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From: gordon@news.colorado.edu (GORDON ALLEN R)
Newsgroups: comp.lang.c
Subject: Re: Problem in opening COM1:
Keywords: msdos COM1 serial port
Message-ID: <gordon.667066564@tramp.Colorado.EDU>
Date: 20 Feb 91 16:16:04 GMT
References: <5205@vela.acs.oakland.edu>
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panguyen@vela.acs.oakland.edu (panguyen) writes:

>#include <stdio.h>
>main()
>{
>  fopen( "COM1", "r+" );
>  fprintf( "CHN %d \r", 3 );
>} 
>This will cough back at me with the following errors,	  

>   Write fault error writing device COM1
>   Abort, Retry, Ignore ?


You can refer to the following for help with serial communications:

The C Toolbox by Hunt, 1986
Supercharging C with Assembly Language by Chesley and Waite, 1987

C Asynch Manager software by Blaise Publ

There is another rather large volume on serial communications with C, but I
don't remember the name.  

Briefly, fopen() works for files not devices, as far as I know, in MS-DOS based
systems. 

-- 
Allen Gordon 
University of Colorado, Boulder
gordon@tramp.colorado.edu 
gordon_A@cubldr.colorado.edu
--
Allen Gordon 
University of Colorado, Boulder
gordon@tramp.colorado.edu 
gordon_A@cubldr.colorado.edu