I had a course named “Calculabilty and Complexity” last year and I implemented a Turing
Machine simulator using Pharo just to see how easy/hard it would be (it was quite easy 🙂 ).
I also wrote a little thing on medium about it  (I just took half an hour to review it and
I thought it was time to publish it).
Just announcing it in case it case someone need/is interested by this.
There is also a github repository for the source code .