Re: [PATCH -ac] Panicking in morse code

Jens Schmidt (j.schmidt@paradise.net.nz)
Sat, 27 Jul 2002 11:25:02 +1200


Hi to all,
I am not a "morse" guy myself, but appreciate this idea.
Here is what I dug out, (Google and my handbooks)

International Morse Code

Letter Morse Letter Morse Digit Morse
A .- N -. 0 -----
B -... O --- 1 .----
C -.-. P .--. 2 ..---
D -.. Q --.- 3 ...--
E . R .-. 4 ....-
F ..-. S ... 5 .....
G --. T - 6 -....
H .... U ..- 7 --...
I .. V ...- 8 ---..
J .--- W .-- 9 ----.
K -.- X -..-
L .-.. Y -.--
M -- Z --..

Punctuation Mark Morse
Full-stop (period) .-.-.-
Comma --..--
Question mark (query) ..--..
Hyphen (-) -....-
Fraction bar (/) -..-.
Double dash (=) -...-

(less common)
Brackets (parentheses) -.--.-
Quotation marks .-..-.
Colon ---...
Apostrophe .----.

Procedure codes
Commence transmission -.-.- (CT)
Wait .-... (AS)
End of message .-.-. (AR)
End of work ...-.- (SK)
The procedure codes are sent as a single character

If the duration of a dot is taken to be one unit then
that of a dash is three units.
The space between the components of one character is one
unit, between characters is three units and between
words seven units.
To indicate that a mistake has been made and for the
receiver to delete the last word send ........ (eight dots).

Regards (73) Jens ZL2TJT

"Richard B. Johnson" wrote:

> On Fri, 26 Jul 2002, Bill Davidsen wrote:
>
> > On Fri, 26 Jul 2002, Daniel Phillips wrote:
> >
> > > On Thursday 25 July 2002 14:51, Bill Davidsen wrote:
> > > > On Fri, 19 Jul 2002, Alan Cox wrote:
> > > >
> > > > > > +static const char * morse[] = {
> > > > > > + ".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", /* A-H */
> > [...snip...]
> > > > >
> > > > > How about using bitmasks here. Say top five bits being the length, lower
> > > > > 5 bits being 1 for dash 0 for dit ?
> > > >
> > > > ??? If the length is 1..5 I suspect you could use the top two bits and fit
> > > > the whole thing in a byte. But since bytes work well, use the top three
> > > > bits for length without the one bit offset. Still a big win over strings,
> > > > although a LOT harder to get right by eye.
> > >
> > > Please read back through the thread and see how 255 different 7 bit codes
> > > complete with lengths can be packed into 8 bits.
> >
> > ???
> > 1 - there are not 255 different 7 bit values, there are 128
> > 2 - morse code has a longest value of 5 elements not 7
>
> The '.' (also called full-stop) is 6 elements long. The ',' is also
> 6 elements long. For a correct implimentation, i.e., one that sounds
> correct, you need to encode a 'pause' element into each symbol. This
> is because the pause between Morse characters is sometimes ahead
> of a character and sometimes behind a character (the pause is ahead
> of characters starting with a dot and after characters ending with a
> dot, including characters of all dots -- except for numbers, which
> have pauses after them). In a previously life, I had to develop
> the correct "fist" to pass the Socond Class Radio Telegraph License.
>
> This means that it is probably best to use one 8-byte character
> for each Morse-code character.
>
> If anybody's interested I have some DOS assembly circa 1987 that
> did this stuff. It ignored the correct "fist", and has spaces after
> each character. It doesn't sound too bad.
>
> > 3 - Alan was talking about len+val representation, not stop-bit patterns,
> > which is what I guess you mean
>
> Cheers,
> Dick Johnson
> Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).
> The US military has given us many words, FUBAR, SNAFU, now ENRON.
> Yes, top management were graduates of West Point and Annapolis.
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/