You would call a specific number and it would play a recording from a cylindrical drum (like an early phonograph record). The drum could be rotated at a precise speed, and the recorded (human, usually female) voice announced the time at 10 second intervals, followed by a “beep” at the time described.
You would call a specific number and it would play a recording from a cylindrical drum (like an early phonograph record). The drum could be rotated at a precise speed, and the recorded (human, usually female) voice announced the time at 10 second intervals, followed by a “beep” at the time described.