There's one in Tempe, AZ that has a 1980s "Dialed digit recorder", but that's a much later microprocessor controlled unit. The mechanism is that of a "Morse in

There's one in Tempe, AZ that has a 1980s "Dialed digit recorder", but that's a much later microprocessor controlled unit. The mechanism is that of a "Morse inker", a recorder used to receive telegraph signals. Here's one that's part of a Siemens telegraph set from 1862 or so.[1] The wiretapping version is the receive part of a telegraph set made portable in a nice wooden box with a carrying handle. All this shows how rare wiretapping once was. Law enforcement had to use repurposed antique telegraph equipment. [1] https://collection.sciencemuseumgroup.org.uk/objects/co32910/siemens-morse-inker-1862 https://collection.sciencemuseumgroup.org.uk/objects/co32910...