Eh? What. There is actually a picture of the dial tone generator in Flickr. Motor was moving generators on various speeds. https://www.flickr.com/photos/947960

Eh? What. There is actually a picture of the dial tone generator in Flickr. Motor was moving generators on various speeds. https://www.flickr.com/photos/9479603@N02/1814546737/in/photostream/ https://www.flickr.com/photos/9479603@N02/1814546737/in/phot... As regards to logistics of tones and stuff. You dont want to know. It involved multi-level signalling of currents and voltages. I am the ultimate expert. I wrote a thesis on Coin-operated Telephone signalling in 1977.