[GreenKeys] Teletype Highspeed (>100 wpm) Equipment Question

[John Nagle]

On 9/2/2012 12:12 PM, Christian Gauger-Cosgrove wrote:
> Thanks for the information!
> 
> And by reperforator-transmitter, I don't mean the Model 35. I know
> about the Model 35... and I *really* want to own a 35ASR.
> 
> I meant an 8-level device similar to the 28RT i.e. punch feeding tape
> right into a crawling head tape reader; in essence it could be used as
> a buffer, a buffer which can be variable speed, which would be useful
> for say... copying 60 wpm RTTY on a 100 wpm machine (punch running at
> 60, reader running at 100).

     You're thinking of gear like that used in Plan-55A store and
forward telegram switches.  That technology didn't go forward into
the ASCII era.  The military went with AUTODIN, starting in 1962,
and Western Union went with InfoMaster, starting around 1972.
Both were mainframe computer based.  Both could do code and speed
conversion in software.  The last WU Plan-55A switch, with paper
tape punches facing paper tape readers, shut down in 1976.

     There's a mention of a Baudot to ASCII converter from 1961
in "http://massis.lcs.mit.edu/archives/history/twx.1961.automation".
It's mentioned as being "quite expensive", so expensive that it
was installed in only a few central offices, and calls were
back-hauled to a CO with a converter when conversion was
necessary.  Those were the units that turned on the REST
lamp and paused the tape reader on ASCII TWX machines.
This happened if you were sending to a slower machine and
the small buffer filled up.

     Early mechanical computing (1900 to the computer era)
didn't have any good storage elements.  Storing one number
was a big deal.

				John Nagle