HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens

                   INT 13,A - Read Long Sector (XT & newer)

       AH = 0A
       AL = number of sectors  (1-121 dec.)
       CH = track number  (0-1023 dec., see below)
       CL = sector number  (1-17 dec., see below)
       DH = head number  (0-15 dec.)
       DL = fixed drive number  (80h=drive 0, 81h=drive 1)
       ES:BX = address of buffer


       on return:
       AH = status  (see INT 13,STATUS)
       AL = number of sectors actually transferred
       CF = 0 if successful
          = 1 if error


       - BIOS disk reads should be retried at least three times and the
         controller should be reset upon error detection
       - many good programming references indicate this function is only
         available on the AT, PS/2 and later systems, but all hard disk
         systems since the XT have this function available
       - reads regular data sectors (128-1024 bytes) with an additional
         4 byte ECC code included
       - a DMA boundary error will occur if the buffer at ES:BX crosses
         a 64K segment boundary
       - only the disk number is checked for validity
       - the parameters in CX change depending on the number of cylinders;
         the track/cylinder number is a 10 bit value taken from the 2 high
         order bits of CL and the 8 bits in CH (low order 8 bits of track):

         │F│E│D│C│B│A│9│8│7│6│5│4│3│2│1│0│  CX
          │ │ │ │ │ │ │ │ │ │ └─┴─┴─┴─┴─┴────  sector number
          │ │ │ │ │ │ │ │ └─┴────────────  high order 2 bits of track number
          └─┴─┴─┴─┴─┴─┴─┴────────────  low order 8 bits of track number

       - see   INT 13,2

Esc or Alt-X to exit int 13,a Home/PgUp/PgDn/End ←↑↓→