[GreenKeys] Fw: Questions on Siemens T100A

[Nico de Jong]

> It is a Siemens T100A, from the early 60s. It is in great shape, just 
> seriously dirty, but at least it seems it was never outdoor, exposed to 
> the elements, which is great news.
>
> http://www.albinarrate.com/index.php?option=com_content&view=article&id=49:tty-siemens-100a&catid=22:vintage&Itemid=38


Looks very much (read : identical) to the ones I used when being a telex 
operator in the dutch PTT

> My first doubt, is... does anyone know what type of socket is the one I 
> show in the page? (link above)
> I have an Olivetti TTY from the late 70s with the same socket, but I have 
> not seen it on Internet so I am afraid it might be a socket used here in 
> Argentina. I haven't yet tried to disassemble it to find out which wire is 
> which one, but I thought I might ask here first.
>
That is an ADO-8 socket. I suppose you want to use it in half-duplex mode, 
meaning one person "talking" at a time. Then you will want to connect pin 3 
and 2 (yellow and brown), and use pin 4 and 1 for the holding current (40 
mA)
Dont bother about the other pins. Some were used for an alarm system.

> Next questions... operation...
> Please confirm or correct my assumptions:
> 1- The keyboard, and the reader, they send the pulses out of the TTY 
> without internal connection to the printer, right?
Correct, either on (pin 1 and 2) or (3 and 4) (can't remember which set it 
is)

> 2- The printer, and the tape puncher, they print the pulses received from 
> outside, without internal connection to the keyboard and reader, right?
Also correct, pins used : see above

> 3- For everything to work at once, I have to loop the wires in the TTY 
> connector, right? (Obviously including in the loop a suitable current 
> source too)
See my remarks regarding half-duplex

> 4- Only once I do that, I will print what I type, and so on... correct?
Yes.

It is quite easy to interface a TTY to a PC, just use a COM port. Settings 
are 50 bps, 5 bit, 1 stopbit, no parity.
Being 5 bit, you will need conversion tables. Give a shout when you get that 
far

All the best

Nico (OZ1BMC)