How does telephone ringing work?
19:03
The Machine that Makes Your Phone Ring
17:32
2600? How Phreaking Really Worked
12:08
Self Winding Master Clocks in Central Offices
15:43
What happens if you leave your phone off the hook?
14:56
Faking It: The Obviously Dubbed Telephone Ring
27:08
At the Connections Museum: the insane telephone technology that led to today's computers
31:12
Full Mechanical: The Panel Telephone Switch
27:31