Sewing machine and computer program product

A computer program product stored on a non-transitory computer-readable medium, comprising instructions for causing a computer of a sewing machine to execute the steps of:

• inputting an instruction to operate a threading mechanism of the sewing machine, the threading mechanism being configured to pass an upper thread through a needle eye of a needle that is attached to a needle bar that has been selected from among a plurality of needle bars;
• causing a display portion of the sewing machine to display replacement information, the display portion being configured to display various information, the replacement information being information pertaining to a replacement needle bar that corresponds to a thread spool for which replacement is necessary and that is at least one of the plurality of needle bars of the sewing machine, a needle can be attached to a lower end of each of the plurality of needle bars, the needle having a needle eye through which can be passed an upper thread that is supplied from a thread spool;
• specifying a replacement-completed needle bar, during a period in which the replacement information is being displayed on the display portion, by:
• (i) detecting that a rotating plate has been rotated in a specified direction by an upper thread that is supplied from a thread spool that has been placed after replacement, and (ii) determining that the instruction to operate the threading mechanism has been input, the specified direction being a direction in which a rotating plate is rotated in a case where the upper thread is pulled toward the needle from the thread spool, the replacement-completed needle bar being a needle bar:
• (i) that corresponds to the thread spool that has been placed after replacement, (ii) that corresponds to a tensioner that has the rotating plate that has been rotated in the specified direction, and (iii) to which is attached the needle that has the needle eye through which the upper thread has been passed by the threading mechanism in a case where the instruction to operate the threading mechanism has been input, the tensioner being one of a plurality of tensioners of the sewing machine, each of the plurality of tensioners having a rotating plate that is configured to impart tension to the upper thread;
• and
• causing the display portion to display a result that has been specified.