INT 13h,  1Ah (26)       Format Hard disk                                ESDI

       On entry:      AH         1Ah
                      AL         Number of blocks in defect table
                      CL         Bit
                                 4 3 2 1 0
                                 . . . . x  +No primary defect map
                                 . . . x .  +No secondary defect map
                                 . . x . .  +Allow logging found surface
                                             errors in the secondary
                                             defect map
                                 . x . . .  +Do extended surface analasys
                                 x . . . .  +Interupt after each cylinder
                                             format