Line-scanning processes in a magnetic-drum-controlled electronic telephone exchange

In an electronic telephone exchange shortly to be installed at Highgate Wood, and using the time-division-multiplex principle, a magnetic drum is used to generate cyclic waveforms which are used to control the testing of subscribers´ lines and also the transmission of informationbetween the drum store and other sections of the exchange. The problem of non-synchronous operation and widely differing time scales between the drum and the speech multiplex are discussed.