From: "Matthias Paul" <MPAUL AT ibh DOT rwth-aachen DOT de>
Organization:  IBH, RWTH-Aachen
To: opendos AT delorie DOT com
Date:          Thu, 17 Apr 1997 19:11:56 GMT+0100
Subject:       Re: Question regarding Opendos and Win#95
Reply-to: Matthias DOT Paul AT post DOT rwth-aachen DOT de
Message-ID: <13F290648C9@ibh.rwth-aachen.de>
Precedence: bulk

On Thu, 17 Apr 1997 Evan Dickinson wrote:

> Using dconfig.sys works, OpenDOS won't execute config.sys after
> dconfig.sys.  You can't, however, chain to a batch file from 
> config.sys. OpenDOS thinks the batch file is supposed to be part 
> of config.sys.  So you still need the 'if "%config%" ...' line in 
> autoexec.bat.

My following comments will go a bit beyond the original topic of Win95 
and OpenDOS, but I still hope, they might be interesting to some 
of you, when trying to have multiple OS installed on the same drive...

You can give the name of the actual AUTOEXEC.BAT file 
with the CONFIG.SYS SHELL= directive using /P[:autoexec.bat] 
or /K:autoexec.bat, depending on what you want to do..., e.g.

 SHELL=c:\opendos\command.com /P:auto_od.bat

Also, batchfiles can be executed as part of CONFIG.SYS when 
temporary loading a command processor using 

 INSTALL=c:\opendos\command.com /c batchjob.bat
 
However, this method has a design flaw, causing the pre-environment 
to be 'closed', that is, no more pre-environment variables can be
set, and later - when loading the permanent command shell - the 
pre-environment is empty.  Using 4DOS as a temporary command 
interpreter instead of COMMAND.COM will avoid this problem.

After all, a major problem is two (or more) operating systems trying 
to use the same configuration files CONFIG.SYS and AUTOEXEC.BAT.  
Fortunately, since DR DOS 6.0 the DRI crew had already implemented 
a very nice but undocumented workaround (and it's still present in 
Novell DOS 7 and OpenDOS 7.01 :-) ):

The SYS utility has an undocumented option /DR:ext.  

Using this option, you can change the filename extension of 
the system and configuration files from their defaults to "ext". 
While making the media bootable, SYS also patches the boot sector 
and system files to use the new extension.  This feature was probably 
introduced to allow coexistence of PC-DOS and DR DOS 6.0, since they 
used the same system file names.  But you can also have multiple 
copies of DR DOS 6.0, Novell DOS (e.g. all the updates), and OpenDOS 
simultanously installed on the same drive (selectable by a boot 
manager like LOADER etc.), and each using its own system and 
configuration files.  Extensions could be for example "DR6", 
"NW7", "U01", "U02", ... "U15", "OD7", ...  

To better understand what will actually happen to the files just try:

 c:\>SYS a: /DR:od7
 
and after this, have a look at the filenames on that drive... ;-)

Hope this could help a little,

 Matthias
 
PS: More info on this topic can be found in NWDOSTIP.TXT 
    (from MPDOSTIP.ZIP).




------------------------------------------------------------------
 Matthias Paul     ! My eMail address has changed. For some time !
 Ubierstrasse 28   ! mails to former <MPaul AT ibh DOT rwth-aachen DOT de>  !
 D-50321 BRUEHL    ! will be forwarded to the new address.       !
 eMail: <Matthias DOT Paul AT post DOT rwth-aachen DOT de>                       
 WWW  : URL: http://www.rhrz.uni-bonn.de/~uzs180/mpdokeng.html    
------------------------------------------------------------------