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From: touch@dsl.cis.upenn.edu (Joe Touch)
Newsgroups: sci.electronics,rec.ham-radio
Subject: Re: morse code
Message-ID: <34784@netnews.upenn.edu>
Date: 14 Dec 90 17:14:47 GMT
References: <1990Dec12.231058.23895@engin.umich.edu> <1990Dec14.012315.7858@zoo.toronto.edu> <1990Dec14.152659.8250@val.com>
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Reply-To: touch@dsl.cis.upenn.edu (Joe Touch)
Organization: University of Pennsylvania
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In article <1990Dec14.152659.8250@val.com> ben@val.com (Ben Thornton) writes:
>henry@zoo.toronto.edu (Henry Spencer) writes:
>I thought that CW *is* a digital mode. 
>
>BNF:
><tone> := true;
><silence> := false;
>

Depends on what you call digital.  Actually, time is part of the
BNF (dot = 3 * dash, etc).  Time is also quantized, so it is digital
in the true sense, just NOT binary.  The BNF would be:

dot := tone-for-dot-interval
no-dot := silence-for-dot-interval
dash := dot dot dot
intra-letter-space := no-dot
no-dash := no-dot no-dot no-dot
inter-letter-space := no-dash
? inter-wordspace := no-dash no-dash no-dash

I'm sure the space between dots and dashes is one dot time, and
the spaces between letters is one dash, and three dot times are
one dash time.  I'm not sure about the space between words, or
if there even is one defined (I think you may just parse the
letter stream into words by context alone).

Joe Touch
PhD Candidate
Dept of Computer and Information Science
Univ of Pennsylvania