In 1674, Gottfried Wilhelm Von Leibnitz made improvements on Pascal’s machine. With Leibnitz’s improvements, it was possible for the machine to divide and multiply as easily as it could add and subtract.
Charles Babbage
( “father of computers “)
( “father of computers “)
Charles Babbage, FRS (26 December 1791 – 18 October 1871)[1] was an English mathematician, philosopher, inventor and mechanical engineer who originated the concept of a programmable computer.[2] Considered a "father of the computer",[3] Babbage is credited with inventing the first mechanical computer that eventually led to more complex designs.[4] Parts of his uncompleted mechanisms are on display in the London Science Museum. In 1991, a perfectly functioning difference engine was constructed from Babbage's original plans. Built to tolerances achievable in the 19th century, the success of the finished engine indicated that Babbage's machine would have worked. Nine years later, the Science Museum completed the printer Babbage had designed for the difference engine.
Read More Charles Babbage ( “father of computers “)......
Charles Babbage made ANALYTICAL ENGINE (In 1833)
DIFFERENTIAL ENGINE (In 1883)
Design
Two types of punched cards used to program the machine. Foreground: "operational cards", for inputting instructions; background: "variable cards", for inputting data.
Babbage's first attempt at a mechanical computing device, the difference engine, was a special-purpose calculator designed to tabulate logarithms and trigonometric functions by evaluating finite differences to create approximating polynomials. Construction of this machine was never completed; Babbage had conflicts with his chief engineer, Joseph Clement, and ultimately the British government withdrew its funding for the project.
During this project he realized that a much more general design, the Analytical Engine, was possible. The input (programs and data) was to be provided to the machine via punched cards, a method being used at the time to direct mechanical looms such as the Jacquard loom. For output, the machine would have a printer, a curve plotter and a bell. The machine would also be able to punch numbers onto cards to be read in later. It employed ordinary base-10 fixed-point arithmetic.
There was to be a store (that is, a memory) capable of holding 1,000 numbers of 40 decimal digits each (ca. 16.7 kB). An arithmetical unit (the "mill") would be able to perform all four arithmetic operations, plus comparisons and optionally square roots. Initially it was conceived as a difference engine curved back upon itself, in a generally circular layout,[9] with the long store exiting off to one side. (Later drawings depict a regularized grid layout.)[10] Like the central processing unit (CPU) in a modern computer, the mill would rely upon its own internal procedures, to be stored in the form of pegs inserted into rotating drums called "barrels", to carry out some of the more complex instructions the user's program might specify.[5] (See microcode for the modern equivalent.)
The programming language to be employed by users was akin to modern day assembly languages. Loops and conditional branching were possible, and so the language as conceived would have been Turing-complete long before Alan Turing's concept. Three different types of punch cards were used: one for arithmetical operations, one for numerical constants, and one for load and store operations, transferring numbers from the store to the arithmetical unit or back. There were three separate readers for the three types of cards.
In 1842, the Italian mathematician Luigi Menabrea, whom Babbage had met while travelling in Italy, wrote a description of the engine in French. In 1843, the description was translated into English and extensively annotated by Ada Byron, Countess of Lovelace, who had become interested in the engine ten years earlier. In recognition of her additions to Menabrea's paper, which included a way to calculate Bernoulli numbers using the machine, she has been described as the first computer programmer. The modern computer programming language Ada is named in her honour.
Construction
Late in his life, Babbage sought ways to build a simplified version of the machine, and assembled a small part of it before his death in 1871. But in 1878, a committee of the British Association for the Advancement of Science recommended against constructing the Analytical Engine, which sank Babbage's efforts for government funding.[clarification needed]
In 1910, Babbage's son Henry Prevost Babbage reported that a part of the mill and the printing apparatus had been constructed and had been used to calculate a (faulty) list of multiples of pi. This constituted only a small part of the whole engine; it was not programmable and had no storage. (Popular images of this section have sometimes been mislabelled, implying that it was the entire mill or even the entire engine.) Henry Babbage's "Analytical Engine Mill" is on display at the Science Museum in London.
Henry Babbage's Analytical Engine Mill, built in 1910, in the Science Museum (London)
Henry also proposed building a demonstration version of the full engine, with a smaller storage capacity: "perhaps for a first machine ten (columns) would do, with fifteen wheels in each". Such a version could manipulate 20 numbers of 25 digits each, and what it could be told to do with those numbers could still be impressive. "It is only a question of cards and time," wrote Henry Babbage in 1888, "... and there is no reason why (twenty thousand) cards should not be used if necessary, in an Analytical Engine for the purposes of the mathematician."
In 1991, the London Science Museum built a complete and working specimen of Babbage's Difference Engine No. 2, a design that incorporated refinements Babbage discovered during the development of the Analytical Engine. This machine was built using materials and engineering tolerances that would have been available to Babbage, quelling the suggestion that Babbage's designs could not have been produced using the manufacturing technology of his time. Swedish engineers Georg and Edvard Scheutz had made a working version of the difference engine in 1853, although on a different scale – table-sized instead of room-sized.
In October 2010, John Graham-Cumming started a campaign to raise funds by "public subscription" to enable serious historical and academic study of Babbage's plans, with a view to then build and test a fully working virtual design which will then in turn enable construction of the physical Analytical Engine.
Influence
Babbage understood that the existence of an automatic computer would kindle interest in the field now known as algorithmic efficiency, writing in his Passages from the Life of a Philosopher, "As soon as an Analytical Engine exists, it will necessarily guide the future course of the science. Whenever any result is sought by its aid, the question will then arise—By what course of calculation can these results be arrived at by the machine in the shortest time?"
Computer science
From 1872 Henry continued diligently with his father's work and then intermittently in retirement in 1875.[19] Percy Ludgate wrote about the engine in 1915 and even designed his own Analytical Engine (it was drawn up in detail but never built). Ludgate's engine would be much smaller than Babbage's of about 8 cubic feet (230 L) and hypothetically would be capable of multiplying two 20-decimal-digit numbers in about six seconds.
Despite this, Babbage's work fell into historical obscurity and the Analytical Engine was unknown to builders of electro-mechanical and electronic computing machines in the 1930s and 1940s when they began their work, resulting in the need to re-invent many of the architectural innovations Babbage had proposed. Howard Aiken, who built the quickly-obsoleted electromechanical calculator, the Harvard Mark I, between 1937 and 1945, praised Babbage's work likely as a way of enhancing his own stature, but knew nothing of the Analytical Engine's architecture during the construction of the Mark I, and considered his visit to the constructed portion of the Analytical Engine "the greatest disappointment of my life". The Mark I showed no influence from the Analytical Engine and lacked the Analytical Engine's most prescient architectural feature, conditional branching. J. Presper Eckert and John W. Mauchly similarly were not aware of the details of Babbage's Analytical Engine work prior to the completion of their design for the first electronic general-purpose computer, the ENIAC.
Fiction
The cyberpunk novelists William Gibson and Bruce Sterling co-authored a steampunk novel of alternative history titled The Difference Engine in which Babbage's Difference and Analytical Engines became available to Victorian society. The novel explores the consequences and implications of the early introduction of computational technology.
There is also mention of the Analytical Engine (or the Clockwork Ouroboros as it is also known there) in The Book of the War, a Faction Paradox anthology edited by Lawrence Miles. This machine was used to calculate a way into the "Eleven Day Empire". Its use resulted in the destruction of the original Houses of Parliament.
In the novel Perdido Street Station, by British author China Miéville, analytical engines similar to Babbage's serve as "brains" for the robotic constructs of the city of New Crobuzon. One such engine even develops sentient thought due to a recursive algorithmic loop.
The British Empire of The Peshawar Lancers by S. M. Stirling features a massive water powered engine at Oxford, used by two of the main characters. It is noted that most of the engines run on steam, and that an even larger one is under construction at the British Capital in Delhi.
In the Michael Flynn novel In the Country of the Blind, a secret society calling itself the Babbage Society secretly financed the building of Babbage Engines in the mid-19th century. In the novel, the Society uses the Babbage engines along with a statistical science called Cliology to predict and manipulate future history. In the process, they predict the rise of the Nazis and accidentally start the US Civil War.
In the Neal Stephenson novel The Diamond Age, ubiquitous molecular nanotechology is described to make use of "rod logic" similar to that imagined by Babbage's design for the Analytical Engine.
Moriarty by Modem, a short story by Jack Nimersheim, describes an alternate history where Babbage's Analytical Engine was indeed completed and had been deemed highly classified by the British government. The characters of Sherlock Holmes and Moriarty had in reality been a set of prototype programs written for the Analytical Engine. This short story follows Holmes as his program is rebooted on modern computers and he is forced to compete against his nemesis yet again in the modern counterparts of Babbage's Analytical Engine.
A similar setting is used by Sydney Padua in the webcomic The Thrilling Adventures of Lovelace and Babbage. It features a pocket universe where Ada Lovelace and Babbage have built the Analytical Engine and use it to fight crime at Queen Victoria's request. The comic is based on thorough research on the biographies and correspondence between Babbage and Lovelace, which is then twisted for humorous effect.
Georgia on My Mind is a novelette by Charles Sheffield which involves two major themes: being widowed and the quest for a legendary Babbage computer.
Hugh Cook's fantasy novels The Wishstone and the Wonderworkers and The Wazir and the Witch feature an Analytical Engine created by the scientist Ivan Petrov. It is used to calculate income tax.
ANALYTICAL ENGINE (In 1833)
The Analytical Engine was a proposed mechanical general-purpose computer designed by English mathematician Charles Babbage. It was first described in 1837 as the successor to Babbage's difference engine, a design for a mechanical calculator. The Analytical Engine incorporated an arithmetical unit, control flow in the form of conditional branching and loops, and integrated memory, making it the first Turing-complete design for a general-purpose computer.
Babbage was never able to complete construction of any of his machines due to conflicts with his chief engineer and inadequate funding. It was not until 100 years later, in the 1940s, that the first general-purpose computers were actually built.
Babbage was never able to complete construction of any of his machines due to conflicts with his chief engineer and inadequate funding. It was not until 100 years later, in the 1940s, that the first general-purpose computers were actually built.
DesignTwo types of punched cards used to program the machine. Foreground: "operational cards", for inputting instructions; background: "variable cards", for inputting data.
Babbage's first attempt at a mechanical computing device, the difference engine, was a special-purpose calculator designed to tabulate logarithms and trigonometric functions by evaluating finite differences to create approximating polynomials. Construction of this machine was never completed; Babbage had conflicts with his chief engineer, Joseph Clement, and ultimately the British government withdrew its funding for the project.
During this project he realized that a much more general design, the Analytical Engine, was possible. The input (programs and data) was to be provided to the machine via punched cards, a method being used at the time to direct mechanical looms such as the Jacquard loom. For output, the machine would have a printer, a curve plotter and a bell. The machine would also be able to punch numbers onto cards to be read in later. It employed ordinary base-10 fixed-point arithmetic.
There was to be a store (that is, a memory) capable of holding 1,000 numbers of 40 decimal digits each (ca. 16.7 kB). An arithmetical unit (the "mill") would be able to perform all four arithmetic operations, plus comparisons and optionally square roots. Initially it was conceived as a difference engine curved back upon itself, in a generally circular layout,[9] with the long store exiting off to one side. (Later drawings depict a regularized grid layout.)[10] Like the central processing unit (CPU) in a modern computer, the mill would rely upon its own internal procedures, to be stored in the form of pegs inserted into rotating drums called "barrels", to carry out some of the more complex instructions the user's program might specify.[5] (See microcode for the modern equivalent.)
The programming language to be employed by users was akin to modern day assembly languages. Loops and conditional branching were possible, and so the language as conceived would have been Turing-complete long before Alan Turing's concept. Three different types of punch cards were used: one for arithmetical operations, one for numerical constants, and one for load and store operations, transferring numbers from the store to the arithmetical unit or back. There were three separate readers for the three types of cards.
In 1842, the Italian mathematician Luigi Menabrea, whom Babbage had met while travelling in Italy, wrote a description of the engine in French. In 1843, the description was translated into English and extensively annotated by Ada Byron, Countess of Lovelace, who had become interested in the engine ten years earlier. In recognition of her additions to Menabrea's paper, which included a way to calculate Bernoulli numbers using the machine, she has been described as the first computer programmer. The modern computer programming language Ada is named in her honour.
Construction
Late in his life, Babbage sought ways to build a simplified version of the machine, and assembled a small part of it before his death in 1871. But in 1878, a committee of the British Association for the Advancement of Science recommended against constructing the Analytical Engine, which sank Babbage's efforts for government funding.[clarification needed]
In 1910, Babbage's son Henry Prevost Babbage reported that a part of the mill and the printing apparatus had been constructed and had been used to calculate a (faulty) list of multiples of pi. This constituted only a small part of the whole engine; it was not programmable and had no storage. (Popular images of this section have sometimes been mislabelled, implying that it was the entire mill or even the entire engine.) Henry Babbage's "Analytical Engine Mill" is on display at the Science Museum in London.
Henry Babbage's Analytical Engine Mill, built in 1910, in the Science Museum (London)
Henry also proposed building a demonstration version of the full engine, with a smaller storage capacity: "perhaps for a first machine ten (columns) would do, with fifteen wheels in each". Such a version could manipulate 20 numbers of 25 digits each, and what it could be told to do with those numbers could still be impressive. "It is only a question of cards and time," wrote Henry Babbage in 1888, "... and there is no reason why (twenty thousand) cards should not be used if necessary, in an Analytical Engine for the purposes of the mathematician."
In 1991, the London Science Museum built a complete and working specimen of Babbage's Difference Engine No. 2, a design that incorporated refinements Babbage discovered during the development of the Analytical Engine. This machine was built using materials and engineering tolerances that would have been available to Babbage, quelling the suggestion that Babbage's designs could not have been produced using the manufacturing technology of his time. Swedish engineers Georg and Edvard Scheutz had made a working version of the difference engine in 1853, although on a different scale – table-sized instead of room-sized.
In October 2010, John Graham-Cumming started a campaign to raise funds by "public subscription" to enable serious historical and academic study of Babbage's plans, with a view to then build and test a fully working virtual design which will then in turn enable construction of the physical Analytical Engine.
Influence
Babbage understood that the existence of an automatic computer would kindle interest in the field now known as algorithmic efficiency, writing in his Passages from the Life of a Philosopher, "As soon as an Analytical Engine exists, it will necessarily guide the future course of the science. Whenever any result is sought by its aid, the question will then arise—By what course of calculation can these results be arrived at by the machine in the shortest time?"
Computer science
From 1872 Henry continued diligently with his father's work and then intermittently in retirement in 1875.[19] Percy Ludgate wrote about the engine in 1915 and even designed his own Analytical Engine (it was drawn up in detail but never built). Ludgate's engine would be much smaller than Babbage's of about 8 cubic feet (230 L) and hypothetically would be capable of multiplying two 20-decimal-digit numbers in about six seconds.
Despite this, Babbage's work fell into historical obscurity and the Analytical Engine was unknown to builders of electro-mechanical and electronic computing machines in the 1930s and 1940s when they began their work, resulting in the need to re-invent many of the architectural innovations Babbage had proposed. Howard Aiken, who built the quickly-obsoleted electromechanical calculator, the Harvard Mark I, between 1937 and 1945, praised Babbage's work likely as a way of enhancing his own stature, but knew nothing of the Analytical Engine's architecture during the construction of the Mark I, and considered his visit to the constructed portion of the Analytical Engine "the greatest disappointment of my life". The Mark I showed no influence from the Analytical Engine and lacked the Analytical Engine's most prescient architectural feature, conditional branching. J. Presper Eckert and John W. Mauchly similarly were not aware of the details of Babbage's Analytical Engine work prior to the completion of their design for the first electronic general-purpose computer, the ENIAC.
Fiction
The cyberpunk novelists William Gibson and Bruce Sterling co-authored a steampunk novel of alternative history titled The Difference Engine in which Babbage's Difference and Analytical Engines became available to Victorian society. The novel explores the consequences and implications of the early introduction of computational technology.
There is also mention of the Analytical Engine (or the Clockwork Ouroboros as it is also known there) in The Book of the War, a Faction Paradox anthology edited by Lawrence Miles. This machine was used to calculate a way into the "Eleven Day Empire". Its use resulted in the destruction of the original Houses of Parliament.
In the novel Perdido Street Station, by British author China Miéville, analytical engines similar to Babbage's serve as "brains" for the robotic constructs of the city of New Crobuzon. One such engine even develops sentient thought due to a recursive algorithmic loop.
The British Empire of The Peshawar Lancers by S. M. Stirling features a massive water powered engine at Oxford, used by two of the main characters. It is noted that most of the engines run on steam, and that an even larger one is under construction at the British Capital in Delhi.
In the Michael Flynn novel In the Country of the Blind, a secret society calling itself the Babbage Society secretly financed the building of Babbage Engines in the mid-19th century. In the novel, the Society uses the Babbage engines along with a statistical science called Cliology to predict and manipulate future history. In the process, they predict the rise of the Nazis and accidentally start the US Civil War.
In the Neal Stephenson novel The Diamond Age, ubiquitous molecular nanotechology is described to make use of "rod logic" similar to that imagined by Babbage's design for the Analytical Engine.
Moriarty by Modem, a short story by Jack Nimersheim, describes an alternate history where Babbage's Analytical Engine was indeed completed and had been deemed highly classified by the British government. The characters of Sherlock Holmes and Moriarty had in reality been a set of prototype programs written for the Analytical Engine. This short story follows Holmes as his program is rebooted on modern computers and he is forced to compete against his nemesis yet again in the modern counterparts of Babbage's Analytical Engine.
A similar setting is used by Sydney Padua in the webcomic The Thrilling Adventures of Lovelace and Babbage. It features a pocket universe where Ada Lovelace and Babbage have built the Analytical Engine and use it to fight crime at Queen Victoria's request. The comic is based on thorough research on the biographies and correspondence between Babbage and Lovelace, which is then twisted for humorous effect.
Georgia on My Mind is a novelette by Charles Sheffield which involves two major themes: being widowed and the quest for a legendary Babbage computer.
Hugh Cook's fantasy novels The Wishstone and the Wonderworkers and The Wazir and the Witch feature an Analytical Engine created by the scientist Ivan Petrov. It is used to calculate income tax.
DIFFERENTIAL ENGINE (In 1883)
1840 – Ada, the first programmer suggested binary data storage rather than decimal.
1880 – Dr.Herman Hollerith developed the punched card that would contain data coded in form of punched
holes.
1880 – Dr.Herman Hollerith developed the punched card that would contain data coded in form of punched
holes.
PUNCHED CARD MACHINE (Tabulating Machine)
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 organs 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 programs and data. Some voting machines use punched cards.
 |
| An 80-column punched card of the type most widely used in the 20th century. Card size was 7 3⁄8 in × 3 1⁄4 in (187.325 mm × 82.55 mm). This example displays the 1964 EBCDIC character set, which added more special characters to earlier encodings. |
History
 |
| Punched cards in use in a Jacquard loom |
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.
Semen Korsakov's punched card
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[6] and savings bonds. The 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, but punched cards were still commonly used for data entry and programming 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 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 interfaces with variable-width type fonts.
Today punched cards are mostly obsolete and replaced with other storage methods, except for a few legacy systems 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 Hollerith). 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 commonly had printing such that the row and column position of a hole 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
Hollerith card as shown in the Railroad Gazette in 1885.
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 U.S. Patent 395,781 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:
"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 board 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 reading board for these cards can be seen at the Columbia University Computing History site. At some point, 31⁄4 by 73⁄8 inches (82.550 by 187.325 mm) 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 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 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.
IBM 80 column punched card formats and character codes
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 7 3⁄8 by 3 1⁄4 inches (187.325 mm × 82.55 mm). The cards were 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. 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.
Herman Hollerith
Herman Hollerith (February 29, 1860 – November 17, 1929) 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