File:B Board Machine Originated Calls.jpg

This photo shows a type of 'B' Board that was used to terminate calls to a manual office from a dial exchange like Panel. An incoming call would show up on the position keys then display the digits inside the box in the middle of the photo. They were received in the PCI 'Panel Call Indicator' format. The Operator would read the display then attempt to terminate the call to the manual line. B Boards were required during the transition period to automatic dial switching from manual exchanges.

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