Hypothetical machine, theorized by Vannevar Bush,1 that individuals could use to store their personal information in electromechanically accessed microfilm documents.
Enormously influential and frequently cited concept.
Vannevar Bush, “As We May Think,” The Atlantic, July 1, 1945, https://www.theatlantic.com/magazine/archive/1945/07/as-we-may-think/303881/.