the microprocessor 301 and also to the display driver 307 the microprocessor 301 receives a signal q from a flip flop 201 included in the detecting circuit 200 to process the same in accordance with a program as shown in fig1 the selected pattern display 305 may be understood as comprising display elements such as the light emitting diodes 101 to 108 in the previously described fig3 embodiment now referring to fig1 operation of the fig9 embodiment will be briefly described when an operator turns on a power supply at the step 401 the microprocessor 301 executes initialization of then at the step 403 the microprocessor 301 determines whether a signal from the detecting circuit 200 i e a signal representing that the attachment is mounted is available if the attachment has not been mounted at that time the microprocessor 301 further determines at the following step 405 whether the presently selected pattern is buttonholing since the attachment has not been mounted at that time even in the case of buttonholing the microprocessor 301 determines that buttonholing is incapable and at the following step 407 drives the light emitting diodes included in the display 305 to display a straight stitch mode the reason is that in case.