A tape cartridge used in the Harvest computer custom-built by IBM for the NSA (National Security Agency). Harvest was an add-on to the IBM Stretch computer used for cryptanalysis and keyword search. Its coprocessor was designed to handle vast amounts of data streamed from a high-speed, automated magnetic tape system. The tape cartridges were loaded and unloaded automatically from a library of up to 640 sealed cartridges. Data could read and written at 1.5 million characters per second. The system was at the time the most sophisticated computer in existence. It remained in use from 1962 to 1976.

Frances Allen, who won the A. M. Turing Award for her work on compilers, worked on the Harvest project in the 1960s.