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From: jbs@mit-eddie.MIT.EDU (Jeff Siegal)
Newsgroups: net.unix-wizards
Subject: Re: dz-11 on a VAX-11/750 at 19,200 baud.
Message-ID: <1230@mit-eddie.MIT.EDU>
Date: Sun, 9-Mar-86 04:01:30 EST
Article-I.D.: mit-eddi.1230
Posted: Sun Mar  9 04:01:30 1986
Date-Received: Mon, 10-Mar-86 20:17:45 EST
References: <1577@brl-smoke.ARPA> <1614@brl-smoke.ARPA>
Reply-To: jbs@eddie.UUCP (Jeff Siegal)
Organization: MIT EECS Dept.
Lines: 27

In article <1614@brl-smoke.ARPA> gwyn@brl.ARPA writes:

>The first paragraph makes it apparent that you have not enabled DC3/DC1
>flow control.  As you overrun the terminal's buffer, it will keep
>sending DC3s to the host to try to get it to stall.  These are probably
>filling up the DZ11 silo faster than the host is able to empty it.  If
>the DZ11 device driver relies on input silo alarm rather than per-
>character interrupt with short-circuit lookahead before RTI, then there
>is not much safety margin.
>
>If you enable flow control, the problem should go away.

Nope.  I intentionally did not enable flow control on the VAX, because
in order to have functional ^S and ^Q keys, flow control must be off
on the terminal (yes, I know this is a misfeature).  I can't disable
the ^S and ^Q keys (as turning on flow control would do) since we need
them for Emacs.  In other words, the terminal is NOT sending DC3's at
all (unless I press ^S).

I can't figure out why the dz-11 thinks data is being sent to it;
sounds like a Unix bug to me.

BTW: Does anyone know if I can set up hardware flow control (DSR/DTR)
with this equipment?

Jeff Siegal - MIT EECS