Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!uunet!jwt!john
From: john@jwt.UUCP (John Temples)
Newsgroups: comp.dcom.modems
Subject: Re: AT I/O card with 16550, available
Message-ID: <1991Apr17.010953.10578@jwt.UUCP>
Date: 17 Apr 91 01:09:53 GMT
References: <1991Apr9.145116.5205@jwt.UUCP> <0ZB0Z2w163w@aegis.or.jp> <1991Apr14.215409.16152@limbic.ssdl.com>
Organization: Private System -- Orlando, FL
Lines: 44

In article <1991Apr14.215409.16152@limbic.ssdl.com> gil@limbic.ssdl.com (Gil Kloepfer Jr.) writes:
>The board worked flawlessly with the National parts.  When swapped
>out with WD16550s, I noticed failed connections.  On an attached
>terminal, it appeared that parts of text from previous lines were
>re-appearing in text of later lines.

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)