Volume 21, Issue 4 (October 1976)
Identification of IBM Keypunch Machines by Their Printed Products
A little over a year ago, the Document Division of the United States Army Criminal Investigation Laboratory received a referral requesting the examination of 44 keypunch cards to determine the machine responsible for their preparation. Supplies were being diverted, and the shortages were covered by the preparation of fraudulent keypunch cards. The contributor of the case also submitted known standards from the 15 keypunch machines most likely to have been responsible for the preparation of the fraudulent cards. The questioned cards were approximately 7 ⅜ in. wide by 3 ¼ in. high (187 by 83 mm), contained a series of punched holes, and bore printed characters consisting of a series of dots along the top of the cards (see sample, Fig. 1). Our first impression was FIG. 1—A sample card from an IBM keypunch machine. that this would be another tedious, complex, time-consuming examination; however, as work progressed on the examination, the case became extremely interesting and very rewarding from a document examiner's viewpoint.