HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens

                        INT 13,3 - Write Disk Sectors

       AH = 03
       AL = number of sectors to write  (1-128 dec.)
       CH = track/cylinder number  (0-1023 dec.)
       CL = sector number  (1-17 dec., see below)
       DH = head number  (0-15 dec.)
       DL = drive number (0=A:, 1=2nd floppy, 80h=drive 0, 81h=drive 1)
       ES:BX = pointer to buffer


       on return:
       AH = 0 if CF=0; otherwise disk status  (see INT 13,STATUS)
       AL = number of sectors written
       CF = 0 if successful
          = 1 if error


       - BIOS disk write attempts should reset the controller on error
       - be sure ES:BX does not cross a 64K segment boundary or a
         DMA boundary error will occur
       - IBM PC XT 286 does not require a value in AL, though it is
         recommended that one be supplied for portability
       - many programming references list only floppy disk register values
       - 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│5-0│  CX
          │ │ │ │ │ │ │ │ │ │  └─────  sector number
          │ │ │ │ │ │ │ │ └─┴───────  high order 2 bits of track/cylinder
          └─┴─┴─┴─┴─┴─┴─┴──────────  low order 8 bits of track/cyl number

       - see   INT 13,B

Esc or Alt-X to exit int 13,3 Home/PgUp/PgDn/End ←↑↓→