tabulator
tabulator
[′tab·yə‚lād·ər]tabulator
A machine that added up numerical data in punch cards. Tabulators were used to prepare invoices, checks and "green-striped" reports as late as the 1970s. Invented by Herman Hollerith in 1890, his tabulator displayed the totals on dials. Subsequent models were able to perform additional arithmetic operations as well as print the results. See Hollerith machine, punch card and continuous forms. |
| First Tabulator - 1890 U.S. Census |
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| After placing the punch card in the reader and pulling the handle down, the dials incremented, and the card was dropped into the sorting box that opened. (Image courtesy of The Computer History Museum, www.computerhistory.org) |
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| A Tabulator in the 1960s |
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| Tabulating machines such as the IBM 407 (left) were used to print millions of reports, invoices and checks. Hollerith's company evolved into IBM, and IBM was always the leading tabulating equipment vendor (see Hollerith machine). (Image courtesy of IBM.) |
Tabulator
an electromechanical digital calculating machine that automatically processes numerical and alphabetic information stored on punch cards and records the results of the computations on continuous paper or special forms. A tabulator is a basic component of a punch-card processing system. Depending on the way in which the information is represented, a distinction is made between numerical and alphanumeric tabulators.
Tabulators can operate in different ways. For example, the tabulator may produce a line-by-line printout of the numerical and alphabetic information read from each card. At the same time, sums or differences are accumulated in accumulators, or counters. After the listing of a group of cards, the tabulator prints the totals for that group.
In another mode of operation, the tabulator prints alphabetic and numerical information characterizing the information being processed, sums in the accumulators the intermediate numerical quantities (without recording them), and finally prints the totals for the given group of cards.
In a third mode of operation, the tabulator makes use of intermediate cycles. It carries out the addition or subtraction of totals stored in the accumulators, compares such totals, and performs multiplication or division of numbers. These processes are carried out over several intermediate cycles.
The capabilities of a tabulator can be substantially expanded by connecting it to auxiliary units. When the tabulator is used with a summary punch, a graphic character-sensitive punch, or a reproducer, summary punch cards can be produced in addition to a printout. When an electronic computer unit is used in conjunction with the tabulator, the tabulator can not only add and subtract numbers but also multiply and divide them in a single machine cycle.
The components of a tabulator include the following: a control unit, a punch-card reader, an arithmetic unit, a storage unit, and a unit for the output of information through printing or through the punching of cards. In accordance with the prescribed program, the control unit coordinates the operation of the other units; it automatically monitors the descriptive information on the cards and automatically transfers the results obtained in the accumulators. The machine can be switched into different modes of operation from the control console. The input unit is a mechanism that feeds punch cards into a brush station with two (upper and lower) sets of brushes that permit the information to be read from the punch cards and transmitted to the arithmetic unit, control unit, or output unit. The arithmetic and storage units are accumulators that carry out the addition and subtraction of numbers and permit a total from one accumulator to be added to or subtracted from a total in another accumulator. The output information is printed by numerical or alphanumeric printers or is punched in cards by a summary punch.
Tabulators are used in data-processing systems to handle large amounts of information where the performance of logical operations is not required.
REFERENCES
Fedorov, M. P., and V. I. Isakov. Tabuliatory T-5 i T-5M. Moscow, 1958.Vinokurov, P. S. Metodika proverki i naladki raboty schetno-perforatsionnykh mashin. Moscow, 1968.
Surin, N. M., and I. B. Shnaiderman. Tabuliator TA80–1. Moscow, 1973.
G. S. RUMIANTSEVA