Punched Drunk: Alcohol, Surveillance and the LCBO, 1927-1975

LCBO Surveillance Technologies

Punch Cards, IBM & Statistical Analysis


How Punch Cards and Sorters Work

These standardized cards allowed for both numeric and alphabetic data to be stored and sorted. As IBM explains in Punch Card Data Processing Principles (1961a: 2-3):

the card is divided into 80 vertical areas called columns or card columns. These are numbered 1 to 80 from the left side of the card to the right. Each column is then divided into twelve punching positions called rows, which are designated from the top to bottom of the card by 12, 11 (sometimes referred to as X), 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. The punching positions for digits 0-9 correspond to the numbers printed on the card. The top edge of the card is known as the 12 edge and the bottom as the 9 edge. These designations are made because cards are fed through machines either 9 edge first or 12 edge first. Digits are recorded by holes punched in the digit punching positions of the card from 0 to 9. The top three punching positions of the card (12, 11 and 0) are known as zone punching positions of the card. In order to accommodate any of the 26 letters in one column, a combination of a zone punch and a digit punch is used. The various combinations of punches which represent the alphabet follow a simple pattern. The first nine letters of the alphabet, A to I, are coded by the combination of a 12 punch and the digit punches of 1 to 9. Letters J through R are coded by an 11 punch and digits 1 through 9. S through Z, the last eight letters, are the combinations of the 0 zone punch and the digit punches 2 through 9. The eleven special characters are recorded by one, two or three punches in a column.

Sorting of the cards themselves was conducted by feeding them into a sorting machine of which the key components consisted of a brush, or “card reader,” and a mechanism to direct the card into one of the 13 pockets of the card sorting machine.

How a sorter works

The sorter pockets were arranged 9,8,7,6,5,4,3,2,1,0,11,12 and R, with the thirteenth or “R” pocket being for unreadable or reject cards. The reading of the information stored on the cards was conducted by the completion of a circuit between a roller and a card reader that passed over the punched card. When the card reader passed over the punched hole it completed the circuit, activating magnetic coils and forcing the card upward along a metal path leading to the corresponding pocket. An IBM personal study booklet explains the sorting process in the following way:

the cards to be sorted are placed in the [machine] 9 edge first, face down. As the cards are read by the [card reader] brush they are directed into a chute whose path ends in one of the sorter pockets. The [figure above]…shows a card with a 4 punch, passing between the brush and the contact roll. Note that the card has passed under the chute entry for pockets 9, 8, 7, 6 and 5. These chutes are thin metal bands which form channels to the sorter pockets. The entry is curved so that while the plate is up, the card will slide underneath without encountering the chute. The [figure above shows] the 9 edge of the card has just passed the 5 chute blade while the brush is [about to] detect the hole punched in the 4 row. This detection of the hole causes a current to flow…to the magnetic coils. The magnets become energized and pull the plate down so that the edge of the card cannot slide under chute 4. This causes the card to enter the chute 4 channel. Once in the channel the card is carried along by the carrier rolls until it falls into the 4 pocket...if no punched hole had been sensed, the plate would not have dropped and the card would have passed under all of the chute blades, consequently dropping into the reject pocket. This is what happens if the column is blank or if reading of the 4 punch has been suppressed (IBM 1961b: 21-23).

Alphabetic information required two punched holes in a single column, and so two passes through the sorting machine were needed in order for these cards to be properly separated. On the second pass pockets 9-1 were turned off allowing the machine to read only the punched holes either in the 0, 11 or 12 positions, and this second pass finalized the alphabetical ordering of the punch cards. In addition to this, sorting would also require an additional pass through the machine for each column that the given “field” had. Fields, such as names or employee numbers, would have multiple columns and so would multiply the number of required passes through the sorting machine by the number of columns devoted to the field. The IBM 80 sorter of 1925 could sort and tabulate 450 cards per minute, while the IBM 82 of 1949 boasted 650, and later models between 1,000 and 2,000 per minute depending on the speed of the machine’s operator and required number of passes (IBM 1961a: 5-9). As IBM reported:

recording information in punched card form offers many advantages. The two most important are: 1. Once information is punched (recorded) in a card, the card is a permanent record. Its information can be used over and over again and will be the same for each use. 2. Each card contains all the necessary information about a single transaction. Therefore, all similar transactions can be easily grouped (Ibid: 1).

Sorting and tabulation offered the LCBO the ability to audit its sales and inventory; however, quantification and comparison of specific and general cases was developed for the Board as an important diagnostic and governmental capacity (Annual Report of the LCBO 1966-1967, 1968: 5, 13; Annual Report of the LCBO 1968-1969, 1970: 6). Not only could one reconstruct an understanding of a particular case through these technologies, but mass analysis provided the basis for comparative assessment and prediction of outcomes.

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