Crossbar's Hidden Superpower: Alternate Routing!
13:48
Relays! They're Electromechanical Switches.
35:12
How does a No. 1 Crossbar work? - Dial Equipment Appreciation, Part 2
23:18
How many different ways can we cause trouble in the 5XB?
31:12
Full Mechanical: The Panel Telephone Switch
27:08
At the Connections Museum: the insane telephone technology that led to today's computers
16:34
Booting up the 3ESS
23:59
Core Memory Explained and Demonstrated
35:35