A surgical system includes a drive unit on a support. The drive unit includes motors or other actuators and a plurality of output elements arranged such that operation of each drive unit linearly translates a corresponding one of the output elements. A surgical device has actuation elements extending through an elongate shaft to a distal articulation section, and an input subsystem carried at the proximal end of the shaft. Linear translatable input elements or pistons of the input subsystem are each associated with a corresponding one of the actuation elements. The input and output elements are positioned such that operation of an actuator linearly translates an output element, causing linear translation of a corresponding input element and engagement of an actuation element. A sterile drape is positionable between the input elements and the output elements.