110 Baud modem

Paul Koning paulkoning at comcast.net
Tue May 9 09:39:00 CDT 2017


So Wikipedia is wrong, since it claims that it was introduced in 1958 for ASCII and 110 Baud.

Then again, 101/103 modem modulation doesn't care about speed (it isn't clocked) up to a limit of 300 baud or so.

I wonder if there is also terminology here: what we now call a "modem" was earlier called a "tuning unit" and that term goes back to 5 bit machines and the 1950s.  It may be more a radio TTY term than a landline term, but the concept is identical.  I remember QST articles around 1958 or so about RTTY tuning units, built out of tubes with a relay (differential relay?) thrown in for good measure. 

	paul

> On May 9, 2017, at 10:32 AM, Pete Lancashire <pete at petelancashire.com> wrote:
> 
> The C version came later with the introduction of ASCII ( 5 to 8 bits ) and 110 baud. So it does not go back to the 50's.
> 
> I do not know when the C version was released. The ASCII Teletype Model 35 was introduced in 1961.
> 
> -pete
> 
> 
> 
> 
> On Tue, May 9, 2017 at 6:47 AM, Paul Koning <paulkoning at comcast.net> wrote:
> 
> > On May 8, 2017, at 10:27 PM, Pete Lancashire via cctalk <cctalk at classiccmp.org> wrote:
> >
> > Bell 101C
> >
> > https://goo.gl/photos/hrhAwvzMBLWWteXu6
> >
> > https://en.wikipedia.org/wiki/Bell_101
> 
> Interesting.  Released in 1958 but that unit is stamped 10 years later.
> 
> It would be nice to see photos of the circuit boards.  And I sure wonder what those rows of large relays are for.
> 
>         paul
> 
> 
> 
> 



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