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From: phil@amd70.UUCP (Phil Ngai)
Newsgroups: net.micro
Subject: Re: modems and heat problems
Message-ID: <4545@amd70.UUCP>
Date: Wed, 25-Apr-84 01:11:31 EST
Article-I.D.: amd70.4545
Posted: Wed Apr 25 01:11:31 1984
Date-Received: Fri, 20-Apr-84 00:44:42 EST
References: <12282@sri-arpa.UUCP>
Organization: AMD, Santa Clara, CA
Lines: 18

Hmmm, we have two Hayes Smartmodem 1200s sitting in a Western Electric
modem rack with very poor air circulation (it's got a door on the
front and no fan) and NEVER had any trouble with them, heat related
or otherwise. We have passed many megabytes through them and logged
many hours of connection time.

I have seen some sleazy circuits which used baud rate clocks which were
a little bit off. As an example, one circuit was about 2% off. No problem,
right? The error adds up. With an average 10 bit character (1 start, 8
data, and 2 stop bits) the accumulated error at the last bit will be 20%.
If the other circuit were off 2% the other way, there'd be a system error
of 40%. It's acceptable, but not what I would call good engineering. It
does save the price of a crystal ($2).

I don't know what your interface board uses, but it seems more likely a
cause of the problem than the Hayes.
-- 
Phil Ngai (408) 988-7777 {ucbvax,decwrl,ihnp4,allegra,intelca}!amd70!phil