INT 83 - JM Pro Tracker v5.0 - ???                                              
	AH = 0Ch
	DX bit 5 = ???
	???
Return: CF clear if successful
	    BX = ??? (FFFFh)
	    CX = ??? (0000h)
	    DX = ???
	CF set on error
	    AX = error code (see #03976)