单词rotary dial
un.: 旋转式拨号
网络: 旋转式拨号盘；旋转拨号；转盘式电话
旋转式拨号
The keypad is a vestige of the rotary dial, which itself is an artefact of the switch from human operators to direct-dialling in the 1920s.
数字键盘演变自转盘拨号器，而转盘拨号器则是1920年代人工接线员向直接拨号转变的产物。
Phone Books Go the Way of Rotary Dial
别了，电话簿