Abstract: A code selectable key duplicating system is adapted to function with a key cutting machine having a key follower for engaging and tracing the contour of a bit notch pattern formed in the blade of a master key and a key cutter coupled to the key follower to reproduce the traced bit notch pattern of the master key in the blade of a key blank. The code selectable duplicating system includes a bit notch simulator which is divided into a selectable series of n adjacent notch segments to form a surface contour creating a simulated bit notch pattern corresponding to the bit notch pattern designated by a coded sequence. An alignment fixture positions the notch pattern simulator relative to the key follower enabling the key follower to trace the simulated bit notch pattern such that the key cutter reproduces the simulated bit notch pattern in the blade of the key blank.