Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!umich!sharkey!tygra!mich-ns!tech
From: tech@mich-ns.UUCP (Mich. Network Sys. TECH SUPPORT)
Newsgroups: comp.dcom.modems
Subject: Re: AT I/O card with 16550, available
Message-ID: <26@mich-ns.UUCP>
Date: 24 Apr 91 22:40:26 GMT
References: <0ZB0Z2w163w@aegis.or.jp> <1991Apr14.215409.16152@limbic.ssdl.com> <1991Apr17.010953.10578@jwt.UUCP>
Reply-To: tech@.UUCP (PUT YOUR NAME HERE)
Organization: Michigan Network Systems, Detroit, MI
Lines: 46

In article <1991Apr17.010953.10578@jwt.UUCP> john@jwt.UUCP (John Temples) writes:
"In article <1991Apr14.215409.16152@limbic.ssdl.com> gil@limbic.ssdl.com (Gil Kloepfer Jr.) writes:
"It certainly sounds like the WD parts were at fault.  Here are my
"experiences with them:
"
"I've got a DigiBoard DigiCHANNEL PC/4 (dumb four port) with an NS chip
"on one port connected to a TB+ at 19200 bps, and a WD chip on another
"port connected to a Wyse terminal at 38400 bps, with the other two (unused)
"ports having WD chips.  This is running under ESIX.
"
"The modem has never exhibited any problems.  I've seen two problems
"with the terminal.  First, when running emacs, if a cursor key is held
"down, emacs will pop up a "Command:" prompt every 10-15 seconds.  So,
"somehow, emacs was seeing either an ESC-x or an ('x' | 0x80) when being
"sent one of ^K, ^L, ^H, or ^J at high speed.  Second, it was not
"possible to exit from WordPerfect 4.2 (UNIX version).  After sending
"the exit command, you would be left with a hung terminal, and an
"unkillable shell attached to it.
"
"These problems were experienced with the ESIX-supplied serial drivers.
"Now, since I had an NS-equipped port on my serial board, it was a
"simple matter of switching cables to see if the WD chips were at fault.
"They weren't.  Both problems persisted.
"
"So then FAS 2.07 came along.  I installed it, and the problems
"remained.  And now I had random hung processes cropping up, so I got
"rid of FAS.  The author then announced problems with 2.07 which could
"cause hung processes.
"
"When FAS 2.08 came out, I thought I'd give it another try, as the hung
"process bug was supposed to be fixed.  Lo and behold, the hung
"processes bug was fixed, and so were my other two problems.
"WordPerfect and emacs now work perfectly.
"
"I don't know what the moral of this story is, but I would have to
"speculate that both the ESIX and FAS 2.07 asy drivers are buggy, and
"that whatever might be wrong with WD 16550 chips, my usage of them
"doesn't bring its problems out.
"-- 
"John W. Temples -- john@jwt.UUCP (uunet!jwt!john)

No matter how good you think 16550's are, when you use a DTE speed of 
38.4kbps or above, you can end up with problems.  Best bet is to get
an intelligent board like the PC/4e, which is only $528. Its worth
the extra $150 to alleviate the headaches.

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