[GreenKeys] : Re: Early Teletype in the principle

[Jim Haynes]

I'm not sure if I'm replying to the right question, but there is a major 
difference.  Prior to Morkrum printing telegraphy (starting with Baudot) 
depended on keeping wheels in synchronism at the sending and receiving 
ends of the circuit.  That was hard.  Howard Krum's breakthrough invention 
was to stop the wheels at the end of each character and start them at the 
beginning of the next, hence called start-stop synchronization.  Then the 
wheels had to stay in synchronism only for the duration of one character. 
That required only that motor speeds at both ends be almost the same, not 
precisely the same.  This resulted in a small waste of line time because 
of the start and stop pulses that were added to the five pulses of the 
character.  But in situations where a single-channel printing telegraph 
was wanted the extra bandwidth to handle the extra pulses was rarely a
problem.

On Fri, 6 Jan 2017, Juha Lahtinen wrote:

> Hello
> Was the idea same as nipkow television.?
> Both type wheels go around in same phase .
> Best Regards. juha
>