Abstract: This invention relates to an automatic sewing machine in which the workpiece is moved under the sewing head by means of a clamp which is driven by stepping motors along two coordinate axis through a predetermined pattern. The stepping motors are connected to the workpiece clamp through a non-linear linkage assembly. The stepping motors are controlled by a coded Programmable Read Only Memory (PROM) which generates signals in timed relation to the operation of the sewing machine. The PROM is coded by first digitizing the stitch coordinates of the predetermined pattern and then modifying each of the coordinate values to compensate for the non-linearity of the linkage system.