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Article #341

com port problem

#341
From: tjb
Date: Sun, 30 Aug 1992 00:28
54 lines
1871 bytes
Hi,
I have an Xt and a 386,
the XT is connected to a printer and a modem
the 386's COM2 is connected to the XT's COM1 through a null-modem
cable.
i want to be able to use the printer&modem from the 386
i can use the printer using a network program, but it's not compatible
with a lot of stuff, and takes up LOTS of memory.
i wanted to use the modem by writing a small C program that
makes the XT transfer COM1 to COM2 and COM2 to COM1
so that COM2(direct link to XT) on the 386 will function as a modem
  386               XT
 ---------      --------------
    COM2  ->   COM1  ->  COM2  ->  modem
    COM2  <-   COM1  <-  COM2  <-  modem

my program so far is:
---------------------------------------------------------
#include <conio.h>
#include <dos.h>
#undef inportb
#undef outportb
#define COM1 0x3f8
#define COM2 0x2f8
#define COM1S 0x3fd
#define COM2S 0x2fd
main()
{
    int com1,com1s,com2,com2s;
    while( !kbhit() )
    {
        com1s = inport( COM1S );
        if( com1s & 2)
        {
            com1 = inport( COM1 );
            outport( COM2, com1 );
            printf("got %d from com1\n",com1);
        }
        com2s = inport( COM2S );
        if( com2s & 2 )
        {
            com2 = inport( COM2 );
            outport( COM1, com2 );
            printf("got %d from com2\n",com2);
        }
    }
}
-----------------------------------------------------------
the program works if i type each letter twice slowly.
does anyone know how to make it work??
Thanks,
Omri Barak
Internet: barak@bguee.bgu.ac.il
Bitner  : barak@bguee
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Message-ID: <29AUG92.20284166@enh.nist.gov>
Path: arc1-ca.pugleaf.net!sparky!uunet!dove!enh.nist.gov!tjb

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Path: arc1-ca.pugleaf.net!sparky!uunet!dove!enh.nist.gov!tjb
From: tjb@enh.nist.gov
Newsgroups: alt.msdos.programmer
Subject: com port problem
Message-ID: <29AUG92.20284166@enh.nist.gov>
Date: 30 Aug 92 00:28:41 GMT
Sender: news@dove.nist.gov
Organization: NIST
Lines: 54