Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!bbn.com!sher
From: sher@bbn.com (Lawrence D. Sher)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: DOS not recognizing printer?
Message-ID: <63793@bbn.BBN.COM>
Date: 19 Apr 91 12:05:43 GMT
References: <1991Apr17.024321.13665@cs.ucla.edu>
Sender: news@bbn.com
Reply-To: sher@labs-n.bbn.com (Lawrence D. Sher)
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Organization: Bolt Beranek and Newman Inc., Cambridge MA
Lines: 20

In article <1991Apr17.024321.13665@cs.ucla.edu> chao@oahu.cs.ucla.edu (Chia-Chi Chao) writes:
>When the computer is booted up, does it check whether the printer is online and
>set a flag somewhere?  On my friend's computer (Epson Equity I) with HP LJIIP,
>Word Perfect 5.1 complains about the printer not being on (online?).  This
>happens when the printer is turned on AFTER the computer is booted up.  If we
>reboot the computer, or turn on the printer first, everything works fine.  

When I replaced an IBM AT Model 239 with a Dell System 310, I encountered this
exact problem.  I called Dell, and, very helpful as usual, they knew the
answer:  An isolation device in the cable to the printer is required.  It
consists of an "adapter plug" with a resistor in each line, around 120 ohms I
vaguely recall.  They sent me one for a modest fee, like $20.  It works.
I don't know any of the underlying details, nor do I know what such a
device is called.  But a "printer isolation adapter plug" would capture
the spirit of it.
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