INT 2fH 4a11H BX=0007H: Get Dblspace Disk Size / Free Space
Compatibility: 6.0+
Expects: AX 4a11H (mux number)
BX 0007H (DoubleSpace fn code)
DL compressed drive to query
──────────────────────────────────────────────────────────────────
Returns: AX DoubleSpace API Error Code (0000H = success)
DS:SI address of DsSpaceInfoRec (see below)
──────────────────────────────────────────────────────────────────
Info: This obtains the true total space and free space available in the
specified volume.
Note: the newer (6.2) DS IOCTL 'S' function is the preferred
method of obtaining this information.
DS:SI on return, DS:SI points to the following data structure:
DsSpaceInfoRec
Offset Size Contents
▀▀▀▀▀▀ ▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
+0 4 lTotSects total data sectors in the disk
+4 4 lFreeSects available sectors in the disk
8 size of a DsSpaceInfoRec (undocumented)
Notes: ■ This changes DS, pointing it into DBLSPACE.BIN local data area.
So take notice (and change it back to point to your local data
area after this call).
■ The return values in lTotSects and lFreeSects are expressed in
512-byte sectors.
■ The maximum physical size of a DoubleSpace compressed volume
is 512 MB. Thus, the largest value you can expect returned in
lTotSects is 1,048,576 (0010 0000H) sectors.
■ Use DOS fn 36H to obtain the estimated storage for the drive.
■ The documented API does not provide an estimated compression
ratio, but you can derive it by comparing lTotSects to the
value obtained from DOS fn 36H.
See Also: DoubleSpace Overview
DS IOCTL 'S' (Get DriveSpace Pointers)
DoubleSpace API
INT 2fH: Multiplex Interrupt
DOS Functions
-♦-