The early history of computing is dominated by hardware development, but once we got non-trivial machines to work, the character of the machines was defined by their software not their hardware. Modern computers can be programmed to emulate computers of yesteryear, and then run original software. Sadly, much software from the past has been lost with cavalier disregard for its historic significance. However, we are having some success in resurrecting past systems, and can run such software as survives so well that past users of these old systems often react with nostalgic glee on first encountering one of these emulations. We can do this even where the software only survives in the form of printer listings. The challenge is to make such emulations relevant to people who never knew the original.