misc.morse-code.rme

#2018#02#03 #secret #codes #security #morse #communication #message #telegraph
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..                                 MORSE CODE                                 ..
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>==================================
"~~> WHO/WHAT/WHEN/WHERE/WHY/HOW ?"
==================================<
   Morse code is a method of transmitting text information as a series of on-off
 tones, lights, or clicks that can be directly understood by a skilled person
 receiving the transmission. It is named after Samuel F.B. Morse, the inventor
 of the telegraph.


>======================================
"~~> INTERNATIONAL MORSE CODE ELEMENTS"
======================================<
 International Morse code is composed of five elements:
   1. short mark, dot or 'dit' ( . ): 'dot duration' is one time unit long
   2. longer mark, dash or 'dah' ( ... or - ): three time units long
   3. inter-element gap between the dots and dashes within a character: one unit
   4. short gap (between letters): three time units long
   5. medium gap (between words): seven time units long

 Since Morse code only requires two states (on/off), we can use binary:
   1. short mark, dot or 'dit' ( . ): 1
   2. longer mark, dash or 'dah' ( ... or - ): 111
   3. intra-character gap (between dots and dashes within character): 0
   4. short gap (between letters): 000
   5. medium gap (between words): 0000000

(Note that the structure dictates alternation because dits/dahs are always
 separated by one of the gaps and gaps are always separated by a dit or dah.)

   Morse messages are generally transmitted by a hand-operated device (e.g. a
 telegraph key) so there are variations introduced by the skill of the sender &
 receiver -- more experienced operators can send/receive at faster speeds. In
 addition, individual operators differ slightly; for example, using slightly
 longer or shorter dashes or gaps, perhaps only for certain characters. This is
 called their "fist"(JARGON), and experienced operators can recognize specific
 individuals by it alone. An operator with a "good fist" sends clearly and is
 easy to copy; conversely those with a "bad fist" is sloppy and hard to copy.


>===========
"~~> TIMING"
===========<
   Here is an example transmission of the phrase "MORSE CODE":
   ('-' represents dahs and '.' represents dits)

      -- --- .-. ... .       -.-. --- -.. .
      M   O   R   S  E        C    O   D  E

   With exact conventional timing:
   ('=' for 'signal on' and '.' for 'signal off'; ignore backslashes and spaces)

      ===.===...===.===.===...=.===.=...=.=.=...=.......\
      (  M  )   (    O    )   (  R  )   ( S )  (E)(SPACE)
                                 ===.=.===.=...===.===.===...===.=.=...=
                                 (    C    )   (    O    )   (  D  )  (E)



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..                                 ~ finis ~                                  ..
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