                            FYI
Note:  The origin of this information may be internal or external
to Novell.  Novell makes every effort within its means to verify
this information.  However, the information provided in this
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          TITLE:  DR DOS & DOS VERSION NUMBERS
   DOCUMENT ID#:  FYI-M-1600
           DATE:  04JAN93
        PRODUCT:  DR DOS
PRODUCT VERSION:  6.0
     SUPERSEDES:

        SYMPTOM:  Applications that check the DOS version number  
                  do not indicate 6.0 but 3.31.

  ISSUE/PROBLEM: Device drivers for disk drives or networks are
sometimes produced for specific versions of DOS or occasionally
will use specific configurations for different versions of DOS.
When applications request the DOS version number from the
operating system (via INT 21), the DR DOS 6.0 operating system
returns 3.31. 

       SOLUTION: This seems as if DR DOS is trying to fool the
application into believing it is another OS. However, this is not
the case. The application needs to know that it should expect
support for DOS 3.3-level calls and disk support for greater than
32 MB partitions using the COMPAQ Extended Interrupt 25 and 26
convention. 

DR DOS must report 3.31 in order to give the application the
correct information it needs in order to work properly. Most DOS
applications use the 3.31 conventions mentioned above and
therefore work without any difficulty. This was one of the
reasons Digital Research decided to create DR DOS based on an
existing DOS format (3.31) rather than creating a new one (such
as 6.0).

Usually, a DOS 3.3 driver works properly. If you have been
running previously with MS/PC-DOS 4.x however, the driver that
you have been using might be designed specifically for version
4.x. This could also be true if the previous OS was MS-DOS 5.
Contact the manufacturer of the driver to see if they have any
specific configuration information or drivers for DOS 3.3x.

There are also some drivers that offer 3.3 disk support but not
3.31. The difference has to do with the capacity of the disk
drive. DOS 3.31 will support greater than 32 MB partitions while
3.3 only supports a maximum of 32MB. If your driver does not work
correctly on large (>32MB) partitions contact the manufacturer
and inquire if they have 3.31 compatible drivers.

Some applications have been designed to go beyond these
conventions and actually attempt to directly manipulate DOS data
structures or replace sections of the operating system code with
their own. These applications depend on having intimate knowledge
of each DOS version they detect and have been written to react
differently for each of those versions. 

If an application uses this type of technique, the manufacturer
will have to design the application to take DR DOS 6.0 into
account as well. While DR DOS does offer 3.31 support it's
structures and code are very different from COMPAQ 3.31. It is
possible that the manufacturer is aware of this and has already
produced another version of your application or driver that runs
under DR DOS. 

Contact the manufacturer to see if there is any information about
upgrades or specific configuration steps for the DR DOS 6.0
operating system. If the manufacturer is interested in more
information about the DR DOS 6.0 operating system, they are
welcome to contact Novell directly at (800) NETWARE.
