Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/5/84; site teneron.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!mtuxo!mtunh!mtung!mtunf!ariel!vax135!cornell!uw-beaver!tektronix!reed!nsc-pdc!teneron!joey
From: joey@teneron.UUCP (Joey Pruett)
Newsgroups: net.dcom
Subject: Asynchronous data slippage
Message-ID: <183@teneron.UUCP>
Date: Mon, 24-Jun-85 15:27:40 EDT
Article-I.D.: teneron.183
Posted: Mon Jun 24 15:27:40 1985
Date-Received: Thu, 27-Jun-85 07:58:34 EDT
Reply-To: joey@teneron.UUCP (Joey Pruett)
Organization: Teneron Corp., Beaverton, OR
Lines: 28
Summary: 

Hollow:

	I am currently working on a device that sits between a modem
(DCE) and a terminal/computer (DTE) and processes the data going in
both directions.  The problem I am experiencing is characters being
dropped from the data stream when sending continuous data (at any baud
rate).  I placed the UARTs I am using (Signetics 2661) into remote
loopback mode (the incoming data is immediately transferred from the
reciever shift register into the transmitter holding register) and
discovered the same problem.  I think I have tracked the source to a
baud rate clock that is slightly slow (about 0.006% off), but everybody
indicates that asynchronous communications have tolerances around
0.5%.  With continuous data coming into the device at 9600 baud, the
output will drop one character approximately every 3.8 seconds.

	Does anybody out there have any ideas or suggestions for what
I can do about this problem?  Is it a problem at all, or does all
async communication have this problem?

	Any and all comments appreciated,

	Joe Pruett
	Teneron Corporation
	6700 SW 105th
	Suite 200
	Beaverton, Oregon
		97005
	(503)646-1599