[GTALUG] Notepad drops carrage return bits.

[James Knott]

On 05/10/2018 07:14 AM, Russell wrote:
> I'm curious now, an answer back drum? Like a single spinning drum whos only task was to provide an ID/handshake signal?

It was a drum encoded with the ID information, typically a company name
etc..  They held, IIRC, 21 characters.  On the Model 32 & 33 Teletypes,
they were solid plastic, with tabs that could be broken off to program
the characters.  Model 28 & 35 Teletypes used a metal drum where the
tabs could be repositioned.  Later devices such as the Texas Instruments
Silent 700 used a diode matrix, where individual diodes could be cut. 
When a certain code was received, typically Figs J, though sometimes
Figs S (Telex was Figs J) on Baudot or WRU on ASCII, the answer back
would be triggered.

> I only ever fooled around with a telex in the radio shack at VE3OSC and all they'd let me touch was the keyboard. 

I also used that station.

> LTRS = long term return signal/state? like HELO OLEH?

No, letters shift.  Since Baudot machines used a 5 bit code, there
weren't enough combinations for all characters.  So, there was a figures
shift (Figs) for printing numbers & punctuation and letters shift (Ltrs)
for text.  A letters shift was all 5 bits mark, figures bits 1, 2, 4 & 5
mark, with bit 3 space.

https://en.wikipedia.org/wiki/Baudot_code

> In industry, timing's are everything. Leveraging a mechanical advantage is as old as the oldest timepiece itself. It would make sense to me that the engineering of the day might take advantage of the mass in motion of a plattens own return movement, in order to advance the roll a notch or three on a sudden stop. I use to see those types of timing geegaws in manufacturing and industry all the time. 

These days, with electronic controllers, it's a simple matter to buffer
and wait as necessary.  However, those Teletypes had a lot of mechanical
activity that had to be properly synced.  For example, in addition to
moving the carriage back in time, the print hammer had to strike at the
right time.

Back when I was a bench tech, I could overhaul, that is strip, clean,
rebuild and test 2 M32 or M33 machines per day or 1 M28 or M35.