INT 2F - SMARTDRV v4.00+ - GET DOUBLE-BUFFER STATUS                             
	AX = 4A10h
	BX = 0005h
	BP = drive number (0=A, 1=B...)
Return: AX = BABEh if double-buffered
	    ES:DI -> 16-byte array of status bytes for fixed disks (see #02802)
SeeAlso: AX=4A10h/BX=0000h,AX=4A10h/BX=0003h,AX=4A10h/BX=0006h


(Table 02802)
Values for SMARTDRV status byte:
 00h	state unknown
 FFh	drive double-buffered
 else	not double-buffered