[GreenKeys] Teletype Data Terminal Accessory

[John Nagle]

Oh, cute. The electronic successor to the Stunt Box.

That thing talks what Teletype seems to have called "8A1" protocol,
which is ANSI 3.28.

https://library.e.abb.com/public/d72e25504b0b2178c2256a720035bd36/REC501ANSI_EN_A.pdf

This is for master/slave polled multidrop communications.
There are multiple Teletype machines on the same circuit.
Those are the slaves. The master is a different and
more elaborate device, probably a computer running a message
switching program. The master polls each station, asking if
it has data (usually a paper tape) to send. If the master
wants to send, it tells everybody on the circuit which
addresses are supposed to get the message, and those
machines switch on and print the message.

Burroughs and AT&T both sold master devices for this.
I once encountered a system which controlled such machines
from a UNIVAC mainframe, although it was 5-bit, not 8 bit.

This was after Plan-55A, but before fully computerized switching.
Late 1960s - early 1970s, from the era when digital ICs were
available but it took way too many ICs to do anything because
each IC did so little.

				John Nagle



> From: "David V. Corbin"<david.corbin at dynconcepts.com>
> To: Paul Heller<paul0926 at comcast.net>, Steven Shumaker
> 	<shumaker at att.net>
> Cc: Greenkeys<greenkeys at mailman.qth.net>
> Subject: Re: [GreenKeys] Teletype Data Terminal Accessory
> Message-ID:
> 	<CO1P222MB0356259CCA2873B8BFDF8F4F9E0EA at CO1P222MB0356.NAMP222.PROD.OUTLOOK.COM>
> 	
> Content-Type: text/plain; charset="utf-8"
> 
> https://www.navy-radio.com/manuals/tty/sales/9100-cat-ctlr-7203.pdf
> 
> Get Outlook for iOS<https://aka.ms/o0ukef>
> ________________________________
> From:greenkeys-bounces at mailman.qth.net  <greenkeys-bounces at mailman.qth.net>  on behalf of Paul Heller<paul0926 at comcast.net>
> Sent: Saturday, August 5, 2023 7:49:21 PM
> To: Steven Shumaker<shumaker at att.net>
> Cc: Greenkeys<greenkeys at mailman.qth.net>
> Subject: Re: [GreenKeys] Teletype Data Terminal Accessory
> 
> Interesting!
> 
> That is a rather outrageous price being asked.
> 
> <https://www.ebay.com/itm/155701599614?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=-RpnOkdHQy2&sssrc=4429486&ssuid=tBxVpSdyQp2&var=&widget_ver=artemis&media=COPY>
> [s-l500.jpg]
> Teletype Data Terminal Accessory<https://www.ebay.com/itm/155701599614?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=-RpnOkdHQy2&sssrc=4429486&ssuid=tBxVpSdyQp2&var=&widget_ver=artemis&media=COPY>
> ebay.com<https://www.ebay.com/itm/155701599614?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=-RpnOkdHQy2&sssrc=4429486&ssuid=tBxVpSdyQp2&var=&widget_ver=artemis&media=COPY>
> 
> 
> Paul
> W2TTY
> 
> ITTY:HTTP://INTERNET-TTY.NET:8000/ITTY<HTTP://internet-tty.net:8000/ITTY>
> ITTY 100:HTTP://INTERNET-TTY.NET:8010/ITTY100
> AUTOSTART:HTTP://INTERNET-TTY.NET:8030/AUTOSTART<HTTP://internet-tty.net:8030/AUTOSTART>
> EUROPE:HTTP://INTERNET-TTY.NET:8040/EUROPE<HTTP://internet-tty.net:8040/EUROPE>
> 
> On Aug 5, 2023, at 5:44 PM, Steven Shumaker<shumaker at att.net>  wrote:
> 
> ?Ebay item no:  155701599614.
> 
> Anyone know what this is and what it talks to?  I see a DB25 shell and some other cables.  Would seem to be a LOT of electronics for a serial to current loop convertor
> 
> Steve