HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens

       INT 21,32 - Get Pointer to Drive Parameter Table (Undocumented)

       AH = 32h
       DL = drive (0=default, 1=A:, 2=B:, 3=C:, ...)

       on return:
       AL =  FF if the drive number in DL was invalid
       DS:BX = address of drive parameter table (DPT)

       - available since DOS 2.0
       - used by DOS commands CHKDSK and RECOVER
       - forces a media check, which clears byte DS:[BX+17h] or DS:[BX+18h]
         in the Drive Parameter Table
       - actually accesses the disk, causing a critical error if a disk
         error occurs
       - can be used to determine if a drive is SUBST'ed by comparing
         DS:[BX+1] and DS:[BX] for a match.  If not equal, then the
         drive is possibly SUBST'ed (though not guaranteed, this may also
         indicate a Bernoulli box)
       - can be used to determine if a drive is a RAM disk; if the disk is
         NOT removable and (DS:[BX+1] == 0), then the disk is a RAM disk
         (see IOCTL,0 bit number 0Bh to determine if the disk is removable)

Esc or Alt-X to exit int 21,32 Home/PgUp/PgDn/End ←↑↓→
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