Tangentially related: if you're fascinated about how all of this vintage equipment used to work, and if you find yourself near downtown Seattle on a sunday with an hour or two to spare, I strongly encourage a visit to: https://www.telcomhistory.org/connections-museum-seattle/
It's an incredibly rare opportunity to see geek geezer volunteers keep this central office telephone switching equipment up and running, and they'll proudly show you how it all works. A combination of aging techs and students constantly maintain equipment ranging from crossbar switches to an ESS.
It's a labor of love, and you'll want to leave something in the tip jar just to say thanks.
It's an incredibly rare opportunity to see geek geezer volunteers keep this central office telephone switching equipment up and running, and they'll proudly show you how it all works. A combination of aging techs and students constantly maintain equipment ranging from crossbar switches to an ESS.
It's a labor of love, and you'll want to leave something in the tip jar just to say thanks.