A surgical instrument (100) e.g. stapler including a housing (110), an endoscopic portion (140), a drive gear, a drive motor (210), a shift motor (220) and an end effector (160) is disclosed. The endoscopic portion extends distally from the housing and defines a longitudinal axis (A-A). The drive gear is disposed at least partially within the housing and is rotatable about a drive gear axis (C-C) which extends therethrough. The drive gear is selectively movable along the drive gear axis. The drive motor is disposed in mechanical cooperation with the drive gear and is configured to rotate the drive gear. The shift motor is disposed in mechanical cooperation with the drive gear and is configured to move the drive gear along the drive gear axis. The end effector is disposed adjacent a distal portion of the endoscopic portion. Objectives are to reduce the force required to operate the instrument, and to enable multiple functions to be performed with one-handed operation.
