INT 1A - SND - UNCONDITIONALLY STOP SOUND                                       
	AX = FF05h
Return: AH = 00h (successful)
Note:	this function is the same as AX=FF03h, but will stop the sound even if
	  SND is currently busy, such as playing background music
SeeAlso: AX=FF00h,AX=FF03h,INT 80/BX=0007h