The Electronic Delay Storage Automatic Calculator (EDSAC) was designed and built at the University of Cambridge under the leadership of Maurice Wilkes. Although the theoretical principles of computing had been set out earlier, the construction of EDSAC brought these ideas into practice. The machine ran its first successful operation on June 5, 1949, utilizing its stored-program architecture, which permitted programs to be loaded into its memory rather than being hardwired. This innovative feature facilitated the flexibility and efficiency needed for computing tasks.

EDSAC was notable for its use of mercury delay lines for memory storage and a total storage capacity of about 1,024 words. The first program it executed was designed to calculate a sequence of Fibonacci numbers, showcasing the EDSAC's potential for handling complex calculations. The successful completion of this operation played a crucial role in demonstrating the effectiveness of electronic digital computers.

Additionally, EDSAC became operational shortly after the development of the Manchester Mark I, which was another early computer. However, EDSAC distinguished itself with its practical design and ease of use. Many computer scientists and engineers were trained on EDSAC, which facilitated the spread of knowledge in computing and paved the way for future developments in the field. The ability to store programs was a game changer, inspiring subsequent designs and contributing significantly to the evolution of modern computing systems.