As the number of cards in the Wyandotte-ASTM system of data retrieval increase, the time to sort for an answer increases accordingly. Simpler and more rapid methods of storage and retrieval are desirable. This paper describes our limited, but promising, experience with an inverted "peek-a-boo" system as it applies to the particular needs of our laboratory. In this system each card represents a characteristic, and each compound has a location in the Cartesian grid of the card. Holes are drilled at the location of the compound having the characteristic described by the card. A complete deck requires 250 cards and can retain information for 10,000 compounds. Searching is based on optical coincidence. Advantages of the system are simplicity, rapidity of output, ease of adding characteristics, and relatively inexpensive equipment.
Naomi E. Schlichter and Ellen Wallace, ""Peek-a-Boo" Data Retrieval in Infrared Spectroscopy," Appl. Spectrosc. 17, 98-101 (1963)