needle swing amplitude data is read out it activates needle swing drive mechanism dv b upon receipt of a pulse from pulse generator p6 which pulse is issued when the needle is positioned at its upper dead point then n which is the address of stitch data common to unit patterns a 3 is increased by 1 and the fabric feed data for stitching signal 2 is read out to activate the fabric feed drive mechanism dv f when the needle is positioned at its lower dead point thus address n is successively incremented by 1 so as to alternately control needle swing amplitude and fabric feed when repeating signal ret 39 is reached the stitch data of c at ram address mn 1 in fig4 is read out although stitch data of c is not shown there this stitch data contains that needle swing amplitude data and that fabric feed data alternately stored in rom which will create unit pattern c the initial address will contain data for needle swing amplitude designated by c 1 of the stitch no 1 in fig3 c and the last address will contain repeating signal ret 39 in the same manner as in unit pattern a.