An electronic typewriter (11) has a line spacing device (29) for rotating a platen roller (16) and a transport device (28) for moving a printing carriage (19) in both directions. The line spacing and transport devices are driven from a single motor (32) via an intermediate gear (40) mounted on a shift member (35). The shift member (35) is displaceable between two operative positions for connecting a driveshaft (33) to the transport device (28) or to the line spacing device (29). A servomechanism (36) which is motorized by the shaft (33) displaces the shift member (35) between the two positions by means of a shift electromagnet (81) which actuates a lever (79) to lock the gear (40) by means of teeth (88) on a slide member (43). Positioning means (44) hold the shift member (35) in each of the two operative positions, and an electronic control means (22) controls the motor (32 ) and the electromagnet (81). The system is of low cost, and is simple, functional and reliable.