Subject: Re: LEDs, LCDs and so on (was Re: More SPARCbook insanity )
To: None <tech-kern@NetBSD.org>
From: Alan Barrett <apb@cequrux.com>
List: tech-kern
Date: 04/19/2005 12:12:28
On Mon, 18 Apr 2005, maximum entropy wrote:
> Greywolf wrote:
> >[Thus spake Michael ("M: ") 7:50am...]
> >M:
> >M:                          `.'     becomes `_*'
> >M:                          `-'     becomes `_***'
> >M:                          ` '     becomes `__'
> >M:                          `\n'    becomes `____'

To interpret this, you also have to read the part of the FreeBSD led(4)
man page that explains that "_" means 0.1 seconds with LED off, and "*"
means 0.1 seconds with LED on.  It's unstated, but implied, that dot,
dash, space, and newline, are the only valid inputs to the morse code
interpreter.

> >Problem:
> >
> >It looks as though '.' will collide with 'n', '-' will collide with 'U',
> >space collides with 'M'.

No, if you want the morse code for "n", you sent "m-.", not "mn";
if you want the morse code for "U", you send "m..-", not "mU", etc.

> I think you mean "'-' will collide with 'B'"...
> 
> It's also kind of silly to try to make up stuff like this, when 
> International Morse Code already has equivalents for many punctuation 
> characters.

They are not making anything up.  You have to send you own dots and
dashes, not higher level characters.  Of course, this makes it less
useful, but they could easily add another layer, such that "Mabc" in the
hypothetical new layer meant the same as "m.- -... -.-." in the existing
layer.

--apb (Alan Barrett)