[GreenKeys] Re: Gears for model 32 machines...

[Jim Haynes]

An alternative is to build an electronic speed converter.  For receive
only that is duck soup, because the machine can always print faster than
the 60wpm signal coming in.  It's more problematic for the transmit
direction, since a fast keyboarder or transmission from tape will
overrun the conversion.  One solution to that is a FIFO buffer, with
some means to indicate when the buffer is about to fill up and tell
the sender to give it a rest.

The late Irv Hoff's line of stuff included the UT-4; and I believe there
was a ready-made version of this by Flesher.  I spoze one wanting to do
this today would just use a microcontroller; I don't know if there are
microcontrollers that incorporate a UART that can be set up for Baudot.

A side benefit of the speed converter is that it acts as a regenerative
repeater.  The main benefit of a regenerative repeater is its ability to
recover when the STOP pulse is missing or mutilated.  A mechanical
teleprinter selector fails to latch up on a missing STOP pulse, and
then continues rotating irregularly until it gets back into sync.
This causes several erroneous characters to be printed.  The regenerator,
being electronic, can detect the missing STOP pulse and stop itself 
anyway.

The other cool thing about using a speed converter is that it lets
spiffy machines like the 28 run at 100 wpm and that is more
impressive to the onlookers than to see it loafing along at 60.
(It will slow down to 60 when receiving 60 wpm signals, but on a
local loop you can run the whole show at 100 wpm.)