Date:	Wed, 14 May 1997 16:21:55 +0100
From:	Matthias Paul <PAUL-MA AT reze-1 DOT rz DOT rwth-aachen DOT de>
Subject:	Re: some stuff
To:	opendos AT delorie DOT com
Reply-to:	Matthias DOT Paul AT post DOT rwth-aachen DOT de
Message-id:	<B007B92EDF@reze-1.rz.rwth-aachen.de>
Organization:	Rechenzentrum RWTH Aachen

On Mon, 12 May 1997, Matt Adam wrote:

> there is one other thing that desperately needs to be fixed with the
> opendos multitasking.  this is the slight problem it has when dealing
> with comm ports.  does it not handle the interrupt vectors properly or
> something?  i tried looking for any type of pertinant data in the source
> code but my C and assembly skills leave a lot to be desired.  

Did you actually have a look into the source code of EMM386 and 
TASKMGR yet?  I thought, we would still have to wait for it... ;-)

The problem TASKMGR has with COM port virtualization is known, 
and some months ago Roger Gross said in the official mailing 
list, they were working on that issue.  At that time, Fran Berry 
(hey, still around??? ;-) had some useful tips and tricks, fiddling 
with the TASKMGR.INI settings, that may help on some systems.  
A discussion of the necessary options can also be found in 
NWDOSTIP.TXT from my MPDOSTIP.ZIP.  IMHO, it should be possible 
to write a seperate COM-port VxD-driver (.386) for better 
virtualization of the comm ports (TASKMGR allows for installing 
VxD-drivers). 

Since you used different machines, your IRQ selections for the 
COM-ports might also cause the problems.  Normally, they should 
not interfere with IRQs, used by other COM-ports or hardware...  
However, using Novell DOS in 1996, I had no problems with COM-ports 
(no FIFOs, four ports with shared IRQs 4 and 3) on my good old 
386sx18 under the multitasking TASKMGR, using a serial mouse at 
1200Bd, and two 9600Bd connections to other machines.  Don't know,
why it worked (except for TASKMGR.INI settings), but it did...

Bye,

 Matthias

 
Errata:

Some days ago, when speaking of DEVICEHIGH options /L, /S, and 
SIZE=, I made a mistake:  The syntax should have been: SIZE=hexsize,
not /SIZE=hexsize.

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