Date: Wed, 16 Jun 1999 13:11:17 +0100
From: Matthias Paul <PAUL-MA AT reze-1 DOT rz DOT rwth-aachen DOT de>
Subject: Re: Again about NTFS problem.
To: opendos AT delorie DOT com
Message-id: <125D1980A2D@reze-1.rz.rwth-aachen.de>
Organization: Rechenzentrum RWTH Aachen
X-Mailer: Pegasus Mail v3.22
Reply-To: opendos AT delorie DOT com

On Tue, 15 Jun 1999 Pavel V. Ozerski wrote:

[PC DOS HIMEM.SYS]
> I understand that HIMEM.SYS bug is very important but I would remember 
> about an another problem.

Well, actually it appears to be a MS-DOS/PC DOS HIMEM.SYS problem, 
not a DR-DOS problem. However, to ensure maximum file-by-file 
compatibility, I too think it would be convenient to improve the 
coexistance again.

[NTFSDOS]
> The answer of one from two authors of this TSR, Mark Russinovich, is
> "You failed to read the requirements: NTFSDOS Requires MS DOS 5 or 
> higher". 

Well, this answer does not sound very encouraging. 

> My question: what are these differences? If DR-DOS does not understand 
> some DOS API functions or interrupts, I think, there are no 
> problems to write a small driver or TSR to make the interface 
> between NTFSDOS and DR-DOS.

DR-DOS 7 emulation of MS-DOS 6 is very very close, even most of the
undocumented stuff is similar. I would expect the differences to be 
in the usual range of differences between DOS versions, even between 
different issues of MS-DOS itself.
 
I haven t used NTFSDOS myself, but I don t think there are any 
fundamental differences that would make it impossible to adapt 
NTFSDOS to run smooth on DR-DOS. From my experience debugging alot 
of other drivers that didn t run on DR-DOS in the first place, 
I would think that almost probably anything that prevents NTFSDOS 
from running under DR-DOS could easily be seen as invalid assumptions 
on the underlaying OS. Fixing these issues not only enabled the 
software to run on DR-DOS, but also helped to make the software 
cleaner. So it should always be a duty to programmers to test their
software on DR-DOS, not only to actually support DR-DOS, but also
to improve their software for MS-DOS.
 
Anyway, if NTFSDOS aborts with something like "Invalid DOS version"
or "Cannot run on DR DOS.", I would try for example:

 SETVER NTFSDOS.EXE 6.128 /X
 
to emulate DOS 6.0, while disabling the DR-DOS BDOS version check
(under Novell DOS 7 and OpenDOS 7.01 try 6.255 instead.). 

If, however, it worked for example with Novell DOS 7, but no longer 
works with DR-DOS 7.02+ ("Cannot run on this issue of DR DOS"), you 
could try something like:

 SETVER NTFSDOS.EXE 6.114 /X
 
to cause DR-DOS 7.02+ to emulate DOS 6.0 and Novell DOS 7 (CPMVer=114=
72h=Novell DOS BDOS). This for example enables some HPFS drivers to
run on DR-DOS 7.02+. If these mascarade things do not help any 
further, it s time to start debugging. I guess, having the sources
of his driver, Mark Russinovich could do it in a couple of hours.

If, however, I would be wrong, and there would be major differences,
I would for sure like to learn about them. I would really like to look 
into this then...

 Matthias
 
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