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From: dj@ctron.com (DJ Delorie)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Anyone have experience using a Uart in loopback mode.
Message-ID: <1441@balrog.ctron.com>
Date: 24 Apr 91 14:29:21 GMT
References: <14466@ccncsu.ColoState.EDU>
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In article <14466@ccncsu.ColoState.EDU>, barbourj@mozart.cs.colostate.edu (jim barbour) writes:
> 
> I have need to simulate a loopback plug connected to my serial port.  Its
> for writing and testing some transport protocols.
> 
> I've figured out how to put my serial port in LoopBack mode, but it will not
> respond once I've done so.
> 

Watch out for this bug - when in loopback mode, you will NOT get the
(transmit or receive, I don't remember) interrupt anymore.  You will
get the other one.  It's far easier and better to get a connector and
connect pins 2 & 3 together, and have a real loopback connector.  If
this isn't feasible, you'll have to adjust the software to compensate
for this bug.

DJ
dj@ctron.com