[GreenKeys] Navy abandons M28 compatibility

[COURYHOUSE at aol.com]

was the Oliver used    one  with the odd shaped   keys!?
 
 
In a message dated 6/9/2013 10:41:08 P.M. US Mountain Standard Time,  
nagle at animats.com writes:

I don't know if any Morkrum Blue Code machines still  exist.
As of 1983, Teletype Corporation had one in their  collection.

http://www.baudot.net/docs/slayton--tty-patents.pdf

The  Blue Code machine was a collection of relays and
solenoids which sat  underneath an Oliver typewriter.
It had three shifts: UPPER, NUMBERS, and  UNSHIFT
(i.e. lower case).  It was a start-stop binary 5-level  machine,
what we're used to in later machines. There were earlier  Morkrum
machines which used a 3-level 4-value code, where each  symbol
time could have either a high or low current or positive  or
negative polarity.  That was a dead end, at least until the
era  of self-equalizing modems in the 1980s.

John Nagle

On 6/9/2013 9:45 PM,  COURYHOUSE at aol.com wrote:
> Wow. did not realize there was an upper  lower  case machine that   early!
> I bet they are   scarce!?
> Ed#
>  
>  
> In a message dated  6/8/2013 11:33:52 A.M. US Mountain Standard Time,  
>  nagle at animats.com writes:
> 
> That was originally for backwards  compatibility with Morse code.
> Morkrum's  first machine, the Blue  Code machine (1910) had upper
> and lower case  characters, with  three shifts, LOWER, CAPITALS,
> and FIGURES, and a 3-row   typewheel.  But printing telegraphs
> were originally used only on  main  lines, so the same message
> would also go over a Morse  link.  Lower  case info was lost
> in Morse  transmission.  Western Union asked for  machines
> without  lower case, and that's how it all started.
> 
> John   Nagle
> 
>  



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