Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 (Tek) 9/28/84 based on 9/17/84; site motel6.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!decwrl!pyramid!hplabs!tektronix!reed!motel6!keith
From: keith@motel6.UUCP (Keith Packard)
Newsgroups: net.bugs.uucp,net.bugs.2bsd
Subject: uucp problems solved with hardware
Message-ID: <201@motel6.UUCP>
Date: Wed, 19-Mar-86 00:25:02 EST
Article-I.D.: motel6.201
Posted: Wed Mar 19 00:25:02 1986
Date-Received: Sat, 22-Mar-86 05:02:19 EST
Distribution: net
Organization: 5440 SE 41st, Portland, OR
Lines: 22
Xref: watmath net.bugs.uucp:719 net.bugs.2bsd:356

To recap, I was having problems with uucp running on my PDP11/73 timing out
when receiving data at 1200 baud from a vax running ultrix.

The problem was identified as overrun errors in the dlv11-e card that
I had attached to my modem, this card has no buffering for data at
all.  Overrun errors were occuring because 2.9BSD spends too much time
at high priority handling disk i/o.  I find it difficult to understand
how it spends over 1/120 of a second at high spl handling such simple
activity but it is the case.

The solution I used was to get a dzv11.  This solved the problem completely
because it has a 16 character input silo which doesn't overflow.

If anyone cares, I modified the dz11 driver to support dzv11 cards
(which have only 4 ports per board) as well as make it support 
dialin and dialout on the same port (with correct interlocking).  I
realize that the original dz driver supported a device class that
ignored carrier, my hacks are suitable for sites which want to use
a given line for *both* dialin and dialout.

Keith Packard
...!tektronix!reed!motel6!keith