NOVELL TECHNICAL INFORMATION DOCUMENT

DOCUMENT PROCESSING INFO:  THIS DOCUENT REPLACES FYI-M-1600
TITLE:  DR DOS & DOS VERSION NUMBERS
DOCUMENT ID:  TID800051
DOCUMENT REVISION:  A
DATE:  17AUG94
AUTHOR:  CEREKSON;DPARTRID
ALERT STATUS:  Yellow
DISTRIBUTION:  Public
INFORMATION TYPE:  Symptom Solution
README FOR:  NA
NOVELL PRODUCT CLASS:

Desktop Products

NOVELL PRODUCT and VERSION:

DR DOS 6.0

CATEGORY:

Kernel

ABSTRACT:

N/A

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SYMPTOM

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

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.

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