Short for Electronic Delay Storage Automatic Calculator, EDSAC was an early computerdated around 1949. EDSAC performed its first calculation at the Cambridge University in England. EDSAC used mercury delay lines for memory and 3,000 vacuum tubes for logic. Programs were input using 5-hole punched tape and output was via a teleprinter.
See also “The Five Generations of Computers” in the Did You Know…? section of Webopedia.