This information applies to both Microsoft DoubleSpace and Microsoft
DriveSpace. For MS-DOS 6.22, use DRVSPACE in place of DBLSPACE for commands
The MS-DOS ability to access hard drives is based on the standard AT ROM
BIOS interface maximum of 1024 cylinders. DMDRVR.BIN and SSTOR.SYS have the
ability to work around the 1024 cylinder limit. The drivers are provided
with the MS-DOS 5 and later Upgrade packages as a convenience, and are
designed to replace existing drivers.
If you use Ontrack Disk Manager, instructions on how to update the
driver can be found in section 2.4 of the MS-DOS 5.0 README.TXT file.
MS-DOS 5.0 is compatible with DMDRVR.BIN versions 4.xx. According
to Ontrack Computer Systems, the version 5.0 driver provided with
MS-DOS 5.0 is derived from the original DMDRVR.BIN version 4.2.
If you use HARDRIVE.SYS, instructions on how to update the driver to
SSTOR.SYS can be found in section 2.5 of the MS-DOS 5.0 README.TXT
file. For MS-DOS 6 and 6.2 instructions, refer to "Setup displays the
'Incompatible hard disk or device driver.' screen" on page 188 of the
"Microsoft MS-DOS User's Guide" for versions 6.x.
Please note the following:
• If you use these drivers, your hard drive does not necessarily
have to have more than 1024 cylinders.
• DMDRVR.BIN and SSTOR.SYS serve the same purpose. DO NOT LOAD both
of the drivers simultaneously. If you have an earlier version of
DMDRVR.BIN, expand the new DMDRVR.BIN to the same location; if you
have HARDRIVE.SYS, expand SSTOR.SYS to the same location.
• It is recommended that you back up the old version of the drivers
to a floppy disk before replacing them.
• DMDRVR.BIN and SSTOR.SYS are provided only with the MS-DOS 5, 6,
and 6.2 Upgrades, not with the OEM (original equipment manufacturer)
For more information on the MS-DOS cylinder limitation, query on the
1024 cylinder limit workarounds
DMDRVR.BIN/Disk Manager is a product of Ontrack Computer Systems.
SSTOR.SYS is a product of Storage Dimensions, Inc.
The products included here are manufactured by vendors independent of
Microsoft; we make no warranty, implied or otherwise, regarding these
products' performance or reliability.