INT 13 - ESDI FIXED DISK - FORMAT UNIT (PS)
        AH = 1Ah
        AL = defect table count
        CL = format modifiers
            bit 4: generate periodic interrupt
            bit 3: perform surface analysis
            bit 2: update secondary defect map
            bit 1: ignore secondary defect map
            bit 0: ignore primary defect map
        DL = drive
        ES:BX -> defect table
Return: CF set on error
        AH = status (see AH=01h)
Note:   if periodic interrupt selected, INT 15/AH=0Fh is called after each
          cylinder is formatted
SeeAlso: INT 15/AH=0Fh