Rebuilding Computer History

They have rebuilt a Colossus computer. And it works.

This is fascinating. They rebuilt a vacuum tube computer and it runs. It took almost twice as long as a modern PC to crack a coded message, which isn't too shabby for a sixty three year old design.
I'm not versed in computer history. Yet my understanding is that the Colossus was one of the first binary digital computers and probably was the first model to be made in any quantity, rather than a one-off experiment.