In a now landmark article for the Atlantic Monthly published in July 1945, entitled “As We May Think,” Bush laid out a vision of a world in which computers would be central to our social and business life. The article remains, to this day, stunning in the accuracy of its perceptions regarding the likely evolution of computing. In an introduction describing the thrust of Bush’s article, the Atlantic Monthly’s Editor wrote, “Now, says Doctor Bush, instruments are at hand which, if properly developed, will give men access to and command over the inherited knowledge of the ages.” No small step for Mankind that.

In the article, Bush looked at recent advances, such as the cathode ray tube, dry photography and microphotography and pondered how logical extensions of these technologies might be applied to create a future miniaturized Encyclopædia Britannica:

“The Encyclopædia Britannica could be reduced to the volume of a matchbox. A library of a million volumes could be compressed into one end of a desk. If the human race has produced since the invention of movable type a total record, in the form of magazines, newspapers, books, tracts, advertising blurbs, correspondence, having a volume corresponding to a billion books, the whole affair, assembled and compressed, could be lugged off in a moving van.”

Although Bush thought in terms of microfilm rather than magnetic drives, optical discs or silicon wafers for data storage, he conjured up a likely playback machine for a high-capacity storage medium that closely resembles the personal computer of today. Bush called it a Memex and described it this way:

“Consider a future device for individual use, which is a sort of mechanized private file and library. It needs a name, and, to coin one at random, ‘memex’, will do. A memex is a device in which an individual stores all his books, records, and communications, and which is mechanized so that it may be consulted with exceeding speed and flexibility. It is an enlarged intimate supplement to his memory. … On the top are slanting translucent screens, on which material can be projected for convenient reading. There is a keyboard and sets of buttons and levers. Otherwise, it looks like an ordinary desk. In one end is the stored material . . . Wholly new forms of encyclopedias will appear ready made with a mesh of associative trails running through them, ready to be dropped into the memex and there amplified.”

Bush did a prescient job describing in 1945 his idea of what a personal computer of the future might look like. This is particularly true given the required reliance on vacuum tubes for the computers in that era. Vacuum tubes were a great limitation for the computers of the time.

Though the transistor was invented in 1947 by physicists at Bell Telephone Laboratories, the shift from slow, heat producing vacuum tubes that often burned out, to cooler, more powerful and reliable transistors did not unfold overnight.

For instance, when the March 1949 issue of Popular Mechanics surveyed the then state of the art ENIAC computer (from “Electronic Numerical Integrator And Computer”), the potential impact of the transistor, let alone the microprocessor chip, was entirely missing: “Where a calculator on the ENIAC is equipped with 18,000 vacuum tubes and weighs 30 tons, computers in the future may have only 1,000 vacuum tubes and perhaps weigh 1.5 tons.”