Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

   ◄Summary►  ◄Notes►  ◄Back►
──────────────────────────────────────────────────────────────────────────────
 
  Description:  Absolute Disk Read
 
  Provides a direct linkage to the MS-DOS BIOS module to read data from a
  logical disk sector into memory.
 
  Input                                     Output
  ══════════════════════════════            ══════════════════════════════
  For access to partitions                  If function successful
   <= 32 MB                                 Carry flag=set
  AL=drive number (0=A, 1=B,                If function unsuccessful
   etc.)                                    Carry flag=set
  CX=number of sectors to read              AX=error code (see Notes)
  DX=starting sector number
  DS:BX=segment:offset of buffer
  For access to partitions
   > 32 MB (MS-DOS 4.0 and later)
  AL=drive number (0=A, 1=B,
   etc.)
  CX=-1
  DS:BX=segment:offset of para-
   meter block (see Notes)
                                    -♦-