In a micro-computer controlled sewing machine a conversion switch is provided which can be switched between a first position and a second position. A manually operable controller, such as a foot pedal, is connected to the conversion switch. The circuit means connects the conversion switch to the micro-computer in the electronic sewing machine. When the conversion switch is in its first position, the operable machine controller will control the rotation speed of the sewing machine. When the conversion is in the second position, the manually operable controller will control the needle swing amplitude.