Electromechanical memory - Impulse regenerator nr 1
13:40
Ericsson XY selector demo
49:10
Video n.° 1 de la radio a válvulas 1554 de Canadian Northern Electric: prueba y prueba de encendido
18:32
Crossbar telephone exchange demo
12:34
How does telephone ringing work?
21:46
The Weird Story Of Electromechanical Memory - 40 bits of the stuff!
7:19
5ESS - Working on a trouble ticket / alarm
10:28
Pre-2000 Strowger selector demonstrator
22:38