Complex sentence: As technology advanced, automatic electro-mechanical switches were introduced and telephones were equipped initially with rotary dials, for pulse-dialing, and then Touch-Tone key pads in the 1960s, which increased the speed of dialing and enabled other vertical telephone features.
Split into simpler sentences: As technology advanced, automatic electromechanical switches were introduced and telephones were equipped with rotary dials, for pulse-dialing. In the 1960s, Touch-Tone key pads increased the speed of dialing and enabled other vertical telephone features.