EDSAC, Electronic Delay Storage Automatic Computer, was built by Maurice Wilkes and colleagues at the University of Cambridge Mathematics Lab, and came into use in May 1949. It was a very well-engineered machine, and Wilkes designed it to be a productive tool for mathematicians from the start. It used mercury delay line tanks for main store (512 words of 36 bits) and half megacycle/sec serial bit rate. Input and output on paper tape, easy program load, nice rememberable machine order-code. See Resurrection issue 2 for some of Wilkes' design decisions.

Simulators of EDSAC included here are:

	edsac.zip – a command line-based emulator by Lee Wittenberg, originally for MS-DOS but updated for Windows, MacOS and Linux. The emulator is provided as C source code with a makefile and a set of example EDSAC programs and library routines.
	to Martin Campbell-Kelly’s website containing another emulator for Windows and for Mac together with many example programs.
	to an open-source and updated version of Martin Campbell-Kelly’s EDSAC emulator by Lee Wittenberg and Martin Campbell-Kelly. This version is written in C++ rather than C and is provided in source code form with a build environment for Windows and Linux.