Int 13 Fn 42  - Ibm/ms Int 13 Extensions - Extended Read                   [d]

   AH = 42h
   DL = drive number
   DS:SI -> disk address packet (see #0204)

Return: CF clear if successful
       AH = 00h
   CF set on error
       AH = error code (see #0166)
       disk address packet's block count field set to number of blocks
         successfully transferred

See Also: AH=02h,AH=41h"INT 13 Ext",AH=43h"INT 13 Ext"

Format of disk address packet:
Offset Size    Description (Table 0204)
 00h   BYTE    10h (size of packet)
 01h   BYTE    reserved (0)
 02h   WORD    number of blocks to transfer (max 007Fh for Phoenix EDD)
 04h   DWORD   -> transfer buffer
 08h   QWORD   starting absolute block number
       (for non-LBA devices, compute as
         (Cylinder*NumHeads + SelectedHead) * SectorPerTrack +
         SelectedSector - 1