> On Sep 12, 2017, at 4:06 AM, Rob Doyle via cctalk <cctalk@classiccmp.org>
> wrote:
>
> On 9/11/2017 8:35 PM, Fred Cisin via cctalk wrote:
>> Etaoin Shrdlu was most importantly one of Walt Kelly's characters in Pogo.
>> ETAOIN SHRDLU ETA name
>> On Mon, 11 Sep 2017, Chris Elmquist via cctalk wrote:
>>> I was told that the name came from this string which could be found in
>>> printed works and that people had always seen it but just read past it
>>> because it didn't fit or make sense.
>> That is canonically "loren ipsum", the filler "greeking" text used to set up
>> layout.
>> Although admittedly ETAOIN SHRDLU was also sometimes used for greeking.
>> ETAOIN SHRDLU
>> is one of the common versions of the list of the relative frequency of
>> letter in English language text.
>> 'e' is the most common letter
>> 't' is the next most common letter
>> 'a' is the third most common letter, etc.
>
> That's interesting. I've always been told that the the same logic was
> used for choosing Morse Code characters - the shortest Morse Code
> sequences were the most common letters. Apparently not exactly,
>
> Morse code decoders use a slightly different sequence which is:
>
> ETIANM SURWDKGO
>
> Notably - the letter O is a fairly long sequence and is out of place.
Keep in mind that you're looking at the "International Morse Code". The
original American Morse Code (see Wikipedia for details) has a number of
differences. Among others, the letter O is quite a lot shorter.
It makes sense for the Linotype to use approximate letter frequencies in its
design. For one thing, the designer had to understand that to know about the
needed number of matrices. The letter E has two rows in the magazine for that
reason; the key draws from either row. Also, by arranging the letters in rough
frequency order, the most used letters travel the shortest distance both from
magazine to assembler, and also from distributor back to magazine. The latter
means they become available for reuse sooner (since the matrices move fairly
slowly through the distributor) which means you're not likely to run out as you
enter text rapidly.
By the way, the Linotype machine is a nice example of a pipelined architecture,
with two independent sections (the magazine feeding the assembler on the one
hand, and the justification/casting/distribution machinery on the other). And
the distribution part consists of several stages with lots of items moving
through at a time.
paul
