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Punched Cards
A brief illustrated technical history
Part of the Punched Card Collection
by Douglas W. Jones
THE UNIVERSITY OF IOWA Department of Computer Science
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The overall dimensions of punched cards used for data processing have remained the same since Herman Hollerith settled on the card format. 7 3/8 inches wide by 3 1/4 inches high by .007 inches thick. Prior to 1929, this was a standard size for many US banknotes, and Hollerith apparently chose it so that he could store cards in boxes made for the Treasury Department. Eventually, most of a century after Hollerith's work, these dimensions came to be standardized as the EIA standard RS-292 media 1 punched card.
The cards used to record the data from the 1890 census had 22 columns with 8 punch positions each (although there was room on the card for a total of 11 punch positions per column). The coding used on those cards did not encode data in columnar fields, but rather, each punch position was assigned a specific meaning. Hollerith continued tinkering with the way data was encoded, adding rows and columns to meet the needs of new applications. 24 colums of 10 positions each in the 1900 census (inferred from the 1900 National Geographic article), although published images of punched cards from the railroad industry in the same era all show 12 row cards with 36 punch positions per card. Cards used in the 1910 census apparantly had 27 columns of 12 positions each. By the end of the 1920's, IBM's established line of punched-card machinery used 45 columns of round holes per card and 12 punch positions in each column.
In 1928, Hollerith's company, now renamed IBM, introduced the rectangular hole 80 column format, almost doubling the amount of data that could be recorded on a card, and by the mid 1930's, IBM was predicting that round-hole cards would soon be things of the past. IBM's 1928 design was the basis of what, decades later, came to be the standard punched card, eventually defined by ANSI X3.21-1967 governing the holes in the card and ANSI X3.26-1980 governing the use of the Hollerith code to encode alphanumeric data on cards.
[round hole sperry punched card]
A high resolution scan is available.
In fact, the round-hole format remained in use into the early 1990s, but in a very limited set of applications! The last use I am aware of is toll tickets on some eastern turnpikes. There are two reasons that the round hole format survived: First, IBM had a patent on their new rectangular format, so competitors were forced to limit themselves to the old format. Second, Remington Rand, one of IBM's major competitors in the pre-computer era, moved from Hollerith's code to a 6-bit code that allowed 90 columns of text to be stored on the old 45 column cards. When Remington Rand bought UNIVAC, they naturally integrated their 90 column card format with UNIVAC computers. In many ways, the UNIVAC card code was superior to IBM's "improved" rectangular hole version!
Oliver J. Jones wrote me that, in addition to surviving on some eastern turnpikes, UNIVAC's 90 column cards also remained in use through the 1960's at Macy's Department store and Lerner Stores, in the retail sector, the US Navy Medical Supply office and the Polaris missle control system, in the military sector, the New York City Tax Department, Long Island Lighting, and more. He sent along an image of the cover from a Remington Rand brochure and a promotional poster.
Mike Albaugh wrote me that he helped dismantle a UNIVAC SS90 system in 1974 or 1975 that had been in use up until the week before. He also saw a similar UNIVAC system in use at the Concord Naval Weapons Station around the same time. These apparently used 90 column cards.
If you look at the punched card equipment sold by IBM after 1931, you will find complete hardware support for IBM's alphanumeric Hollerith code, but you will also find that the majority of the machines sold were limited to numeric applicatons. At a time when, for example, the University of Iowa was punching student names on cards using the Hollerith code, other universities were developing 4-digit numeric encodings of common names so that they could avoid the need for the more expensive alphanumeric equipment.
The book Practical Applicatons of the Punched Card Method in Colleges and Universities, edited by G. W. Baehne an published by Collumbia University Press in 1935, contains an excellent summary of the state of the art in punched card data processing in 1935, including an appendix that appears to be a reprint of IBM's catalog for that year and many illustrated descriptions of typical applicatons.
When cards were used to store fixed-format information for data processing applications, they were almost always printed with format information, so that a casual reader could easily determine what punches on the card held what information. This printing could be quite specialized to one application, or it could merely set off fields in a standard way, with no indication on the card of what the purpose was.
[punched card retail form]
The card shown here is typical of those used with IBM's line of card processing equipment from the 1930's onward. This particular example was printed for a range of retail applications where it must have been expected that the customer would handle the cards, as indicated by the warning: Do not fold or mutilate. This warning would be unnecessary if the card were only to be handled by data processing workers. While most fields of this card have no clear purpose, it contains an interesting and very specialized feature, a tab the cashier was supposed to tear off along a perforated line when the card was processed. A card with this tab removed would be seen by card processing equipment as having a punch in column 1, row 12.
It is important to note that the typical card processing applications from the 1890's to the 1950's did not require the use of computers! A deck of cards from a retail application, for example, could be sorted by the category field on a card sorter, and then each category could be run through a tabulating machine to sum the price fields of all cards in that category or similar accounting functions.
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