The EDSAC was the world’s first stored-program computer to operate a regular computing service. Designed and built at Cambridge University, England, the EDSAC performed its first calculation on 6th May 1949. The Edsac simulator is a faithful software evocation of the EDSAC computer as it existed in 1949-51. The user interface has all the controls and displays of the original machine, and the system includes a library of original programs, subroutines, and debugging software. The simulator is intended for use in teaching the history of computing; as a tutorial introduction to the classic “von Neumann” computer; or as an historical experience for current computer practitioners. [via] Link.
The Edsac Simulator