Abstract: A system comprising a read-only memory storing output data relating to the stitching movement of the needle for a plurality of stitch patterns or to the feeding movement of the feed dog for the stitch patterns and order instructing data specifying the order in which the output data is to be read out, the output data and order instructing data being stored in the memory as divided into bight relating data and feed relating data, and an address unit including a bight register and a feed register. Based on the data read out from the memory with each advancement of the stitching and feeding timings alternately given in timed relation to the machine main shaft, the register stores the address data for the data to be read out with the next same stitching or feeding timing. When forming a stitch pattern such as a symmetric pattern which requires the use of data codes representing the same amount of movement, the same stored data is repeatedly read out according to the order instructing data.