IBM Verifier for Punched Cards

This key-driven, manual verifier has 15 black rubber keys. Twelve are for the 12 columns on a punch card. These are labeled from 0 to 9, X, and blank. Two other keys move the card one space, and the last key releases the card. Cards are fed manually from the left. A mechanism at the center of the machine senses whether or not a hole has been punched in a given line. If one depresses a key corresponding to a hole punched on the card, the card advances one place to the left. If the hole on the card does not match what is punched, the card does not move. Depressing the blank key at the front of the verifier then cuts a hole at the bottom of the column in which the error occurs. Erroneous cards are then retyped on a card punch. If the hole and the key typed match, the card advances one column.
A mark stamped on the base of the machine toward the left reads: 05111993-A0.
IBM introduced verifiers as part of its line of punch card equipment around 1917. Cards with 12 columns date from the early 1930s onward.
C. J. Basche, L. R. Johnson, J. H. Palmer and E. W. Pugh, IBM’s Early Computers, Cambridge: MIT Press, 1986, pp. 7–8, 11.
Currently not on view
Object Name
date made
ca 1935
International Business Machines Corporation
Physical Description
rubber (overall material)
metal (overall material)
overall: 15 cm x 44.5 cm x 14 cm; 5 29/32 in x 17 17/32 in x 5 1/2 in
place made
United States: New York, Endicott
ID Number
accession number
catalog number
Computers & Business Machines
Tabulating Equipment
See more items in
Medicine and Science: Mathematics
Tabulating Equipment
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of John T. Welch
Additional Media

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