Newsgroups: comp.sys.ibm.pc.misc
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uupsi!rodan.acs.syr.edu!amichiel
From: amichiel@rodan.acs.syr.edu (Allen J Michielsen)
Subject: Re: printing via the serial port
Message-ID: <1991May22.150442.19424@rodan.acs.syr.edu>
Sender: amichiel@sunrise.acs.syr.edu
Organization: Syracuse University, Syracuse, NY
References: <91136.142619SASDDI@vm.sas.com> <91141.093332SASDDI@vm.sas.com> <53863@rphroy.UUCP>
Date: Wed, 22 May 91 15:04:42 GMT

In article <53863@rphroy.UUCP> rhaar@gmr.com writes:
>(text deleted .....)
>|>    MODE COM1:baud,parity,bits,stop-bits,P
>|>    MODE LPT1=COM1
>|> Unfortunately, it's not working.  The printer is set for 1200 baud,
>|>    ECHO hi > LPT1
>|> Nothing.  The printer stays quiet, and the system locks up until I....
>|> effect) and asks the ubiquitous question: Abort, Retry, Ignore?).

>You may well need a null modem. It sounds to me like you did... right. 
>You might want to get your hands on an RS232 "breakout" box
 
   DOS requires hardware handshaking when using the serial port as a generic
printer port.  This can be easily 'disabled' by 'enabling' the input all the
time. RTS pin 4 on a db25 & dtr pin 20 are output's which can be tied to
cts pin 5, dsr pin 6, & cd pin 8, & ri pin 22 as needed.  You should only
HAVE to connect either 4 or 20 to 5 &/or 6, but due to random variations
in how the serial port was cloned, it's common for it to be buggered up
by the mfg (so I included the other 2 pins to try also).

al


-- 
Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University
 InterNet: amichiel@rodan.acs.syr.edu  amichiel@sunrise.acs.syr.edu
 Bitnet: AMICHIEL@SUNRISE