[GreenKeys] CRLF or not CRLF?

[Jeffrey Angus]

Ok, let me try this again.

RTTY is two tones. Either sent AFSK detected directly, or FSK detected 
with a BFO
resulting in two audio tones.
These in turn go through a terminal unit that decodes the two tones into 
direct
keying Mark (on) and Space (off).
This keyed signal, hopefully close to the original transmitted signal, 
is fed directly
to a mechanical decoder/printer.
Teletype, Kleinschmidt, Mite, Lorenz, Creed and such.
The machines decode the signal keying directly.
The terminal units themselves do not decode the signal into characters.

The CV-89, Twin City TU, HAL ST-6, ST-6000, MFJ 1224 and Dovetrons are 
terminal
units. They convert RTTY signals from a radio receiver to a keyed local 
loop that is
connected to a Teletype machine. That is ALL that they do. An exception 
is the HAL
ST-8000A that does not have a keyed current loop output but has low 
lever signals
instead, but it still just a mirror of the two tones fed into it.

Things like the MFJ 1289, Kantronics KAM and AEA PK-232 are not terminal 
units.
They are decoders, they have to be told what they are decoding. ASCII or 
Baudot,
and what speed, 60, 66, 75, 100, 110 WPM etc. and their output is an 
ASCII 8-level
code regardless of what the input signal is. A 5-level Baudot two-tone 
signal input
is output as an 8-level ASCII signal at either RS-232 or TTL signal levels.

It was my impression that the whole idea of having a "special category" 
for those that
run mechanical machines is that the machines are doing the decoding. And 
not the
use of a decoder and using the machine as a "dumb terminal."




-- 
Jeff-1.0
www.foxsmercantile.com