Herman Hollerith (1860-1929)

Herman Hollerith (, – , ) was an who developed a mechanical system based on to rapidly tabulate statistics from thousands and millions of data.
Personal Life
He was born on February 29, 1860 in Buffalo, New York to Johann George Hollerith (1808-1869); and Franciska Brunn, both of . He graduated from , with a bachelor's degree in 1879. In 1880 he listed himself as a mining engineer while living in Manhattan, and he completed his Ph.D. in 1890 at the . In 1890 he married Lucia Beverley Talcott (1865-?) of Vera Cruz, Mexico and they had six children. He died in 1929 of a heart attack and was buried in the Oak Hill Cemetery in Georgetown, Virginia.
[]
Electronic tabulation of statistical data
Hollerith spent 1882 on the Mechanical Engineering faculty at . During that year he developed a prototype of a system for storing data on punched cards which was partly inspired by the system used by railroad conductors in which holes punched in various places on a passenger's ticket identified the holder's passenger status. Urged on by , he developed a mechanism for reading the presence or absence of holes in the cards using spring-mounted needles that passed through the holes to make electrical connections to trigger a counter to record one more of each value. The key idea (due to Billings) was that all personal data could be coded numerically. Hollerith saw that the numbers could be punched in specified column on the cards, the cards sorted mechanically, and the appropriate columns totalled. He described his idea in Patent No. 395,782 of January 8, 1889 as follows:
The herein described method of compiling statistics which consists in recording separate statistical items pertaining to the individual by holes or combinations of holed punched in sheets of electrically non-conducting material, and bearing a specific relation to each other and to a standard, and then counting or tallying such statistical items separately or in combination by means of mechanical counters operated by electro-magnets the circuits through which are controlled by the perforated sheets, substantially as and for the purpose set forth.
Tabulating Machine Company
He built machines under contract for the , which used them to tabulate the 1890 census in much less time than the 1880 census. He started his own business in 1896 when he founded . Most of the major census bureaus around the world leased his equipment and purchased his cards, as did major insurance companies. To make his system work he invented the first automatic card-feed mechanism, the first key punch (i.e. punch that was operated from a ) allowing a skilled operator to punch 200-300 cards per hour, and a wiring panel in his Type I Tabulator allowing it to do different jobs without having to be rebuilt (the first step towards programming). The 1890 Tabulator was to operate only on 1890 Census cards. These inventions were the foundation of the modern information processing industry.
International Business Machines
In 1911 his firm merged with two others to form the Computing Tabulating Recording (CTR) Corporation. Under the presidency of it was renamed in .
External links
Hollerith's patents from 1889:


This article was originally based on material from the , which is under the .
Timeline
1860 Birth of Herman Hollerith
1880 in Manhattan
1890 US Census compiled with his tabulating machine
1929 Death of Herman Hollerith
The punched card predates considerably. As early as used perforated paper loop in a loom to establish the pattern to be reproduced on cloth, and in his co-worker improved on his design by using perforated paper cards attached to one another, which made it easier to change the program quickly. The Bouchon-Falcon loom was semi-automatic and required manual feed of the program. used punched cards in as a control device for the more automatic , which met with great success.
, who originated the idea of a programmable computer, adopted Jacquard's system of punched cards to control the sequence of computations in the design for his in . Such cards were used as an input method for the primitive calculating machines of the late . The version by , patented on , and used with mechanical tabulating machines in the , was a piece of cardboard about by 215 mm, with round holes. This was the same size as the of the time, so that storage cabinets designed for money could be used for his cards. 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". In that year, punched cards were made a standard size, exactly 7-3/8 by 3-1/4 inch (187.325 by 82.55 ), reportedly corresponding to the , though some sources characterise this assertion as .
To compensate for the cyclical nature of the Census Bureau's demand for his machines, Hollerith founded the Tabulating Machine Company () which was one of three companies that merged to form in .
The IBM 80-column punching format, with rectangular holes, eventually won out over the 90-character format, which used 45 columns (2 characters in each) of 12 round holes. IBM (Hollerith) punched cards are made of smooth stock, .007 of an inch thick. There are about 143 cards to the inch thickness; a group of such cards is called a deck. Punch cards were widely known as just IBM cards.
Functional details
A reproducing punch, like this one from IBM, could make exact copies of a deck of cards.
The method is quite simple: On a piece of light-weight cardboard, successive positions either have a hole punched through them or are left intact. The rectangular bits of paper punched out are called . Thus, each punch location on the card represents a single digit (or ""). Each column on the card contained several punch positions (multiple bits).
IBM punch card format
The IBM card format, which became standard, held 80 columns of 12 punch locations each, representing 80 characters. Originally only numeric information was coded with 1 or 2 punchs per column: digits (digit[0-9]) and signs (zone[12,11] – sometimes overpunching the ). Later, codes were introduced for upper-case letters and special characters. A column with 2 punches (zone[12,11,0] + digit[1-9]) was a letter; 3 punches (zone[12,11,0] + digit[2-4] + 8) was a special character. The introduction of in allowed columns with as many as 6 punches (zones[12,11,0,8,9] + digit[1-7]). The punch cards were 7 and 3/8 inches long by 3 and 1/4 inches high and were 0.007 inch thick with one of the upper corners cut at an angle.
Corner cut
A major reason for the corner cut was so the punch card could not be inserted backwards or upside down. If the punch card was inserted backwards or upside down it hit a small plastic pin in the machine called the corner cut pin. This would engage a micro switch and halt the machine operation until the card was inserted properly with the corner cut on the correct side of the punch card as used in that system. Stopping the machine meant the machine would not continue to sort or validate.
Many computer installations used cards with the opposite corner cut (sometimes no corner cut) as "job separators", so that an operator could stack several job decks in the card reader at the same time and be able to quickly separate the decks manually when he removed them from the stacker. These cards were prepunched (e.g., a command to start a new job) in large quantities in advance. This was especially useful when the main computer did not read the cards directly, but instead read their images from that was prepared offline by or smaller computers.
Data was entered on a machine called a , which was like a large, very noisy typewriter. Often the text was also printed at the top of the card, allowing humans to read the text as well. This was done using a machine called an interpreter. Later model keypunches could do this as well. Multi-character data, such as words or large numbers, was stored in adjacent card columns known as fields. For applications in which accuracy was critical, the practice was to have two different operators key the same data, with the second using a card-verifier instead of a card-punch. Verified cards would be marked with a rounded notch on the right end. Failed cards would be replaced by a key punch operator. There was a great demand for key-punch operators, usually women, who worked full-time on key punch and verifier machines.
Electromechanical equipment (called ) for punching, sorting, tabulating and printing the cards was manufactured. These machines allowed sophisticated data processing tasks to be accomplished long before computers were invented. The card readers used an electrical (metal brush) or, later, optical sensor to detect which positions on the card contained a hole. They had high-speed mechanical feeders to process around one hundred cards per minute. All processing was done with electromechanical counters and relays. The machines were programmed using wire patch panels.
Other formats
A System 3 punch card.
Other schemes, sizes of card, and hole shapes were tried at various times. Mark sense cards had printed ovals that humans would fill in with a pencil. Specialized card punches could detect these marks and punch the corresponding information into the card. There were also with all the punch positions perforated so data could be punched out manually, one hole at a time, with a device like a blunt pin with its wire bent into a finger-ring on the other end. In the early , IBM introduced a new, smaller, round-hole, 96-column card format along with the computer.
Aperture cards are a specialized use of punch cards for storing "". A drawing is photographed onto and the image is mounted in a window on the right half of the punch card. Information about the drawing, e.g. the drawing number, is punched in the left half.
IBM punch cards could be used with early computers in a binary mode where every column (or row) was treated as a simple bitfield, and every combination of holes was permitted . In this binary mode, cards could be made in which every possible punch position had a hole: these were called "." For example, the scientific computers treated every row as two 36-bit words, usually in columns 1-72, ignoring the last 8 columns (but this was programable using a plugboard in the card reader and punch to select the 72 columns used). Other computers, like the , used every possible hole.
Advantages
In its earliest uses, the punch card was not just a data recording medium, but a controlling element of the data processing operation. Electrical pulses produced when the read brushes passed through holes punched in the cards directly triggered electro-mechanical counters, , and . Cards were inexpensive and provided a permanent record of each transaction. Large organizations had warehouses filled with punch card records.
One reason punch cards persisted into the early computer age was that an expensive computer was not required to encode information onto the cards. When the time came to transfer punch card information into the computer, the process could occur at very high speed, either by the computer itself or by a separate, smaller computer (e.g. an ) that read the cards and wrote the data onto magnetic tapes or, later, on removable hard disks, that could then be mounted on the larger computer, thus making best use of expensive computer time.
Obsolescence
Punched-card systems fell out of favor in the mid to late 1970s, as storage became cost effective, and affordable meant that users could edit their work with the computer directly rather than requiring the intermediate step of the punched cards.
However, their influence lives on through many standard conventions and file formats. The terminals that replaced the punched cards displayed 80 columns of text, for compatibility with existing software. Many programs still operate on the convention of 80 text columns, although strict adherence to that is fading as newer systems employ with variable-width type fonts.
Dimpled and hanging chads
The term for the punched card area which is removed during a punch is chad. One notorious problem with a punched card system of tabulation is the incomplete punch; this can lead to a smaller hole than expected, or to a mere slit on the card, or to a mere dimple on the card. Thus a chad which is still attached to the card is a . This technical problem was claimed by the Democratic Party to have influenced the in the state of ; critics claimed that which used punched cards to tabulate votes generated improperly rendered records of several hundred votes, spread out over an entire state, which allegedly tipped the vote in favor of over .
Some consider it to be a minor scandal that punch card-based voting machines have continued to be used over the next several years, including the . Others who have used the system for years without the slightest problem cannot understand how it could be such an issue.

Внимание, отключите Adblock

Вы посетили наш сайт со включенным блокировщиком рекламы!
Ссылка для скачивания станет доступной сразу после отключения Adblock!

Скачать