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

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