INT 26h (38)             Absolute Disk Write

    Writes one or more sectors on a specified logical disk.

       On entry:      AL         Drive number (0=A, 1=B)
                      CX         Number of sectors to write
                      DX         Starting sector number
                      DS:DX      Address of sectors to write

       Returns:       AX         Error code (if CF is set; see below)
                      Flags      DOS leaves the flags on the stack

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    This interrupt reads one or more sectors from a disk drive, and is
    comparable to the service provided by the ROM BIOS in Interrupt 13h.

    See the descrition on INT 25h for the full details.