The relays are for controlling the modes function/mode. For example if the unit is put in local mode, or when an incoming call is "Answered" the motor will start running.
On Tue, May 9, 2017 at 8:22 AM, Anders Nelson via cctalk < cctalk@classiccmp.org> wrote: > Good lord, is that a pile of relays to click out bits rotary-style? > > =o > > -- > Anders Nelson > > +1 (517) 775-6129 > > www.erogear.com > > On Tue, May 9, 2017 at 7:39 AM, Paul Koning via cctalk < > cctalk@classiccmp.org> wrote: > > > 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 <p...@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 <paulkon...@comcast.net> > > wrote: > > > > > > > On May 8, 2017, at 10:27 PM, Pete Lancashire via cctalk < > > cctalk@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 > > > > > > > > > > > > > > > > > >
