INT 13 - ESDI FIXED DISK - FORMAT UNIT (PS)

	AH = 1Ah
	AL = defect table entry count
	CL = format modifiers (see #00250)
	DL = drive (80h,81h)
	ES:BX -> defect table (see #00251), ignored if AL=00h
Return: CF set on error
	CF clear if successful
	AH = status (see #00234 at AH=01h)
Note:	if periodic interrupt selected, INT 15/AH=0Fh is called after each
	  cylinder is formatted
SeeAlso: AH=07h,INT 15/AH=0Fh