qa.hlp (Table of Contents; Topic list)
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documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.
Int 21H Function 1CH
   Summary  Notes  Back
──────────────────────────────────────────────────────────────────────────────
 
  Description:  Get Drive Data
 
  Obtains allocation information about the specified disk drive and a
  pointer to the media identification byte from its file allocation table.
 
  Input                     Output
  ══════════════            ══════════════════════════════════════════════
  AH=1CH                    If function successful
  DL=drive code             AL=sectors per cluster
     (0=default,            DS:BX=segment:offset of media ID byte
     1=A, etc.)             CX=size of physical sector (bytes)
                            DX=number of clusters for default or specified
                               drive
                            If function unsuccessful (invalid drive or
                             critical error)
                            AL=FFH
                                    -♦-