relays and contacts.-Ladder logic:The schematic diagrams for relay logic circuits are often called line diagrams, because the inputs and outputs are essentially drawn in a series of lines...
to allow counts of combination of holes, e.g. to count married females.
Later designs standardized the coding
Hollerith code
Hollerith Code is the 12-bit code used on a punched-card.In 1896, Herman Hollerith formed a company called the Tabulating Machine Company. This company developed a line of machines that used punched cards for tabulation...
, with twelve rows, where the lower ten rows coded digits 0 through 9. This allowed groups of holes to represent numbers that could be added, instead of simply counting units. 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.
IBM 80 column punched card format
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
card format, designed in 1928,
had rectangular holes, 80 columns with 12 punch locations each, one character to each column. Card size was exactly by inches (187.325 mm × 82.55 mm). The cards were made of smooth stock, 0.007 inch thick. There are about 143 cards to the inch (/cm). In 1964, IBM changed from square to round corners. They came typically in boxes of 2000 cards or as continuous form
Continuous stationery
Continuous stationery or Continuous form paper is paper which is designed for use with dot-matrix printers and line printers. Other names for continuous stationery include fan-fold paper, sprocket feed paper, burst paper, tractor-feed paper, and pin feed paper...
cards. Continuous form cards could be both pre-numbered and pre-punched for document control (checks, for example).
The lower ten positions represented (from top to bottom) the digits 0 through 9. The top two positions of a column were called zone punches, 12 (top) and 11. Originally only numeric information was punched, with 1 punch per column indicating the digit. Signs could be added to a field by overpunching the least significant digit
Least significant bit
In computing, the least significant bit is the bit position in a binary integer giving the units value, that is, determining whether the number is even or odd. The lsb is sometimes referred to as the right-most bit, due to the convention in positional notation of writing less significant digits...
with a zone punch: 12 for plus and 11 for minus. Zone punches had other uses in processing as well, such as indicating a master record.
Reference: Note: The Y and X zones were also called the 12 and 11 zones, respectively.
______________________________________________
/&-0123456789ABCDEFGHIJKLMNOPQR/STUVWXYZ
Y / x xxxxxxxxx
X| 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
|________________________________________________
EBCDIC
Extended Binary Coded Decimal Interchange Code is an 8-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems....
"&" was 12 only, "-" was 11 only, and "/" was 0 + 1). With these changes, the information represented in a column by a combination of zones [12, 11] and digits [1-9] was dependent on the use of that column. For example the combination "12-1" was 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" had some other use. The introduction of EBCDIC
EBCDIC
Extended Binary Coded Decimal Interchange Code is an 8-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems....
in 1964 allowed 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. 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.
For some computer applications, binary
Binary numeral system
The binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. More specifically, the usual base-2 system is a positional notation with a radix of 2...
formats were used, where each hole represented a single binary digit (or "bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
"), every column (or row) was treated as a simple bitfield, and every combination of holes was permitted. For example, the IBM 711 card reader used with the 704/709/7090/7094 series scientific computers treated every row as two 36-bit words, ignoring 8 columns. (The specific 72 columns used were selectable using a plugboard
Plugboard
A plugboard, or control panel , is an array of jacks, or hubs, into which patch cords can be inserted to complete an electrical circuit. Control panels were used to direct the operation of some unit record equipment...
control panel, which was almost always wired to select columns 1-72.) Sometimes the ignored columns (usually 73–80) were used to contain a sequence number for each card, so the card deck could be sorted to the correct order in case it was dropped. Other computers, such as the IBM 1130
IBM 1130
The IBM 1130 Computing System was introduced in 1965. It was IBM's least-expensive computer to date, and was aimed at price-sensitive, computing-intensive technical markets like education and engineering. It succeeded the IBM 1620 in that market segment. The IBM 1800 was a process control variant...
or System/360
System/360
The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...
, used every column. The IBM 1402
IBM 1402
The IBM 1402 was a high speed card reader/punch introduced on October 5, 1959 as a peripheral input/output device for the IBM 1401 computer. It was later used with other computers of the IBM 1400 series and IBM 7000 series product lines...
could be used in "column binary" mode, which stored two characters in every column, or one 36-bit word in three columns. However, most of the older card punches were not intended to punch more than 3 holes in a column, so they couldn't be used to produce binary cards.
Lace card
A lace card is a punched card with all holes punched . They were mainly used as practical jokes to cause unwanted disruption in card readers...
s" lacked structural strength, and would frequently buckle and jam inside the machine.
The 80-column card format dominated the industry, becoming known as just IBM cards, even though other companies made cards and equipment to process them.
One of the most common printed punched cards was the IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
5081, a general purpose layout with no field divisions. Indeed, it was so common that other card vendors used the same number (see image at right) and even users knew its number.
Mark sense cards
- Mark senseMark senseElectrographic is a term used for punched card and page scanning technology that allowed cards or pages marked with a pencil to be processed or converted into punched cards. That technology was sold by IBM, its developer, under the term mark sense...
(Electrographic) cards, developed by Reynold B. JohnsonReynold B. JohnsonReynold B. Johnson was an American inventor and computer pioneer. A long-time employee of IBM, Johnson is said to be the "father" of the disk drive...
at IBM, had 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
- Aperture cardAperture cardAn aperture card is a type of punched card with a cut-out window into which a chip of microfilm is mounted. Such a card is used for archiving or for making multiple inexpensive copies of a document for ease of distribution...
s have a cut-out hole on the right side of the punched card. A 35 mm microfilm chip containing a microformMicroformMicroforms are any forms, either films or paper, containing microreproductions of documents for transmission, storage, reading, and printing. Microform images are commonly reduced to about one twenty-fifth of the original document size...
image is mounted in the hole. Aperture cards are used for engineering drawingEngineering drawingAn engineering drawing, a type of technical drawing, is used to fully and clearly define requirements for engineered items.Engineering drawing produces engineering drawings . More than just the drawing of pictures, it is also a language—a graphical language that communicates ideas and information...
s from all engineering disciplines. Information about the drawing, for example the drawing number, is typically punched and printed on the remainder of the card. Aperture cards have some advantages over fully digital systems for archival purposes.
IBM Stub cards or Short cards
The 80-column card could be scored, on either end, creating a stub that could be torn off, leaving a stub card or short card. A common length for stub cards was 51-columns. Stub cards were used in applications requiring tags, labels, or carbon copies..IBM Port-A-Punch
Unfortunately, the resulting holes were "furry" (i.e. not cleanly cut, owing to the perforations) and sometimes caused problems with the equipment used to read the cards.
IBM 96 column punched card format
System/3
The IBM System/3 was a low-end business computer aimed at new customers and organizations that still used IBM 1400 series computers or unit record equipment...
computer. The IBM 5496 Data Recorder, a keypunch machine with print and verify functions, and the IBM 5486 Card Sorter were made for these 96-column cards.
These cards had tiny (1 mm), circular holes, smaller than those in paper tape. Data was stored in six-bit binary-coded decimal
Binary-coded decimal
In computing and electronic systems, binary-coded decimal is a digital encoding method for numbers using decimal notation, with each decimal digit represented by its own binary sequence. In BCD, a numeral is usually represented by four bits which, in general, represent the decimal range 0 through 9...
code, with three rows of 32 characters each, or 8-bit EBCDIC
EBCDIC
Extended Binary Coded Decimal Interchange Code is an 8-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems....
. 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 data.
Powers/Remington Rand UNIVAC card formats
IBM punched card manufacturing
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 had its own printing plate).
IBM initially required that its customers use only IBM manufactured cards with IBM machines, which were leased, not sold. IBM viewed its business as providing a service and that the cards were part of the machine. In 1932 the government took IBM to court on this issue. IBM fought all the way to the Supreme Court and lost; the court ruling that IBM could only set card specifications. In another case, heard in 1955, IBM signed a consent decree
Consent decree
A consent decree is a final, binding judicial decree or judgment memorializing a voluntary agreement between parties to a suit in return for withdrawal of a criminal charge or an end to a civil litigation...
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
Thomas J. Watson
Thomas John Watson, Sr. was president of International Business Machines , who oversaw that company's growth into an international force from 1914 to 1956...
.
Cultural impact
While punched cards have not been widely used for a generation, the impact was so great for most of the 20th century that they still appear from time to time in popular culture. For example:- Artist and architect Maya LinMaya LinMaya Ying Lin is an American artist who is known for her work in sculpture and landscape art. She is the designer of the Vietnam Veterans Memorial in Washington, D.C.-Personal life:...
in 2004 designed a controversial public artPublic artThe term public art properly refers to works of art in any media that have been planned and executed with the specific intention of being sited or staged in the physical public domain, usually outside and accessible to all...
installation at Ohio UniversityOhio UniversityOhio University is a public university located in the Midwestern United States in Athens, Ohio, situated on an campus...
, titled "Input", that looks like a punched card from the air. - Do Not Fold, Bend, Spindle or Mutilate: Computer Punch Card Art - a mail art exhibit by the Washington Pavilion in Sioux Falls, South Dakota.
- The Red McCombs School of Business at the University of Texas at Austin has artistic representations of punched cards decorating its exterior walls.
- At the University of Wisconsin - Madison, the exterior windows of the Engineering Research Building were modeled after a punched card layout, during its construction in 1966.
- In the Simpsons episode Much Apu About NothingMuch Apu About Nothing"Much Apu About Nothing" is the 23rd episode of The Simpsons seventh season. It originally aired on the Fox network in the United States on May 5, 1996. In the episode, a referendum is created that will require all illegal immigrants from Springfield to be deported...
, Apu showed Bart his Ph.D. thesis, the world's first computer tic-tac-toe game, stored in a box full of punched cards. - In the FuturamaFuturamaFuturama is an American animated science fiction sitcom created by Matt Groening and developed by Groening and David X. Cohen for the Fox Broadcasting Company. The series follows the adventures of a late 20th-century New York City pizza delivery boy, Philip J...
episode Mother's Day, as several robots are seen shouting 'Hey hey! Hey ho! 100110!' in protest, one of them burns a punch-card in a manner reminiscent of draft-card burningDraft-card burningDraft-card burning was a symbol of protest performed by thousands of young American men as part of the opposition to the involvement of the United States in the Vietnam War. Beginning in May 1964, some activists burned their draft cards at anti-war rallies and demonstrations. By May 1965 it was...
. In another episode, Put Your Head On My Shoulder, Bender offers a dating service. He hands characters punch-cards so they can put in what they want, before throwing them in his chest cabinet and 'calculating' the 'match' for the person. Bender is shown both 'folding', 'bending', and 'mutilating' the card, accentuating the fact that he is making up the 'calculations'. - In the 1964–65 Free Speech MovementFree Speech MovementThe Free Speech Movement was a student protest which took place during the 1964–1965 academic year on the campus of the University of California, Berkeley under the informal leadership of students Mario Savio, Brian Turner, Bettina Aptheker, Steve Weissman, Art Goldberg, Jackie Goldberg, and...
punched cards became a
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
- A legacy of the 80 column punched card format is that most character-based terminals display 80 characters per rowCharacters per lineIn typography and computing characters per line or terminal width refers to the maximal number of monospaced characters that may appear on a single line...
. As of November 2011 some character interface defaults, such as the command prompt window's width in Microsoft Windows, remain set at 80 columns and some file formats, such as FITSFITSFlexible Image Transport System is a digital file format used to store, transmit, and manipulate scientific and other images. FITS is the most commonly used digital file format in astronomy...
, still use 80-character card imageCard imageA card image is an archaic term for an ASCII string, usually 80 bytes in length. "Card image" refers to a punched card. IBM cards were 80 characters in length, UNIVAC cards were 90 characters. A single card typically held a single line of text, for example a line of FORTRAN code...
s.
Standards
- ANSI INCITS 21-1967 (R2002), Rectangular Holes in Twelve-Row Punched Cards (formerly ANSI X3.21-1967 (R1997)) Specifies the size and location of rectangular holes in twelve-row 3+1/4 in punched cards.
- ANSI X3.11 - 1990 American National Standard Specifications for General Purpose Paper Cards for Information Processing
- ANSI X3.26 - 1980/R1991) Hollerith Punched Card Code
- ISO 1681:1973 Information processing - Unpunched paper cards - Specification
- ISO 6586:1980 Data processing - Implementation of the ISO 7- bit and 8- bit coded character sets on punched cards. Defines ISO 7-bit and 8-bit character sets on punched cards as well as the representation of 7-bit and 8-bit combinations on 12-row punched cards. Derived from, and compatible with, the Hollerith Code, ensuring compatibility with existing punched card files.
Card handling equipment
Creation and processing of punched cards was handled by a variety of devices, including:- Card punches
- Card readersPunched card readerA punched card reader or just card reader is a computer input device used to read data from punched cards. A card punch is a output device that punches holes in cards under computer control...
- Keypunches
- Unit record equipmentUnit record equipmentBefore the advent of electronic computers, data processing was performed using electromechanical devices called unit record equipment, electric accounting machines or tabulating machines. Unit record machines were as ubiquitous in industry and government in the first half of the twentieth century...
- Voting machines
See also
- Card imageCard imageA card image is an archaic term for an ASCII string, usually 80 bytes in length. "Card image" refers to a punched card. IBM cards were 80 characters in length, UNIVAC cards were 90 characters. A single card typically held a single line of text, for example a line of FORTRAN code...
- Computer programming in the punch card eraComputer programming in the punch card eraFrom the invention of computer programming languages up to the mid-1980s, many if not most computer programmers created, edited and stored their programs on punched cards. The practice was nearly universal with IBM computers in the era. A punched card is a flexible write-once medium that encodes,...
- History of computing hardwareHistory of computing hardwareThe history of computing hardware is the record of the ongoing effort to make computer hardware faster, cheaper, and capable of storing more data....
- Paper data storagePaper data storagePaper 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...
- Hollerith codeHollerith codeHollerith Code is the 12-bit code used on a punched-card.In 1896, Herman Hollerith formed a company called the Tabulating Machine Company. This company developed a line of machines that used punched cards for tabulation...
as precedor of ASCIIASCIIThe American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
Code
Further reading
An accessible book of recollections (sometimes with errors), with photographs and descriptions of many unit record machines. Includes a description of Samas punched cards and illustration of an Underwood Samas punched card.External links
(Collection shows examples of left, right, and no corner cuts.)- VintageTech - a U.S. company that converts punched cards to conventional media article about modern-day use of punched cards
- UNIVAC Punch Card Gallery (Shows examples of both left and right corner cuts.)
- Cardamation - a U.S. company still supplying punched card equipment and supplies .
- An Emulator for Punched cards
- Povarov G.N. Semen Nikolayevich Korsakov. Machines for the Comparison of Philosophical Ideas. In: Trogemann, Georg; Ernst, Wolfgang and Nitussov, Alexander, Computing in Russia: The History of Computer Devices and Information Technology Revealed (pp 47–49), Verlag, 2001. Translated by Alexander Y. Nitussov. ISBN 3-528-05757-2, 9783528057572
- Korsakov S.N. A Depiction of a New Research Method, Using Machines which Compare Ideas, Ed. by Alexander Mikhailov, MEPhI, 2009