[GreenKeys] Stop bits and TTY-Connect

[gil smith]

Ah, Jim, you are right of course.  Setting the output to 1.0-stop will 
indeed allow the buffers to be paced by the input.  Didn't occur to me at 
the time, as I was trying to ensure proper stops for machines, and was 
working with ascii input mostly.  A 1.5 stop will still be necessary for an 
ascii-to-baudot connection, but it can be dropped to 1.0 stop for a 
baudot-to-baudot connection.  Easy enough to tweak.

I need to dig out a TD to see if it puts out 1.42-stop when reading, and 
try a couple of tests.

thanks,

gil

At 08:48 PM 2/27/2005, you wrote:
>...If I understand this, it says that a machine
>set up for 7.42 code has the transmitting shaft running at 364.36 RPM,
>or maybe 367.92.  I'm not sure why there are two figures.  Possibly one
>is for sync motors and one is for governed motors, since for some reason
>they didn't run both kinds of motors at the same speed and they are
>constrained by gears having to have an integral number of teeth.
>Anyway this shows the receive shaft running at 416.41 or 420.48 RPM.
>Then you see that for 7.00 code and 60 WPM the transmitter runs at
>390 RPM and the receiver still runs at 420 RPM.  So the receiver always
>runs ahead of the transmitter even at 7.00 code.
>
>Accordingly, unless I'm missing something, you ought to set up your
>circuit to generate a 1.0 stop bit.  If you get 7.42 in that's what
>you will put out, since you don't get characters any faster.  If you
>get 7.00 in there is the small possibility that your circuit will be
>overrun if the incoming baud rate is slightly higher than the outgoing.
>I guess you could beat even that be generating 6.5 code, since you'll
>never get input that fast and what comes out will be 7.0 or 7.42.
>
>jhhaynes at earthlink dot net



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