INT F3 - SoundBlasterA common sound card developed by Creative Labs. - POINTER TO ECHO VALUE
Note:	this is not a vector, but a pointer to a DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address. containing the echo
	  value selected with SET-ECHO.EXE
SeeAlso: INT 2F/AX=FBFBh/ES=0000h