A walk through the 5XB [annotated]
16:31
How does call tracing work? (Part 1)
24:03
[5XB] Bob tells a story about barging in on someone's line.
23:40
No 5 Crossbar Tour
27:08
At the Connections Museum: the insane telephone technology that led to today's computers
19:17
1ESS (Olympia WA. Whitehall office c. 1986)
16:34
Booting up the 3ESS
23:20
How does a No. 1 Crossbar Marker work?
27:06