The 3-Slot Payphone Part 1
57:39
The 3-Slot Payphone Part 2
1:40:10
The Line Finder In The Step-By-Step Telephone Switching System
49:45
551A PBX Description and Operation
1:10:41
The Selector In The Step-By-Step Telephone Switching System Part 1
1:09:35
The Connector In The Step-By-Step Telephone Switching System
14:28
The Coming of the Dial (1933)
21:28
The Telephone Exchange (1982) British Telecom Schools Film
49:14