Full Mechanical: The Panel Telephone Switch
35:12
How does a No. 1 Crossbar work? - Dial Equipment Appreciation, Part 2
19:03
The Machine that Makes Your Phone Ring
26:27
The 5XB Trouble Recorder
17:40
Plugging a Vintage Telephone Exchange Into The Internet So People Can Use It
17:32
2600? How Phreaking Really Worked
27:08
At the Connections Museum: the insane telephone technology that led to today's computers
49:45
551A PBX Description and Operation
22:28