[NeedMoreTea]

The Analytical Engine was Turing complete so loops and conditionals would have been possible, but Babbage didn't get near building it.

The London Science Museum built a fully working Difference Engine, to Victorian tolerances so it could have actually worked.

I heard of a project to build a modern working replica but I don't know if anything ever came of it.

[jgrahamc]

That would be https://plan28.org/ which I'm involved in. Blog for updates: http://blog.plan28.org/

[NeedMoreTea]

Thanks! Nice to see it's still progressing.