EDSAC, Electronic Delay Storage Automatic Computer, was the first large-scale, fully functional, stored-program electronic digital computer. When it first ran on May 6, 1949, it was fully functional, with a fully realized instruction set, paper tape for input, and a teleprinter for output. Memory was a set of mercury baths through which generated and regenerated acoustic pulses represented the bits of data.

Articles on that refer to EDSAC

The Age Intelligent Machines, Chapter Six: Electronic Roots By Ray Kurzweil
The Age of Spiritual Machines: Timeline By Ray Kurzweil
Chapter One: The Law of Time and Chaos By Ray Kurzweil

Related Links

The Cambridge EDSAC