From: Thomas Demmer <demmer AT LSTM DOT Ruhr-UNI-Bochum DOT De>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: COM-Schnittstelle mit Streams ansprechen ?
Date: Thu, 28 Aug 1997 13:48:11 +0200
Organization: Lehrstuhl fuer Stroemungsmechanik
Lines: 51
Message-ID: <3405657B.4DB2F673@LSTM.Ruhr-UNI-Bochum.De>
References: <01bcb2f5$5e2d73e0$ab23e8c3 AT uk>
NNTP-Posting-Host: c64.lstm.ruhr-uni-bochum.de
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Precedence: bulk

Uwe Klatt wrote:
> 
> Hallo,
> 
> wie kann ich in "C" (GCC) eine COM-Schnittstelle mit Streams ansprechen ?
> Bisher habe ich folgendes versucht:
>  stream = fopen("COM2","a+b");
> 
> allerding funktioniert hier nur das Schreiben.
> Das Lesen klappt nicht !?
> 
> Wer kann mir da einen Tip geben ?
> 
> (Unter LINUX mit dem GCC klappts !!!???)
> 
> Tschau
> Uwe
This is an English speaking news group, so it is at least
unpolite to write in a different language. And it'll cut
down the number of people able and willing to answer. 

The problem is that the usual BIOS does not handle reading
properly (i.e. Interrupt-driven), so simply opening
the device under plain DOS will get you nowhere. 

The cure is either to find/buy/steal/write a good device driver
on OS level that allows doing what you want.

Or take Bill Curie's BCSERIO.ZIP and use the low-level access
functions. 

Or add a layer using the __FSEXT* and bcserio for getting 
unix-like behavior. See 
ftp://ftp.lstm.ruhr-uni-bochum.de/pub/djgpp/bcserio.[ch]
for an example how use that stuff (Beware: It was wor djgpp2.0,
so some of the code won't act under 2.01 as it should)

-- 
Ciao
Tom

*************************************************************
* Thomas Demmer                                             *
* Lehrstuhl fuer Stroemungsmechanik                         *
* Ruhr-Uni-Bochum                                           *
* Universitaetsstr. 150                                     *
* D-44780  Bochum                                           *
* Tel: +49 234 700 6434                                     *
* Fax: +49 234 709 4162                                     *
* http://www.lstm.ruhr-uni-bochum.de/~demmer                *
*************************************************************