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)