I've been enjoying the videos of 'Look Mum No Computer', building his own 60's based, electromechanical telephone exchange, is his Museum of everything else. ht

I've been enjoying the videos of 'Look Mum No Computer', building his own 60's based, electromechanical telephone exchange, is his Museum of everything else. https://www.youtube.com/watch?v=tK1lH8pjXTo https://www.youtube.com/watch?v=tK1lH8pjXTo His second channel has some more dedicated content on telephone systems, https://www.youtube.com/playlist?list=PLKnS0AB2CTN_eu8k8rgaOW0PWFH2Qv9U https://www.youtube.com/playlist?list=PLKnS0AB2CTN_eu8k8rgaO... He has spent a fair amount of time building it out, from initially receiving his first exchanging and getting it to work, and adding more to it It fun just to watch how the system selects lines and routes around the exchange. Other interesting things, like how the dial and engaged tones are generated, and how prerecorded messages are played back to a number that is no longer in service, something like, 'This number no longer exists, please try again'