sentences:  Most Minolta A-mount compatible lenses, whether built by Minolta or one of the aftermarket lens manufacturers, are focused "externally" by a shaft connecting the autofocus computer "and" motor inside the camera body that mechanically connects to the internal focusing gears inside of the lens body.A couple of later Minolta lenses do have a built-in ultrasonic focus motor (SSM lenses), like other SLR and DSLR systems (i.e.Canon and Nikon), where the AF computer is inside the camera body and there is a digital interface connecting body to an electric motor and the focusing gears built into the lens body.