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Path: utzoo!mnetor!seismo!rochester!ur-tut!ur-valhalla!micropen!dave
From: dave@micropen (David F. Carlson)
Newsgroups: comp.unix.wizards
Subject: cu (call up) SYS V.2 corruption
Message-ID: <164@micropen>
Date: Mon, 16-Mar-87 10:39:53 EST
Article-I.D.: micropen.164
Posted: Mon Mar 16 10:39:53 1987
Date-Received: Wed, 18-Mar-87 06:37:47 EST
Organization: Micropen Direct Writing Systems, Pittsford, NY
Lines: 25
Keywords: interrupt rate  data corruption

I am runnning some dumb (as in no DMA etc) serial boards on my
SYS V.2 box (Microport on an AT clone with Digicom/8 port boards).
I have a phenomenon which I cannot explain.  Guesses anyone?

Description:
	When there is a high rate of interrupts (UUCICO running) the
	cu(1) between one machine and another identical machine has doubled
	characters, missing characters and garbled characters.  The
	cu line has no parity enabled so overruns and other interrupt
	related problems are immediately suspect.  However, none of the
	other 4 terminals on the same board experience any problems.  They
	are running in full duplex, as is the cu session.  Also, any uucp
	between the two machines during this period is munged too, so it
	is not the cu session, but the serial board to serial board connection
	that is suspect.  Why do only machine to machine connections fail?
	(Assume correctly that the other machine is totally idle with no other
	interrupt traffic.)  Any guesses are appreciated.  Flames to buy
	a "real" computer or ya68kub to /dev/null.


-- 
David F. Carlson, Micropen, Inc.
...!{seismo}!rochester!ur-valhalla!micropen!dave

"The faster I go, the behinder I get." --Lewis Carroll